<?php
/**
 * Deepl Autotranslate Plugin
 *
 * @author     Jennifer Graul <me@netali.de>
 */

if(!defined('DOKU_INC')) die();

use \dokuwiki\HTTP\DokuHTTPClient;
use \dokuwiki\plugin\deeplautotranslate\MenuItem;

class action_plugin_deeplautotranslate extends DokuWiki_Action_Plugin {

    // manual mapping of ISO-languages to DeepL-languages to fix inconsistent naming
    private $langs = [
        'bg' => 'BG',
        'cs' => 'CS',
        'da' => 'DA',
        'de' => 'DE',
        'de-informal' => 'DE',
        'el' => 'EL',
        'en' => 'EN-GB',
        'es' => 'ES',
        'et' => 'ET',
        'fi' => 'FI',
        'fr' => 'FR',
        'hu' => 'HU',
        'hu-formal' => 'HU',
        'it' => 'IT',
        'ja' => 'JA',
        'lt' => 'LT',
        'lv' => 'LV',
        'nl' => 'NL',
        'pl' => 'PL',
        'pt' => 'PT-PT',
        'ro' => 'RO',
        'ru' => 'RU',
        'sk' => 'SK',
        'sl' => 'SL',
        'sv' => 'SV',
        'zh' => 'ZH'
    ];

    /**
     * Register its handlers with the DokuWiki's event controller
     */
    public function register(Doku_Event_Handler $controller) {
        $controller->register_hook('ACTION_ACT_PREPROCESS','BEFORE', $this, 'preprocess');
        $controller->register_hook('COMMON_PAGETPL_LOAD','AFTER', $this, 'autotrans_editor');
        $controller->register_hook('MENU_ITEMS_ASSEMBLY', 'AFTER', $this, 'add_menu_button');
    }

    public function add_menu_button(Doku_Event $event): void {
        global $ID;
        global $ACT;

        if ($ACT != 'show') return;

        if ($event->data['view'] != 'page') return;

        if (!$this->getConf('show_button')) return;

        $split_id = explode(':', $ID);
        $lang_ns = array_shift($split_id);
        // check if we are in a language namespace
        if (array_key_exists($lang_ns, $this->langs)) {
            if($this->getConf('default_lang_in_ns') and $lang_ns === $this->get_default_lang()) {
                // if the default lang is in a namespace and we are in that namespace --> check for push translation
                if (!$this->check_do_push_translate()) return;
            } else {
                // in language namespace --> check if we should translate
                if (!$this->check_do_translation(true)) return;
            }
        } else {
            // do not show the button if we are not in a language namespace and the default language is in a namespace
            if($this->getConf('default_lang_in_ns')) return;
            // not in language namespace and default language is npt in a namespace --> check if we should show the push translate button
            if (!$this->check_do_push_translate()) return;
        }

        array_splice($event->data['items'], -1, 0, [new MenuItem()]);
    }

    public function preprocess(Doku_Event  $event, $param): void {
        global $ID;

        // check if action is show or translate
        if ($event->data != 'show' and $event->data != 'translate') return;

        $split_id = explode(':', $ID);
        $lang_ns = array_shift($split_id);
        // check if we are in a language namespace
        if (array_key_exists($lang_ns, $this->langs)) {
            if($this->getConf('default_lang_in_ns') and $lang_ns === $this->get_default_lang()) {
                // if the default lang is in a namespace and we are in that namespace --> push translate
                $this->push_translate($event);
            } else {
                // in language namespace --> autotrans direct
                $this->autotrans_direct($event);
            }
        } else {
            // not in language namespace --> push translate
            $this->push_translate($event);
        }
    }

    private function autotrans_direct(Doku_Event $event): void {
        global $ID;

        // abort if action is translate and the translate button is disabled
        if ($event->data == 'translate' and !$this->getConf('show_button')) return;

        // do nothing on show action when mode is not direct
        if ($event->data == 'show' and $this->get_mode() != 'direct') return;

        // allow translation of existing pages is we are in the translate action
        $allow_existing = ($event->data == 'translate');

        // reset action to show
        $event->data = 'show';

        if (!$this->check_do_translation($allow_existing)) {
            return;
        }

        $org_page_info = $this->get_org_page_info();
        $translated_text = $this->deepl_translate($org_page_info["text"], $this->get_target_lang(), $org_page_info["ns"]);

        if ($translated_text === '') {
            return;
        }

        saveWikiText($ID, $translated_text, 'Automatic translation');

        msg($this->getLang('msg_translation_success'), 1);

        // reload the page after translation
        send_redirect(wl($ID));
    }

    public function autotrans_editor(Doku_Event $event, $param): void {
        if ($this->get_mode() != 'editor') return;

        if (!$this->check_do_translation()) return;

        $org_page_info = $this->get_org_page_info();

        $event->data['tpl'] = $this->deepl_translate($org_page_info["text"], $this->get_target_lang(), $org_page_info["ns"]);
    }

    private function push_translate(Doku_Event $event): void {
        global $ID;

        // check if action is translate
        if ($event->data != 'translate') return;

        // check if button is enabled
        if (!$this->getConf('show_button')) {
            send_redirect(wl($ID));
            return;
        }

        if (!$this->check_do_push_translate()) {
            send_redirect(wl($ID));
            return;
        }

        // push translate
        $push_langs = $this->get_push_langs();
        $org_page_text = rawWiki($ID);
        foreach ($push_langs as $lang) {
            // skip invalid languages
            if (!array_key_exists($lang, $this->langs)) {
                msg($this->getLang('msg_translation_fail_invalid_lang') . $lang, -1);
                continue;
            }

            if ($this->getConf('default_lang_in_ns')) {
                // if default lang is in ns: replace language namespace in ID
                $split_id = explode(':', $ID);
                array_shift($split_id);
                $lang_id = implode(':', $split_id);
                $lang_id = $lang . ':' . $lang_id;
            } else {
                // if default lang is not in ns: add language namespace to ID
                $lang_id = $lang . ':' . $ID;
            }

            // check permissions
            $perm = auth_quickaclcheck($ID);
            $exists = page_exists($lang_id);
            if (($exists and $perm < AUTH_EDIT) or (!$exists and $perm < AUTH_CREATE)) {
                msg($this->getLang('msg_translation_fail_no_permissions') . $lang_id, -1);
                continue;
            }

            $translated_text = $this->deepl_translate($org_page_text, $lang, getNS($ID));
            saveWikiText($lang_id, $translated_text, 'Automatic push translation');
        }

        msg($this->getLang('msg_translation_success'), 1);

        // reload the page after translation to clear the action
        send_redirect(wl($ID));
    }

    private function get_mode(): string {
        global $ID;
        if ($this->getConf('editor_regex')) {
            if (preg_match('/' . $this->getConf('editor_regex') . '/', $ID) === 1) return 'editor';
        }
        if ($this->getConf('direct_regex')) {
            if (preg_match('/' . $this->getConf('direct_regex') . '/', $ID) === 1) return 'direct';
        }
        return $this->getConf('mode');
    }

    private function get_target_lang(): string {
        global $ID;
        $split_id = explode(':', $ID);
        return array_shift($split_id);
    }

    private function get_default_lang(): string {
        global $conf;

        if (empty($conf['lang_before_translation'])) {
            $default_lang = $conf['lang'];
        } else {
            $default_lang = $conf['lang_before_translation'];
        }

        return $default_lang;
    }

    private function get_org_page_info(): array {
        global $ID;

        $split_id = explode(':', $ID);
        array_shift($split_id);
        $org_id = implode(':', $split_id);

        // if default lang is in ns: add default ns in front of org id
        if ($this->getConf('default_lang_in_ns')) {
            $org_id = $this->get_default_lang() . ':' . $org_id;
        }

        return array("ns" => getNS($org_id), "text" => rawWiki($org_id));
    }

    private function check_do_translation($allow_existing = false): bool {
        global $INFO;
        global $ID;

        // only translate if the current page does not exist
        if ($INFO['exists'] and !$allow_existing) return false;

        // permission check
        $perm = auth_quickaclcheck($ID);
        if (($INFO['exists'] and $perm < AUTH_EDIT) or (!$INFO['exists'] and $perm < AUTH_CREATE)) return false;

        // skip blacklisted namespaces and pages
        if ($this->getConf('blacklist_regex')) {
            if (preg_match('/' . $this->getConf('blacklist_regex') . '/', $ID) === 1) return false;
        }

        $split_id = explode(':', $ID);
        $lang_ns = array_shift($split_id);
        // only translate if the current page is in a language namespace
        if (!array_key_exists($lang_ns, $this->langs)) return false;

        $org_id = implode(':', $split_id);

        // if default lang is in ns: add default ns in front of org id
        if ($this->getConf('default_lang_in_ns')) {
            $org_id = $this->get_default_lang() . ':' . $org_id;
        }

        // check if the original page exists
        if (!page_exists($org_id)) return false;

        return true;
    }

    private function check_do_push_translate(): bool {
        global $ID;
        global $INFO;

        if (!$INFO['exists']) return false;

        // if default language is in namespace: only allow push translation from that namespace
        if($this->getConf('default_lang_in_ns')) {
            $split_id = explode(':', $ID);
            $lang_ns = array_shift($split_id);

            if ($lang_ns !== $this->get_default_lang()) return false;
        }

        $push_langs = $this->get_push_langs();
        // push_langs empty --> push_translate disabled --> abort
        if (empty($push_langs)) return false;

        // skip blacklisted namespaces and pages
        if ($this->getConf('blacklist_regex')) {
            // blacklist regex match --> abort
            if (preg_match('/' . $this->getConf('blacklist_regex') . '/', $ID) === 1) return false;
        }

        return true;
    }

    private function deepl_translate($text, $target_lang, $org_ns): string {
        if (!trim($this->getConf('api_key'))) return '';

        $text = $this->patch_links($text, $target_lang, $org_ns);

        $text = $this->insert_ignore_tags($text);

        $data = [
            'auth_key' => $this->getConf('api_key'),
            'target_lang' => $this->langs[$target_lang],
            'tag_handling' => 'xml',
            'ignore_tags' => 'ignore',
            'text' => $text
        ];

        if ($this->getConf('api') == 'free') {
            $url = 'https://api-free.deepl.com/v2/translate';
        } else {
            $url = 'https://api.deepl.com/v2/translate';
        }

        $http = new DokuHTTPClient();
        $raw_response = $http->post($url, $data);

        if ($http->status >= 400) {
            // add error messages
            switch ($http->status) {
                case 403:
                    msg($this->getLang('msg_translation_fail_bad_key'), -1);
                    break;
                case 456:
                    msg($this->getLang('msg_translation_fail_quota_exceeded'), -1);
                    break;
                default:
                    msg($this->getLang('msg_translation_fail'), -1);
                    break;
            }

            // if any error occurred return an empty string
            return '';
        }

        $json_response = json_decode($raw_response, true);
        $translated_text = $json_response['translations'][0]['text'];

        $translated_text = $this->remove_ignore_tags($translated_text);

        return $translated_text;
    }

    private function get_push_langs(): array {
        $push_langs = trim($this->getConf('push_langs'));

        if ($push_langs === '') return array();

        return explode(' ', $push_langs);
    }

    private function patch_links($text, $target_lang, $ns): string {
        /*
         * 1. Find links in [[ aa:bb ]] or [[ aa:bb | cc ]]
         * 2. Extract aa:bb
         * 3. Check if lang:aa:bb exists
         * 3.1. --> Yes --> replace
         * 3.2. --> No --> leave it as it is
         */


        /*
         * LINKS
         */

        preg_match_all('/\[\[([\s\S]*?)(#[\s\S]*?)?((\|)([\s\S]*?))?]]/', $text, $matches, PREG_SET_ORDER);

        foreach ($matches as $match) {

            if (strpos($match[1], '://') !== false) {
                // external link --> skip
                continue;
            }

            $resolved_id = $match[1];

            resolve_pageid($ns, $resolved_id, $exists);

            $resolved_id_full = $resolved_id;

            // if the link already points to a target in a language namespace drop it and add the new language namespace
            $split_id = explode(':', $resolved_id);
            $lang_ns = array_shift($split_id);
            if (array_key_exists($lang_ns, $this->langs)) {
                $resolved_id = implode(':', $split_id);
            }

            $lang_id = $target_lang . ':' . $resolved_id;

            if (!page_exists($lang_id)) {
                // Page in target lang does not exist --> replace with absolute ID in case it was a relative ID
                $new_link = '[[' . $resolved_id_full . $match[2] . $match[3] . ']]';
            } else {
                // Page in target lang exists --> replace link
                $new_link = '[[' . $lang_id . $match[2] . $match[3] . ']]';
            }

            $text = str_replace($match[0], $new_link, $text);

        }

        /*
         * MEDIA
         */

        preg_match_all('/\{\{([\s\S]*?)(\?[\s\S]*?)?(\|([\s\S]*?))?}}/', $text, $matches, PREG_SET_ORDER);

        foreach ($matches as $match) {

            if (strpos($match[1], '://') !== false) {
                // external image --> skip
                continue;
            }

            $resolved_id = $match[1];

            resolve_mediaid($ns, $resolved_id, $exists);

            $resolved_id_full = $resolved_id;

            // if the link already points to a target in a language namespace drop it and add the new language namespace
            $split_id = explode(':', $resolved_id);
            $lang_ns = array_shift($split_id);
            if (array_key_exists($lang_ns, $this->langs)) {
                $resolved_id = implode(':', $split_id);
            }

            $lang_id = $target_lang . ':' . $resolved_id;

            $lang_id_fn = mediaFN($lang_id);

            if (!file_exists($lang_id_fn)) {
                // media in target lang does not exist --> replace with absolute ID in case it was a relative ID
                $new_link = '{{' . $resolved_id_full . $match[2] . $match[3] . '}}';
            } else {
                // media in target lang exists --> replace it
                $new_link = '{{' . $lang_id . $match[2] . $match[3] . '}}';
            }

            $text = str_replace($match[0], $new_link, $text);

        }

        return $text;
    }

    private function insert_ignore_tags($text): string {
        // ignore every other xml-like tags (the tags themselves, not their content), otherwise deepl would break the formatting
        $text = preg_replace('/<[\s\S]+?>/', '<ignore>${0}</ignore>', $text);

        // prevent deepl from breaking headings
        $text = preg_replace('/={1,6}/', '<ignore>${0}</ignore>', $text);

        // fix for the template plugin
        $text = preg_replace('/\{\{template>[\s\S]*?}}/', '<ignore>${0}</ignore>', $text);

        // ignore links in wikitext (outside of dokuwiki-links)
        $text = preg_replace('/\S+:\/\/\S+/', '<ignore>${0}</ignore>', $text);

        // ignore link/media ids but translate the text (if existing)
        $text = preg_replace('/\[\[([\s\S]*?)(#[\s\S]*?)?((\|)([\s\S]*?))?]]/', '<ignore>[[${1}${2}${4}</ignore>${5}<ignore>]]</ignore>', $text);
        $text = preg_replace('/\{\{([\s\S]*?)(\?[\s\S]*?)?((\|)([\s\S]*?))?}}/', '<ignore>{{${1}${2}${4}</ignore>${5}<ignore>}}</ignore>', $text);

        // prevent deepl from messing with tables
        $text = str_replace("^", "<ignore>^</ignore>", $text);
        $text = str_replace("|", "<ignore>|</ignore>", $text);

        // prevent deepl from doing strange things with dokuwiki syntax
        $text = str_replace("''", "<ignore>''</ignore>", $text);
        $text = str_replace("//", "<ignore>//</ignore>", $text);
        $text = str_replace("**", "<ignore>**</ignore>", $text);
        $text = str_replace("__", "<ignore>__</ignore>", $text);
        $text = str_replace("\\\\", "<ignore>\\\\</ignore>", $text);

        // prevent deepl from messing with smileys
        $smileys = array_keys(getSmileys());
        foreach ($smileys as $smiley) {
            $text = str_replace($smiley, "<ignore>" . $smiley . "</ignore>", $text);
        }

        // ignore code tags
        $text = preg_replace('/(<php[\s\S]*?>[\s\S]*?<\/php>)/', '<ignore>${1}</ignore>', $text);
        $text = preg_replace('/(<file[\s\S]*?>[\s\S]*?<\/file>)/', '<ignore>${1}</ignore>', $text);
        $text = preg_replace('/(<code[\s\S]*?>[\s\S]*?<\/code>)/', '<ignore>${1}</ignore>', $text);

        // ignore the expressions from the ignore list
        $ignored_expressions = explode(':', $this->getConf('ignored_expressions'));

        foreach ($ignored_expressions as $expression) {
            $text = str_replace($expression, '<ignore>' . $expression . '</ignore>', $text);
        }

        return $text;
    }

    private function remove_ignore_tags($text): string {
        $ignored_expressions = explode(':', $this->getConf('ignored_expressions'));

        foreach ($ignored_expressions as $expression) {
            $text = str_replace('<ignore>' . $expression . '</ignore>', $expression, $text);
        }

        // prevent deepl from messing with tables
        $text = str_replace("<ignore>^</ignore>", "^", $text);
        $text = str_replace("<ignore>|</ignore>", "|", $text);

        $text = str_replace("<ignore>''</ignore>", "''", $text);
        $text = str_replace("<ignore>//</ignore>", "//", $text);
        $text = str_replace("<ignore>**</ignore>", "**", $text);
        $text = str_replace("<ignore>__</ignore>", "__", $text);
        $text = str_replace("<ignore>\\\\</ignore>", "\\\\", $text);

        // ignore links in wikitext (outside of dokuwiki-links)
        $text = preg_replace('/<ignore>(\S+:\/\/\S+)<\/ignore>/', '${1}', $text);

        $text = preg_replace('/<ignore>\[\[([\s\S]*?)(\|)?(<\/ignore>)([\s\S]*?)?<ignore>]]<\/ignore>/', '[[${1}${2}${4}]]', $text);
        $text = preg_replace('/<ignore>\{\{([\s\S]*?)(\|)?(<\/ignore>)([\s\S]*?)?<ignore>}}<\/ignore>/', '{{${1}${2}${4}}}', $text);

        // prevent deepl from messing with smileys
        $smileys = array_keys(getSmileys());
        foreach ($smileys as $smiley) {
            $text = str_replace("<ignore>" . $smiley . "</ignore>", $smiley, $text);
        }

        $text = preg_replace('/<ignore>(<php[\s\S]*?>[\s\S]*?<\/php>)<\/ignore>/', '${1}', $text);
        $text = preg_replace('/<ignore>(<file[\s\S]*?>[\s\S]*?<\/file>)<\/ignore>/', '${1}', $text);
        $text = preg_replace('/<ignore>(<code[\s\S]*?>[\s\S]*?<\/code>)<\/ignore>/', '${1}', $text);

        // fix for the template plugin
        $text = preg_replace('/<ignore>(\{\{template>[\s\S]*?}})<\/ignore>/', '${1}', $text);

        // prevent deepl from breaking headings
        $text = preg_replace('/<ignore>(={1,6})<\/ignore>/','${1}', $text);

        // ignore every other xml-like tags (the tags themselves, not their content), otherwise deepl would break the formatting
        $text = preg_replace('/<ignore>(<[\s\S]+?>)<\/ignore>/', '${1}', $text);

        // restore < and > for example from arrows (-->) in wikitext
        $text = str_replace('&gt;', '>', $text);
        $text = str_replace('&lt;', '<', $text);

        // restore & in wikitext
        $text = str_replace('&amp;', '&', $text);

        return $text;
    }
}