Fix recovery middleware to render gitea style page. (#13857)

* Some changes to fix recovery

* Move Recovery to middlewares

* Remove trace code

* Fix lint

* add session middleware and remove dependent on macaron for sso

* Fix panic 500 page rendering

* Fix bugs

* Fix fmt

* Fix vendor

* recover unnecessary change

* Fix lint and addd some comments about the copied codes.

* Use util.StatDir instead of com.StatDir

Co-authored-by: 6543 <6543@obermui.de>

modules/translation/translation.go

@@ -0,0 +1,92 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package translation
+
+import (
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/options"
+	"code.gitea.io/gitea/modules/setting"
+
+	macaron_i18n "gitea.com/macaron/i18n"
+	"github.com/unknwon/i18n"
+	"golang.org/x/text/language"
+)
+
+// Locale represents an interface to translation
+type Locale interface {
+	Language() string
+	Tr(string, ...interface{}) string
+}
+
+var (
+	matcher language.Matcher
+)
+
+// InitLocales loads the locales
+func InitLocales() {
+	localeNames, err := options.Dir("locale")
+
+	if err != nil {
+		log.Fatal("Failed to list locale files: %v", err)
+	}
+	localFiles := make(map[string][]byte)
+
+	for _, name := range localeNames {
+		localFiles[name], err = options.Locale(name)
+
+		if err != nil {
+			log.Fatal("Failed to load %s locale file. %v", name, err)
+		}
+	}
+
+	// These codes will be used once macaron removed
+	/*tags := make([]language.Tag, len(setting.Langs))
+	for i, lang := range setting.Langs {
+		tags[i] = language.Raw.Make(lang)
+	}
+	matcher = language.NewMatcher(tags)
+	for i, name := range setting.Names {
+		i18n.SetMessage(setting.Langs[i], localFiles[name])
+	}
+	i18n.SetDefaultLang("en-US")*/
+
+	// To be compatible with macaron, we now have to use macaron i18n, once macaron
+	// removed, we can use i18n directly
+	macaron_i18n.I18n(macaron_i18n.Options{
+		SubURL:       setting.AppSubURL,
+		Files:        localFiles,
+		Langs:        setting.Langs,
+		Names:        setting.Names,
+		DefaultLang:  "en-US",
+		Redirect:     false,
+		CookieDomain: setting.SessionConfig.Domain,
+	})
+}
+
+// Match matches accept languages
+func Match(tags ...language.Tag) (tag language.Tag, index int, c language.Confidence) {
+	return matcher.Match(tags...)
+}
+
+// locale represents the information of localization.
+type locale struct {
+	Lang string
+}
+
+// NewLocale return a locale
+func NewLocale(lang string) Locale {
+	return &locale{
+		Lang: lang,
+	}
+}
+
+func (l *locale) Language() string {
+	return l.Lang
+}
+
+// Tr translates content to target language.
+func (l *locale) Tr(format string, args ...interface{}) string {
+	return i18n.Tr(l.Lang, format, args...)
+}