1 files changed, 303 insertions, 0 deletions
diff --git a/modules/translation/translation.go b/modules/translation/translation.go
new file mode 100644
index 0000000..16eb55e
--- /dev/null
+++ b/modules/translation/translation.go
@@ -0,0 +1,303 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package translation
+
+import (
+	"context"
+	"html/template"
+	"sort"
+	"strings"
+	"sync"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/options"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/translation/i18n"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/dustin/go-humanize"
+	"golang.org/x/text/language"
+	"golang.org/x/text/message"
+	"golang.org/x/text/number"
+)
+
+type contextKey struct{}
+
+var ContextKey any = &contextKey{}
+
+// Locale represents an interface to translation
+type Locale interface {
+	Language() string
+	TrString(string, ...any) string
+
+	Tr(key string, args ...any) template.HTML
+	TrN(cnt any, key1, keyN string, args ...any) template.HTML
+
+	TrSize(size int64) ReadableSize
+
+	PrettyNumber(v any) string
+}
+
+// LangType represents a lang type
+type LangType struct {
+	Lang, Name string // these fields are used directly in templates: {{range .AllLangs}}{{.Lang}}{{.Name}}{{end}}
+}
+
+var (
+	lock *sync.RWMutex
+
+	allLangs   []*LangType
+	allLangMap map[string]*LangType
+
+	matcher       language.Matcher
+	supportedTags []language.Tag
+)
+
+// AllLangs returns all supported languages sorted by name
+func AllLangs() []*LangType {
+	return allLangs
+}
+
+// InitLocales loads the locales
+func InitLocales(ctx context.Context) {
+	if lock != nil {
+		lock.Lock()
+		defer lock.Unlock()
+	} else if !setting.IsProd && lock == nil {
+		lock = &sync.RWMutex{}
+	}
+
+	refreshLocales := func() {
+		i18n.ResetDefaultLocales()
+		localeNames, err := options.AssetFS().ListFiles("locale", true)
+		if err != nil {
+			log.Fatal("Failed to list locale files: %v", err)
+		}
+
+		localeData := make(map[string][]byte, len(localeNames))
+		for _, name := range localeNames {
+			localeData[name], err = options.Locale(name)
+			if err != nil {
+				log.Fatal("Failed to load %s locale file. %v", name, err)
+			}
+		}
+
+		supportedTags = make([]language.Tag, len(setting.Langs))
+		for i, lang := range setting.Langs {
+			supportedTags[i] = language.Raw.Make(lang)
+		}
+
+		matcher = language.NewMatcher(supportedTags)
+		for i := range setting.Names {
+			var localeDataBase []byte
+			if i == 0 && setting.Langs[0] != "en-US" {
+				// Only en-US has complete translations. When use other language as default, the en-US should still be used as fallback.
+				localeDataBase = localeData["locale_en-US.ini"]
+				if localeDataBase == nil {
+					log.Fatal("Failed to load locale_en-US.ini file.")
+				}
+			}
+
+			key := "locale_" + setting.Langs[i] + ".ini"
+			if err = i18n.DefaultLocales.AddLocaleByIni(setting.Langs[i], setting.Names[i], localeDataBase, localeData[key]); err != nil {
+				log.Error("Failed to set messages to %s: %v", setting.Langs[i], err)
+			}
+		}
+		if len(setting.Langs) != 0 {
+			defaultLangName := setting.Langs[0]
+			if defaultLangName != "en-US" {
+				log.Info("Use the first locale (%s) in LANGS setting option as default", defaultLangName)
+			}
+			i18n.DefaultLocales.SetDefaultLang(defaultLangName)
+		}
+	}
+
+	refreshLocales()
+
+	langs, descs := i18n.DefaultLocales.ListLangNameDesc()
+	allLangs = make([]*LangType, 0, len(langs))
+	allLangMap = map[string]*LangType{}
+	for i, v := range langs {
+		l := &LangType{v, descs[i]}
+		allLangs = append(allLangs, l)
+		allLangMap[v] = l
+	}
+
+	// Sort languages case-insensitive according to their name - needed for the user settings
+	sort.Slice(allLangs, func(i, j int) bool {
+		return strings.ToLower(allLangs[i].Name) < strings.ToLower(allLangs[j].Name)
+	})
+
+	if !setting.IsProd {
+		go options.AssetFS().WatchLocalChanges(ctx, func() {
+			lock.Lock()
+			defer lock.Unlock()
+			refreshLocales()
+		})
+	}
+}
+
+// Match matches accept languages
+func Match(tags ...language.Tag) language.Tag {
+	_, i, _ := matcher.Match(tags...)
+	return supportedTags[i]
+}
+
+// locale represents the information of localization.
+type locale struct {
+	i18n.Locale
+	Lang, LangName string // these fields are used directly in templates: ctx.Locale.Lang
+	msgPrinter     *message.Printer
+}
+
+var _ Locale = (*locale)(nil)
+
+// NewLocale return a locale
+func NewLocale(lang string) Locale {
+	if lock != nil {
+		lock.RLock()
+		defer lock.RUnlock()
+	}
+
+	langName := "unknown"
+	if l, ok := allLangMap[lang]; ok {
+		langName = l.Name
+	} else if len(setting.Langs) > 0 {
+		lang = setting.Langs[0]
+		langName = setting.Names[0]
+	}
+
+	i18nLocale, _ := i18n.GetLocale(lang)
+	l := &locale{
+		Locale:   i18nLocale,
+		Lang:     lang,
+		LangName: langName,
+	}
+	if langTag, err := language.Parse(lang); err != nil {
+		log.Error("Failed to parse language tag from name %q: %v", l.Lang, err)
+		l.msgPrinter = message.NewPrinter(language.English)
+	} else {
+		l.msgPrinter = message.NewPrinter(langTag)
+	}
+	return l
+}
+
+func (l *locale) Language() string {
+	return l.Lang
+}
+
+// Language specific rules for translating plural texts
+var trNLangRules = map[string]func(int64) int{
+	// the default rule is "en-US" if a language isn't listed here
+	"en-US": func(cnt int64) int {
+		if cnt == 1 {
+			return 0
+		}
+		return 1
+	},
+	"lv-LV": func(cnt int64) int {
+		if cnt%10 == 1 && cnt%100 != 11 {
+			return 0
+		}
+		return 1
+	},
+	"ru-RU": func(cnt int64) int {
+		if cnt%10 == 1 && cnt%100 != 11 {
+			return 0
+		}
+		return 1
+	},
+	"zh-CN": func(cnt int64) int {
+		return 0
+	},
+	"zh-HK": func(cnt int64) int {
+		return 0
+	},
+	"zh-TW": func(cnt int64) int {
+		return 0
+	},
+	"fr-FR": func(cnt int64) int {
+		if cnt > -2 && cnt < 2 {
+			return 0
+		}
+		return 1
+	},
+}
+
+func (l *locale) Tr(s string, args ...any) template.HTML {
+	return l.TrHTML(s, args...)
+}
+
+// TrN returns translated message for plural text translation
+func (l *locale) TrN(cnt any, key1, keyN string, args ...any) template.HTML {
+	var c int64
+	if t, ok := cnt.(int); ok {
+		c = int64(t)
+	} else if t, ok := cnt.(int16); ok {
+		c = int64(t)
+	} else if t, ok := cnt.(int32); ok {
+		c = int64(t)
+	} else if t, ok := cnt.(int64); ok {
+		c = t
+	} else {
+		return l.Tr(keyN, args...)
+	}
+
+	ruleFunc, ok := trNLangRules[l.Lang]
+	if !ok {
+		ruleFunc = trNLangRules["en-US"]
+	}
+
+	if ruleFunc(c) == 0 {
+		return l.Tr(key1, args...)
+	}
+	return l.Tr(keyN, args...)
+}
+
+type ReadableSize struct {
+	PrettyNumber   string
+	TranslatedUnit string
+}
+
+func (bs ReadableSize) String() string {
+	return bs.PrettyNumber + " " + bs.TranslatedUnit
+}
+
+// TrSize returns array containing pretty formatted size and localized output of FileSize
+// output of humanize.IBytes has to be split in order to be localized
+func (l *locale) TrSize(s int64) ReadableSize {
+	us := uint64(s)
+	if s < 0 {
+		us = uint64(-s)
+	}
+	untranslated := humanize.IBytes(us)
+	if s < 0 {
+		untranslated = "-" + untranslated
+	}
+	numberVal, unitVal, found := strings.Cut(untranslated, " ")
+	if !found {
+		log.Error("no space in go-humanized size of %d: %q", s, untranslated)
+	}
+	numberVal = l.PrettyNumber(numberVal)
+	unitVal = l.TrString("munits.data." + strings.ToLower(unitVal))
+	return ReadableSize{numberVal, unitVal}
+}
+
+func (l *locale) PrettyNumber(v any) string {
+	// TODO: this mechanism is not good enough, the complete solution is to switch the translation system to ICU message format
+	if s, ok := v.(string); ok {
+		if num, err := util.ToInt64(s); err == nil {
+			v = num
+		} else if num, err := util.ToFloat64(s); err == nil {
+			v = num
+		}
+	}
+	return l.msgPrinter.Sprintf("%v", number.Decimal(v))
+}
+
+func init() {
+	// prepare a default matcher, especially for tests
+	supportedTags = []language.Tag{language.English}
+	matcher = language.NewMatcher(supportedTags)
+}