// Copyright 2015 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package tpl

import (
	"fmt"

	"github.com/nicksnyder/go-i18n/i18n/bundle"
	jww "github.com/spf13/jwalterweatherman"
)

type translate struct {
	translateFuncs map[string]bundle.TranslateFunc

	current bundle.TranslateFunc
}

var translater *translate = &translate{translateFuncs: make(map[string]bundle.TranslateFunc)}

// SetTranslateLang sets the translations language to use during template processing.
// This construction is unfortunate, but the template system is currently global.
func SetTranslateLang(lang string) error {
	if f, ok := translater.translateFuncs[lang]; ok {
		translater.current = f
		return nil
	}
	jww.WARN.Printf("Translation func for language %v not found", lang)
	return nil
}

func SetI18nTfuncs(bndl *bundle.Bundle) {
	for _, lang := range bndl.LanguageTags() {
		tFunc, err := bndl.Tfunc(lang)
		if err == nil {
			translater.translateFuncs[lang] = tFunc
			continue
		}
		jww.WARN.Printf("could not load translations for language %q (%s), will not translate!\n", lang, err.Error())
		translater.translateFuncs[lang] = bundle.TranslateFunc(func(id string, args ...interface{}) string {
			// TODO: depending on the site mode, we might want to fall back on the default
			// language's translation.
			// TODO: eventually, we could add --i18n-warnings and print something when
			// such things happen.
			return fmt.Sprintf("[i18n: %s]", id)
		})
	}

}

func I18nTranslate(id string, args ...interface{}) (string, error) {
	if translater == nil || translater.current == nil {
		return "", fmt.Errorf("i18n not initialized, have you configured everything properly?")
	}
	return translater.current(id, args...), nil
}