Add plugin manager

internal/config/plugin_installer.go

@@ -0,0 +1,630 @@
+package config
+
+import (
+	"archive/zip"
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"sync"
+
+	"github.com/blang/semver"
+	lua "github.com/yuin/gopher-lua"
+	"github.com/zyedidia/json5"
+	ulua "github.com/zyedidia/micro/internal/lua"
+	"github.com/zyedidia/micro/internal/util"
+)
+
+var (
+	allPluginPackages PluginPackages
+)
+
+// CorePluginName is a plugin dependency name for the micro core.
+const CorePluginName = "micro"
+
+// PluginChannel contains an url to a json list of PluginRepository
+type PluginChannel string
+
+// PluginChannels is a slice of PluginChannel
+type PluginChannels []PluginChannel
+
+// PluginRepository contains an url to json file containing PluginPackages
+type PluginRepository string
+
+// PluginPackage contains the meta-data of a plugin and all available versions
+type PluginPackage struct {
+	Name        string
+	Description string
+	Author      string
+	Tags        []string
+	Versions    PluginVersions
+}
+
+// PluginPackages is a list of PluginPackage instances.
+type PluginPackages []*PluginPackage
+
+// PluginVersion descripes a version of a PluginPackage. Containing a version, download url and also dependencies.
+type PluginVersion struct {
+	pack    *PluginPackage
+	Version semver.Version
+	Url     string
+	Require PluginDependencies
+}
+
+func (pv *PluginVersion) Pack() *PluginPackage {
+	return pv.pack
+}
+
+// PluginVersions is a slice of PluginVersion
+type PluginVersions []*PluginVersion
+
+// PluginDependency descripes a dependency to another plugin or micro itself.
+type PluginDependency struct {
+	Name  string
+	Range semver.Range
+}
+
+// PluginDependencies is a slice of PluginDependency
+type PluginDependencies []*PluginDependency
+
+func (pp *PluginPackage) String() string {
+	buf := new(bytes.Buffer)
+	buf.WriteString("Plugin: ")
+	buf.WriteString(pp.Name)
+	buf.WriteRune('\n')
+	if pp.Author != "" {
+		buf.WriteString("Author: ")
+		buf.WriteString(pp.Author)
+		buf.WriteRune('\n')
+	}
+	if pp.Description != "" {
+		buf.WriteRune('\n')
+		buf.WriteString(pp.Description)
+	}
+	return buf.String()
+}
+
+func fetchAllSources(count int, fetcher func(i int) PluginPackages) PluginPackages {
+	wgQuery := new(sync.WaitGroup)
+	wgQuery.Add(count)
+
+	results := make(chan PluginPackages)
+
+	wgDone := new(sync.WaitGroup)
+	wgDone.Add(1)
+	var packages PluginPackages
+	for i := 0; i < count; i++ {
+		go func(i int) {
+			results <- fetcher(i)
+			wgQuery.Done()
+		}(i)
+	}
+	go func() {
+		packages = make(PluginPackages, 0)
+		for res := range results {
+			packages = append(packages, res...)
+		}
+		wgDone.Done()
+	}()
+	wgQuery.Wait()
+	close(results)
+	wgDone.Wait()
+	return packages
+}
+
+// Fetch retrieves all available PluginPackages from the given channels
+func (pc PluginChannels) Fetch() PluginPackages {
+	return fetchAllSources(len(pc), func(i int) PluginPackages {
+		return pc[i].Fetch()
+	})
+}
+
+// Fetch retrieves all available PluginPackages from the given channel
+func (pc PluginChannel) Fetch() PluginPackages {
+	resp, err := http.Get(string(pc))
+	if err != nil {
+		fmt.Println("Failed to query plugin channel:\n", err)
+		return PluginPackages{}
+	}
+	defer resp.Body.Close()
+	decoder := json5.NewDecoder(resp.Body)
+
+	var repositories []PluginRepository
+	if err := decoder.Decode(&repositories); err != nil {
+		fmt.Println("Failed to decode channel data:\n", err)
+		return PluginPackages{}
+	}
+	return fetchAllSources(len(repositories), func(i int) PluginPackages {
+		return repositories[i].Fetch()
+	})
+}
+
+// Fetch retrieves all available PluginPackages from the given repository
+func (pr PluginRepository) Fetch() PluginPackages {
+	resp, err := http.Get(string(pr))
+	if err != nil {
+		fmt.Println("Failed to query plugin repository:\n", err)
+		return PluginPackages{}
+	}
+	defer resp.Body.Close()
+	decoder := json5.NewDecoder(resp.Body)
+
+	var plugins PluginPackages
+	if err := decoder.Decode(&plugins); err != nil {
+		fmt.Println("Failed to decode repository data:\n", err)
+		return PluginPackages{}
+	}
+	if len(plugins) > 0 {
+		return PluginPackages{plugins[0]}
+	}
+	return nil
+	// return plugins
+}
+
+// UnmarshalJSON unmarshals raw json to a PluginVersion
+func (pv *PluginVersion) UnmarshalJSON(data []byte) error {
+	var values struct {
+		Version semver.Version
+		Url     string
+		Require map[string]string
+	}
+
+	if err := json5.Unmarshal(data, &values); err != nil {
+		return err
+	}
+	pv.Version = values.Version
+	pv.Url = values.Url
+	pv.Require = make(PluginDependencies, 0)
+
+	for k, v := range values.Require {
+		// don't add the dependency if it's the core and
+		// we have a unknown version number.
+		// in that case just accept that dependency (which equals to not adding it.)
+		if k != CorePluginName || !isUnknownCoreVersion() {
+			if vRange, err := semver.ParseRange(v); err == nil {
+				pv.Require = append(pv.Require, &PluginDependency{k, vRange})
+			}
+		}
+	}
+	return nil
+}
+
+// UnmarshalJSON unmarshals raw json to a PluginPackage
+func (pp *PluginPackage) UnmarshalJSON(data []byte) error {
+	var values struct {
+		Name        string
+		Description string
+		Author      string
+		Tags        []string
+		Versions    PluginVersions
+	}
+	if err := json5.Unmarshal(data, &values); err != nil {
+		return err
+	}
+	pp.Name = values.Name
+	pp.Description = values.Description
+	pp.Author = values.Author
+	pp.Tags = values.Tags
+	pp.Versions = values.Versions
+	for _, v := range pp.Versions {
+		v.pack = pp
+	}
+	return nil
+}
+
+// GetAllPluginPackages gets all PluginPackages which may be available.
+func GetAllPluginPackages() PluginPackages {
+	if allPluginPackages == nil {
+		getOption := func(name string) []string {
+			data := GetGlobalOption(name)
+			if strs, ok := data.([]string); ok {
+				return strs
+			}
+			if ifs, ok := data.([]interface{}); ok {
+				result := make([]string, len(ifs))
+				for i, urlIf := range ifs {
+					if url, ok := urlIf.(string); ok {
+						result[i] = url
+					} else {
+						return nil
+					}
+				}
+				return result
+			}
+			return nil
+		}
+
+		channels := PluginChannels{}
+		for _, url := range getOption("pluginchannels") {
+			channels = append(channels, PluginChannel(url))
+		}
+		repos := []PluginRepository{}
+		for _, url := range getOption("pluginrepos") {
+			repos = append(repos, PluginRepository(url))
+		}
+		allPluginPackages = fetchAllSources(len(repos)+1, func(i int) PluginPackages {
+			if i == 0 {
+				return channels.Fetch()
+			}
+			return repos[i-1].Fetch()
+		})
+	}
+	return allPluginPackages
+}
+
+func (pv PluginVersions) find(ppName string) *PluginVersion {
+	for _, v := range pv {
+		if v.pack.Name == ppName {
+			return v
+		}
+	}
+	return nil
+}
+
+// Len returns the number of pluginversions in this slice
+func (pv PluginVersions) Len() int {
+	return len(pv)
+}
+
+// Swap two entries of the slice
+func (pv PluginVersions) Swap(i, j int) {
+	pv[i], pv[j] = pv[j], pv[i]
+}
+
+// Less returns true if the version at position i is greater then the version at position j (used for sorting)
+func (pv PluginVersions) Less(i, j int) bool {
+	return pv[i].Version.GT(pv[j].Version)
+}
+
+// Match returns true if the package matches a given search text
+func (pp PluginPackage) Match(text string) bool {
+	text = strings.ToLower(text)
+	for _, t := range pp.Tags {
+		if strings.ToLower(t) == text {
+			return true
+		}
+	}
+	if strings.Contains(strings.ToLower(pp.Name), text) {
+		return true
+	}
+
+	if strings.Contains(strings.ToLower(pp.Description), text) {
+		return true
+	}
+
+	return false
+}
+
+// IsInstallable returns true if the package can be installed.
+func (pp PluginPackage) IsInstallable() error {
+	_, err := GetAllPluginPackages().Resolve(GetInstalledVersions(true), PluginDependencies{
+		&PluginDependency{
+			Name:  pp.Name,
+			Range: semver.Range(func(v semver.Version) bool { return true }),
+		}})
+	return err
+}
+
+// SearchPlugin retrieves a list of all PluginPackages which match the given search text and
+// could be or are already installed
+func SearchPlugin(texts []string) (plugins PluginPackages) {
+	plugins = make(PluginPackages, 0)
+
+pluginLoop:
+	for _, pp := range GetAllPluginPackages() {
+		for _, text := range texts {
+			if !pp.Match(text) {
+				continue pluginLoop
+			}
+		}
+
+		if err := pp.IsInstallable(); err == nil {
+			plugins = append(plugins, pp)
+		}
+	}
+	return
+}
+
+func isUnknownCoreVersion() bool {
+	_, err := semver.ParseTolerant(util.Version)
+	return err != nil
+}
+
+func newStaticPluginVersion(name, version string) *PluginVersion {
+	vers, err := semver.ParseTolerant(version)
+
+	if err != nil {
+		if vers, err = semver.ParseTolerant("0.0.0-" + version); err != nil {
+			vers = semver.MustParse("0.0.0-unknown")
+		}
+	}
+	pl := &PluginPackage{
+		Name: name,
+	}
+	pv := &PluginVersion{
+		pack:    pl,
+		Version: vers,
+	}
+	pl.Versions = PluginVersions{pv}
+	return pv
+}
+
+// GetInstalledVersions returns a list of all currently installed plugins including an entry for
+// micro itself. This can be used to resolve dependencies.
+func GetInstalledVersions(withCore bool) PluginVersions {
+	result := PluginVersions{}
+	if withCore {
+		result = append(result, newStaticPluginVersion(CorePluginName, util.Version))
+	}
+
+	for _, p := range Plugins {
+		version := GetInstalledPluginVersion(p.Name)
+		if pv := newStaticPluginVersion(p.Name, version); pv != nil {
+			result = append(result, pv)
+		}
+	}
+
+	return result
+}
+
+// GetInstalledPluginVersion returns the string of the exported VERSION variable of a loaded plugin
+func GetInstalledPluginVersion(name string) string {
+	plugin := ulua.L.GetGlobal(name)
+	if plugin != lua.LNil {
+		version := ulua.L.GetField(plugin, "VERSION")
+		if str, ok := version.(lua.LString); ok {
+			return string(str)
+
+		}
+	}
+	return ""
+}
+
+// DownloadAndInstall downloads and installs the given plugin and version
+func (pv *PluginVersion) DownloadAndInstall() error {
+	fmt.Printf("Downloading %q (%s) from %q\n", pv.pack.Name, pv.Version, pv.Url)
+	resp, err := http.Get(pv.Url)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	data, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+	zipbuf := bytes.NewReader(data)
+	z, err := zip.NewReader(zipbuf, zipbuf.Size())
+	if err != nil {
+		return err
+	}
+	targetDir := filepath.Join(ConfigDir, "plug", pv.pack.Name)
+	dirPerm := os.FileMode(0755)
+	if err = os.MkdirAll(targetDir, dirPerm); err != nil {
+		return err
+	}
+
+	// Check if all files in zip are in the same directory.
+	// this might be the case if the plugin zip contains the whole plugin dir
+	// instead of its content.
+	var prefix string
+	allPrefixed := false
+	for i, f := range z.File {
+		parts := strings.Split(f.Name, "/")
+		if i == 0 {
+			prefix = parts[0]
+		} else if parts[0] != prefix {
+			allPrefixed = false
+			break
+		} else {
+			// switch to true since we have at least a second file
+			allPrefixed = true
+		}
+	}
+
+	// Install files and directory's
+	for _, f := range z.File {
+		parts := strings.Split(f.Name, "/")
+		if allPrefixed {
+			parts = parts[1:]
+		}
+
+		targetName := filepath.Join(targetDir, filepath.Join(parts...))
+		if f.FileInfo().IsDir() {
+			if err := os.MkdirAll(targetName, dirPerm); err != nil {
+				return err
+			}
+		} else {
+			basepath := filepath.Dir(targetName)
+
+			if err := os.MkdirAll(basepath, dirPerm); err != nil {
+				return err
+			}
+
+			content, err := f.Open()
+			if err != nil {
+				return err
+			}
+			defer content.Close()
+			target, err := os.Create(targetName)
+			if err != nil {
+				return err
+			}
+			defer target.Close()
+			if _, err = io.Copy(target, content); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (pl PluginPackages) Get(name string) *PluginPackage {
+	for _, p := range pl {
+		if p.Name == name {
+			return p
+		}
+	}
+	return nil
+}
+
+func (pl PluginPackages) GetAllVersions(name string) PluginVersions {
+	result := make(PluginVersions, 0)
+	p := pl.Get(name)
+	if p != nil {
+		for _, v := range p.Versions {
+			result = append(result, v)
+		}
+	}
+	return result
+}
+
+func (req PluginDependencies) Join(other PluginDependencies) PluginDependencies {
+	m := make(map[string]*PluginDependency)
+	for _, r := range req {
+		m[r.Name] = r
+	}
+	for _, o := range other {
+		cur, ok := m[o.Name]
+		if ok {
+			m[o.Name] = &PluginDependency{
+				o.Name,
+				o.Range.AND(cur.Range),
+			}
+		} else {
+			m[o.Name] = o
+		}
+	}
+	result := make(PluginDependencies, 0, len(m))
+	for _, v := range m {
+		result = append(result, v)
+	}
+	return result
+}
+
+// Resolve resolves dependencies between different plugins
+func (all PluginPackages) Resolve(selectedVersions PluginVersions, open PluginDependencies) (PluginVersions, error) {
+	if len(open) == 0 {
+		return selectedVersions, nil
+	}
+	currentRequirement, stillOpen := open[0], open[1:]
+	if currentRequirement != nil {
+		if selVersion := selectedVersions.find(currentRequirement.Name); selVersion != nil {
+			if currentRequirement.Range(selVersion.Version) {
+				return all.Resolve(selectedVersions, stillOpen)
+			}
+			return nil, fmt.Errorf("unable to find a matching version for \"%s\"", currentRequirement.Name)
+		}
+		availableVersions := all.GetAllVersions(currentRequirement.Name)
+		sort.Sort(availableVersions)
+
+		for _, version := range availableVersions {
+			if currentRequirement.Range(version.Version) {
+				resolved, err := all.Resolve(append(selectedVersions, version), stillOpen.Join(version.Require))
+
+				if err == nil {
+					return resolved, nil
+				}
+			}
+		}
+		return nil, fmt.Errorf("unable to find a matching version for \"%s\"", currentRequirement.Name)
+	}
+	return selectedVersions, nil
+}
+
+func (pv PluginVersions) install() {
+	anyInstalled := false
+	currentlyInstalled := GetInstalledVersions(true)
+
+	for _, sel := range pv {
+		if sel.pack.Name != CorePluginName {
+			shouldInstall := true
+			if pv := currentlyInstalled.find(sel.pack.Name); pv != nil {
+				if pv.Version.NE(sel.Version) {
+					fmt.Println("Uninstalling", sel.pack.Name)
+					UninstallPlugin(sel.pack.Name)
+				} else {
+					shouldInstall = false
+				}
+			}
+
+			if shouldInstall {
+				if err := sel.DownloadAndInstall(); err != nil {
+					fmt.Println(err)
+					return
+				}
+				anyInstalled = true
+			}
+		}
+	}
+	if anyInstalled {
+		fmt.Println("One or more plugins installed.")
+	} else {
+		fmt.Println("Nothing to install / update")
+	}
+}
+
+// UninstallPlugin deletes the plugin folder of the given plugin
+func UninstallPlugin(name string) {
+	for _, p := range Plugins {
+		if p.Name == name {
+			p.Loaded = false
+			if err := os.RemoveAll(filepath.Join(ConfigDir, "plug", p.DirName)); err != nil {
+				fmt.Println(err)
+				return
+			}
+		}
+	}
+}
+
+// Install installs the plugin
+func (pl PluginPackage) Install() {
+	selected, err := GetAllPluginPackages().Resolve(GetInstalledVersions(true), PluginDependencies{
+		&PluginDependency{
+			Name:  pl.Name,
+			Range: semver.Range(func(v semver.Version) bool { return true }),
+		}})
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	selected.install()
+}
+
+// UpdatePlugins updates the given plugins
+func UpdatePlugins(plugins []string) {
+	// if no plugins are specified, update all installed plugins.
+	if len(plugins) == 0 {
+		for _, p := range Plugins {
+			plugins = append(plugins, p.Name)
+		}
+	}
+
+	fmt.Println("Checking for plugin updates")
+	microVersion := PluginVersions{
+		newStaticPluginVersion(CorePluginName, util.Version),
+	}
+
+	var updates = make(PluginDependencies, 0)
+	for _, name := range plugins {
+		pv := GetInstalledPluginVersion(name)
+		r, err := semver.ParseRange(">=" + pv) // Try to get newer versions.
+		if err == nil {
+			updates = append(updates, &PluginDependency{
+				Name:  name,
+				Range: r,
+			})
+		}
+	}
+
+	selected, err := GetAllPluginPackages().Resolve(microVersion, updates)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	selected.install()
+}