Add pagination of the results

Sorting and scoring still requires the loading of all the found pages,
but the summary is only computed for the pages on the page.

.gitignore

@@ -1 +1,3 @@
 /oddmu
+test.md
+/testdata/

LICENSE

@@ -1,27 +1,667 @@
-Copyright (c) 2012 The Go Authors. All rights reserved.
+This software is Copyright (c) 2015–2023 by Alex Schroeder.
 
-Redistribution and use in source and binary forms, with or without
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+This is free software, licensed under:
 
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+  The GNU Affero General Public License, Version 3, November 2007
 
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+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU Affero General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU Affero General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If your software can interact with users remotely through a computer
+network, you should also make sure that it provides a way for users to
+get its source.  For example, if your program is a web application, its
+interface could display a "Source" link that leads users to an archive
+of the code.  There are many ways you could offer source, and different
+solutions will be better for different programs; see section 13 for the
+specific requirements.
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU AGPL, see
+<http://www.gnu.org/licenses/>.

Makefile

@@ -25,4 +25,4 @@ test:
 upload:
 	go build
 	rsync --itemize-changes --archive oddmu oddmu.service *.html README.md sibirocobombus.root:/home/oddmu/
-	ssh sibirocobombus.root "systemctl restart oddmu"
+	ssh sibirocobombus.root "systemctl restart oddmu; systemctl restart alex"

README.md

@@ -1,14 +1,173 @@
 # Oddµ: A minimal wiki
 
 This program runs a wiki. It serves all the Markdown files (ending in
-`.md`) into web pages and allows you to edit them.
+`.md`) into web pages and allows you to edit them. If your files don't
+provide their own title (`# title`), the file name (without `.md`) is
+used for the title. Subdirectories are created as necessary.
 
-This is a minimal wiki. There is no version history. It probably makes
-sense to only use it as one person or in very small groups.
+This is a minimal wiki. There is no version history. It's well suited
+as a *secondary* medium: collaboration and conversation happens
+elsewhere, in chat, on social media. The wiki serves as the text
+repository that results from these discussions.
 
-It's very minimal and only uses Markdown. No wiki extras, so double
-square brackets are not a link. If you're used to that, it'll be
-strange as you need to repeat the name: `[like this](like this)`.
+The wiki lists no recent changes. The expectation is that the people
+that care were involved in the discussions beforehand.
+
+The wiki also produces no feed. The assumption is that announcements
+are made on social media: blogs, news aggregators, discussion forums,
+the fediverse, but humans. There is no need for bots.
+
+As you'll see below, the idea is that the webserver handles as many
+tasks as possible. It logs requests, does rate limiting, handles
+encryption, gets the certificates, and so on. The web server acts as a
+reverse proxy and the wiki ends up being a content management system
+with almost no structure – or endless malleability, depending on your
+point of view.
+
+And last but not least: µ is the letter mu, so Oddµ is usually written
+Oddmu. 🙃
+
+## Markdown
+
+This wiki uses a [Markdown
+library](https://github.com/gomarkdown/markdown) to generate the web
+pages from Markdown. There are two extensions Oddmu adds to the
+library: local links and hashtags.
+
+Local links use double square brackets `[[like this]]`. If you need to
+change the link text, you need to use regular Markdown. Don't forget
+to [percent-encode](https://en.wikipedia.org/wiki/Percent-encoding)
+the link target. Example: `[here](like%20this)`.
+
+Hashtags link to searches for the hashtag. Hashtags are separate from
+titles because there is no space after the hash. Use the underscore to
+use hashtags consisting of multiple words.
+
+```
+# Title
+
+Text
+
+#Tag #Another_Tag
+```
+
+The Markdown processor comes with a few extensions, some of which are
+enable by default:
+
+* emphasis markers inside words are ignored
+* tables are supported
+* fenced code blocks are supported
+* autolinking of "naked" URLs are supported
+* strikethrough using two tildes is supported (`~~like this~~`)
+* it is strict about prefix heading rules
+* you can specify an id for headings (`{#id}`)
+* trailing backslashes turn into line breaks
+* definition lists are supported
+* MathJax is supported (but needs a separte setup)
+
+A table with footers and a columnspan:
+
+```text
+Name    | Age
+--------|------
+Bob     ||
+Alice   | 23
+========|======
+Total   | 23
+```
+
+A definition list:
+
+```text
+Cat
+: Fluffy animal everyone likes
+
+Internet
+: Vector of transmission for pictures of cats
+```
+
+## Templates
+
+The template files are the HTML files in the working directory:
+`add.html`, `edit.html`, `search.html`, `upload.html` and `view.html`.
+Feel free to change the templates and restart the server. The first
+change you should make is to replace the email address in `view.html`.
+😄
+
+See [Structuring the web
+with HTML](https://developer.mozilla.org/en-US/docs/Learn/HTML) to
+learn more about HTML.
+
+Modifying the styles in the templates would be another good start to
+get a feel for it. See [Learn to style HTML using
+CSS](https://developer.mozilla.org/en-US/docs/Learn/CSS) to learn more
+about style sheets.
+
+The templates can refer to the following properties of a page:
+
+`{{.Title}}` is the page title. If the page doesn't provide its own
+title, the page name is used.
+
+`{{.Name}}` is the page name, escaped for use in URLs. More
+specifically, it is URI escaped except for the slashes. The page name
+doesn't include the `.md` extension.
+
+`{{.Html}}` is the rendered Markdown, as HTML.
+
+`{{printf "%s" .Body}}` is the Markdown, as a string (the data itself
+is a byte array and that's why we need to call `printf`).
+
+For the `search.html` template only:
+
+`{{.Page}}` is the page number in the results.
+
+`{{.Previous}}` and `{{.Next}} are the previous and next page number
+in the results since doing arithmetics in templates is hard. The first
+page number is 1.
+
+`{{.More}}` indicates if there are any more search results.
+
+`{{.Results}}` indicates if there were any search results.
+
+`{{.Items}}` is an array of pages, each containing a search result. A
+search result is a page (with the properties seen above). Thus, to
+refer to them, you need to use a `{{range .Items}}` … `{{end}}`
+construct.
+
+For search results, `{{.Html}}` is the rendered Markdown of a page
+summary, as HTML.
+
+`{{.Score}}` is a numerical score for search results.
+
+The `upload.html` template cannot refer to anything.
+
+When calling the `save` action, the page name is take from the URL and
+the page content is taken from the `body` form parameter. To
+illustrate, here's how to edit a page using `curl`:
+
+```sh
+curl --form body="Did you bring a towel?" \
+  http://localhost:8080/save/welcome
+```
+
+The wiki uses the standard
+[html/template](https://pkg.go.dev/html/template) library to do this.
+There's more information on writing templates in the documentation for
+the [text/template](https://pkg.go.dev/text/template) library.
+
+## Non-English hyphenation
+
+Automatic hyphenation by the browser requires two things: The style
+sheet must indicate `hyphen: auto` for an HTML element such as `body`,
+and that element must have a `lang` set (usually a two letter language
+code such as `de` for German). This happens in the template files,
+such as `view.html` and `search.html`.
+
+Oddmu uses the [lingua](github.com/pemistahl/lingua-go) library to
+detect languages. If you know that you're only going to use a small
+number of languages – or just a single language! – you can set the
+environment variable ODDMU_LANGUAGES to a comma-separated list of ISO
+639-1 codes, e.g. "en" or "en,de,fr,pt".
 
 ## Building
 
@@ -18,10 +177,12 @@ go build
 
 ## Test
 
+The working directory is where pages are saved and where templates are
+loaded from. You need a copy of the template files in this directory.
+Here's how to start it in the source directory:
+
 ```sh
-mkdir wiki
-cd wiki
-go run ..
+go run .
 ```
 
 The program serves the local directory as a wiki on port 8080. Point
@@ -33,18 +194,29 @@ If you ran it in the source directory, try
 http://localhost:8080/view/README – this serves the README file you're
 currently reading.
 
+You can change the port by setting the ODDMU_PORT environment
+variable.
+
 ## Deploying it using systemd
 
-As root:
+As root, on your server:
 
 ```sh
-# on your server
 adduser --system --home /home/oddmu oddmu
 ```
 
-Copy all the files into `/home/oddmu` on your server: `oddmu`, `oddmu.service`, `view.html` and `edit.html`.
+Copy all the files into `/home/oddmu` to your server: `oddmu`,
+`oddmu.service`, and all the template files ending in `.html`.
 
-Set the ODDMU_PORT environment variable in the `oddmu.service` file (or accept the default, 8080).
+Edit the `oddmu.service` file. These are the three lines you most
+likely have to take care of:
+
+```
+ExecStart=/home/oddmu/oddmu
+WorkingDirectory=/home/oddmu
+Environment="ODDMU_PORT=8080"
+Environment="ODDMU_LANGUAGES=en,de"
+```
 
 Install the service file and enable it:
 
@@ -71,12 +243,12 @@ Edit the first page using `lynx`:
 lynx http://localhost:8080/view/index
 ```
 
-## Web Server Setup
+## Web server setup
 
 HTTPS is not part of the wiki. You probably want to configure this in
-your webserver. If you're using Apache, you might have set up a site
-like the following. In my case, that'd be
-`/etc/apache2/sites-enabled/500-transjovian.conf`:
+your webserver. I guess you could use stunnel, too. If you're using
+Apache, you might have set up a site like I did, below. In my case,
+that'd be `/etc/apache2/sites-enabled/500-transjovian.conf`:
 
 ```apache
 MDomain transjovian.org
@@ -91,27 +263,32 @@ MDCertificateAgreement accepted
     ServerAdmin alex@alexschroeder.ch
     ServerName transjovian.org
     SSLEngine on
-
-    RewriteEngine on
-    RewriteRule ^/$ http://%{HTTP_HOST}:8080/view/index [redirect]
-    RewriteRule ^/(view|edit|save)/(.*) http://%{HTTP_HOST}:8080/$1/$2 [proxy]
+    ProxyPassMatch ^/(search|(view|edit|save|add|append|upload|drop)/(.*))?$ http://localhost:8080/$1
 </VirtualHost>
 ```
 
 First, it manages the domain, getting the necessary certificates. It
 redirects regular HTTP traffic from port 80 to port 443. It turns on
-the SSL engine for port 443. It redirects `/` to `/view/index` and any
-path that starts with `/view/`, `/edit/` or `/save/` is proxied to
-port 8080 where the Oddmu program can handle it.
+the SSL engine for port 443. It proxies the requests for the wiki to
+port 8080.
 
 Thus, this is what happens:
 
-* The user tells the browser to visit `http://transjovian.org` (on port 80)
-* Apache redirects this to `http://transjovian.org/` by default (still on port 80)
-* Our first virtual host redirects this to `https://transjovian.org/` (encrypted, on port 443)
-* Our second virtual host redirects this to `https://transjovian.org/wiki/view/index` (still on port 443)
-* This is proxied to `http://transjovian.org:8080/view/index` (no on port 8080, without encryption)
-* The wiki converts `index.md` to HTML, adds it to the template, and serves it.
+* The user tells the browser to visit `transjovian.org`
+* The browser sends a request for `http://transjovian.org` (on port 80)
+* Apache redirects this to `https://transjovian.org/` by default (now on port 443)
+* This is proxied to `http://transjovian.org:8080/` (no encryption, on port 8080)
+
+Restart the server, gracefully:
+
+```
+apachectl graceful
+```
+
+To serve both HTTP and HTTPS, don't redirect from the first virtual
+host to the second – instead just proxy to the wiki like you did for
+the second virtual host: use a copy of the `ProxyPassMatch` directive
+instead of `RewriteEngine on` and `RewriteRule`.
 
 ## Access
 
@@ -143,12 +320,12 @@ To delete remove a user:
 htpasswd -D .htpasswd berta
 ```
 
-Modify your site configuration and protect the `/edit/` and `/save/`
-URLs with a password by adding the following to your `<VirtualHost
-*:443>` section:
+Modify your site configuration and protect the `/edit/`, `/save/`,
+`/add/`, `/append/`, `/upload/` and `/drop/` URLs with a password by
+adding the following to your `<VirtualHost *:443>` section:
 
 ```apache
-<LocationMatch "^/(edit|save)/">
+<LocationMatch "^/(edit|save|add|append|upload|drop)/">
   AuthType Basic
   AuthName "Password Required"
   AuthUserFile /home/oddmu/.htpasswd
@@ -156,18 +333,7 @@ URLs with a password by adding the following to your `<VirtualHost
 </LocationMatch>
 ```
 
-## Configuration
-
-Feel free to change the templates `view.html` and `edit.html` and
-restart the server. Modifying the styles in the templates would be a
-good start.
-
-You can remove the auto-generated titles from the files, for example.
-If your Markdown files start with a level 1 title, then edit
-`view.html` and remove the line that says `<h1>{{.Title}}</h1>` (this
-is what people see when reading the page). Optionally also remove the
-line that says `<title>{{.Title}}</title>` (this is what gets used for
-tabs and bookmarks).
+## Serve static files
 
 If you want to serve static files as well, add a document root to your
 webserver configuration. Using Apache, for example:
@@ -181,9 +347,12 @@ DocumentRoot /home/oddmu/static
 
 Create this directory, making sure to give it a permission that your
 webserver can read (world readable file, world readable and executable
-directory). Populate it with files. For example, create a file called
-`robots.txt` containing the following, tellin all robots that they're
-not welcome.
+directory). Populate it with files.
+
+Make sure that none of the static files look like the wiki paths
+`/view/`, `/edit/`, `/save/`, `/add/`, `/append/`, `/upload/`, `/drop/`
+or `/search`. For example, create a file called `robots.txt`
+containing the following, tellin all robots that they're not welcome.
 
 ```text
 User-agent: *
@@ -196,19 +365,102 @@ and without needing a wiki page.
 [Wikipedia](https://en.wikipedia.org/wiki/Robot_exclusion_standard)
 has more information.
 
-## Customization (with recompilation)
+## Different logins for different access rights
 
-The Markdown parser can be customized and
-[extensions](https://pkg.go.dev/github.com/gomarkdown/markdown/parser#Extensions)
-can be added. There's an example in the
-[usage](https://github.com/gomarkdown/markdown#usage) section. You'll
-need to make changes to the `viewHandler` yourself.
+What if you have a site with various subdirectories and each
+subdirectory is for a different group of friends? You can set this up
+using your webserver. One way to do this is to require specific
+usernames (which must have a password in the password file mentioned
+above.
+
+This requires a valid login by the user "alex" or "berta":
+
+```apache
+<LocationMatch "^/(edit|save|add|append|upload|drop)/intetebi/">
+  Require user alex berta
+</LocationMatch>
+```
+
+## Private wikis
+
+Based on the above, you can prevent people from reading the wiki, too.
+The `LocationMatch` must cover the `/view/` URLs. In order to protect
+*everything*, use a [Location directive](https://httpd.apache.org/docs/current/mod/core.html#location)
+that matches everything:
+
+```apache
+<Location />
+  AuthType Basic
+  AuthName "Password Required"
+  AuthUserFile /home/oddmu/.htpasswd
+  Require valid-user
+</Location>
+```
+
+## Virtual hosting
+
+Virtual hosting in this context means that the program serves two
+different sites for two different domains from the same machine. Oddmu
+doesn't support that, but your webserver does. Therefore, start an
+Oddmu instance for every domain name, each listening on a different
+port. Then set up your web server such that ever domain acts as a
+reverse proxy to a different Oddmu instance.
+
+## Understanding search
+
+The index indexes trigrams. Each group of three characters is a
+trigram. A document with content "This is a test" is turned to lower
+case and indexed under the trigrams "thi", "his", "is ", "s i", " is",
+"is ", "s a", " a ", "a t", " te", "tes", "est".
+
+Each query is split into words and then processed the same way. A
+query with the words "this test" is turned to lower case and produces
+the trigrams "thi", "his", "tes", "est". This means that the word
+order is not considered when searching for documents.
+
+This also means that there is no stemming. Searching for "testing"
+won't find "This is a test" because there are no matches for the
+trigrams "sti", "tin", "ing".
+
+These trigrams are looked up in the index, resulting in the list of
+documents. Each document found is then scored. Each of the following
+increases the score by one point:
+
+- the entire phrase matches
+- a word matches
+- a word matches at the beginning of a word
+- a word matches at the end of a word
+- a word matches as a whole word
+
+A document with content "This is a test" when searched with the phrase
+"this test" therefore gets a score of 8: the entire phrase does not
+match but each word gets four points.
+
+Trigrams are sometimes strange: In a text containing the words "main"
+and "rail", a search for "mail" returns a match because the trigrams
+"mai" and "ail" are found. In this situation, the result has a score
+of 0.
 
 ## Limitations
 
 Page titles are filenames with `.md` appended. If your filesystem
-cannot handle it, it can't be a page title. Specifically, *no slashes*
-in filenames.
+cannot handle it, it can't be a page name.
+
+The pages are indexed as the server starts and the index is kept in
+memory. If you have a ton of pages, this surely wastes a lot of
+memory.
+
+Files may not end with a tilde (`~`) – these are backup files.
+
+You cannot edit uploaded files. If you upload a file called
+`hello.txt` and attempt to edit it by using `/edit/hello.txt` you will
+create a page with the name `hello.txt.md` instead.
+
+You cannot delete uploaded files via the web.
+
+## Bugs
+
+If you spot any, [contact](https://alexschroeder.ch/wiki/Contact) me.
 
 ## References
 

TODO.md

@@ -0,0 +1,6 @@
+Upload files should use path info so that we can use Apache to
+restrict access to directories.
+
+Automatically scale or process files.
+
+Post by Delta Chat? That is, allow certain encrypted emails to post.

add.html

@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <meta name="format-detection" content="telephone=no">
+    <meta name="viewport" content="width=device-width">
+    <title>Add to {{.Title}}</title>
+    <style>
+html { max-width: 70ch; padding: 2ch; margin: auto; color: #111; background: #ffe; }
+form, textarea { width: 100%; }
+    </style>
+  </head>
+  <body>
+    <h1>Adding to {{.Title}}</h1>
+    <form action="/append/{{.Name}}" method="POST">
+      <textarea name="body" rows="20" cols="80" placeholder="Text" lang="" autofocus required></textarea>
+      <p><input type="submit" value="Add">
+        <a href="/view/{{.Name}}"><button type="button">Cancel</button></a></p>
+    </form>
+  </body>
+</html>

add_append.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"net/http"
+)
+
+// addHandler uses the "add.html" template to present an empty edit
+// page. What you type there is appended to the page using the
+// appendHandler.
+func addHandler(w http.ResponseWriter, r *http.Request, name string) {
+	p, err := loadPage(name)
+	if err != nil {
+		p = &Page{Title: name, Name: name}
+	} else {
+		p.handleTitle(false)
+	}
+	renderTemplate(w, "add", p)
+}
+
+// appendHandler takes the "body" form parameter and appends it. The
+// browser is redirected to the page view.
+func appendHandler(w http.ResponseWriter, r *http.Request, name string) {
+	body := r.FormValue("body")
+	p, err := loadPage(name)
+	if err != nil {
+		p = &Page{Title: name, Name: name, Body: []byte(body)}
+	} else {
+		p.handleTitle(false)
+		p.Body = append(p.Body, []byte(body)...)
+	}
+	err = p.save()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(w, r, "/view/"+name, http.StatusFound)
+}

add_append_test.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"net/url"
+	"os"
+	"regexp"
+	"testing"
+)
+
+// wipes testdata
+func TestAddAppend(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+	index.load()
+
+	p := &Page{Name: "testdata/fire", Body: []byte(`# Fire
+Orange sky above
+Reflects a distant fire
+It's not `)}
+	p.save()
+
+	data := url.Values{}
+	data.Set("body", "barbecue")
+
+	assert.Regexp(t, regexp.MustCompile("a distant fire"),
+		assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/testdata/fire", nil))
+	assert.NotRegexp(t, regexp.MustCompile("a distant fire"),
+		assert.HTTPBody(makeHandler(addHandler, true), "GET", "/add/testdata/fire", nil))
+	HTTPRedirectTo(t, makeHandler(appendHandler, true), "POST", "/append/testdata/fire", data, "/view/testdata/fire")
+	assert.Regexp(t, regexp.MustCompile("It’s not barbecue"),
+		assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/testdata/fire", nil))
+
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}

commands.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func commands() {
+	if len(os.Args) == 3 && os.Args[1] == "html" {
+		p, err := loadPage(os.Args[2])
+		if err != nil {
+			fmt.Println(err)
+		} else {
+			p.renderHtml()
+			fmt.Println(p.Html)
+		}
+	} else if len(os.Args) > 2 && os.Args[1] == "search" {
+		index.load()
+		for _, q := range os.Args[2:] {
+			items, more := search(q, 1)
+			fmt.Printf("Search %s: %d results\n", q, len(items))
+			for _, p := range items {
+				fmt.Printf("* %s (%d)\n", p.Title, p.Score)
+			}
+			if more {
+				fmt.Printf("There are more results\n")
+			}
+		}
+	} else {
+		fmt.Printf("Unknown command: %v\n", os.Args[1:])
+		fmt.Print("Without any arguments, serves a wiki.\n")
+		fmt.Print("  Environment variable ODDMUSE_PORT controls the port.\n")
+		fmt.Print("  Environment variable ODDMUSE_LANGAUGES controls the languages detected.\n")
+		fmt.Print("html PAGENAME\n")
+		fmt.Print("  Print the HTML of the page.\n")
+		fmt.Print("search TERMS\n")
+		fmt.Print("  Print the titles of the page with score.\n")
+	}
+}

concurrency_test.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+// Use go test -race to see whether this is a race condition.
+func TestLoadAndSearch(t *testing.T) {
+	index.reset()
+	go index.load()
+	q := "Oddµ"
+	pages, _ := search(q, 1)
+	assert.Zero(t, len(pages))
+}

edit.html

@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html>
+<html lang="en">
   <head>
     <meta charset="utf-8">
     <meta name="format-detection" content="telephone=no">
@@ -12,10 +12,12 @@ form, textarea { width: 100%; }
   </head>
   <body>
     <h1>Editing {{.Title}}</h1>
+    <form action="/save/{{.Name}}" method="POST">
+      <textarea name="body" rows="20" cols="80" placeholder="# Title
 
-    <form action="/save/{{.Title}}" method="POST">
-      <div><textarea name="body" rows="20" cols="80">{{printf "%s" .Body}}</textarea></div>
-      <p><input type="submit" value="Save"></p>
+Text" lang="" autofocus>{{printf "%s" .Body}}</textarea>
+      <p><input type="submit" value="Save">
+        <a href="/view/{{.Name}}"><button type="button">Cancel</button></a></p>
     </form>
   </body>
 </html>

edit_save.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"net/http"
+)
+
+// editHandler uses the "edit.html" template to present an edit page.
+// When editing, the page title is not overriden by a title in the
+// text. Instead, the page name is used. The edit is saved using the
+// saveHandler.
+func editHandler(w http.ResponseWriter, r *http.Request, name string) {
+	p, err := loadPage(name)
+	if err != nil {
+		p = &Page{Title: name, Name: name}
+	} else {
+		p.handleTitle(false)
+	}
+	renderTemplate(w, "edit", p)
+}
+
+// saveHandler takes the "body" form parameter and saves it. The
+// browser is redirected to the page view.
+func saveHandler(w http.ResponseWriter, r *http.Request, name string) {
+	body := r.FormValue("body")
+	p := &Page{Name: name, Body: []byte(body)}
+	err := p.save()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(w, r, "/view/"+name, http.StatusFound)
+}

edit_save_test.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"net/url"
+	"os"
+	"regexp"
+	"testing"
+)
+
+// wipes testdata
+func TestEditSave(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+
+	data := url.Values{}
+	data.Set("body", "Hallo!")
+
+	HTTPRedirectTo(t, makeHandler(viewHandler, true), "GET", "/view/testdata/alex", nil, "/edit/testdata/alex")
+	assert.HTTPStatusCode(t, makeHandler(editHandler, true), "GET", "/edit/testdata/alex", nil, 200)
+	HTTPRedirectTo(t, makeHandler(saveHandler, true), "POST", "/save/testdata/alex", data, "/view/testdata/alex")
+	assert.Regexp(t, regexp.MustCompile("Hallo!"),
+		assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/testdata/alex", nil))
+
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}

go.mod

@@ -3,12 +3,23 @@ module alexschroeder.ch/cgit/oddmu
 go 1.21.0
 
 require (
-	github.com/gomarkdown/markdown v0.0.0-20230716120725-531d2d74bc12
+	github.com/dgryski/go-trigram v0.0.0-20160407183937-79ec494e1ad0
+	github.com/gomarkdown/markdown v0.0.0-20230912175223-14b07df9d538
 	github.com/microcosm-cc/bluemonday v1.0.25
+	github.com/pemistahl/lingua-go v1.4.0
+	github.com/stretchr/testify v1.8.4
 )
 
 require (
+	github.com/anthonynsimon/bild v0.13.0 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/gorilla/css v1.0.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/shopspring/decimal v1.3.1 // indirect
+	golang.org/x/exp v0.0.0-20221106115401-f9659909a136 // indirect
+	golang.org/x/image v0.0.0-20190703141733-d6a02ce849c9 // indirect
 	golang.org/x/net v0.12.0 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,10 +1,69 @@
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/anthonynsimon/bild v0.13.0 h1:mN3tMaNds1wBWi1BrJq0ipDBhpkooYfu7ZFSMhXt1C8=
+github.com/anthonynsimon/bild v0.13.0/go.mod h1:tpzzp0aYkAsMi1zmfhimaDyX1xjn2OUc1AJZK/TF0AE=
+github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
+github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
+github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
+github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
+github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgryski/go-trigram v0.0.0-20160407183937-79ec494e1ad0 h1:b+7JSiBM+hnLQjP/lXztks5hnLt1PS46hktG9VOJgzo=
+github.com/dgryski/go-trigram v0.0.0-20160407183937-79ec494e1ad0/go.mod h1:qzKC/DpcxK67zaSHdCmIv3L9WJViHVinYXN2S7l3RM8=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/gomarkdown/markdown v0.0.0-20230716120725-531d2d74bc12 h1:uK3X/2mt4tbSGoHvbLBHUny7CKiuwUip3MArtukol4E=
 github.com/gomarkdown/markdown v0.0.0-20230716120725-531d2d74bc12/go.mod h1:JDGcbDT52eL4fju3sZ4TeHGsQwhG9nbDV21aMyhwPoA=
+github.com/gomarkdown/markdown v0.0.0-20230912175223-14b07df9d538 h1:ePDpFu7l0QUV46/9A7icfL2wvIOzTJLCWh4RO2NECzE=
+github.com/gomarkdown/markdown v0.0.0-20230912175223-14b07df9d538/go.mod h1:JDGcbDT52eL4fju3sZ4TeHGsQwhG9nbDV21aMyhwPoA=
+github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
+github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/gorilla/css v1.0.0 h1:BQqNyPTi50JCFMTw/b67hByjMVXZRwGha6wxVGkeihY=
 github.com/gorilla/css v1.0.0/go.mod h1:Dn721qIggHpt4+EFCcTLTU/vk5ySda2ReITrtgBl60c=
+github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
+github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
+github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/microcosm-cc/bluemonday v1.0.25 h1:4NEwSfiJ+Wva0VxN5B8OwMicaJvD8r9tlJWm9rtloEg=
 github.com/microcosm-cc/bluemonday v1.0.25/go.mod h1:ZIOjCQp1OrzBBPIJmfX4qDYFuhU02nx4bn030ixfHLE=
+github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
+github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pemistahl/lingua-go v1.4.0 h1:ifYhthrlW7iO4icdubwlduYnmwU37V1sbNrwhKBR4rM=
+github.com/pemistahl/lingua-go v1.4.0/go.mod h1:ECuM1Hp/3hvyh7k8aWSqNCPlTxLemFZsRjocUf3KgME=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
+github.com/shopspring/decimal v1.3.1 h1:2Usl1nmF/WZucqkFZhnfFYxxxu8LG21F6nPQBE5gKV8=
+github.com/shopspring/decimal v1.3.1/go.mod h1:DKyhrW/HYNuLGql+MJL6WCR6knT2jwCFRcu2hWCYk4o=
+github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
+github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
+github.com/spf13/cobra v0.0.5/go.mod h1:3K3wKZymM7VvHMDS9+Akkh4K60UwM26emMESw8tLCHU=
+github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
+github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/spf13/viper v1.3.2/go.mod h1:ZiWeW+zYFKm7srdB9IoDzzZXaJaI5eL9QjNiN/DMA2s=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
+github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
+golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
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+golang.org/x/exp v0.0.0-20221106115401-f9659909a136/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
+golang.org/x/image v0.0.0-20190703141733-d6a02ce849c9 h1:uc17S921SPw5F2gJo7slQ3aqvr2RwpL7eb3+DZncu3s=
+golang.org/x/image v0.0.0-20190703141733-d6a02ce849c9/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/net v0.12.0 h1:cfawfvKITfUsFCeJIHJrbSxpeu/E81khclypR0GVT50=
 golang.org/x/net v0.12.0/go.mod h1:zEVYFnQC7m/vmpQFELhcD1EWkZlX69l4oqgmer6hfKA=
+golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
+google.golang.org/protobuf v1.31.0 h1:g0LDEJHgrBl9N9r17Ru3sqWhkIx2NB67okBHPwC7hs8=
+google.golang.org/protobuf v1.31.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

highlight.go

@@ -0,0 +1,13 @@
+package main
+
+import (
+	"regexp"
+)
+
+// highlight splits the query string q into terms and highlights them
+// using the bold tag. Return the highlighted string.
+// This assumes that q already has all its meta characters quoted.
+func highlight(q string, re *regexp.Regexp, s string) string {
+	s = re.ReplaceAllString(s, "<b>$1</b>")
+	return s
+}

highlight_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestHighlight(t *testing.T) {
+
+	s := `The windows opens
+A wave of car noise hits me
+No birds to be heard.`
+
+	h := `The <b>window</b>s opens
+A wave of car noise hits me
+No birds to be heard.`
+
+	q := "window"
+	re, _ := re(q)
+	r := highlight(q, re, s)
+	if r != h {
+		t.Logf("The highlighting is wrong in ｢%s｣", r)
+		t.Fail()
+	}
+}
+
+func TestOverlap(t *testing.T) {
+
+	s := `Sit with me my love
+Kids shout and so do parents
+I hear the fountain`
+
+	h := `Sit with me my love
+Kids <b>shout</b> and so do parents
+I hear the fountain`
+
+	q := "shout out"
+	re, _ := re(q)
+	r := highlight(q, re, s)
+	if r != h {
+		t.Logf("The highlighting is wrong in ｢%s｣", r)
+		t.Fail()
+	}
+}

index.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	trigram "github.com/dgryski/go-trigram"
+	"io/fs"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+// Index contains the two maps used for search. Make sure to lock and
+// unlock as appropriate.
+type Index struct {
+	sync.RWMutex
+
+	// index is a struct containing the trigram index for search.
+	// It is generated at startup and updated after every page
+	// edit. The index is case-insensitive.
+	index trigram.Index
+
+	// documents is a map, mapping document ids of the index to
+	// page names.
+	documents map[trigram.DocID]string
+}
+
+// idx is the global Index per wiki.
+var index Index
+
+// reset resets the Index. This assumes that the index is locked!
+func (idx *Index) reset() {
+	idx.index = nil
+	idx.documents = nil
+}
+
+// add reads a file and adds it to the index. This must happen while
+// the idx is locked, which is true when called from loadIndex.
+func (idx *Index) add(path string, info fs.FileInfo, err error) error {
+	if err != nil {
+		return err
+	}
+	filename := path
+	if info.IsDir() || strings.HasPrefix(filename, ".") || !strings.HasSuffix(filename, ".md") {
+		return nil
+	}
+	name := strings.TrimSuffix(filename, ".md")
+	p, err := loadPage(name)
+	if err != nil {
+		return err
+	}
+	id := idx.index.Add(strings.ToLower(string(p.Body)))
+	idx.documents[id] = p.Name
+	return nil
+}
+
+// load loads all the pages and indexes them. This takes a while.
+// It returns the number of pages indexed.
+func (idx *Index) load() (int, error) {
+	idx.Lock()
+	defer idx.Unlock()
+	idx.index = make(trigram.Index)
+	idx.documents = make(map[trigram.DocID]string)
+	err := filepath.Walk(".", idx.add)
+	if err != nil {
+		idx.reset()
+		return 0, err
+	}
+	n := len(idx.documents)
+	return n, nil
+}
+
+// updateIndex updates the index for a single page. The old text is
+// loaded from the disk and removed from the index first, if it
+// exists.
+func (p *Page) updateIndex() {
+	index.Lock()
+	defer index.Unlock()
+	var id trigram.DocID
+	// This function does not rely on files actually existing, so
+	// let's quickly find the document id.
+	for docId, name := range index.documents {
+		if name == p.Name {
+			id = docId
+			break
+		}
+	}
+	if id == 0 {
+		id = index.index.Add(strings.ToLower(string(p.Body)))
+		index.documents[id] = p.Name
+	} else {
+		o, err := loadPage(p.Name)
+		if err == nil {
+			index.index.Delete(strings.ToLower(string(o.Body)), id)
+		}
+		index.index.Insert(strings.ToLower(string(p.Body)), id)
+	}
+}
+
+func searchDocuments(q string) []string {
+	words := strings.Fields(strings.ToLower(q))
+	var trigrams []trigram.T
+	for _, word := range words {
+		trigrams = trigram.Extract(word, trigrams)
+	}
+	index.RLock()
+	ids := index.index.QueryTrigrams(trigrams)
+	names := make([]string, len(ids))
+	for i, id := range ids {
+		names[i] = index.documents[id]
+	}
+	index.RUnlock()
+	return names
+}

index.md

@@ -1,3 +1,5 @@
+# Welcome to Oddµ
+
 Hello! 🙃
 
 Check out the [README](README).

index_test.go

@@ -0,0 +1,97 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"os"
+	"strings"
+	"testing"
+)
+
+// TestIndex relies on README.md being indexed
+func TestIndex(t *testing.T) {
+	index.load()
+	q := "Oddµ"
+	pages, _ := search(q, 1)
+	assert.NotZero(t, len(pages))
+	for _, p := range pages {
+		assert.NotContains(t, p.Title, "<b>")
+		assert.True(t, strings.Contains(string(p.Body), q) || strings.Contains(string(p.Title), q))
+		assert.NotZero(t, p.Score, "Score %d for %s", p.Score, p.Name)
+	}
+}
+
+func TestSearchHashtag(t *testing.T) {
+	index.load()
+	q := "#Another_Tag"
+	pages, _ := search(q, 1)
+	assert.NotZero(t, len(pages))
+}
+
+func TestIndexUpdates(t *testing.T) {
+	name := "test"
+	_ = os.Remove(name + ".md")
+	index.load()
+	p := &Page{Name: name, Body: []byte("This is a test.")}
+	p.save()
+
+	// Find the phrase
+	pages, _ := search("This is a test", 1)
+	found := false
+	for _, p := range pages {
+		if p.Name == name {
+			found = true
+			break
+		}
+	}
+	assert.True(t, found)
+
+	// Find the phrase, case insensitive
+	pages, _ = search("this is a test", 1)
+	found = false
+	for _, p := range pages {
+		if p.Name == name {
+			found = true
+			break
+		}
+	}
+	assert.True(t, found)
+
+	// Find some words
+	pages, _ = search("this test", 1)
+	found = false
+	for _, p := range pages {
+		if p.Name == name {
+			found = true
+			break
+		}
+	}
+	assert.True(t, found)
+
+	// Update the page and no longer find it with the old phrase
+	p = &Page{Name: name, Body: []byte("Guvf vf n grfg.")}
+	p.save()
+	pages, _ = search("This is a test", 1)
+	found = false
+	for _, p := range pages {
+		if p.Name == name {
+			found = true
+			break
+		}
+	}
+	assert.False(t, found)
+
+	// Find page using a new word
+	pages, _ = search("Guvf", 1)
+	found = false
+	for _, p := range pages {
+		if p.Name == name {
+			found = true
+			break
+		}
+	}
+	assert.True(t, found)
+
+	t.Cleanup(func() {
+		_ = os.Remove(name + ".md")
+	})
+}

languages.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"errors"
+	"github.com/pemistahl/lingua-go"
+	"os"
+	"strings"
+)
+
+// getLangauges returns the environment variable ODDMU_LANGUAGES or
+// all languages.
+func getLanguages() ([]lingua.Language, error) {
+	v := os.Getenv("ODDMU_LANGUAGES")
+	if v == "" {
+		return lingua.AllLanguages(), nil
+	}
+	codes := strings.Split(v, ",")
+	if len(codes) == 1 {
+		return nil, errors.New("detection unnecessary")
+	}
+
+	var langs []lingua.Language
+	for _, lang := range codes {
+		langs = append(langs, lingua.GetLanguageFromIsoCode639_1(lingua.GetIsoCode639_1FromValue(lang)))
+	}
+	return langs, nil
+}
+
+// detector is the LanguageDetector initialized at startup by loadLanguages.
+var detector lingua.LanguageDetector
+
+// loadLanguages initializes the detector using the languages returned
+// by getLanguages and returns the number of languages loaded.
+func loadLanguages() int {
+	langs, err := getLanguages()
+	if err == nil {
+		detector = lingua.NewLanguageDetectorBuilder().
+			FromLanguages(langs...).
+			WithPreloadedLanguageModels().
+			WithLowAccuracyMode().
+			Build()
+	} else {
+		detector = nil
+	}
+	return len(langs)
+}
+
+// language returns the language used for a string, as a lower case
+// ISO 639-1 string, e.g. "en" or "de".
+func language(s string) string {
+	if detector == nil {
+		return os.Getenv("ODDMU_LANGUAGES")
+	}
+	if language, ok := detector.DetectLanguageOf(s); ok {
+		return strings.ToLower(language.IsoCode639_1().String())
+	}
+	return ""
+}

languages_test.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"os"
+	"testing"
+)
+
+func TestAllLanguage(t *testing.T) {
+	os.Unsetenv("ODDMU_LANGUAGES")
+	loadLanguages()
+	l := language(`
+My back hurts at night
+My shoulders won't budge today
+Winter bones I say`)
+	assert.Equal(t, "en", l)
+}
+
+func TestSomeLanguages(t *testing.T) {
+	os.Setenv("ODDMU_LANGUAGES", "en,de")
+	loadLanguages()
+	l := language(`
+Kühle Morgenluft
+Keine Amsel singt heute
+Mensch im Dämmerlicht
+`)
+	assert.Equal(t, "de", l)
+}
+
+func TestOneLanguages(t *testing.T) {
+	os.Setenv("ODDMU_LANGUAGES", "en")
+	loadLanguages()
+	l := language(`
+Schwer wiegt die Luft hier
+Atme ein, ermahn' ich mich
+Erinnerungen
+`)
+	assert.Equal(t, "en", l)
+}
+
+func TestWrongLanguages(t *testing.T) {
+	os.Setenv("ODDMU_LANGUAGES", "de,fr")
+	loadLanguages()
+	l := language(`
+Something drifts down there
+Head submerged oh god a man
+Drowning as we stare
+`)
+	assert.NotEqual(t, "en", l)
+}

oddmu.service

@@ -17,7 +17,6 @@ Environment="ODDMU_PORT=8080"
 ReadWritePaths=/home/oddmu
 ProtectHostname=yes
 RestrictSUIDSGID=yes
-UMask=0077
 RemoveIPC=yes
 MemoryDenyWriteExecute=yes
 

page.go

@@ -0,0 +1,208 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/gomarkdown/markdown"
+	"github.com/gomarkdown/markdown/ast"
+	"github.com/gomarkdown/markdown/parser"
+	"github.com/microcosm-cc/bluemonday"
+	"html/template"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// Page is a struct containing information about a single page. Title
+// is the title extracted from the page content using titleRegexp.
+// Name is the filename without extension (so a filename of "foo.md"
+// results in the Name "foo"). Body is the Markdown content of the
+// page and Html is the rendered HTML for that Markdown. Score is a
+// number indicating how well the page matched for a search query.
+type Page struct {
+	Title    string
+	Name     string
+	Language string
+	Body     []byte
+	Html     template.HTML
+	Score    int
+}
+
+// santize uses bluemonday to sanitize the HTML.
+func sanitize(s string) template.HTML {
+	return template.HTML(bluemonday.UGCPolicy().Sanitize(s))
+}
+
+// santizeBytes uses bluemonday to sanitize the HTML.
+func sanitizeBytes(bytes []byte) template.HTML {
+	return template.HTML(bluemonday.UGCPolicy().SanitizeBytes(bytes))
+}
+
+// nameEscape returns the page name safe for use in URLs. That is,
+// percent escaping is used except for the slashes.
+func nameEscape(s string) string {
+	parts := strings.Split(s, "/")
+	for i, part := range parts {
+		parts[i] = url.PathEscape(part)
+	}
+	return strings.Join(parts, "/")
+}
+
+// save saves a Page. The filename is based on the Page.Name and gets
+// the ".md" extension. Page.Body is saved, without any carriage
+// return characters ("\r"). Page.Title and Page.Html are not saved.
+// There is no caching. Before removing or writing a file, the old
+// copy is renamed to a backup, appending "~". There is no error
+// checking for this.
+func (p *Page) save() error {
+	filename := p.Name + ".md"
+	s := bytes.ReplaceAll(p.Body, []byte{'\r'}, []byte{})
+	if len(s) == 0 {
+		_ = os.Rename(filename, filename+"~")
+		return os.Remove(filename)
+	}
+	p.Body = s
+	p.updateIndex()
+	d := filepath.Dir(filename)
+	if d != "." {
+		err := os.MkdirAll(d, 0755)
+		if err != nil {
+			fmt.Printf("Creating directory %s failed", d)
+			return err
+		}
+	}
+	_ = os.Rename(filename, filename+"~")
+	return os.WriteFile(filename, s, 0644)
+}
+
+// loadPage loads a Page given a name. The filename loaded is that
+// Page.Name with the ".md" extension. The Page.Title is set to the
+// Page.Name (and possibly changed, later). The Page.Body is set to
+// the file content. The Page.Html remains undefined (there is no
+// caching).
+func loadPage(name string) (*Page, error) {
+	filename := name + ".md"
+	body, err := os.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &Page{Title: name, Name: name, Body: body, Language: ""}, nil
+}
+
+// handleTitle extracts the title from a Page and sets Page.Title, if
+// any. If replace is true, the page title is also removed from
+// Page.Body. Make sure not to save this! This is only for rendering.
+func (p *Page) handleTitle(replace bool) {
+	s := string(p.Body)
+	m := titleRegexp.FindStringSubmatch(s)
+	if m != nil {
+		p.Title = m[1]
+		if replace {
+			p.Body = []byte(strings.Replace(s, m[0], "", 1))
+		}
+	}
+}
+
+// wikiLink returns an inline parser function. This indirection is
+// required because we want to call the previous definition in case
+// this is not a wikiLink.
+func wikiLink(p *parser.Parser,	fn func(p *parser.Parser, data []byte, offset int) (int, ast.Node)) func(p *parser.Parser, data []byte, offset int) (int, ast.Node) {
+	return func (p *parser.Parser, original []byte, offset int) (int, ast.Node) {
+		data := original[offset:]
+		n := len(data)
+		// minimum: [[X]]
+		if n < 5 || data[1] != '[' {
+			return fn(p, original, offset)
+		}
+		i := 2
+		for i+1 < n && data[i] != ']' && data[i+1] != ']' {
+			i++
+		}
+		text := data[2:i+1]
+		link := &ast.Link{
+			Destination: []byte(url.PathEscape(string(text))),
+		}
+		ast.AppendChild(link, &ast.Text{Leaf: ast.Leaf{Literal: text}})
+		return i+3, link
+	}
+}
+
+func hashtag(p *parser.Parser, data []byte, offset int) (int, ast.Node) {
+	data = data[offset:]
+	i := 0
+	n := len(data)
+	for i < n && !parser.IsSpace(data[i]) {
+		i++
+	}
+	if i == 0 {
+		return 0, nil
+	}
+	link := &ast.Link{
+		Destination: append([]byte("/search?q=%23"), data[1:i]...),
+		Title:       data[0:i],
+	}
+	text := bytes.ReplaceAll(data[0:i], []byte("_"), []byte(" "))
+	ast.AppendChild(link, &ast.Text{Leaf: ast.Leaf{Literal: text}})
+	return i, link
+}
+
+// renderHtml renders the Page.Body to HTML and sets Page.Html.
+func (p *Page) renderHtml() {
+	parser := parser.New()
+	prev := parser.RegisterInline('[', nil)
+	parser.RegisterInline('[', wikiLink(parser, prev))
+	parser.RegisterInline('#', hashtag)
+	maybeUnsafeHTML := markdown.ToHTML(p.Body, parser, nil)
+	p.Name = nameEscape(p.Name)
+	p.Html = sanitizeBytes(maybeUnsafeHTML)
+	p.Language = language(p.plainText())
+}
+
+// plainText renders the Page.Body to plain text and returns it,
+// ignoring all the Markdown and all the newlines. The result is one
+// long single line of text.
+func (p *Page) plainText() string {
+	parser := parser.New()
+	doc := markdown.Parse(p.Body, parser)
+	text := []byte("")
+	ast.WalkFunc(doc, func(node ast.Node, entering bool) ast.WalkStatus {
+		if entering && node.AsLeaf() != nil {
+			text = append(text, node.AsLeaf().Literal...)
+			text = append(text, []byte(" ")...)
+		}
+		return ast.GoToNext
+	})
+	// Some Markdown still contains newlines
+	for i, c := range text {
+		if c == '\n' {
+			text[i] = ' '
+		}
+	}
+	// Remove trailing space
+	for len(text) > 0 && text[len(text)-1] == ' ' {
+		text = text[0 : len(text)-1]
+	}
+	return string(text)
+}
+
+// score sets Page.Title and computes Page.Score.
+func (p *Page) score(q string) {
+	p.handleTitle(true)
+	p.Score = score(q, string(p.Body)) + score(q, p.Title)
+}
+
+// summarize sets Page.Html to an extract and sets Page.Language.
+func (p *Page) summarize(q string) {
+	t := p.plainText()
+	p.Html = sanitize(snippets(q, t))
+	p.Language = language(t)
+}
+
+func (p *Page) Dir() string {
+	d := filepath.Dir(p.Name)
+	if d == "." {
+		return ""
+	}
+	return d
+}

page_test.go

@@ -0,0 +1,107 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"os"
+	"regexp"
+	"testing"
+)
+
+func TestPageTitle(t *testing.T) {
+	p := &Page{Body: []byte(`# Ache
+My back aches for you
+I sit, stare and type for hours
+But yearn for blue sky`)}
+	p.handleTitle(false)
+	assert.Equal(t, "Ache", p.Title)
+	assert.Regexp(t, regexp.MustCompile("^# Ache"), string(p.Body))
+	p.handleTitle(true)
+	assert.Regexp(t, regexp.MustCompile("^My back"), string(p.Body))
+}
+
+func TestPagePlainText(t *testing.T) {
+	p := &Page{Body: []byte(`# Water
+The air will not come
+To inhale is an effort
+The summer heat kills`)}
+	r := "Water The air will not come To inhale is an effort The summer heat kills"
+	assert.Equal(t, r, p.plainText())
+}
+
+func TestPageHtml(t *testing.T) {
+	p := &Page{Body: []byte(`# Sun
+Silver leaves shine bright
+They droop, boneless, weak and sad
+A cruel sun stares down`)}
+	p.renderHtml()
+	r := `<h1>Sun</h1>
+
+<p>Silver leaves shine bright
+They droop, boneless, weak and sad
+A cruel sun stares down</p>
+`
+	assert.Equal(t, r, string(p.Html))
+}
+
+func TestPageHtmlHashtag(t *testing.T) {
+	p := &Page{Body: []byte(`# Comet
+Stars flicker above
+Too faint to focus, so far
+I am cold, alone
+
+#Haiku #Cold_Poets`)}
+	p.renderHtml()
+	r := `<h1>Comet</h1>
+
+<p>Stars flicker above
+Too faint to focus, so far
+I am cold, alone</p>
+
+<p><a href="/search?q=%23Haiku" rel="nofollow">#Haiku</a> <a href="/search?q=%23Cold_Poets" rel="nofollow">#Cold Poets</a></p>
+`
+	assert.Equal(t, r, string(p.Html))
+}
+
+func TestPageHtmlWikiLink(t *testing.T) {
+	p := &Page{Body: []byte(`# Photos and Books
+Blue and green and black
+Sky and grass and [ragged cliffs](cliffs)
+Our [[time together]]
+`)}
+	p.renderHtml()
+	r := `<h1>Photos and Books</h1>
+
+<p>Blue and green and black
+Sky and grass and <a href="cliffs" rel="nofollow">ragged cliffs</a>
+Our <a href="time%20together" rel="nofollow">time together</a></p>
+`
+	assert.Equal(t, r, string(p.Html))
+}
+
+// wipes testdata
+func TestPageDir(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+	index.load()
+	p := &Page{Name: "testdata/moon", Body: []byte(`# Moon
+From bed to bathroom
+A slow shuffle in the dark
+Moonlight floods the aisle`)}
+	p.save()
+
+	o, err := loadPage("testdata/moon")
+	assert.NoError(t, err, "load page")
+	assert.Equal(t, p.Body, o.Body)
+	assert.FileExists(t, "testdata/moon.md")
+
+	// Saving an empty page deletes it.
+	p = &Page{Name: "testdata/moon", Body: []byte("")}
+	p.save()
+	assert.NoFileExists(t, "testdata/moon.md")
+
+	// But the backup still exists.
+	assert.FileExists(t, "testdata/moon.md~")
+
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}

score.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"regexp"
+	"strings"
+)
+
+// score splits the query string q into terms and scores the text
+// based on those terms. This assumes that q already has all its meta
+// characters quoted.
+func score(q string, s string) int {
+	score := 0
+	re, err := regexp.Compile("(?i)" + q)
+	if err == nil {
+		m := re.FindAllString(s, -1)
+		if m != nil {
+			// Score increases for each full match of q.
+			score += len(m)
+		}
+	}
+	for _, v := range strings.Fields(q) {
+		re, err := regexp.Compile(`(?is)(\pL?)(` + v + `)(\pL?)`)
+		if err != nil {
+			continue
+		}
+		for _, m := range re.FindAllStringSubmatch(s, -1) {
+			// Term matched increases the score.
+			score++
+			// Terms matching at the beginning and
+			// end of words and matching entire
+			// words increase the score further.
+			if len(m[1]) == 0 {
+				score++
+			}
+			if len(m[3]) == 0 {
+				score++
+			}
+			if len(m[1]) == 0 && len(m[3]) == 0 {
+				score++
+			}
+		}
+	}
+	return score
+}

score_test.go

@@ -0,0 +1,104 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestScore(t *testing.T) {
+
+	s := `The windows opens
+A wave of car noise hits me
+No birds to be heard.`
+
+	q := "window"
+	// Score:
+	// - q itself
+	// - the single token
+	// - the beginning of a word
+	c := score(q, s)
+	if c != 3 {
+		t.Logf("%s score is %d", q, c)
+		t.Fail()
+	}
+	q = "windows"
+	c = score(q, s)
+	// Score:
+	// - q itself
+	// - the single token
+	// - the beginning of a word
+	// - the end of a word
+	// - the whole word
+	if c != 5 {
+		t.Logf("%s score is %d", q, c)
+		t.Fail()
+	}
+	q = "car noise"
+	c = score(q, s)
+	// Score:
+	// - car noise (+1)
+	// - car, with beginning, end, whole word (+4)
+	// - noise, with beginning, end, whole word (+4)
+	if c != 9 {
+		t.Logf("%s score is %d", q, c)
+		t.Fail()
+	}
+	q = "noise car"
+	c = score(q, s)
+	// Score:
+	// - the car token
+	// - the noise token
+	// - each with beginning, end and whole token (3 each)
+	if c != 8 {
+		t.Logf("%s score is %d", q, c)
+		t.Fail()
+	}
+}
+
+func TestScoreLong(t *testing.T) {
+	s := `We are immersed in a sea of dead people. All the dead that have gone before us, silent now, just staring, gaping. As we move and talk and fret, never once stopping to ask ourselves – or them! – what it was all about. Instead we drown ourselves in noise. Incessantly we babble, surrounded by false friends claiming that all is well. And look at us! Yes, we are well. Patting our backs and expecting a pat – and we do! – we smugly do enjoy.`
+	q := "all is well"
+	c := score(q, s)
+	// Score:
+	// - all is well (1)
+	// - all, beginning, end, whole word (+4 × 3 = 12)
+	// - is, beginning, end, whole word (+4 × 1 = 4), and as a substring (1)
+	// - well, beginning, end, whole word (+4 × 2 = 8)
+	if c != 26 {
+		t.Logf("%s score is %d", q, c)
+		t.Fail()
+	}
+}
+
+func TestScoreSubstring(t *testing.T) {
+	s := `The loneliness of space means that receiving messages means knowledge that other people are out there. Not satellites pinging forever. Not bots searching and probing. Instead, humans. People who care. Curious and cautious.`
+	q := "search probe"
+	c := score(q, s)
+	// Score:
+	// - search, beginning (2)
+	// - probe (0)
+	if c != 2 {
+		t.Logf("%s score is %d", q, c)
+		t.Fail()
+	}
+	q = "ear"
+	c = score(q, s)
+	// Score:
+	// - ear, all (2)
+	if c != 2 {
+		t.Logf("%s score is %d", q, c)
+		t.Fail()
+	}
+}
+
+func TestScorePageAndMarkup(t *testing.T) {
+	s := `The Transjovian Council accepts new members. If you think we'd be a good fit, apply for an account. Contact [Alex Schroeder](https://alexschroeder.ch/wiki/Contact). Mail is best. Encrypted mail is best. [Delta Chat](https://delta.chat/de/) is a messenger app that uses encrypted mail. It's the bestest best.`
+	p := &Page{Title: "Test", Name: "Test", Body: []byte(s)}
+	q := "wiki"
+	p.score(q)
+	// "wiki" is not visible in the plain text but the score is no affected:
+	// - wiki, all, whole, beginning, end (5)
+	if p.Score != 5 {
+		t.Logf("%s score is %d", q, p.Score)
+		t.Fail()
+	}
+}

search.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"slices"
+	"strconv"
+	"unicode"
+	"unicode/utf8"
+)
+
+// Search is a struct containing the result of a search. Query is the
+// query string and Items is the array of pages with the result.
+// Currently there is no pagination of results! When a page is part of
+// a search result, Body and Html are simple extracts.
+type Search struct {
+	Query   string
+	Items   []*Page
+	Previous int
+	Page    int
+	Next    int
+	More    bool
+	Results bool
+}
+
+func sortItems(a, b *Page) int {
+	// Sort by score
+	if a.Score < b.Score {
+		return 1
+	} else if a.Score > b.Score {
+		return -1
+	}
+	// If the score is the same and both page names start
+	// with a number (like an ISO date), sort descending.
+	ra, _ := utf8.DecodeRuneInString(a.Title)
+	rb, _ := utf8.DecodeRuneInString(b.Title)
+	if unicode.IsNumber(ra) && unicode.IsNumber(rb) {
+		if a.Title < b.Title {
+			return 1
+		} else if a.Title > b.Title {
+			return -1
+		} else {
+			return 0
+		}
+	}
+	// Otherwise sort ascending.
+	if a.Title < b.Title {
+		return -1
+	} else if a.Title > b.Title {
+		return 1
+	} else {
+		return 0
+	}
+}
+
+// load the pages named.
+func load(names []string) []*Page {
+	items := make([]*Page, len(names))
+	for i, name := range names {
+		p, err := loadPage(name)
+		if err != nil {
+			fmt.Printf("Error loading %s\n", name)
+		} else {
+			items[i] = p
+		}
+	}
+	return items
+}
+
+// search returns a sorted []Page where each page contains an extract
+// of the actual Page.Body in its Page.Html. Page size is 20. The
+// boolean return value indicates whether there are more results.
+func search(q string, page int) ([]*Page, bool) {
+	if len(q) == 0 {
+		return make([]*Page, 0), false
+	}
+	names := searchDocuments(q)
+	items := load(names)
+	for _, p := range items {
+		p.score(q)
+	}
+	slices.SortFunc(items, sortItems)
+	from := 20*(page-1)
+	if from > len(names) {
+		return make([]*Page, 0), false
+	}
+	to := from + 20
+	if to > len(names) {
+		to = len(names)
+	}
+	items = items[from:to]
+	for _, p := range items {
+		p.summarize(q)
+	}
+	return items, to < len(names)
+}
+
+// searchHandler presents a search result. It uses the query string in
+// the form parameter "q" and the template "search.html". For each
+// page found, the HTML is just an extract of the actual body.
+func searchHandler(w http.ResponseWriter, r *http.Request) {
+	q := r.FormValue("q")
+	page, err := strconv.Atoi(r.FormValue("page"))
+	if err != nil {
+		page = 1
+	}
+	items, more := search(q, page)
+	s := &Search{Query: q, Items: items, Previous: page-1, Page: page, Next: page+1, Results: len(items) > 0, More: more}
+	renderTemplate(w, "search", s)
+}

search.html

@@ -0,0 +1,50 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <meta name="format-detection" content="telephone=no">
+    <meta name="viewport" content="width=device-width">
+    <title>Search for {{.Query}}</title>
+    <style>
+html { max-width: 65ch; padding: 2ch; margin: auto; color: #111; background: #ffe; }
+body { hyphens: auto; }
+header a { margin-right: 1ch; }
+form { display: inline-block; }
+input#search { width: 20ch; }
+button { background: #eee; color: inherit; border-radius: 4px; border-width: 1px; }
+img { max-width: 20%; }
+.result { font-size: larger }
+.score { font-size: smaller; opacity: 0.8; }
+    </style>
+  </head>
+  <body>
+    <header>
+      <a href="#main">Skip navigation</a>
+      <a href="/view/index">Home</a>
+      <form role="search" action="/search" method="GET">
+        <label for="search">Search:</label>
+        <input id="search" type="text" value="{{.Query}}" spellcheck="false" name="q" required>
+        <button>Go</button>
+      </form>
+    </header>
+    <main id="main">
+      <h1>Search for {{.Query}}</h1>
+      {{if .Results}}
+      <p>
+        {{if gt .Page 2}}<a href="/search?q={{.Query}}&page=1">First</a>{{end}}
+        {{if gt .Page 1}}<a href="/search?q={{.Query}}&page={{.Previous}}">Previous</a>{{end}}
+        Page {{.Page}}
+        {{if .More}}<a href="/search?q={{.Query}}&page={{.Next}}">Next</a>{{end}}
+      {{range .Items}}
+      <article lang="{{.Language}}">
+        <p><a class="result" href="/view/{{.Name}}">{{.Title}}</a>
+          <span class="score">{{.Score}}</span></p>
+        <blockquote>{{.Html}}</blockquote>
+      </article>
+      {{end}}
+      {{else}}
+      <p>No results.</p>
+      {{end}}
+    </main>
+  </body>
+</html>

search_test.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"net/url"
+	"testing"
+)
+
+func TestSearch(t *testing.T) {
+	data := url.Values{}
+	data.Set("q", "oddµ")
+	assert.Contains(t,
+		assert.HTTPBody(searchHandler, "GET", "/search", data), "Welcome")
+}

snippets.go

@@ -0,0 +1,97 @@
+package main
+
+import (
+	"regexp"
+	"strings"
+)
+
+// re returns a regular expression matching any word in q.
+func re(q string) (*regexp.Regexp, error) {
+	q = regexp.QuoteMeta(q)
+	re, err := regexp.Compile(`\s+`)
+	if err != nil {
+		return nil, err
+	}
+	words := re.ReplaceAllString(q, "|")
+	re, err = regexp.Compile(`(?i)(` + words + `)`)
+	if err != nil {
+		return nil, err
+	}
+	return re, nil
+}
+
+func snippets(q string, s string) string {
+	// Look for Snippets
+	snippetlen := 100
+	maxsnippets := 4
+	re, err := re(q)
+	// If the compilation didn't work, truncate and return
+	if err != nil || len(s) <= snippetlen {
+		if len(s) > 400 {
+			s = s[0:400] + " …"
+		}
+		return s
+	}
+	// show a snippet from the beginning of the document
+	j := strings.LastIndex(s[:snippetlen], " ")
+	if j == -1 {
+		// OK, look for a longer word
+		j = strings.Index(s, " ")
+		if j == -1 {
+			// Or just truncate the body.
+			if len(s) > 400 {
+				s = s[0:400] + " …"
+			}
+			return highlight(q, re, s)
+		}
+	}
+	t := s[0:j]
+	res := t + " …"
+	s = s[j:] // avoid rematching
+	jsnippet := 0
+	for jsnippet < maxsnippets {
+		m := re.FindStringSubmatch(s)
+		if m == nil {
+			break
+		}
+		jsnippet++
+		j = strings.Index(s, m[1])
+		wl := len(m[1])
+		if j > -1 {
+			// get the substring containing the start of
+			// the match, ending on word boundaries
+			from := j - snippetlen/2
+			if from < 0 {
+				from = 0
+			}
+			start := strings.Index(s[from:], " ")
+			if start == -1 {
+				start = 0
+			} else {
+				start += from
+			}
+			to := j + wl + snippetlen/2
+			if to > len(s) {
+				to = len(s)
+			}
+			end := strings.LastIndex(s[:to], " ")
+			if end == -1 || end <= j+wl {
+				// OK, look for a longer word
+				end = strings.Index(s[to:], " ")
+				if end == -1 {
+					end = len(s)
+				} else {
+					end += to
+				}
+			}
+			t = s[start:end]
+			res = res + t
+			if len(s) > end {
+				res = res + " …"
+			}
+			// truncate text to avoid rematching the same string.
+			s = s[end:]
+		}
+	}
+	return highlight(q, re, res)
+}

snippets_test.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestSnippets(t *testing.T) {
+	s := `We are immersed in a sea of dead people. All the dead that have gone before us, silent now, just staring, gaping. As we move and talk and fret, never once stopping to ask ourselves – or them! – what it was all about. Instead we drown ourselves in noise. Incessantly we babble, surrounded by false friends claiming that all is well. And look at us! Yes, we are well. Patting our backs and expecting a pat – and we do! – we smugly do enjoy.`
+
+	h := `We are immersed in a sea of dead people. <b>All</b> the dead that have gone before us, silent now, just … to ask ourselves – or them! – what it was <b>all</b> about. Instead we drown ourselves in no<b>is</b>e. … surrounded by false friends claiming that <b>all</b> <b>is</b> <b>well</b>. And look at us! Yes, we are <b>well</b>. …`
+
+	q := "all is well"
+	r := snippets(q, s)
+	assert.Equal(t, h, r)
+}
+
+func TestSnippetsLong(t *testing.T) {
+	s := `VWwXetig mty8fORN UNia4NFm SQsfyFHk BLDdgVnc AcvKP2fs q8KxPH1A IaCzFj96 J0S2fqca jp3ElV9f ULIZ1aMX GSUO1pLI p7vuJie8 kPfc0ONq EthfIUjm u74guCZ8 IiJYxlR6 5j5LlapY TGO98fOQ fO2RUb1g W8zaPa0v ps0haNzW OOeFwf1h 1N3td7zk 0OoMX8Ek aTd3Ciea 2T1aK9WH QbYfUojs nP59gqvR tqoEK3vJ zJ7JmRby qKReayLo 9BIwFgID 4Q4Tk3HH 1VLdDzSx q0hKUOKm vWkUXz9S 684uXanc gIaJNRFc gabtBO9A EhIh4VtT gJ3p9LYL jPVFqc65 QmMu8FUT vV0iphek 9Vvye5xS q7rJJyxa yHiIEMHA Ce8KLI1B FdbpdvWY qLk23poI aRoZ5LTu fWNL8rcj RpZyI052 HTxj28Q0 GiOjJ1UN iW7zrxBD QPpkiBVE nvOAkh7p c2prdKB8 9DAYvYo5 BPSN8wmO Q2oNZouQ zfEjm5aC lLMDotic hi585ip4 c7LYN3LZ xGmpN32s lcF83ipK 0IwvvEe1 tQxKHCCa u51OKNIE kdEsXUHG tTpUtwbG T6E4hMYv nVpbxCPH 0aACMPtu Oq945xMi wlPQHJ1e bROJU0e7 wdBjAYPt gjIaTuLu bicVsgYN L3a5NLwf 30zu9OHL qtDs1PJM OmTsSOZc v4eM7s8f MQlppFcY 6HTWrZPZ Raj94J30 kcSQPdTQ zsOhnhCQ sQDQkA3a uBP00Du8 qoq7syqj urFj9bqQ TV1EDcpC 4jKGRY27 vb3KgZQy EJillDeB UN4YYoLI hWgf1kqn o1B5s6Wm 98fQL4W0 PXaQeRc2 E45QBYtr od4CfqUo YsPizANv WFJj0nhM h7maM5WQ HuDYldsX qy1NLYCZ ZkvkuCxI hcD6Hyod sDiFWy4n tElzo9YK NNdt31gx NaeEtqmR MGwCCYWu y80zQlGX OAYoTGVY wYs20iOY j4eZDalG HDcd6eWZ Wvxqh0RI jykQ3bNt qRjxSxt6 4HjBIMK1 AIX5UEPr 1HQKp2ZH Fie3kxjb tzwmAigF QntpzTJO 9jQiDIDE LD0OlrSk 8PfSKmt4 MQBr2cK0 FLUQLq2h JfmjaCYv DqkdKyr8 ZtGnI5rj iqhACPMu UsY6ZIpT NjjgMBPV RW4YRcnZ Gyr9nest 9tIXI0km plugRQRv AlFpi0PJ DLcM8Zoq Auk5RBWs tMpfMMlU p6jGYq3Z rTIBTHVM zGFwFwQi j4O1AY21 BJnaiScY`
+	// match at the very beginning: the first 100 characters or less
+	assert.Equal(t,
+		"<b>VWwXetig</b> mty8fORN UNia4NFm SQsfyFHk BLDdgVnc AcvKP2fs q8KxPH1A IaCzFj96 J0S2fqca jp3ElV9f ULIZ1aMX …",
+		snippets("VWwXetig", s))
+	// the first 100 … the match, at most 50 (50 from the start of the match)
+	assert.Equal(t,
+		"VWwXetig mty8fORN UNia4NFm SQsfyFHk BLDdgVnc AcvKP2fs q8KxPH1A IaCzFj96 J0S2fqca jp3ElV9f ULIZ1aMX … <b>GSUO1pLI</b> p7vuJie8 kPfc0ONq EthfIUjm u74guCZ8 IiJYxlR6 …",
+		snippets("GSUO1pLI", s))
+	// the first 100 … less than 50, the match, at most 50
+	assert.Equal(t,
+		"VWwXetig mty8fORN UNia4NFm SQsfyFHk BLDdgVnc AcvKP2fs q8KxPH1A IaCzFj96 J0S2fqca jp3ElV9f ULIZ1aMX … GSUO1pLI p7vuJie8 <b>kPfc0ONq</b> EthfIUjm u74guCZ8 IiJYxlR6 5j5LlapY TGO98fOQ …",
+		snippets("kPfc0ONq", s))
+	// the first 100 … 50, the match, at most 50
+	assert.Equal(t,
+		"VWwXetig mty8fORN UNia4NFm SQsfyFHk BLDdgVnc AcvKP2fs q8KxPH1A IaCzFj96 J0S2fqca jp3ElV9f ULIZ1aMX … u74guCZ8 IiJYxlR6 5j5LlapY TGO98fOQ fO2RUb1g <b>W8zaPa0v</b> ps0haNzW OOeFwf1h 1N3td7zk 0OoMX8Ek aTd3Ciea …",
+		snippets("W8zaPa0v", s))
+	// match at the very end
+	assert.Equal(t,
+		"VWwXetig mty8fORN UNia4NFm SQsfyFHk BLDdgVnc AcvKP2fs q8KxPH1A IaCzFj96 J0S2fqca jp3ElV9f ULIZ1aMX … tMpfMMlU p6jGYq3Z rTIBTHVM zGFwFwQi j4O1AY21 <b>BJnaiScY</b>",
+		snippets("BJnaiScY", s))
+	// match near the end
+	assert.Equal(t,
+		"VWwXetig mty8fORN UNia4NFm SQsfyFHk BLDdgVnc AcvKP2fs q8KxPH1A IaCzFj96 J0S2fqca jp3ElV9f ULIZ1aMX … Auk5RBWs tMpfMMlU p6jGYq3Z rTIBTHVM zGFwFwQi <b>j4O1AY21</b> BJnaiScY",
+		snippets("j4O1AY21", s))
+
+}

upload.html

@@ -0,0 +1,40 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8">
+    <meta name="format-detection" content="telephone=no">
+    <meta name="viewport" content="width=device-width">
+    <title>Upload File</title>
+    <style>
+html { max-width: 70ch; padding: 2ch; margin: auto; color: #111; background: #ffe; }
+body { hyphens: auto; }
+form, textarea { width: 100%; }
+label { display: inline-block; width: 20ch }
+    </style>
+  </head>
+  <body lang="en">
+    <h1>Upload File</h1>
+    <form action="/drop/{{.}}" method="POST" enctype="multipart/form-data">
+      <p>When uploading pictures from a phone, its filename is going to be something cryptic like IMG_1234.JPG.
+        Please provide your own filename.
+      <p><label for="text">Filename to use:</label>
+        <input id="text" name="name" type="text" placeholder="image.jpg" autofocus required>
+      <p>If the uploaded file is a picture from a phone, it is going to be too big for your site.
+        Sadly, resizing only works for JPG and PNG files. Luckily, most pictures from a phone camera are JPG images.
+        Feel free to specify a max width of 1200 pixels, for example.
+      <p><label for="maxwidth">Max width:</label>
+        <input id="maxwidth" name="maxwidth" type="number" min="10" placeholder="1200">
+      <p>If the uploaded file is a JPEG-encoded picture, like most pictures from a phone, you can specify a quality.
+        Typically, a quality of 60 is not too bad and a quality of 90 is more than enough.
+      <p><label for="quality">Quality:</label>
+        <input id="quality" name="quality" type="number" min="1" max="99" placeholder="75">
+      <p>Finally, pick the file or photo to upload.
+        Picture metadata is only removed if the picture gets resized.
+        Providing a new max width is recommended for all pictures.
+      <p><label for="file">Pick file to upload:</label>
+        <input type="file" name="file" required>
+      <p><input type="submit" value="Save">
+        <a href="/view/index"><button type="button">Cancel</button></a></p>
+    </form>
+  </body>
+</html>

upload_drop.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	"github.com/anthonynsimon/bild/imgio"
+	"github.com/anthonynsimon/bild/transform"
+	"image/jpeg"
+	"io"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+// uploadHandler uses the "upload.html" template to enable uploads.
+// The file is saved using the saveUploadHandler.
+func uploadHandler(w http.ResponseWriter, r *http.Request, dir string) {
+	renderTemplate(w, "upload", dir)
+}
+
+// dropHandler takes the "name" form field and the "file" form
+// file and saves the file under the given name. The browser is
+// redirected to the view of that file.
+func dropHandler(w http.ResponseWriter, r *http.Request, dir string) {
+	d := path.Dir(dir)
+	// ensure the directory exists
+	fi, err := os.Stat(d)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	if !fi.IsDir() {
+		http.Error(w, "file exists", http.StatusInternalServerError)
+		return
+	}
+	name := r.FormValue("name")
+	filename := filepath.Base(name)
+	if filename == "." || filepath.Dir(name) != "." {
+		http.Error(w, "no filename", http.StatusInternalServerError)
+		return
+	}
+	file, _, err := r.FormFile("file")
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	defer file.Close()
+	// backup an existing file with the same name
+	_, err = os.Stat(filename)
+	if err != nil {
+		os.Rename(filename, filename+"~")
+	}
+	// create the new file
+	path := d + "/" + filename
+	dst, err := os.Create(path)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	defer dst.Close()
+	if _, err := io.Copy(dst, file); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+	// if a resize was requested
+	maxwidth := r.FormValue("maxwidth")
+	if len(maxwidth) > 0 {
+		mw, err := strconv.Atoi(maxwidth)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		ext := strings.ToLower(filepath.Ext(path))
+		var encoder imgio.Encoder
+		switch ext {
+		case ".png":
+			encoder = imgio.PNGEncoder()
+		case ".jpg", ".jpeg":
+			q := jpeg.DefaultQuality
+			quality := r.FormValue("quality")
+			if len(quality) > 0 {
+				q, err = strconv.Atoi(quality)
+				if err != nil {
+					http.Error(w, err.Error(), http.StatusInternalServerError)
+					return
+				}
+			}
+			encoder = imgio.JPEGEncoder(q)
+		default:
+			http.Error(w, "only .png, .jpg, or .jpeg files are supported", http.StatusInternalServerError)
+			return
+		}
+		img, err := imgio.Open(path)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		rect := img.Bounds()
+		width := rect.Max.X - rect.Min.X
+		if width > mw {
+			height := (rect.Max.Y - rect.Min.Y) * mw / width
+			img = transform.Resize(img, mw, height, transform.Linear)
+			if err := imgio.Save(path, img, encoder); err != nil {
+				http.Error(w, err.Error(), http.StatusInternalServerError)
+				return
+			}
+		}
+
+	}
+	http.Redirect(w, r, "/view/"+path, http.StatusFound)
+}

upload_drop_test.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"bytes"
+	"github.com/stretchr/testify/assert"
+	"image"
+	"image/jpeg"
+	"image/png"
+	"mime/multipart"
+	"os"
+	"regexp"
+	"testing"
+)
+
+// wipes testdata
+func TestUpload(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+	// for uploads, the directory is not created automatically
+	os.MkdirAll("testdata", 0755)
+	assert.HTTPStatusCode(t, makeHandler(uploadHandler, false), "GET", "/upload/testdata/", nil, 200)
+	form := new(bytes.Buffer)
+	writer := multipart.NewWriter(form)
+	field, err := writer.CreateFormField("name")
+	assert.NoError(t, err)
+	_, err = field.Write([]byte("ok.txt"))
+	assert.NoError(t, err)
+	file, err := writer.CreateFormFile("file", "example.txt")
+	assert.NoError(t, err)
+	file.Write([]byte("Hello!"))
+	err = writer.Close()
+	assert.NoError(t, err)
+	HTTPUploadAndRedirectTo(t, makeHandler(dropHandler, false), "/drop/testdata/",
+		writer.FormDataContentType(), form, "/view/testdata/ok.txt")
+	assert.Regexp(t, regexp.MustCompile("Hello!"),
+		assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/testdata/ok.txt", nil))
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}
+
+// wipes testdata
+func TestUploadPng(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+	// for uploads, the directory is not created automatically
+	os.MkdirAll("testdata", 0755)
+	form := new(bytes.Buffer)
+	writer := multipart.NewWriter(form)
+	field, _ := writer.CreateFormField("name")
+	field.Write([]byte("ok.png"))
+	file, _ := writer.CreateFormFile("file", "ok.png")
+	img := image.NewRGBA(image.Rect(0, 0, 20, 20))
+	png.Encode(file, img)
+	writer.Close()
+	HTTPUploadAndRedirectTo(t, makeHandler(dropHandler, false), "/drop/testdata/",
+		writer.FormDataContentType(), form, "/view/testdata/ok.png")
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}
+
+// wipes testdata
+func TestUploadJpg(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+	// for uploads, the directory is not created automatically
+	os.MkdirAll("testdata", 0755)
+	form := new(bytes.Buffer)
+	writer := multipart.NewWriter(form)
+	field, _ := writer.CreateFormField("name")
+	field.Write([]byte("ok.jpg"))
+	file, _ := writer.CreateFormFile("file", "ok.jpg")
+	img := image.NewRGBA(image.Rect(0, 0, 20, 20))
+	jpeg.Encode(file, img, &jpeg.Options{Quality: 90})
+	writer.Close()
+	HTTPUploadAndRedirectTo(t, makeHandler(dropHandler, false), "/drop/testdata/",
+		writer.FormDataContentType(), form, "/view/testdata/ok.jpg")
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}

view.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"net/http"
+	"os"
+)
+
+// rootHandler just redirects to /view/index.
+func rootHandler(w http.ResponseWriter, r *http.Request) {
+	http.Redirect(w, r, "/view/index", http.StatusFound)
+}
+
+// viewHandler serves existing files (including markdown files with
+// the .md extension). If the requested file does not exist, a page
+// with the same name is loaded. This means adding the .md extension
+// and using the "view.html" template to render the HTML. Both
+// attempts fail, the browser is redirected to an edit page.
+func viewHandler(w http.ResponseWriter, r *http.Request, name string) {
+	body, err := os.ReadFile(name)
+	if err == nil {
+		w.Write(body)
+		return
+	}
+	p, err := loadPage(name)
+	if err == nil {
+		p.handleTitle(true)
+		p.renderHtml()
+		renderTemplate(w, "view", p)
+		return
+	}
+	http.Redirect(w, r, "/edit/"+name, http.StatusFound)
+}

view.html

@@ -1,19 +1,42 @@
 <!DOCTYPE html>
-<html>
+<html lang="{{.Language}}">
   <head>
     <meta charset="utf-8">
     <meta name="format-detection" content="telephone=no">
     <meta name="viewport" content="width=device-width">
     <title>{{.Title}}</title>
     <style>
-html { max-width: 70ch; padding: 2ch; margin: auto; color: #111; background: #ffe; }
+html { max-width: 65ch; padding: 1ch; margin: auto; color: #111; background: #ffe; }
+body { hyphens: auto; }
+header a { margin-right: 1ch; }
+form { display: inline-block; }
+input#search { width: 12ch; }
+button { background: #eee; color: inherit; border-radius: 4px; border-width: 1px; }
+footer { border-top: 1px solid #888 }
+img { max-width: 100%; }
     </style>
   </head>
   <body>
-    <h1>{{.Title}}</h1>
-    <p><a href="/edit/{{.Title}}">Edit this page</a></p>
-    <div>
-{{.Html}}
-    </div>
+    <header>
+      <a href="#main">Skip navigation</a>
+      <a href="/view/index">Home</a>
+      <a href="/edit/{{.Name}}">Edit</a>
+      <a href="/add/{{.Name}}">Add</a>
+      <a href="/upload/{{.Dir}}">Upload</a>
+      <form role="search" action="/search" method="GET">
+        <label for="search">Search:</label>
+        <input id="search" type="text" spellcheck="false" name="q" required>
+        <button>Go</button>
+      </form>
+    </header>
+    <main id="main">
+      <h1>{{.Title}}</h1>
+      {{.Html}}
+    </main>
+    <footer>
+      <address>
+        Comments? Send mail to Alex Schroeder <<a href="mailto:alex@alexschroeder.ch">alex@alexschroeder.ch</a>>
+      </address>
+    </footer>
   </body>
 </html>

view_test.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"os"
+	"regexp"
+	"testing"
+)
+
+func TestRootHandler(t *testing.T) {
+	HTTPRedirectTo(t, rootHandler, "GET", "/", nil, "/view/index")
+}
+
+// relies on index.md in the current directory!
+func TestViewHandler(t *testing.T) {
+	assert.Regexp(t, regexp.MustCompile("Welcome to Oddµ"),
+		assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/index", nil))
+}
+
+// wipes testdata
+func TestPageTitleWithAmp(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+
+	p := &Page{Name: "testdata/Rock & Roll", Body: []byte("Dancing")}
+	p.save()
+
+	assert.Regexp(t, regexp.MustCompile("Rock & Roll"),
+		assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/testdata/Rock%20%26%20Roll", nil))
+
+	p = &Page{Name: "testdata/Rock & Roll", Body: []byte("# Sex & Drugs & Rock'n'Roll\nOh no!")}
+	p.save()
+
+	assert.Regexp(t, regexp.MustCompile("Sex & Drugs"),
+		assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/testdata/Rock%20%26%20Roll", nil))
+
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}
+
+func TestPageTitleWithQuestionMark(t *testing.T) {
+	_ = os.RemoveAll("testdata")
+
+	p := &Page{Name: "testdata/How about no?", Body: []byte("No means no")}
+	p.save()
+
+	body := assert.HTTPBody(makeHandler(viewHandler, true), "GET", "/view/testdata/How%20about%20no%3F", nil)
+	assert.Contains(t, body, "No means no")
+	assert.Contains(t, body, "<a href=\"/edit/testdata/How%20about%20no%3F\">Edit</a>")
+
+	t.Cleanup(func() {
+		_ = os.RemoveAll("testdata")
+	})
+}

wiki.go

@@ -1,92 +1,59 @@
 package main
 
 import (
-	"os"
 	"fmt"
-	"github.com/microcosm-cc/bluemonday"
-	"github.com/gomarkdown/markdown"
 	"html/template"
 	"net/http"
+	"os"
 	"regexp"
 )
 
-var templates = template.Must(template.ParseFiles("edit.html", "view.html"))
+// Templates are parsed at startup.
+var templates = template.Must(
+	template.ParseFiles("edit.html", "add.html", "view.html",
+		"search.html", "upload.html"))
 
-var validPath = regexp.MustCompile("^/(edit|save|view)/([^/]+)$")
+// validPath is a regular expression where the second group matches a
+// page, so when the editHandler is called, a URL path of "/edit/foo"
+// results in the editHandler being called with title "foo". The
+// regular expression doesn't define the handlers (this happens in the
+// main function).
+var validPath = regexp.MustCompile("^/([^/]+)/(.*)$")
 
-type Page struct {
-	Title string
-	Body  []byte
-	Html  template.HTML
-}
+// titleRegexp is a regular expression matching a level 1 header line
+// in a Markdown document. The first group matches the actual text and
+// is used to provide an title for pages. If no title exists in the
+// document, the page name is used instead.
+var titleRegexp = regexp.MustCompile("(?m)^#\\s*(.*)\n+")
 
-func (p *Page) save() error {
-	filename := p.Title + ".md"
-	return os.WriteFile(filename, p.Body, 0600)
-}
-
-func loadPage(title string) (*Page, error) {
-	filename := title + ".md"
-	body, err := os.ReadFile(filename)
-	if err != nil {
-		return nil, err
-	}
-	return &Page{Title: title, Body: body}, nil
-}
-
-func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
-	err := templates.ExecuteTemplate(w, tmpl+".html", p)
+// renderTemplate is the helper that is used render the templates with
+// data.
+func renderTemplate(w http.ResponseWriter, tmpl string, data any) {
+	err := templates.ExecuteTemplate(w, tmpl+".html", data)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 	}
 }
 
-func rootHandler(w http.ResponseWriter, r *http.Request) {
-	http.Redirect(w, r, "/view/index", http.StatusFound)
-}
-
-func viewHandler(w http.ResponseWriter, r *http.Request, title string) {
-	p, err := loadPage(title)
-	if err != nil {
-		http.Redirect(w, r, "/edit/"+title, http.StatusFound)
-		return
-	}
-	maybeUnsafeHTML := markdown.ToHTML(p.Body, nil, nil)
-	html := bluemonday.UGCPolicy().SanitizeBytes(maybeUnsafeHTML)
-	p.Html = template.HTML(html);
-	renderTemplate(w, "view", p)
-}
-
-func editHandler(w http.ResponseWriter, r *http.Request, title string) {
-	p, err := loadPage(title)
-	if err != nil {
-		p = &Page{Title: title}
-	}
-	renderTemplate(w, "edit", p)
-}
-
-func saveHandler(w http.ResponseWriter, r *http.Request, title string) {
-	body := r.FormValue("body")
-	p := &Page{Title: title, Body: []byte(body)}
-	err := p.save()
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-	http.Redirect(w, r, "/view/"+title, http.StatusFound)
-}
-
-func makeHandler(fn func (http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
+// makeHandler returns a handler that uses the URL path without the
+// first path element as its argument, e.g. if the URL path is
+// /edit/foo/bar, the editHandler is called with "foo/bar" as its
+// argument. This uses the second group from the validPath regular
+// expression. The boolean argument indicates whether the following
+// path is required. When false, a URL /upload/ is OK.
+func makeHandler(fn func(http.ResponseWriter, *http.Request, string), required bool) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		m := validPath.FindStringSubmatch(r.URL.Path)
-		if m == nil {
+		if m != nil && (!required || len(m[2]) > 0) {
+			fn(w, r, m[2])
+		} else {
 			http.NotFound(w, r)
-			return
 		}
-		fn(w, r, m[2])
 	}
 }
 
+// getPort returns the environment variable ODDMU_PORT or the default
+// port, "8080".
 func getPort() string {
 	port := os.Getenv("ODDMU_PORT")
 	if port == "" {
@@ -95,13 +62,49 @@ func getPort() string {
 	return port
 }
 
-func main() {
-	http.HandleFunc("/", rootHandler)
-	http.HandleFunc("/view/", makeHandler(viewHandler))
-	http.HandleFunc("/edit/", makeHandler(editHandler))
-	http.HandleFunc("/save/", makeHandler(saveHandler))
-
-	port := getPort()
-	fmt.Println("Serving a wiki on port " + port)
-	http.ListenAndServe(":" + port, nil)
+// scheduleLoadIndex calls index.load and prints some messages before
+// and after. For testing, call index.load directly and skip the
+// messages.
+func scheduleLoadIndex() {
+	fmt.Print("Indexing pages\n")
+	n, err := index.load()
+	if err == nil {
+		fmt.Printf("Indexed %d pages\n", n)
+	} else {
+		fmt.Println("Indexing failed")
+	}
+}
+
+// scheduleLoadLanguages calls loadLanguages and prints some messages before
+// and after. For testing, call loadLanguages directly and skip the
+// messages.
+func scheduleLoadLanguages() {
+	fmt.Print("Loading languages\n")
+	n := loadLanguages()
+	fmt.Printf("Loaded %d languages\n", n)
+}
+
+func serve() {
+	http.HandleFunc("/", rootHandler)
+	http.HandleFunc("/view/", makeHandler(viewHandler, true))
+	http.HandleFunc("/edit/", makeHandler(editHandler, true))
+	http.HandleFunc("/save/", makeHandler(saveHandler, true))
+	http.HandleFunc("/add/", makeHandler(addHandler, true))
+	http.HandleFunc("/append/", makeHandler(appendHandler, true))
+	http.HandleFunc("/upload/", makeHandler(uploadHandler, false))
+	http.HandleFunc("/drop/", makeHandler(dropHandler, false))
+	http.HandleFunc("/search", searchHandler)
+	go scheduleLoadIndex()
+	go scheduleLoadLanguages()
+	port := getPort()
+	fmt.Printf("Serving a wiki on port %s\n", port)
+	http.ListenAndServe(":"+port, nil)
+}
+
+func main() {
+	if len(os.Args) == 1 {
+		serve()
+	} else {
+		commands()
+	}
 }

wiki_test.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"bytes"
+	"github.com/stretchr/testify/assert"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+)
+
+// HTTPHeaders is a helper that returns HTTP headers of the response. It returns
+// nil if building a new request fails.
+func HTTPHeaders(handler http.HandlerFunc, method, url string, values url.Values, header string) []string {
+	w := httptest.NewRecorder()
+	req, err := http.NewRequest(method, url+"?"+values.Encode(), nil)
+	if err != nil {
+		return nil
+	}
+	handler(w, req)
+	return w.Result().Header[header]
+}
+
+// HTTPRedirectTo checks that the request results in a redirect and it
+// checks the destination of the redirect. It returns whether the
+// request did in fact result in a redirect. Note: This method assumes
+// that POST requests ignore the query part of the URL.
+func HTTPRedirectTo(t *testing.T, handler http.HandlerFunc, method, url string, values url.Values, destination string) bool {
+	w := httptest.NewRecorder()
+	var req *http.Request
+	var err error
+	if method == http.MethodPost {
+		body := strings.NewReader(values.Encode())
+		req, err = http.NewRequest(method, url, body)
+		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	} else {
+		req, err = http.NewRequest(method, url+"?"+values.Encode(), nil)
+	}
+	assert.NoError(t, err)
+	handler(w, req)
+	code := w.Code
+	isRedirectCode := code >= http.StatusMultipleChoices && code <= http.StatusTemporaryRedirect
+	assert.True(t, isRedirectCode, "Expected HTTP redirect status code for %q but received %d", url+"?"+values.Encode(), code)
+	headers := w.Result().Header["Location"]
+	assert.True(t, len(headers) == 1 && headers[0] == destination,
+		"Expected HTTP redirect location %s for %q but received %v", destination, url+"?"+values.Encode(), headers)
+	return isRedirectCode
+}
+
+// HTTPUploadAndRedirectTo checks that the request results in a redirect and it
+// checks the destination of the redirect. It returns whether the
+// request did in fact result in a redirect.
+func HTTPUploadAndRedirectTo(t *testing.T, handler http.HandlerFunc, url, contentType string, body *bytes.Buffer, destination string) bool {
+	w := httptest.NewRecorder()
+	req, err := http.NewRequest("POST", url, body)
+	req.Header.Set("Content-Type", contentType)
+	assert.NoError(t, err)
+	handler(w, req)
+	code := w.Code
+	isRedirectCode := code >= http.StatusMultipleChoices && code <= http.StatusTemporaryRedirect
+	assert.True(t, isRedirectCode, "Expected HTTP redirect status code for %q but received %d", url, code)
+	headers := w.Result().Header["Location"]
+	assert.True(t, len(headers) == 1 && headers[0] == destination,
+		"Expected HTTP redirect location %s for %q but received %v", destination, url, headers)
+	return isRedirectCode
+}