<?php
/**
 * The plugin's own REST routes, for the editor's sidebar. The browser never sees
 * the connection token: these routes call Ojelio from the server.
 *
 * @package Ojelio
 */

namespace Ojelio;

use WP_Error;
use WP_REST_Request;
use WP_REST_Response;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class Rest {

	const NS = 'ojelio/v1';

	public static function boot() {
		add_action( 'rest_api_init', array( __CLASS__, 'routes' ) );
	}

	public static function routes() {
		$post = array(
			'id' => array(
				'type'     => 'integer',
				'required' => true,
			),
		);
		register_rest_route(
			self::NS,
			'/posts/(?P<id>\d+)',
			array(
				'methods'             => 'GET',
				'callback'            => array( __CLASS__, 'state' ),
				'permission_callback' => array( __CLASS__, 'can_edit' ),
				'args'                => $post,
			)
		);
		register_rest_route(
			self::NS,
			'/posts/(?P<id>\d+)/videos',
			array(
				array(
					'methods'             => 'GET',
					'callback'            => array( __CLASS__, 'list_videos' ),
					'permission_callback' => array( __CLASS__, 'can_edit' ),
					'args'                => $post,
				),
				array(
					'methods'             => 'POST',
					'callback'            => array( __CLASS__, 'create_video' ),
					'permission_callback' => array( __CLASS__, 'can_edit' ),
					'args'                => $post,
				),
			)
		);
		register_rest_route(
			self::NS,
			'/posts/(?P<id>\d+)/videos/(?P<video>[a-z0-9]{6,32})/save',
			array(
				'methods'             => 'POST',
				'callback'            => array( __CLASS__, 'save_again' ),
				'permission_callback' => array( __CLASS__, 'can_edit' ),
				'args'                => $post,
			)
		);
		register_rest_route(
			self::NS,
			'/posts/(?P<id>\d+)/videos/(?P<video>[a-z0-9]{6,32})/download',
			array(
				'methods'             => 'GET',
				'callback'            => array( __CLASS__, 'download_link' ),
				'permission_callback' => array( __CLASS__, 'can_edit' ),
				'args'                => $post,
			)
		);
	}

	/** "Try again" on a video that could not be saved: WP-Cron tries at once. */
	public static function save_again( WP_REST_Request $request ) {
		$post_id = (int) $request['id'];
		$video   = Videos::find( $post_id, (string) $request['video'] );
		if ( ! $video || 'completed' !== $video['status'] ) {
			return new WP_Error( 'ojelio_no_video', __( 'This video is not ready to be saved.', 'ojelio' ), array( 'status' => 404 ) );
		}
		Media::retry( $post_id, $video['id'] );
		return array( 'videos' => self::present( Videos::of_post( $post_id ) ) );
	}

	/** A fresh link to the MP4 (an hour long), for saving it by hand. */
	public static function download_link( WP_REST_Request $request ) {
		$video = Videos::find( (int) $request['id'], (string) $request['video'] );
		if ( ! $video ) {
			return new WP_Error( 'ojelio_no_video', __( 'This post has no such video.', 'ojelio' ), array( 'status' => 404 ) );
		}
		$fresh = Connection::call( 'GET', '/videos/' . rawurlencode( $video['id'] ) );
		if ( is_wp_error( $fresh ) ) {
			return self::error( $fresh );
		}
		if ( empty( $fresh['files']['video'] ) ) {
			return new WP_Error( 'ojelio_no_file', __( 'Ojelio has no file for this video.', 'ojelio' ), array( 'status' => 409 ) );
		}
		return array( 'url' => $fresh['files']['video'] );
	}

	/** The videos as the sidebar shows them: with their Media Library files once saved. */
	public static function present( array $videos ) {
		return array_map(
			static function ( $video ) {
				$id = isset( $video['attachment_id'] ) ? (int) $video['attachment_id'] : 0;
				if ( $id && ! get_post( $id ) ) {
					// Deleted from the Media Library since.
					$id = 0;
				}
				$poster              = isset( $video['poster_id'] ) ? (int) $video['poster_id'] : 0;
				$video['media']      = $id ? array(
					'id'       => $id,
					'url'      => wp_get_attachment_url( $id ),
					'poster'   => $poster ? wp_get_attachment_url( $poster ) : null,
					'edit_url' => get_edit_post_link( $id, 'raw' ),
				) : null;
				$video['saving']     = 'completed' === $video['status'] && ! $id && Videos::needs_work( $video );
				$video['gave_up']    = Media::gave_up( $video );
				return $video;
			},
			$videos
		);
	}

	/** Anyone who can edit the post can make its video (plan, 5.2). */
	public static function can_edit( WP_REST_Request $request ) {
		return current_user_can( 'edit_post', (int) $request['id'] );
	}

	/** Everything the sidebar needs to open: the connection, the options and where they start, the content, the videos. */
	public static function state( WP_REST_Request $request ) {
		$post = get_post( (int) $request['id'] );
		if ( ! $post ) {
			return new WP_Error( 'ojelio_no_post', __( 'This post does not exist.', 'ojelio' ), array( 'status' => 404 ) );
		}
		$answer = array(
			'connected'    => (bool) Connection::get(),
			'can_manage'   => current_user_can( Settings::CAPABILITY ),
			'settings_url' => Connection::settings_url(),
			'links'        => array(
				'terms'   => Api::app_url( '/terms' ),
				'credits' => Api::app_url( '/credits' ),
			),
			'videos'       => self::present( Videos::refresh( $post->ID ) ),
		);
		if ( ! $answer['connected'] ) {
			return $answer;
		}
		$options = Settings::options();
		if ( is_wp_error( $options ) ) {
			// Disconnected in Ojelio, or Ojelio unreachable: said in the sidebar.
			$answer['connected'] = (bool) Connection::get();
			$answer['error']     = $options->get_error_message();
			return $answer;
		}
		$payload = Payload::from_post( $post );
		return array_merge(
			$answer,
			array(
				'options' => self::choices( $options ),
				'start'   => self::start( $options ),
				'content' => array(
					'words'    => $payload['words'],
					'images'   => count( array_filter( $payload['blocks'], array( __CLASS__, 'is_image' ) ) ),
					'left_out' => $payload['left_out'],
				),
			)
		);
	}

	public static function list_videos( WP_REST_Request $request ) {
		return array( 'videos' => self::present( Videos::refresh( (int) $request['id'] ) ) );
	}

	public static function create_video( WP_REST_Request $request ) {
		$post = get_post( (int) $request['id'] );
		if ( ! $post ) {
			return new WP_Error( 'ojelio_no_post', __( 'This post does not exist.', 'ojelio' ), array( 'status' => 404 ) );
		}
		if ( true !== $request->get_param( 'rights_confirmed' ) ) {
			return new WP_Error( 'ojelio_rights', __( 'Confirm that you have the rights to use this content.', 'ojelio' ), array( 'status' => 400 ) );
		}
		$request_id = (string) $request->get_param( 'request_id' );
		if ( ! preg_match( '/^[A-Za-z0-9-]{8,64}$/', $request_id ) ) {
			return new WP_Error( 'ojelio_request', __( 'The request is not valid. Reload the editor and try again.', 'ojelio' ), array( 'status' => 400 ) );
		}
		$lists = Settings::options();
		if ( is_wp_error( $lists ) ) {
			return self::error( $lists );
		}
		$chosen = self::chosen( $request->get_json_params(), $lists );
		if ( is_wp_error( $chosen ) ) {
			return $chosen;
		}
		$video = Videos::create( $post, $chosen, $request_id );
		if ( is_wp_error( $video ) ) {
			return self::error( $video );
		}
		return new WP_REST_Response( array( 'video' => $video, 'videos' => self::present( Videos::of_post( $post->ID ) ) ), 201 );
	}

	// ---- The options -------------------------------------------------------------------

	/** The lists the sidebar offers, with their labels. */
	private static function choices( array $options ) {
		$labelled = static function ( $values, $label_of ) {
			return array_map(
				static function ( $value ) use ( $label_of ) {
					return array( 'value' => $value, 'label' => call_user_func( $label_of, $value ) );
				},
				$values
			);
		};
		return array(
			'formats'   => $labelled( $options['formats'], array( Settings::class, 'format_label' ) ),
			'languages' => $labelled( $options['languages'], array( Settings::class, 'language_label' ) ),
			'seconds'   => $labelled( $options['seconds'], array( Settings::class, 'seconds_label' ) ),
			'text'      => $options['text'],
			'narrators' => $options['narrators'],
			'styles'    => $options['styles'],
			'music'     => $options['music'],
			'defaults'  => $options['defaults'],
			'locked'    => ! empty( $options['options_locked'] ),
		);
	}

	/**
	 * Where each option starts: the site's default, then (for the language) the
	 * site's own language, then the brand kit's.
	 */
	private static function start( array $options ) {
		$site = Settings::defaults();
		$kit  = $options['defaults'];
		$pick = static function ( $name, $list, $fallback ) use ( $site ) {
			return '' !== $site[ $name ] && in_array( (string) $site[ $name ], array_map( 'strval', $list ), true ) ? $site[ $name ] : $fallback;
		};
		$locale   = self::language_of_site( $options['languages'] );
		$language = $pick( 'language', $options['languages'], $locale ? $locale : $kit['language'] );
		return array(
			'format'               => $pick( 'format', $options['formats'], $kit['format'] ),
			'language'             => $language,
			'seconds'              => (int) $pick( 'seconds', $options['seconds'], $kit['seconds'] ),
			'text'                 => $kit['text'],
			'narrator'             => isset( $kit['narrators'][ $language ] ) ? $kit['narrators'][ $language ] : '',
			'style'                => $kit['style'],
			'music'                => $kit['music'],
			'review_before_render' => (bool) $kit['review_before_render'],
		);
	}

	/** The site's language, when Ojelio narrates in it: pt_BR and pt_PT to pt-BR, any English to en-US. */
	private static function language_of_site( array $languages ) {
		$locale = strtolower( determine_locale() );
		foreach ( $languages as $language ) {
			if ( 0 === strpos( $locale, strtolower( substr( $language, 0, 2 ) ) ) ) {
				return $language;
			}
		}
		return null;
	}

	/**
	 * The sidebar's request, checked against the workspace's lists: only known
	 * values reach Ojelio.
	 *
	 * @return array|WP_Error The API fields.
	 */
	private static function chosen( $params, array $lists ) {
		$params = is_array( $params ) ? $params : array();
		$fields = array();
		$one_of = static function ( $name, array $allowed ) use ( $params ) {
			if ( ! isset( $params[ $name ] ) || '' === $params[ $name ] ) {
				return null;
			}
			foreach ( $allowed as $value ) {
				if ( (string) $value === (string) $params[ $name ] ) {
					return $value;
				}
			}
			return false;
		};
		$ids      = static function ( array $items ) {
			return wp_list_pluck( $items, 'id' );
		};
		$language = $one_of( 'language', $lists['languages'] );
		$narrators = array_filter(
			$lists['narrators'],
			static function ( $narrator ) use ( $language, $lists ) {
				return $narrator['language'] === ( $language ? $language : $lists['defaults']['language'] );
			}
		);
		$checks = array(
			'format'   => $lists['formats'],
			'language' => $lists['languages'],
			'seconds'  => $lists['seconds'],
			'text'     => $lists['text'],
			'narrator' => $ids( $narrators ),
			'style'    => $ids( $lists['styles'] ),
			'music'    => array_merge( $ids( $lists['music'] ), array( 'none' ) ),
		);
		foreach ( $checks as $name => $allowed ) {
			$value = $one_of( $name, $allowed );
			if ( false === $value ) {
				$names = array(
					'format'   => __( 'format', 'ojelio' ),
					'language' => __( 'language', 'ojelio' ),
					'seconds'  => __( 'length', 'ojelio' ),
					'text'     => __( 'text', 'ojelio' ),
					'narrator' => __( 'narrator', 'ojelio' ),
					'style'    => __( 'style', 'ojelio' ),
					'music'    => __( 'music', 'ojelio' ),
				);
				return new WP_Error(
					'ojelio_option',
					/* translators: %s: the name of an option, such as "format" or "narrator". */
					sprintf( __( 'The %s chosen is no longer offered. Reload the editor and choose again.', 'ojelio' ), $names[ $name ] ),
					array( 'status' => 400 )
				);
			}
			if ( null !== $value ) {
				$fields[ $name ] = $value;
			}
		}
		// An exact text sets its own length.
		if ( isset( $fields['text'] ) && 'exact' === $fields['text'] ) {
			unset( $fields['seconds'] );
		}
		if ( isset( $params['review_before_render'] ) ) {
			$fields['review_before_render'] = (bool) $params['review_before_render'];
		}
		return $fields;
	}

	/** An API error for the sidebar: its message, the code, and a status the editor reads as an error. */
	private static function error( WP_Error $error ) {
		$data   = $error->get_error_data();
		$status = is_array( $data ) && isset( $data['status'] ) && $data['status'] >= 400 ? (int) $data['status'] : 502;
		return new WP_Error( $error->get_error_code(), $error->get_error_message(), array( 'status' => 'ojelio_not_connected' === $error->get_error_code() ? 409 : $status ) );
	}

	private static function is_image( $block ) {
		return 'image' === $block['type'];
	}
}