Switch to blackfriday, remove Gemtext instructions

https://github.com/pemistahl/lingua-go/discussions/50

README.md

@@ -47,8 +47,8 @@ some of which are enable by default:
 * MathJax is supported (but needs a separte setup)
 
 See the section on
-[extensions](https://github.com/gomarkdown/markdown#extensions) in the
-Markdown library for information on the various extensions.
+[extensions](https://github.com/russross/blackfriday#extensions) in
+the Blackfriday library for information on the various extensions.
 
 A table with footers and a columnspan:
 
@@ -217,8 +217,9 @@ MDCertificateAgreement accepted
 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/`, `/save/` or `/search/` is
-proxied to port 8080 where the Oddmu program can handle it.
+path that starts with `/view/`, `/edit/`, `/save/`, `/add/`,
+`/append/` or `/search/` is proxied to port 8080 where the Oddmu
+program can handle it.
 
 Thus, this is what happens:
 
@@ -265,12 +266,12 @@ 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/` and `/append/` URLs with a password by adding the following to
+your `<VirtualHost *:443>` section:
 
 ```apache
-<LocationMatch "^/(edit|save)/">
+<LocationMatch "^/(edit|save|add|append)/">
   AuthType Basic
   AuthName "Password Required"
   AuthUserFile /home/oddmu/.htpasswd
@@ -295,10 +296,9 @@ webserver can read (world readable file, world readable and executable
 directory). Populate it with files.
 
 Make sure that none of the static files look like the wiki paths
-`/view/`, `/edit/`, `/save/` or `/search/`.
-
-For example, create a file called `robots.txt` containing the
-following, tellin all robots that they're not welcome.
+`/view/`, `/edit/`, `/save/`, `/add/`, `/append/` or `/search/`. For
+example, create a file called `robots.txt` containing the following,
+tellin all robots that they're not welcome.
 
 ```text
 User-agent: *
@@ -346,50 +346,8 @@ that matches everything:
 ## Customization (with recompilation)
 
 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.
-
-### Render Gemtext
-
-In a first approximation, Gemtext is valid Markdown except for the
-rocket links (`=>`). Here's how to modify the `loadPage` so that a
-`.gmi` file is loaded if no `.md` is found, and the rocket links are
-translated into Markdown:
-
-```go
-func loadPage(name string) (*Page, error) {
-	filename := name + ".md"
-	body, err := os.ReadFile(filename)
-	if err == nil {
-		return &Page{Title: name, Name: name, Body: body}, nil
-	}
-	filename = name + ".gmi"
-	body, err = os.ReadFile(filename)
-	if err == nil {
-		re := regexp.MustCompile(`(?m)^=>\s*(\S+)\s+(.+)`)
-		body = []byte(re.ReplaceAllString(string(body), `* [$2]($1)`))
-		return &Page{Title: name, Name: name, Body: body}, nil
-	}
-	return nil, err
-}
-```
-
-There is a small problem, however: By default, Markdown expects an
-empty line before a list begins. The following change to `renderHtml`
-uses the `NoEmptyLineBeforeBlock` extension for the parser:
-
-```go
-func (p* Page) renderHtml() {
-    // Here is where a new extension is added!
-	extensions := parser.CommonExtensions | parser.NoEmptyLineBeforeBlock
-	markdownParser := parser.NewWithExtensions(extensions)
-	maybeUnsafeHTML := markdown.ToHTML(p.Body, markdownParser, nil)
-	html := bluemonday.UGCPolicy().SanitizeBytes(maybeUnsafeHTML)
-	p.Html = template.HTML(html);
-}
-```
+[extensions](https://github.com/russross/blackfriday#extensions) can
+be added. You'll need to make changes to `renderHtml` yourself.
 
 ## Understanding search
 
@@ -421,15 +379,15 @@ 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
-"software" and "#socialmedia", a search for "#software" returns a
-result because the trigram "#so" is part of "#socialmedia".
+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

TODO.md

@@ -1,6 +1,3 @@
-Easily prepend or append text for use with a mobile browser. Like
-comments.
-
 Upload files.
 
 Automatically scale or process files.
@@ -9,15 +6,7 @@ Post by Delta Chat? That is, allow certain encrypted emails to post.
 
 Convert the existing wiki.
 
-Investigate how to run a multi-lingual wiki where an appropriate
-template is used based on the language of the page. This is important
-because the template needs to use the appropriate `lang` attribute for
-hyphenation to work.
-
 Investigate how to run a multi-linugual wiki where an appropriate
 version of a page is served based on language preferences of the user.
 This is a low priority issue since it's probably only of interest for
 corporate or governmental sites.
-
-Switch from trigram search to a simple full text search engine?
-https://artem.krylysov.com/blog/2020/07/28/lets-build-a-full-text-search-engine/

add.html

@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+  <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">
+      <div><textarea name="body" rows="20" cols="80" placeholder="Text" autofocus></textarea></div>
+      <p><input type="submit" value="Add">
+        <a href="/view/{{.Name}}"><button>Cancel</button></a></p>
+    </form>
+  </body>
+</html>

edit.html

@@ -12,9 +12,10 @@ form, textarea { width: 100%; }
   </head>
   <body>
     <h1>Editing {{.Title}}</h1>
-
     <form action="/save/{{.Name}}" method="POST">
-      <div><textarea name="body" rows="20" cols="80">{{printf "%s" .Body}}</textarea></div>
+      <div><textarea name="body" rows="20" cols="80" placeholder="# Title
+
+Text" autofocus>{{printf "%s" .Body}}</textarea></div>
       <p><input type="submit" value="Save">
         <a href="/view/{{.Name}}"><button>Cancel</button></a></p>
     </form>

go.mod

@@ -4,16 +4,20 @@ go 1.21.0
 
 require (
 	github.com/dgryski/go-trigram v0.0.0-20160407183937-79ec494e1ad0
-	github.com/gomarkdown/markdown v0.0.0-20230716120725-531d2d74bc12
 	github.com/microcosm-cc/bluemonday v1.0.25
+	github.com/pemistahl/lingua-go v1.4.0
+	github.com/russross/blackfriday/v2 v2.1.0
 )
 
 require (
 	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/pemistahl/lingua-go v1.4.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/shopspring/decimal v1.3.1 // indirect
+	github.com/stretchr/testify v1.8.4 // indirect
 	golang.org/x/exp v0.0.0-20221106115401-f9659909a136 // 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

@@ -1,19 +1,27 @@
 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/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/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/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/microcosm-cc/bluemonday v1.0.25 h1:4NEwSfiJ+Wva0VxN5B8OwMicaJvD8r9tlJWm9rtloEg=
 github.com/microcosm-cc/bluemonday v1.0.25/go.mod h1:ZIOjCQp1OrzBBPIJmfX4qDYFuhU02nx4bn030ixfHLE=
 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/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 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/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 golang.org/x/exp v0.0.0-20221106115401-f9659909a136 h1:Fq7F/w7MAa1KJ5bt2aJ62ihqp9HDcRuyILskkpIAurw=
 golang.org/x/exp v0.0.0-20221106115401-f9659909a136/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
 golang.org/x/net v0.12.0 h1:cfawfvKITfUsFCeJIHJrbSxpeu/E81khclypR0GVT50=
@@ -22,3 +30,6 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8T
 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/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

page.go

@@ -3,11 +3,9 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"github.com/gomarkdown/markdown"
-	"github.com/gomarkdown/markdown/ast"
-	"github.com/gomarkdown/markdown/parser"
 	"github.com/microcosm-cc/bluemonday"
 	"github.com/pemistahl/lingua-go"
+	"github.com/russross/blackfriday/v2"
 	"html/template"
 	"os"
 	"path/filepath"
@@ -103,35 +101,39 @@ func (p *Page) handleTitle(replace bool) {
 
 // renderHtml renders the Page.Body to HTML and sets Page.Html.
 func (p *Page) renderHtml() {
-	maybeUnsafeHTML := markdown.ToHTML(p.Body, nil, nil)
+	maybeUnsafeHTML := blackfriday.Run(p.Body)
 	p.Html = sanitizeBytes(maybeUnsafeHTML)
-	p.Language = p.language(p.plainText())
+	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)
+	optList := []blackfriday.Option{blackfriday.WithExtensions(blackfriday.CommonExtensions)}
+	parser := blackfriday.New(optList...)
+	ast := parser.Parse(p.Body)
 	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(" ")...)
+	ast.Walk(func(node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
+		if entering && node.Type == blackfriday.Text {
+			s := node.Literal
+			if len(s) == 0 {
+				return blackfriday.GoToNext
+			}
+			// Some Markdown still contains newlines
+			for i, c := range s {
+				if c == '\n' {
+					s[i] = ' '
+				}
+			}
+			if len(text) > 0 && text[len(text)-1] != ' ' && s[0] != ' ' {
+				text = append(text, ' ')
+			}
+
+			text = append(text, s...)
 		}
-		return ast.GoToNext
+		return blackfriday.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)
 }
 
@@ -141,17 +143,12 @@ func (p *Page) summarize(q string) {
 	p.Score = score(q, string(p.Body)) + score(q, p.Title)
 	t := p.plainText()
 	p.Html = sanitize(snippets(q, t))
-	p.Language = p.language(t)
+	p.Language = language(t)
 }
 
-func (p *Page) language (s string) string {
+func language(s string) string {
 	if language, ok := detector.DetectLanguageOf(s); ok {
-		switch language {
-		case lingua.English:
-			return "en"
-		case lingua.German:
-			return "de"
-		}
+		return strings.ToLower(language.IsoCode639_1().String())
 	}
 	return ""
 }

page_test.go

@@ -2,8 +2,9 @@ package main
 
 import (
 	"os"
-	"strings"
+	"regexp"
 	"testing"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestPageTitle(t *testing.T) {
@@ -12,19 +13,10 @@ My back aches for you
 I sit, stare and type for hours
 But yearn for blue sky`)}
 	p.handleTitle(false)
-	if p.Title != "Ache" {
-		t.Logf("The page title was not extracted correctly: %s", p.Title)
-		t.Fail()
-	}
-	if !strings.HasPrefix(string(p.Body), "# Ache") {
-		t.Logf("The page title was removed: %s", p.Body)
-		t.Fail()
-	}
+	assert.Equal(t, "Ache", p.Title)
+	assert.Regexp(t, regexp.MustCompile("^# Ache"), string(p.Body))
 	p.handleTitle(true)
-	if !strings.HasPrefix(string(p.Body), "My back") {
-		t.Logf("The page title was not removed: %s", p.Body)
-		t.Fail()
-	}
+	assert.Regexp(t, regexp.MustCompile("^My back"), string(p.Body))
 }
 
 func TestPagePlainText(t *testing.T) {
@@ -32,12 +24,8 @@ func TestPagePlainText(t *testing.T) {
 The air will not come
 To inhale is an effort
 The summer heat kills`)}
-	s := p.plainText()
 	r := "Water The air will not come To inhale is an effort The summer heat kills"
-	if s != r {
-		t.Logf("The plain text version is wrong: %s", s)
-		t.Fail()
-	}
+	assert.Equal(t, r, p.plainText())
 }
 
 func TestPageHtml(t *testing.T) {
@@ -46,17 +34,13 @@ Silver leaves shine bright
 They droop, boneless, weak and sad
 A cruel sun stares down`)}
 	p.renderHtml()
-	s := string(p.Html)
 	r := `<h1>Sun</h1>
 
 <p>Silver leaves shine bright
 They droop, boneless, weak and sad
 A cruel sun stares down</p>
 `
-	if s != r {
-		t.Logf("The HTML is wrong: %s", s)
-		t.Fail()
-	}
+	assert.Equal(t, r, string(p.Html))
 }
 
 func TestPageDir(t *testing.T) {
@@ -68,11 +52,17 @@ A slow shuffle in the dark
 Moonlight floods the aisle`)}
 	p.save()
 	o, err := loadPage("testdata/moon")
-	if err != nil || string(o.Body) != string(p.Body) {
-		t.Logf("File in subdirectory not loaded: %s", p.Name)
-		t.Fail()
-	}
+	assert.NoError(t, err, "load page")
+	assert.Equal(t, p.Body, o.Body)
 	t.Cleanup(func() {
 		_ = os.RemoveAll("testdata")
 	})
 }
+
+func TestLanguage(t *testing.T) {
+	l := language(`
+My back hurts at night
+My shoulders won't budge today
+Winter bones I say`)
+	assert.Equal(t, "en", l)
+}

view.html

@@ -18,7 +18,8 @@ img { max-width: 100%; }
     <header>
       <a href="#main">Skip navigation</a>
       <a href="/view/index">Home</a>
-      <a href="/edit/{{.Name}}">Edit this page</a>
+      <a href="/edit/{{.Name}}">Edit</a>
+      <a href="/add/{{.Name}}">Add</a>
       <form role="search" action="/search" method="GET">
         <input type="text" spellcheck="false" name="q" required>
         <button>Search</button>

wiki.go

@@ -10,7 +10,8 @@ import (
 )
 
 // Templates are parsed at startup.
-var templates = template.Must(template.ParseFiles("edit.html", "view.html", "search.html"))
+var templates = template.Must(
+	template.ParseFiles("edit.html", "add.html", "view.html", "search.html"))
 
 // validPath is a regular expression where the second group matches a
 // page, so when the handler for "/edit/" is called, a URL path of
@@ -65,7 +66,8 @@ func viewHandler(w http.ResponseWriter, r *http.Request, name string) {
 
 // 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.
+// 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 {
@@ -89,6 +91,38 @@ func saveHandler(w http.ResponseWriter, r *http.Request, name string) {
 	http.Redirect(w, r, "/view/"+name, http.StatusFound)
 }
 
+// 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)
+}
+
 // 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
@@ -130,6 +164,8 @@ func main() {
 	http.HandleFunc("/view/", makeHandler(viewHandler))
 	http.HandleFunc("/edit/", makeHandler(editHandler))
 	http.HandleFunc("/save/", makeHandler(saveHandler))
+	http.HandleFunc("/add/", makeHandler(addHandler))
+	http.HandleFunc("/append/", makeHandler(appendHandler))
 	http.HandleFunc("/search", searchHandler)
 	fmt.Print("Indexing all pages\n")
 	loadIndex()