<?php
/**
 * @package Polylang-Pro
 */

defined( 'ABSPATH' ) || exit; // Don't access directly

/**
 * A class to bulk translate posts.
 *
 * @since 2.4
 */
class PLL_Bulk_Translate {

	/**
	 * @var PLL_Model
	 */
	protected $model;

	/**
	 * Reference to the current WP_Screen object.
	 *
	 * @since 2.7
	 *
	 * @var WP_Screen|null
	 */
	protected $current_screen;

	/**
	 * Stores the results of the bulk action when it's done.
	 *
	 * @since 2.7
	 *
	 * @var array|null
	 */
	protected $results;

	/**
	 * References the options for the bulk action.
	 *
	 * @since 2.7
	 *
	 * @var PLL_Bulk_Translate_Option[]
	 */
	protected $options = array();

	/**
	 * PLL_Bulk_Translate constructor.
	 *
	 * @since 2.4
	 *
	 * @param PLL_Model $model Shared instance of the current PLL_Model.
	 */
	public function __construct( $model ) {
		$this->model = $model;

		add_action( 'admin_enqueue_scripts', array( $this, 'admin_enqueue_scripts' ) );
	}

	/**
	 * Enqueues script and style.
	 *
	 * @since 2.8
	 *
	 * @return void
	 */
	public function admin_enqueue_scripts() {
		$screen = get_current_screen();

		if ( $screen && in_array( $screen->base, array( 'edit', 'upload' ) ) ) {
			$suffix = defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ? '' : '.min';
			wp_enqueue_script(
				'pll_bulk_translate',
				plugins_url( '/js/build/bulk-translate' . $suffix . '.js', POLYLANG_ROOT_FILE ),
				array( 'jquery', 'wp-ajax-response' ),
				POLYLANG_VERSION,
				true
			);

			wp_enqueue_style(
				'pll_bulk_translate',
				plugins_url( '/css/build/bulk-translate' . $suffix . '.css', POLYLANG_ROOT_FILE ),
				array(),
				POLYLANG_VERSION
			);
		}
	}

	/**
	 * Registers options of the Translate bulk action.
	 *
	 * @since 2.7
	 *
	 * @param PLL_Bulk_Translate_Option[] $options An array of {@see PLL_Bulk_Translate_Option} to register.
	 * @return void
	 */
	public function register_options( $options ) {
		if ( ! is_array( $options ) ) {
			$options = array( $options );
		}

		foreach ( $options as $option ) {
			if ( array_key_exists( $option->get_name(), $this->options ) ) {
				if ( WP_DEBUG ) {
					trigger_error( // phpcs:ignore WordPress.PHP.DevelopmentFunctions
						sprintf(
							'Error when trying to register Bulk Translate option with name \'%s\' : an option with this name already exists.',
							esc_attr( $option->get_name() )
						)
					);
				}
				continue;
			}
			$this->options[ $option->get_name() ] = $option;
		}
	}

	/**
	 * Add actions and filters.
	 *
	 * Verifies the post type is allowed for translation and that the post status isn't 'trashed'.
	 *
	 * @since 2.4
	 * @since 2.7 hooked on 'current_screen' and takes the screen as parameter.
	 *
	 * @param WP_Screen $current_screen Instance of the current WP_Screen.
	 * @return void
	 */
	public function init( $current_screen ) {
		/**
		 * Filter the list of post types enabling the bulk translate.
		 *
		 * @since 2.4
		 *
		 * @param string[] $post_types List of post types.
		 */
		$post_types = apply_filters( 'pll_bulk_translate_post_types', $this->model->get_translated_post_types() );

		// phpcs:ignore WordPress.Security.NonceVerification
		if ( ! in_array( $current_screen->post_type, $post_types ) || ( array_key_exists( 'post_status', $_GET ) && 'trash' === $_GET['post_status'] ) ) {
			return;
		}

		/**
		 * Fires before `PLL_Bulk_Translate` init.
		 * This is the perfect place to register options of the Translate bulk action.
		 *
		 * @since 3.6.5
		 * @see PLL_Bulk_Translate::register_options()
		 *
		 * @param PLL_Bulk_Translate $bulk_translate Instance of `PLL_Bulk_Translate`.
		 */
		do_action( 'pll_bulk_translate_options_init', $this );

		$this->options = array_filter(
			$this->options,
			function ( $option ) {
				return $option->is_available();
			}
		);

		$this->current_screen = $current_screen;

		if ( ! empty( $this->options ) ) {
			add_filter( "bulk_actions-{$current_screen->id}", array( $this, 'add_bulk_action' ) );
			add_filter( "handle_bulk_actions-{$current_screen->id}", array( $this, 'handle_bulk_action' ), 10, 2 );
			add_action( 'admin_footer', array( $this, 'display_form' ) );
			add_action( 'admin_notices', array( $this, 'display_notices' ) );
			// Special case where the wp_redirect() happens before the bulk action is triggered.
			if ( 'edit' === $current_screen->base ) {
				add_filter( 'wp_redirect', array( $this, 'parse_request_before_redirect' ) );
			}
		}
	}

	/**
	 * Retrieves the needed data in the request body and sanitize it.
	 *
	 * @since 2.7
	 *
	 * @param array $request {
	 *   Parameters from the HTTP Request.
	 *
	 *   @type int[]    $post               The list of post ids to bulk translate. Must be set if `$post` is not.
	 *   @type int[]    $media              The list of media ids to bulk translate.  Must be set if `$media` is not.
	 *   @type string   $translate          The translation action ('pll_copy_post' for copy, 'pll_sync_post' for synchronization).
	 *   @type string[] $pll-translate-lang The list of language slugs to translate to.
	 * }
	 * @return WP_Error|array {
	 *   @type int[]    $item_ids           The sanitized list of post (or media) ids to translate.
	 *   @type string   $translate          The sanitized translation action.
	 *   @type string[] $pll-translate-lang The sanitized list of language slugs to translate to.
	 * }
	 */
	protected function parse_request( $request ) {
		$args = array();

		$screens_content_keys = array(
			'upload' => 'media',
			'edit'   => 'post',
		);

		if ( ! empty( $this->current_screen ) && isset( $screens_content_keys[ $this->current_screen->base ] ) ) {
			$item_key = $screens_content_keys[ $this->current_screen->base ];

			if ( isset( $request[ $item_key ] ) && is_array( $request[ $item_key ] ) ) {
				$args['item_ids'] = array_filter( array_map( 'absint', $request[ $item_key ] ) );
			}
		}

		if ( empty( $args['item_ids'] ) ) {
			return new WP_Error( 'pll_no_items_selected', __( 'No item has been selected. Please make sure to select at least one item to be translated.', 'polylang-pro' ) );
		}

		foreach ( $args['item_ids'] as $item_id ) {
			if ( ! current_user_can( 'read_post', (int) $item_id ) ) {
				return new WP_Error( 'pll_user_cannot_read_item', __( 'You are not allowed to read a selected item.', 'polylang-pro' ) );
			}
		}

		$args['translate'] = sanitize_key( $request['translate'] );

		if ( isset( $request['pll-translate-lang'] ) && is_array( $request['pll-translate-lang'] ) ) {
			$args['pll-translate-lang'] = array_intersect( $request['pll-translate-lang'], $this->model->get_languages_list( array( 'fields' => 'slug' ) ) );
		}

		if ( empty( $args['pll-translate-lang'] ) ) {
			return new WP_Error( 'pll_no_target_language', __( 'Error: No target language has been selected. Please make sure to select at least one target language.', 'polylang-pro' ) );
		}

		return $args;
	}

	/**
	 * Handle the Translate bulk action.
	 *
	 * @since 2.4
	 * @since 2.7 Use a transient to store notices.
	 *
	 * @param string $sendback The URL to redirect to, with parameters.
	 * @param string $action   Name of the requested bulk action.
	 *
	 * @return string The URL to redirect to.
	 */
	public function handle_bulk_action( $sendback, $action ) {
		if ( 'pll_translate' !== $action ) {
			return $sendback;
		}

		check_admin_referer( 'pll_translate', '_pll_translate_nonce' );

		$query_args = $this->parse_request( $_GET ); // Errors returned by this method are already handled by `parse_request_before_redirect()`.

		if ( ! is_wp_error( $query_args ) ) {
			$selected_option = $this->options[ $query_args['translate'] ];

			$error = $selected_option->do_bulk_action( $query_args['item_ids'], $query_args['pll-translate-lang'] );
			$this->add_settings_error( $error );
		}

		return $sendback;
	}

	/**
	 * Add a bulk action
	 *
	 * @since 2.4
	 *
	 * @param array $actions List of bulk actions.
	 *
	 * @return array
	 */
	public function add_bulk_action( $actions ) {
		$actions['pll_translate'] = __( 'Translate', 'polylang-pro' );
		return $actions;
	}

	/**
	 * Displays the Bulk translate form.
	 *
	 * @since 2.4
	 *
	 * @return void
	 */
	public function display_form() {
		global $post_type;
		$model = $this->model;
		$bulk_translate_options = $this->options;
		usort(
			$bulk_translate_options,
			function ( $first_element, $second_element ) {
				return $first_element->get_priority() - $second_element->get_priority();
			}
		);
		include __DIR__ . '/view-bulk-translate.php';
	}

	/**
	 * Displays the notices if some have been registered.
	 *
	 * Because WordPress triggers a {@see wp_redirect()}, these notices are stored in a transient.
	 *
	 * @since 2.7
	 *
	 * @return void
	 */
	public function display_notices() {
		$transient_name = 'pll_bulk_translate_' . get_current_user_id();

		/** @var string[][] */
		$notices = get_transient( $transient_name );

		if ( empty( $notices ) ) {
			return;
		}

		foreach ( $notices as $notice ) {
			/*
			 * Backward compatibility for PHP < 8.0.0.
			 * Unpacking operator `...` supports string-keyed associative array only since PHP 8.0.0.
			 */
			add_settings_error( ...array_values( $notice ) );
		}

		settings_errors( 'polylang' );
		delete_transient( $transient_name );
	}

	/**
	 * Fixes the case when no post is selected and a redirect is fired before we can handle the bulk action.
	 *
	 * @since 2.7
	 *
	 * @param string $sendback The destination URL.
	 *
	 * @return string Unmodified $sendback.
	 */
	public function parse_request_before_redirect( $sendback ) {
		if ( ! isset( $_GET['action'], $_REQUEST['_pll_translate_nonce'] ) || 'pll_translate' !== $_GET['action'] || ! wp_verify_nonce( $_REQUEST['_pll_translate_nonce'], 'pll_translate' ) ) {
			return $sendback;
		}

		$error = $this->parse_request( $_GET );

		if ( is_wp_error( $error ) ) {
			$this->add_settings_error( $error );
		}

		return $sendback;
	}

	/**
	 * Registers errors if any.
	 *
	 * @since 3.6
	 *
	 * @param WP_Error $error Error object.
	 * @return void
	 */
	private function add_settings_error( WP_Error $error ) {
		if ( ! $error->has_errors() ) {
			return;
		}

		pll_add_notice( $error );
		set_transient( 'pll_bulk_translate_' . get_current_user_id(), get_settings_errors( 'polylang' ) );
	}
}
