split a bunch of lists free of UI templates, and also fixed profile language display

util/languagelist.go

@@ -0,0 +1,94 @@
+/*
+ * Amsterdam Web Communities System
+ * Copyright (c) 2025 Erbosoft Metaverse Design Solutions, All Rights Reserved
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+// Package util contains utility definitions.
+package util
+
+import (
+	_ "embed"
+	"slices"
+	"strings"
+	"sync"
+
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/text/language"
+	"golang.org/x/text/language/display"
+)
+
+//go:embed languages.txt
+var knownLanguages string
+
+// Language is a type for a list of all supported languages.
+type Language struct {
+	Tag  string // the BCP 47 tag, such as "en-US"
+	Name string // the human-readable name, like "American English"
+}
+
+// cachedLanguageList is the cached language list.
+var cachedLanguageList []Language = nil
+
+// mapping from language tag names to actual language entries
+var languageTagMapper map[string]*Language
+
+// languageListMutex controls access to internalGetLanguageList.
+var languageListMutex sync.Mutex
+
+// AmLanguageList returns a list of all known languages.
+func AmLanguageList() []Language {
+	languageListMutex.Lock()
+	defer languageListMutex.Unlock()
+	if cachedLanguageList == nil {
+		langs := strings.Split(knownLanguages, "\n")
+		enNamer := display.English.Tags()
+		cachedLanguageList = make([]Language, 0, len(langs))
+		for _, l := range langs {
+			tag, err := language.Parse(l)
+			if err == nil {
+				cachedLanguageList = append(cachedLanguageList, Language{
+					Tag:  tag.String(),
+					Name: enNamer.Name(tag),
+				})
+			} else {
+				log.Errorf("*** PUKE on parsing language tag %s: %v", l, err)
+			}
+		}
+
+		slices.SortFunc(cachedLanguageList, func(a Language, b Language) int {
+			return strings.Compare(a.Name, b.Name)
+		})
+		languageTagMapper = make(map[string]*Language)
+		for i := range cachedLanguageList {
+			languageTagMapper[strings.ToLower(cachedLanguageList[i].Tag)] = &(cachedLanguageList[i])
+		}
+	}
+	return cachedLanguageList
+}
+
+/* AmLanguageInLanguage displays a language name in any other language.
+ * Parameters:
+ *     lang - The language to be displayed.
+ *     inLang - The language to display the other language's name in.
+ * Returns:
+ *     The full translated language name.
+ */
+func AmLanguageInLanguage(lang language.Tag, inLang language.Tag) string {
+	namer := display.Tags(inLang)
+	if namer == nil {
+		namer = display.English.Tags()
+	}
+	s := namer.Name(lang)
+	if s == "" {
+		s = display.English.Tags().Name(lang)
+	}
+	return s
+}
+
+func init() {
+	go AmLanguageList() // preload the list in the background
+}