/**
 * Copyright (c) 2014 Vincent Petry <pvince81@owncloud.com>
 * Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
 * Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
 *
 * @author Christoph Wurst <christoph@winzerhof-wurst.at>
 * @author Daniel Kesselberg <mail@danielkesselberg.de>
 * @author Joas Schilling <coding@schilljs.com>
 * @author John Molakvoæ <skjnldsv@protonmail.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Roeland Jago Douma <roeland@famdouma.nl>
 * @author Vincent Petry <vincent@nextcloud.com>
 *
 * @license AGPL-3.0-or-later
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 */

import _ from 'underscore'
import $ from 'jquery'
import DOMPurify from 'dompurify'
import Handlebars from 'handlebars'
import identity from 'lodash/fp/identity'
import escapeHTML from 'escape-html'
import { generateFilePath } from '@nextcloud/router'

import OC from './index'
import {
	getAppTranslations,
	hasAppTranslations,
	registerAppTranslations,
	unregisterAppTranslations,
} from './l10n-registry'

/**
 * L10N namespace with localization functions.
 *
 * @namespace OC.L10n
 */
const L10n = {

	/**
	 * Load an app's translation bundle if not loaded already.
	 *
	 * @param {string} appName name of the app
	 * @param {Function} callback callback to be called when
	 * the translations are loaded
	 * @return {Promise} promise
	 */
	load(appName, callback) {
		// already available ?
		if (hasAppTranslations(appName) || OC.getLocale() === 'en') {
			const deferred = $.Deferred()
			const promise = deferred.promise()
			promise.then(callback)
			deferred.resolve()
			return promise
		}

		const self = this
		const url = generateFilePath(appName, 'l10n', OC.getLocale() + '.json')

		// load JSON translation bundle per AJAX
		return $.get(url)
			.then(
				function(result) {
					if (result.translations) {
						self.register(appName, result.translations, result.pluralForm)
					}
				})
			.then(callback)
	},

	/**
	 * Register an app's translation bundle.
	 *
	 * @param {string} appName name of the app
	 * @param {object<string, string>} bundle bundle
	 */
	register(appName, bundle) {
		registerAppTranslations(appName, bundle, this._getPlural)
	},

	/**
	 * @private
	 */
	_unregister: unregisterAppTranslations,

	/**
	 * Translate a string
	 *
	 * @param {string} app the id of the app for which to translate the string
	 * @param {string} text the string to translate
	 * @param {object} [vars] map of placeholder key to value
	 * @param {number} [count] number to replace %n with
	 * @param {Array} [options] options array
	 * @param {boolean} [options.escape=true] enable/disable auto escape of placeholders (by default enabled)
	 * @param {boolean} [options.sanitize=true] enable/disable sanitization (by default enabled)
	 * @return {string}
	 */
	translate(app, text, vars, count, options) {
		const defaultOptions = {
			escape: true,
			sanitize: true,
		}
		const allOptions = options || {}
		_.defaults(allOptions, defaultOptions)

		const optSanitize = allOptions.sanitize ? DOMPurify.sanitize : identity
		const optEscape = allOptions.escape ? escapeHTML : identity

		// TODO: cache this function to avoid inline recreation
		// of the same function over and over again in case
		// translate() is used in a loop
		const _build = function(text, vars, count) {
			return text.replace(/%n/g, count).replace(/{([^{}]*)}/g,
				function(a, b) {
					const r = vars[b]
					if (typeof r === 'string' || typeof r === 'number') {
						return optSanitize(optEscape(r))
					} else {
						return optSanitize(a)
					}
				}
			)
		}
		let translation = text
		const bundle = getAppTranslations(app)
		const value = bundle.translations[text]
		if (typeof (value) !== 'undefined') {
			translation = value
		}

		if (typeof vars === 'object' || count !== undefined) {
			return optSanitize(_build(translation, vars, count))
		} else {
			return optSanitize(translation)
		}
	},

	/**
	 * Translate a plural string
	 *
	 * @param {string} app the id of the app for which to translate the string
	 * @param {string} textSingular the string to translate for exactly one object
	 * @param {string} textPlural the string to translate for n objects
	 * @param {number} count number to determine whether to use singular or plural
	 * @param {object} [vars] map of placeholder key to value
	 * @param {Array} [options] options array
	 * @param {boolean} [options.escape=true] enable/disable auto escape of placeholders (by default enabled)
	 * @return {string} Translated string
	 */
	translatePlural(app, textSingular, textPlural, count, vars, options) {
		const identifier = '_' + textSingular + '_::_' + textPlural + '_'
		const bundle = getAppTranslations(app)
		const value = bundle.translations[identifier]
		if (typeof (value) !== 'undefined') {
			const translation = value
			if ($.isArray(translation)) {
				const plural = bundle.pluralFunction(count)
				return this.translate(app, translation[plural], vars, count, options)
			}
		}

		if (count === 1) {
			return this.translate(app, textSingular, vars, count, options)
		} else {
			return this.translate(app, textPlural, vars, count, options)
		}
	},

	/**
	 * The plural function taken from symfony
	 *
	 * @param {number} number the number of elements
	 * @return {number}
	 * @private
	 */
	_getPlural(number) {
		let language = OC.getLanguage()
		if (language === 'pt-BR') {
			// temporary set a locale for brazilian
			language = 'xbr'
		}

		if (typeof language === 'undefined' || language === '') {
			return (number === 1) ? 0 : 1
		}

		if (language.length > 3) {
			language = language.substring(0, language.lastIndexOf('-'))
		}

		/*
		 * The plural rules are derived from code of the Zend Framework (2010-09-25),
		 * which is subject to the new BSD license (http://framework.zend.com/license/new-bsd).
		 * Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
		 */
		switch (language) {
		case 'az':
		case 'bo':
		case 'dz':
		case 'id':
		case 'ja':
		case 'jv':
		case 'ka':
		case 'km':
		case 'kn':
		case 'ko':
		case 'ms':
		case 'th':
		case 'tr':
		case 'vi':
		case 'zh':
			return 0

		case 'af':
		case 'bn':
		case 'bg':
		case 'ca':
		case 'da':
		case 'de':
		case 'el':
		case 'en':
		case 'eo':
		case 'es':
		case 'et':
		case 'eu':
		case 'fa':
		case 'fi':
		case 'fo':
		case 'fur':
		case 'fy':
		case 'gl':
		case 'gu':
		case 'ha':
		case 'he':
		case 'hu':
		case 'is':
		case 'it':
		case 'ku':
		case 'lb':
		case 'ml':
		case 'mn':
		case 'mr':
		case 'nah':
		case 'nb':
		case 'ne':
		case 'nl':
		case 'nn':
		case 'no':
		case 'oc':
		case 'om':
		case 'or':
		case 'pa':
		case 'pap':
		case 'ps':
		case 'pt':
		case 'so':
		case 'sq':
		case 'sv':
		case 'sw':
		case 'ta':
		case 'te':
		case 'tk':
		case 'ur':
		case 'zu':
			return (number === 1) ? 0 : 1

		case 'am':
		case 'bh':
		case 'fil':
		case 'fr':
		case 'gun':
		case 'hi':
		case 'hy':
		case 'ln':
		case 'mg':
		case 'nso':
		case 'xbr':
		case 'ti':
		case 'wa':
			return ((number === 0) || (number === 1)) ? 0 : 1

		case 'be':
		case 'bs':
		case 'hr':
		case 'ru':
		case 'sh':
		case 'sr':
		case 'uk':
			return ((number % 10 === 1) && (number % 100 !== 11)) ? 0 : (((number % 10 >= 2) && (number % 10 <= 4) && ((number % 100 < 10) || (number % 100 >= 20))) ? 1 : 2)

		case 'cs':
		case 'sk':
			return (number === 1) ? 0 : (((number >= 2) && (number <= 4)) ? 1 : 2)

		case 'ga':
			return (number === 1) ? 0 : ((number === 2) ? 1 : 2)

		case 'lt':
			return ((number % 10 === 1) && (number % 100 !== 11)) ? 0 : (((number % 10 >= 2) && ((number % 100 < 10) || (number % 100 >= 20))) ? 1 : 2)

		case 'sl':
			return (number % 100 === 1) ? 0 : ((number % 100 === 2) ? 1 : (((number % 100 === 3) || (number % 100 === 4)) ? 2 : 3))

		case 'mk':
			return (number % 10 === 1) ? 0 : 1

		case 'mt':
			return (number === 1) ? 0 : (((number === 0) || ((number % 100 > 1) && (number % 100 < 11))) ? 1 : (((number % 100 > 10) && (number % 100 < 20)) ? 2 : 3))

		case 'lv':
			return (number === 0) ? 0 : (((number % 10 === 1) && (number % 100 !== 11)) ? 1 : 2)

		case 'pl':
			return (number === 1) ? 0 : (((number % 10 >= 2) && (number % 10 <= 4) && ((number % 100 < 12) || (number % 100 > 14))) ? 1 : 2)

		case 'cy':
			return (number === 1) ? 0 : ((number === 2) ? 1 : (((number === 8) || (number === 11)) ? 2 : 3))

		case 'ro':
			return (number === 1) ? 0 : (((number === 0) || ((number % 100 > 0) && (number % 100 < 20))) ? 1 : 2)

		case 'ar':
			return (number === 0) ? 0 : ((number === 1) ? 1 : ((number === 2) ? 2 : (((number % 100 >= 3) && (number % 100 <= 10)) ? 3 : (((number % 100 >= 11) && (number % 100 <= 99)) ? 4 : 5))))

		default:
			return 0
		}
	},
}

export default L10n

/**
 * Returns the user's locale
 *
 * @return {string} locale string
 */
export const getLocale = () => $('html').data('locale') ?? 'en'

/**
 * Returns the user's language
 *
 * @return {string} language string
 */
export const getLanguage = () => $('html').prop('lang')

Handlebars.registerHelper('t', function(app, text) {
	return L10n.translate(app, text)
})