<?php
/**
 * Comment endpoints.
 *
 * @package SpaceBay
 */

namespace SpaceBay\Rest;

use SpaceBay\Content\Reactions;
use SpaceBay\Feed\Comments;
use SpaceBay\Feed\Formatter;
use SpaceBay\Feed\PostAccess;
use SpaceBay\Feed\Posts;
use SpaceBay\Spaces\SpaceAccess;
use SpaceBay\Spaces\SpaceRepository;
use WP_Error;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;

defined( 'ABSPATH' ) || exit;

/**
 * Lists, adds, edits, deletes and likes comments.
 */
final class CommentsController extends Controller {

	/**
	 * Registers the routes.
	 *
	 * @return void
	 */
	public function register_routes() {
		register_rest_route(
			$this->namespace,
			'/posts/(?P<id>\d+)/comments',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_items' ),
					'permission_callback' => array( $this, 'permission_community' ),
					'args'                => $this->paging_args( 50 ),
				),
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'create_item' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
					'args'                => array(
						'message'   => array(
							'type'     => 'string',
							'required' => true,
						),
						'parent_id' => array(
							'type'    => 'integer',
							'default' => 0,
						),
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/comments/(?P<id>\d+)',
			array(
				array(
					'methods'             => WP_REST_Server::EDITABLE,
					'callback'            => array( $this, 'update_item' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
					'args'                => array(
						'message' => array(
							'type'     => 'string',
							'required' => true,
						),
					),
				),
				array(
					'methods'             => WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'delete_item' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/comments/(?P<id>\d+)/like',
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'toggle_like' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
					'args'                => array(
						'on' => array(
							'type'     => 'boolean',
							'required' => true,
						),
					),
				),
			)
		);
	}

	/**
	 * Lists comments of a post.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function get_items( $request ) {
		$found = $this->readable_post( $request['id'] );

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

		$result = Comments::for_post( $found['post']['id'], $request['page'], $request['per_page'] );

		return $this->paged_response( Formatter::comments( $result['items'], $found['space'], get_current_user_id() ), $result['total'], $request['per_page'] );
	}

	/**
	 * Adds a comment or reply.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function create_item( $request ) {
		$found = $this->readable_post( $request['id'] );

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

		$comment = Comments::create(
			$found['post'],
			$found['space'],
			array(
				'message'   => $request['message'],
				'parent_id' => $request['parent_id'],
			),
			get_current_user_id()
		);

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

		$items    = Formatter::comments( array( $comment ), $found['space'], get_current_user_id() );
		$response = rest_ensure_response( $items[0] );
		$response->set_status( 201 );

		return $response;
	}

	/**
	 * Edits a comment.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function update_item( $request ) {
		$found = $this->changeable_comment( $request['id'] );

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

		$comment = Comments::update( $found['comment'], $request['message'], $found['space'], get_current_user_id() );

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

		$items = Formatter::comments( array( $comment ), $found['space'], get_current_user_id() );

		return rest_ensure_response( $items[0] );
	}

	/**
	 * Deletes a comment and its replies.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function delete_item( $request ) {
		$found = $this->changeable_comment( $request['id'] );

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

		$keep   = ! SpaceAccess::can_moderate( $found['space'], get_current_user_id() );
		$result = Comments::delete( $found['comment'], $keep );

		return rest_ensure_response(
			array(
				'deleted'      => true,
				'id'           => $found['comment']['id'],
				'replies_kept' => $keep,
				'parent_id'    => $result['parent_id'],
				'promoted_ids' => $result['promoted_ids'],
				'deleted_ids'  => $result['ids'],
			)
		);
	}

	/**
	 * Likes or unlikes a comment.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function toggle_like( $request ) {
		$limited = \SpaceBay\Support\RateLimit::hit( 'react', get_current_user_id(), 60 );

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

		$found = $this->readable_comment( $request['id'] );

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

		$user_id = get_current_user_id();

		if ( ! PostAccess::can_comment( $found['space'], $user_id ) ) {
			return new WP_Error( 'spacebay_cannot_react', __( 'Join this space to like comments.', 'spacebay' ), array( 'status' => 403 ) );
		}

		Reactions::set( 'comment', $found['comment']['id'], $user_id, 'like', (bool) $request['on'] );
		$items = Formatter::comments( array( Comments::find( $found['comment']['id'] ) ), $found['space'], $user_id );

		return rest_ensure_response( $items[0] );
	}

	/**
	 * Returns a readable post and its space.
	 *
	 * @param int $id Post ID.
	 * @return array{post: array, space: array}|WP_Error
	 */
	private function readable_post( $id ) {
		$post  = Posts::find( $id );
		$space = $post ? SpaceRepository::find( $post['space_id'] ) : null;

		if ( ! $post || ! $space || 'published' !== $post['status'] || ! SpaceAccess::can_read( $space, get_current_user_id() ) ) {
			return new WP_Error( 'spacebay_post_not_found', __( 'Post not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		return array(
			'post'  => $post,
			'space' => $space,
		);
	}

	/**
	 * Returns a readable comment with its post and space.
	 *
	 * @param int $id Comment ID.
	 * @return array{comment: array, post: array, space: array}|WP_Error
	 */
	private function readable_comment( $id ) {
		$comment = Comments::find( $id );

		if ( ! $comment || 'published' !== $comment['status'] ) {
			return new WP_Error( 'spacebay_comment_not_found', __( 'Comment not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		$found = $this->readable_post( $comment['post_id'] );

		if ( is_wp_error( $found ) ) {
			return new WP_Error( 'spacebay_comment_not_found', __( 'Comment not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		$found['comment'] = $comment;

		return $found;
	}

	/**
	 * Returns a comment the viewer may change.
	 *
	 * @param int $id Comment ID.
	 * @return array|WP_Error
	 */
	private function changeable_comment( $id ) {
		$found = $this->readable_comment( $id );

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

		if ( ! PostAccess::can_change( $found['space'], $found['comment']['user_id'], get_current_user_id() ) ) {
			return $this->forbidden();
		}

		return $found;
	}
}