<?php

/**
 * Add per-post Publicize Connection data.
 *
 * { # Post Object
 *   ...
 *   jetpack_publicize_connections: { # Defined below in this file. See schema for more detail.
 *     id:           (string)  Connection unique_id
 *     service_name: (string)  Service slug
 *     display_name: (string)  User name/display name of user/connection on Service
 *     enabled:      (boolean) Is this connection slated to be shared to? context=edit only
 *     done:         (boolean) Is this post (or connection) done sharing? context=edit only
 *     toggleable:   (boolean) Can the current user change the `enabled` setting for this Connection+Post? context=edit only
 *   }
 *   ...
 *   meta: { # Not defined in this file. Handled in modules/publicize/publicize.php via `register_meta()`
 *     jetpack_publicize_message: (string) The message to use instead of the post's title when sharing.
 *   }
 *   ...
 * }
 *
 * @since 6.8.0
 */
class WPCOM_REST_API_V2_Post_Publicize_Connections_Field extends WPCOM_REST_API_V2_Field_Controller {
	protected $object_type = 'post';
	protected $field_name  = 'jetpack_publicize_connections';

	public $memoized_updates = array();

	/**
	 * Registers the jetpack_publicize_connections field. Called
	 * automatically on `rest_api_init()`.
	 */
	public function register_fields() {
		$this->object_type = get_post_types_by_support( 'publicize' );

		foreach ( $this->object_type as $post_type ) {
			// Adds meta support for those post types that don't already have it.
			// Only runs during REST API requests, so it doesn't impact UI.
			if ( ! post_type_supports( $post_type, 'custom-fields' ) ) {
				add_post_type_support( $post_type, 'custom-fields' );
			}

			add_filter( 'rest_pre_insert_' . $post_type, array( $this, 'rest_pre_insert' ), 10, 2 );
			add_action( 'rest_insert_' . $post_type, array( $this, 'rest_insert' ), 10, 3 );
		}

		parent::register_fields();
	}

	/**
	 * Defines data structure and what elements are visible in which contexts
	 */
	public function get_schema() {
		return array(
			'$schema' => 'http://json-schema.org/draft-04/schema#',
			'title'   => 'jetpack-publicize-post-connections',
			'type'    => 'array',
			'context' => array( 'view', 'edit' ),
			'items'   => $this->post_connection_schema(),
			'default' => array(),
		);
	}

	private function post_connection_schema() {
		return array(
			'$schema'    => 'http://json-schema.org/draft-04/schema#',
			'title'      => 'jetpack-publicize-post-connection',
			'type'       => 'object',
			'properties' => array(
				'id'           => array(
					'description' => __( 'Unique identifier for the Publicize Connection', 'jetpack' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit' ),
					'readonly'    => true,
				),
				'service_name' => array(
					'description' => __( 'Alphanumeric identifier for the Publicize Service', 'jetpack' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit' ),
					'readonly'    => true,
				),
				'display_name' => array(
					'description' => __( 'Username of the connected account', 'jetpack' ),
					'type'        => 'string',
					'context'     => array( 'view', 'edit' ),
					'readonly'    => true,
				),
				'enabled'      => array(
					'description' => __( 'Whether to share to this connection', 'jetpack' ),
					'type'        => 'boolean',
					'context'     => array( 'edit' ),
				),
				'done'         => array(
					'description' => __( 'Whether Publicize has already finished sharing for this post', 'jetpack' ),
					'type'        => 'boolean',
					'context'     => array( 'edit' ),
					'readonly'    => true,
				),
				'toggleable'   => array(
					'description' => __( 'Whether `enable` can be changed for this post/connection', 'jetpack' ),
					'type'        => 'boolean',
					'context'     => array( 'edit' ),
					'readonly'    => true,
				),
			),
		);
	}

	/**
	 * @param int $post_id
	 * @return true|WP_Error
	 */
	function permission_check( $post_id ) {
		global $publicize;

		if ( $publicize->current_user_can_access_publicize_data( $post_id ) ) {
			return true;
		}

		return new WP_Error(
			'invalid_user_permission_publicize',
			__( 'Sorry, you are not allowed to access Publicize data for this post.', 'jetpack' ),
			array( 'status' => rest_authorization_required_code() )
		);
	}

	/**
	 * Getter permission check
	 *
	 * @param array $post_array Response data from Post Endpoint
	 * @return true|WP_Error
	 */
	function get_permission_check( $post_array, $request ) {
		return $this->permission_check( isset( $post_array['id'] ) ? $post_array['id'] : 0 );

	}

	/**
	 * Setter permission check
	 *
	 * @param WP_Post $post
	 * @return true|WP_Error
	 */
	public function update_permission_check( $value, $post, $request ) {
		return $this->permission_check( isset( $post->ID ) ? $post->ID : 0 );
	}

	/**
	 * Getter: Retrieve current list of connected social accounts for a given post.
	 *
	 * @see Publicize::get_filtered_connection_data()
	 *
	 * @param array           $post_array Response from Post Endpoint
	 * @param WP_REST_Request
	 *
	 * @return array List of connections
	 */
	public function get( $post_array, $request ) {
		global $publicize;

		$schema     = $this->post_connection_schema();
		$properties = array_keys( $schema['properties'] );

		$connections = $publicize->get_filtered_connection_data( $post_array['id'] );

		$output_connections = array();
		foreach ( $connections as $connection ) {
			$output_connection = array();
			foreach ( $properties as $property ) {
				if ( isset( $connection[ $property ] ) ) {
					$output_connection[ $property ] = $connection[ $property ];
				}
			}

			$output_connection['id'] = (string) $connection['unique_id'];

			$output_connections[] = $output_connection;
		}

		return $output_connections;
	}

	/**
	 * Prior to updating the post, first calculate which Services to
	 * Publicize to and which to skip.
	 *
	 * @param object $post Post data to insert/update.
	 * @param WP_REST_Request $request
	 * @return Filtered $post
	 */
	public function rest_pre_insert( $post, $request ) {
		if ( ! isset( $request['jetpack_publicize_connections'] ) ) {
			return $post;
		}

		$permission_check = $this->update_permission_check( $request['jetpack_publicize_connections'], $post, $request );

		if ( is_wp_error( $permission_check ) ) {
			return $permission_check;
		}

		// memoize
		$this->get_meta_to_update( $request['jetpack_publicize_connections'], isset( $post->ID ) ? $post->ID : 0 );

		return $post;
	}

	/**
	 * After creating a new post, update our cached data to reflect
	 * the new post ID.
	 *
	 * @param WP_Post $post
	 * @param WP_REST_Request $request
	 * @param bool $is_new
	 */
	public function rest_insert( $post, $request, $is_new ) {
		if ( ! $is_new ) {
			// An existing post was edited - no need to update
			// our cache - we started out knowing the correct
			// post ID.
			return;
		}

		if ( ! isset( $request['jetpack_publicize_connections'] ) ) {
			return;
		}

		if ( ! isset( $this->memoized_updates[0] ) ) {
			return;
		}

		$this->memoized_updates[ $post->ID ] = $this->memoized_updates[0];
		unset( $this->memoized_updates[0] );
	}

	protected function get_meta_to_update( $requested_connections, $post_id = 0 ) {
		global $publicize;

		if ( isset( $this->memoized_updates[$post_id] ) ) {
			return $this->memoized_updates[$post_id];
		}

		$available_connections = $publicize->get_filtered_connection_data( $post_id );

		$changed_connections = array();

		// Build lookup mappings
		$available_connections_by_unique_id    = array();
		$available_connections_by_service_name = array();
		foreach ( $available_connections as $available_connection ) {
			$available_connections_by_unique_id[ $available_connection['unique_id'] ] = $available_connection;

			if ( ! isset( $available_connections_by_service_name[ $available_connection['service_name'] ] ) ) {
				$available_connections_by_service_name[ $available_connection['service_name'] ] = array();
			}
			$available_connections_by_service_name[ $available_connection['service_name'] ][] = $available_connection;
		}

		// Handle { service_name: $service_name, enabled: (bool) }
		foreach ( $requested_connections as $requested_connection ) {
			if ( ! isset( $requested_connection['service_name'] ) ) {
				continue;
			}

			if ( ! isset( $available_connections_by_service_name[ $requested_connection['service_name'] ] ) ) {
				continue;
			}

			foreach ( $available_connections_by_service_name[ $requested_connection['service_name'] ] as $available_connection ) {
				$changed_connections[ $available_connection['unique_id'] ] = $requested_connection['enabled'];
			}
		}

		// Handle { id: $id, enabled: (bool) }
		// These override the service_name settings
		foreach ( $requested_connections as $requested_connection ) {
			if ( ! isset( $requested_connection['id'] ) ) {
				continue;
			}

			if ( ! isset( $available_connections_by_unique_id[ $requested_connection['id'] ] ) ) {
				continue;
			}

			$changed_connections[ $requested_connection['id'] ] = $requested_connection['enabled'];
		}

		// Set all changed connections to their new value
		foreach ( $changed_connections as $unique_id => $enabled ) {
			$connection = $available_connections_by_unique_id[ $unique_id ];

			if ( $connection['done'] || ! $connection['toggleable'] ) {
				continue;
			}

			$available_connections_by_unique_id[ $unique_id ]['enabled'] = $enabled;
		}

		$meta_to_update = array();
		// For all connections, ensure correct post_meta
		foreach ( $available_connections_by_unique_id as $unique_id => $available_connection ) {
			if ( $available_connection['enabled'] ) {
				$meta_to_update[$publicize->POST_SKIP . $unique_id] = null;
			} else {
				$meta_to_update[$publicize->POST_SKIP . $unique_id] = 1;
			}
		}

		$this->memoized_updates[$post_id] = $meta_to_update;

		return $meta_to_update;
	}

	/**
	 * Update the connections slated to be shared to.
	 *
	 * @param array           $requested_connections
	 *              Items are either `{ id: (string) }` or `{ service_name: (string) }`
	 * @param WP_Post         $post
	 * @param WP_REST_Request
	 */
	public function update( $requested_connections, $post, $request ) {
		foreach ( $this->get_meta_to_update( $requested_connections, $post->ID ) as $meta_key => $meta_value ) {
			if ( is_null( $meta_value ) ) {
				delete_post_meta( $post->ID, $meta_key );
			} else {
				update_post_meta( $post->ID, $meta_key, $meta_value );
			}
		}
	}
}

if ( Jetpack::is_module_active( 'publicize' ) ) {
	wpcom_rest_api_v2_load_plugin( 'WPCOM_REST_API_V2_Post_Publicize_Connections_Field' );
}