/*
 * SPDX-FileCopyrightText: 2023 jordi fita mas <jfita@peritasoft.com>
 * SPDX-License-Identifier: AGPL-3.0-only
 */

package locale

import (
	"context"
	"net/http"

	"github.com/leonelquinteros/gotext"
	"golang.org/x/text/language"

	"dev.tandem.ws/tandem/camper/pkg/database"
)

type Locale struct {
	*gotext.Locale
	CurrencyPattern string
	Language        language.Tag
}

type Locales map[language.Tag]*Locale

func (m Locales) Tags() []language.Tag {
	keys := make([]language.Tag, len(m))
	i := 0
	for k := range m {
		keys[i] = k
		i++
	}
	return keys
}

func MustGetAll(db *database.DB) Locales {
	availableLanguages := mustGetAvailableLanguages(db)
	locales := map[language.Tag]*Locale{}
	for _, lang := range availableLanguages {
		locale := newLocale(lang)
		locale.AddDomain("camper")
		locales[lang.tag] = locale
	}
	return locales
}

func newLocale(lang availableLanguage) *Locale {
	return &Locale{
		gotext.NewLocale("locale", lang.tag.String()),
		lang.currencyPattern,
		lang.tag,
	}
}

func Match(r *http.Request, locales Locales, defaultLocale *Locale, matcher language.Matcher) *Locale {
	var locale *Locale
	// TODO: find user locale
	if locale == nil {
		t, _, err := language.ParseAcceptLanguage(r.Header.Get("Accept-Language"))
		if err == nil {
			tag, _, _ := matcher.Match(t...)
			var ok bool
			locale, ok = locales[tag]
			for !ok && !tag.IsRoot() {
				tag = tag.Parent()
				locale, ok = locales[tag]
			}
		}
	}
	if locale == nil {
		locale = defaultLocale
	}
	return locale
}

type availableLanguage struct {
	tag             language.Tag
	currencyPattern string
}

func mustGetAvailableLanguages(db *database.DB) []availableLanguage {
	rows, err := db.Query(context.Background(), "select lang_tag, currency_pattern from language where selectable")
	if err != nil {
		panic(err)
	}
	defer rows.Close()

	var languages []availableLanguage
	for rows.Next() {
		var langTag string
		var currencyPattern string
		err = rows.Scan(&langTag, &currencyPattern)
		if err != nil {
			panic(err)
		}
		languages = append(languages, availableLanguage{language.MustParse(langTag), currencyPattern})
	}
	if rows.Err() != nil {
		panic(rows.Err())
	}

	return languages
}