<?php

/**
 * Class TRP_Machine_Translator
 *
 * Facilitates Machine Translation calls
 */
class TRP_Machine_Translator {
    protected $settings;
	protected $referer;
	protected $url_converter;
	protected $machine_translator_logger;
	protected $machine_translation_codes;
	protected $trp_languages;
    /**
     * TRP_Machine_Translator constructor.
     *
     * @param array $settings         Settings option.
     */
    public function __construct( $settings ){
        $this->settings = $settings;

        $trp                             = TRP_Translate_Press::get_trp_instance();
        if ( ! $this->machine_translator_logger ) {
            $this->machine_translator_logger = $trp->get_component('machine_translator_logger');
        }
        if ( ! $this->trp_languages ) {
            $this->trp_languages = $trp->get_component('languages');
        }
        $this->machine_translation_codes = $this->trp_languages->get_iso_codes($this->settings['translation-languages']);
    }

    /**
     * Whether automatic translation is available.
     *
     * @param array $languages
     * @return bool
     */
    public function is_available( $languages = array() ){
        if( !empty( $this->settings['trp_machine_translation_settings']['machine-translation'] ) &&
            $this->settings['trp_machine_translation_settings']['machine-translation'] == 'yes'
        ) {
            if ( empty( $languages ) ){
                // can be used to simply know if machine translation is available
                return true;
            }

            return $this->check_languages_availability($languages);

        }else {
            return false;
        }
    }

    public function check_languages_availability( $languages, $force_recheck = false ){
        if ( !method_exists( $this, 'get_supported_languages' ) || !method_exists( $this, 'get_engine_specific_language_codes' )){
            return true;
        }
        $force_recheck = ( current_user_can('manage_options') &&
            !empty( $_GET['trp_recheck_supported_languages']) && $_GET['trp_recheck_supported_languages'] === '1' &&
            wp_verify_nonce( $_GET['trp_recheck_supported_languages_nonce'], 'trp_recheck_supported_languages' ) ) ? true : $force_recheck;
        $data = get_option('trp_db_stored_data', array() );
        if ( isset( $_GET['trp_recheck_supported_languages'] )) {
            unset($_GET['trp_recheck_supported_languages'] );
        }

        // if supported languages are not stored, fetch them and update option
        if ( empty( $data['trp_mt_supported_languages'][$this->settings['trp_machine_translation_settings']['translation-engine']]['last-checked'] ) || $force_recheck ){
            if ( empty( $data['trp_mt_supported_languages'] ) ) {
                $data['trp_mt_supported_languages'] = array();
            }
            if ( empty( $data['trp_mt_supported_languages'][ $this->settings['trp_machine_translation_settings']['translation-engine'] ] ) ) {
                $data['trp_mt_supported_languages'][ $this->settings['trp_machine_translation_settings']['translation-engine'] ] = array( 'languages' => array() );
            }

            $data['trp_mt_supported_languages'][$this->settings['trp_machine_translation_settings']['translation-engine']]['languages'] = $this->get_supported_languages();
            $data['trp_mt_supported_languages'][$this->settings['trp_machine_translation_settings']['translation-engine']]['last-checked'] = date("Y-m-d H:i:s" );
            update_option('trp_db_stored_data', $data );
        }

        $languages_iso_to_check = $this->get_engine_specific_language_codes( $languages );

        $all_are_available = !array_diff($languages_iso_to_check, $data['trp_mt_supported_languages'][$this->settings['trp_machine_translation_settings']['translation-engine']]['languages']);

        return apply_filters('trp_mt_available_supported_languages', $all_are_available, $languages, $this->settings );
    }

    public function get_last_checked_supported_languages(){
        $data = get_option('trp_db_stored_data', array() );
        if ( empty( $data['trp_mt_supported_languages'][$this->settings['trp_machine_translation_settings']['translation-engine']]['last-checked'] ) ){
            $this->check_languages_availability( $this->settings['translation-languages'], true);
        }
        return $data['trp_mt_supported_languages'][$this->settings['trp_machine_translation_settings']['translation-engine']]['last-checked'];
    }

    /**
     * Output an SVG based on translation engine and error flag.
     *
     * @param bool $show_errors true to show an error SVG, false if not.
     */
    public function automatic_translation_svg_output( $show_errors ) {
        if ( method_exists( $this, 'automatic_translate_error_check' ) ) {
            if ( $show_errors ) {
                trp_output_svg( 'error' );
            } else {
                trp_output_svg( 'check' );
            }
        }
        
    }

    /**
     * Check the automatic translation API keys for Google Translate and DeepL.
     *
     * @param TRP_Translate_Press $machine_translator Machine translator instance.
     * @param string $translation_engine              The translation engine (can be google_translate_v2 and deepl).
     * @param string $api_key                         The API key to check.
     *
     * @return array [ (string) $message, (bool) $error ].
     */
    public function automatic_translate_error_check( $machine_translator, $translation_engine, $api_key ) {
        $is_error       = false;
        $return_message = '';

        switch ( $translation_engine ) {
            case 'google_translate_v2':
                if ( empty( $api_key ) ) {
                    $is_error = true;
                    $return_message = __( 'Please enter your Google Translate key.', 'translatepress-multilingual' );
                } else {
                    // Perform test.
                    $response = $machine_translator->test_request();
                    $code     = wp_remote_retrieve_response_code( $response );
                    if ( 200 !== $code ) {
                        $is_error        = true;
                        $translate_response = trp_gt_response_codes( $code );
                        $return_message     = $translate_response['message'];
                    }
                }
                break;
            case 'deepl':
                if ( empty( $api_key ) ) {
                    $is_error = true;
                    $return_message = __( 'Please enter your DeepL API key.', 'translatepress-multilingual' );
                } else {
                    // Perform test.
                    $response = $machine_translator->test_request();
                    $code     = wp_remote_retrieve_response_code( $response );
                    if ( 200 !== $code && method_exists( 'TRP_DeepL', 'deepl_response_codes' ) ) {
                        $is_error        = true;
                        $translate_response = TRP_DeepL::deepl_response_codes( $code );
                        $return_message     = $translate_response['message'];
                    }
                }
                break;
            default:
                break;
        }
        return array(
            'message' => $return_message,
            'error'   => $is_error,
        );
    }

	/**
	 * Return site referer
	 *
	 * @return string
	 */
	public function get_referer(){
		if( ! $this->referer ) {
			if( ! $this->url_converter ) {
				$trp = TRP_Translate_Press::get_trp_instance();
				$this->url_converter = $trp->get_component( 'url_converter' );
			}

			$this->referer = $this->url_converter->get_abs_home();
		}

		return $this->referer;
	}

    /**
     * Verifies that the machine translation request is valid
     * @deprecated  since TP 1.6.0 (only here to support Deepl Add-on version 1.0.0)
     *
     * @param  string $to_language language we're looking to translate to
     * @return bool
     */
    public function verify_request( $to_language ){

        if( empty( $this->get_api_key() ) ||
            empty( $to_language ) || $to_language == $this->settings['default-language'] ||
            empty( $this->machine_translation_codes[$this->settings['default-language']] )
          )
            return false;

        // Method that can be extended in the child class to add extra validation
        if( !$this->extra_request_validations( $to_language ) )
            return false;

        // Check if crawlers are blocked
        if( !empty( $this->settings['trp_machine_translation_settings']['block-crawlers'] ) && $this->settings['trp_machine_translation_settings']['block-crawlers'] == 'yes' && $this->is_crawler() )
            return false;

        // Check if daily quota is met
        if( $this->machine_translator_logger->quota_exceeded() )
            return false;

        return true;

    }

    /**
     * Verifies that the machine translation request is valid
     *
     * @param  string $target_language_code language we're looking to translate to
     * @param  string $source_language_code language we're looking to translate from
     * @return bool
     */
    public function verify_request_parameters($target_language_code, $source_language_code){
        if( empty( $this->get_api_key() ) ||
            empty( $target_language_code ) || empty( $source_language_code ) ||
            empty( $this->machine_translation_codes[$target_language_code] ) ||
            empty( $this->machine_translation_codes[$source_language_code] ) ||
            $this->machine_translation_codes[$target_language_code] == $this->machine_translation_codes[$source_language_code]
        )
            return false;

        // Method that can be extended in the child class to add extra validation
        if( !$this->extra_request_validations( $target_language_code ) )
            return false;

        // Check if crawlers are blocked
        if( !empty( $this->settings['trp_machine_translation_settings']['block-crawlers'] ) && $this->settings['trp_machine_translation_settings']['block-crawlers'] == 'yes' && $this->is_crawler() )
            return false;

        // Check if daily quota is met
        if( $this->machine_translator_logger->quota_exceeded() )
            return false;

        return true;
    }

    /**
     * Verifies user agent to check if the request is being made by a crawler
     *
     * @return boolean
     */
    private function is_crawler(){
        if( !isset( $_SERVER['HTTP_USER_AGENT'] ) )
            return false;

        $crawlers = apply_filters( 'trp_machine_translator_crawlers', 'rambler|abacho|acoi|accona|aspseek|altavista|estyle|scrubby|lycos|geona|ia_archiver|alexa|sogou|skype|facebook|twitter|pinterest|linkedin|naver|bing|google|yahoo|duckduckgo|yandex|baidu|teoma|xing|java\/1.7.0_45|bot|crawl|slurp|spider|mediapartners|\sask\s|\saol\s' );

        return preg_match( '/'. $crawlers .'/i', $_SERVER['HTTP_USER_AGENT'] );
    }

    private function get_placeholders( $count ){
	    $placeholders = array();
	    for( $i = 1 ; $i <= $count; $i++ ){
            $placeholders[] = '1TP' . $i . 'T';
        }
	    return $placeholders;
    }

    /**
     * Function to be used externally
     *
     * @param $strings
     * @param $target_language_code
     * @param $source_language_code
     * @return array
     */
    public function translate($strings, $target_language_code, $source_language_code = null ){
        if ( !empty($strings) && is_array($strings) && method_exists( $this, 'translate_array' ) && apply_filters( 'trp_disable_automatic_translations_due_to_error', false ) === false ) {

            /* google has a problem translating this characters ( '%', '$', '#' )...for some reasons it puts spaces after them so we need to 'encode' them and decode them back. hopefully it won't break anything important */
            $trp_exclude_words_from_automatic_translation = apply_filters('trp_exclude_words_from_automatic_translation', array('%', '$', '#'));
            $placeholders = $this->get_placeholders(count($trp_exclude_words_from_automatic_translation));
            $shortcode_tags_to_execute = apply_filters( 'trp_do_these_shortcodes_before_automatic_translation', array('trp_language') );

            $strings = array_unique($strings);
            $original_strings = $strings;
            foreach ($strings as $key => $string) {
                /* html_entity_decode is needed before replacing the character "#" from the list because characters like &#8220; (8220 utf8)
                 * will get an extra space after '&' which will break the character, rendering it like this: & #8220;
                 */
                $strings[$key] = str_replace($trp_exclude_words_from_automatic_translation, $placeholders, html_entity_decode( $string ));
                $strings[$key] = trp_do_these_shortcodes( $strings[$key], $shortcode_tags_to_execute );
            }

            if ( $this->settings['trp_machine_translation_settings']['translation-engine'] === 'deepl' && defined( 'TRP_DL_PLUGIN_VERSION' ) && TRP_DL_PLUGIN_VERSION === '1.0.0' ) {
                // backwards compatibility with deepl version 1.0.0 which doesn't have the third function parameter $source_language_code
                $machine_strings = $this->translate_array($strings, $target_language_code);
            }else {
                $machine_strings = $this->translate_array($strings, $target_language_code, $source_language_code);
            }

            $machine_strings_return_array = array();
            if (!empty($machine_strings)) {
                foreach ($machine_strings as $key => $machine_string) {
                    $machine_strings_return_array[$original_strings[$key]] = str_ireplace( $placeholders, $trp_exclude_words_from_automatic_translation, $machine_string );
                }
            }
            return $machine_strings_return_array;
        }else {
            return array();
        }
    }


    public function test_request(){}

    public function get_api_key(){
        return false;
    }

    public function extra_request_validations( $to_language ){
        return true;
    }
}
