<?php
/**
 * Report, review queue, member approval and moderator team endpoints.
 *
 * @package SpaceBay
 */

namespace SpaceBay\Rest;

use SpaceBay\Core\Capabilities;
use SpaceBay\Feed\Formatter;
use SpaceBay\Members\Profiles;
use SpaceBay\Moderation\Moderation;
use SpaceBay\Moderation\Reports;
use SpaceBay\Spaces\SpaceAccess;
use SpaceBay\Support\RateLimit;
use SpaceBay\Support\Time;
use WP_Error;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;
use WP_User;

defined( 'ABSPATH' ) || exit;

/**
 * Lets members report content and moderators act on reports.
 */
final class ModerationController extends Controller {

	/**
	 * Registers the routes.
	 *
	 * @return void
	 */
	public function register_routes() {
		register_rest_route(
			$this->namespace,
			'/reports',
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'create_report' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
					'args'                => array(
						'object_type' => array(
							'type'     => 'string',
							'enum'     => Reports::TYPES,
							'required' => true,
						),
						'object_id'   => array(
							'type'     => 'integer',
							'required' => true,
							'minimum'  => 1,
						),
						'reason'      => array(
							'type'     => 'string',
							'enum'     => Reports::REASONS,
							'required' => true,
						),
						'note'        => array(
							'type'      => 'string',
							'default'   => '',
							'maxLength' => 500,
						),
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/moderation/counts',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_counts' ),
					'permission_callback' => array( $this, 'permission_moderate' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/moderation/queue',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_queue' ),
					'permission_callback' => array( $this, 'permission_moderate' ),
					'args'                => array_merge(
						$this->paging_args( 50 ),
						array(
							'type' => array(
								'type'    => 'string',
								'enum'    => array_merge( array( 'all' ), Reports::TYPES ),
								'default' => 'all',
							),
						)
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/moderation/queue/(?P<type>post|comment|member|message)/(?P<id>\d+)',
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'decide' ),
					'permission_callback' => array( $this, 'permission_moderate' ),
					'args'                => array(
						'action' => array(
							'type'     => 'string',
							'enum'     => array( 'approve', 'remove' ),
							'required' => true,
						),
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/moderation/members',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_members' ),
					'permission_callback' => array( $this, 'permission_moderate' ),
					'args'                => array_merge(
						$this->paging_args( 50 ),
						array(
							'status' => array(
								'type'    => 'string',
								'enum'    => array( 'pending', 'blocked' ),
								'default' => 'pending',
							),
						)
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/moderation/members/(?P<id>\d+)',
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'update_member' ),
					'permission_callback' => array( $this, 'permission_moderate' ),
					'args'                => array(
						'status' => array(
							'type'     => 'string',
							'enum'     => array( 'active', 'blocked' ),
							'required' => true,
						),
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/moderators',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_moderators' ),
					'permission_callback' => array( $this, 'permission_manage' ),
				),
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'add_moderator' ),
					'permission_callback' => array( $this, 'permission_manage' ),
					'args'                => array(
						'user_id' => array(
							'type'     => 'integer',
							'required' => true,
							'minimum'  => 1,
						),
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/moderators/(?P<id>\d+)',
			array(
				array(
					'methods'             => WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'remove_moderator' ),
					'permission_callback' => array( $this, 'permission_manage' ),
				),
			)
		);
	}

	/**
	 * Saves a report from a member.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function create_report( $request ) {
		$user_id = get_current_user_id();
		$type    = $request['object_type'];
		$id      = absint( $request['object_id'] );
		$author  = $this->reportable_author( $type, $id, $user_id );

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

		if ( $author === $user_id ) {
			return new WP_Error( 'spacebay_report_self', __( 'You cannot report yourself.', 'spacebay' ), array( 'status' => 400 ) );
		}

		$limited = RateLimit::hit( 'report', $user_id, 10 );

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

		$result = Reports::add( $type, $id, $user_id, $request['reason'], $request['note'] );

		if ( ! $result['duplicate'] ) {
			/**
			 * Fires after a member reports a post, comment or member.
			 *
			 * @since 1.0.0
			 *
			 * @param string $type        "post", "comment" or "member".
			 * @param int    $id          Object ID.
			 * @param int    $reporter_id Reporting member.
			 * @param string $reason      Reason key.
			 */
			do_action( 'spacebay_content_reported', $type, $id, $user_id, $request['reason'] );
			Moderation::after_report( $type, $id );
		}

		return rest_ensure_response( array( 'reported' => true ) );
	}

	/**
	 * Numbers shown as badges.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response
	 */
	public function get_counts( $request ) {
		unset( $request );

		return rest_ensure_response(
			array(
				'queue'   => Reports::open_count(),
				'members' => count( Profiles::ids_with_status( 'pending' ) ),
			)
		);
	}

	/**
	 * Lists reported and held items.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response
	 */
	public function get_queue( $request ) {
		$result = Reports::queue( $request['type'], $request['page'], $request['per_page'] );
		$items  = array();

		$total = $result['total'];

		foreach ( $result['items'] as $item ) {
			$formatted = $this->format_item( $item );

			// Content deleted elsewhere, for example with its space, leaves the queue.
			if ( ! $formatted['exists'] ) {
				Reports::resolve( $item['object_type'], $item['object_id'], 'removed', 0 );
				--$total;
				continue;
			}

			$items[] = $formatted;
		}

		return $this->paged_response( $items, max( 0, $total ), $request['per_page'] );
	}

	/**
	 * Applies a moderator decision.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function decide( $request ) {
		$type   = $request['type'];
		$id     = absint( $request['id'] );
		$result = 'approve' === $request['action']
			? Moderation::approve( $type, $id, get_current_user_id() )
			: Moderation::remove( $type, $id, get_current_user_id() );

		if ( is_wp_error( $result ) && 'spacebay_content_gone' !== $result->get_error_code() ) {
			return $result;
		}

		return rest_ensure_response(
			array(
				'done'  => true,
				'queue' => Reports::open_count(),
			)
		);
	}

	/**
	 * Lists members who wait for approval or are suspended.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response
	 */
	public function get_members( $request ) {
		$ids      = Profiles::ids_with_status( $request['status'] );
		$per_page = (int) $request['per_page'];
		$page_ids = array_slice( array_reverse( $ids ), ( max( 1, (int) $request['page'] ) - 1 ) * $per_page, $per_page );
		$authors  = Formatter::authors( $page_ids );
		$show     = current_user_can( Capabilities::MANAGE );
		$items    = array();

		foreach ( $page_ids as $user_id ) {
			$user = get_userdata( $user_id );

			if ( ! $user || ! isset( $authors[ $user_id ] ) ) {
				continue;
			}

			$items[] = array_merge(
				$authors[ $user_id ],
				array(
					'email'         => $show ? $user->user_email : '',
					'registered_at' => Time::iso( $user->user_registered ),
					'status'        => $request['status'],
				)
			);
		}

		return $this->paged_response( $items, count( $ids ), $per_page );
	}

	/**
	 * Approves, suspends or restores a member.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function update_member( $request ) {
		$id     = absint( $request['id'] );
		$result = Moderation::set_member_status( $id, $request['status'], get_current_user_id() );

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

		if ( 'active' === $request['status'] ) {
			Reports::resolve( 'member', $id, 'dismissed', get_current_user_id() );
		}

		return rest_ensure_response(
			array(
				'id'      => $id,
				'status'  => $request['status'],
				'members' => count( Profiles::ids_with_status( 'pending' ) ),
			)
		);
	}

	/**
	 * Lists community moderators and managers.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response
	 */
	public function get_moderators( $request ) {
		unset( $request );

		$ids     = Moderation::moderator_ids();
		$authors = Formatter::authors( $ids );
		$items   = array();

		foreach ( $ids as $user_id ) {
			$user = get_userdata( $user_id );

			if ( $user && isset( $authors[ $user_id ] ) ) {
				$items[] = array_merge(
					$authors[ $user_id ],
					array(
						'is_manager' => user_can( $user, Capabilities::MANAGE ),
						'removable'  => ! user_can( $user, Capabilities::MANAGE ) && ! empty( $user->caps[ Capabilities::MODERATE ] ),
					)
				);
			}
		}

		return rest_ensure_response( $items );
	}

	/**
	 * Makes a member a community moderator.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function add_moderator( $request ) {
		$user = get_userdata( absint( $request['user_id'] ) );

		if ( ! $user instanceof WP_User || ( is_multisite() && ! is_user_member_of_blog( $user->ID ) ) ) {
			return new WP_Error( 'spacebay_member_not_found', __( 'Member not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		$user->add_cap( Capabilities::MODERATE );
		Profiles::set_status( $user->ID, 'active' );

		return $this->get_moderators( $request );
	}

	/**
	 * Removes the moderator role from a member.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function remove_moderator( $request ) {
		$user = get_userdata( absint( $request['id'] ) );

		if ( ! $user instanceof WP_User ) {
			return new WP_Error( 'spacebay_member_not_found', __( 'Member not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		if ( user_can( $user, Capabilities::MANAGE ) ) {
			return new WP_Error( 'spacebay_cannot_remove', __( 'Administrators always moderate the community.', 'spacebay' ), array( 'status' => 400 ) );
		}

		$user->remove_cap( Capabilities::MODERATE );

		return $this->get_moderators( $request );
	}

	/**
	 * Author of something the member may report, or an error.
	 *
	 * @param string $type    Object type.
	 * @param int    $id      Object ID.
	 * @param int    $user_id Reporter.
	 * @return int|WP_Error Author ID.
	 */
	private function reportable_author( $type, $id, $user_id ) {
		$missing = new WP_Error( 'spacebay_report_not_found', __( 'This no longer exists.', 'spacebay' ), array( 'status' => 404 ) );

		if ( 'member' === $type ) {
			$user    = get_userdata( $id );
			$profile = $user ? Profiles::get( $id ) : null;

			return $user && ( ! $profile || 'active' === $profile['status'] ) ? (int) $user->ID : $missing;
		}

		if ( 'message' === $type ) {
			$message = \SpaceBay\Messages\Messages::find( $id );

			// Only someone in the conversation can report a message, and only a real one.
			if ( ! $message || 'text' !== $message['type'] || 'published' !== $message['status'] || ! \SpaceBay\Messages\Messages::visible_to( $message, $user_id ) ) {
				return $missing;
			}

			return (int) $message['user_id'];
		}

		$found = Moderation::content( $type, $id );

		if ( ! $found || 'published' !== $found['row']['status'] || 'published' !== $found['post']['status'] || ! SpaceAccess::can_read( $found['space'], $user_id ) ) {
			return $missing;
		}

		return (int) $found['row']['user_id'];
	}

	/**
	 * Formats one queue item for moderators.
	 *
	 * @param array $item Queue item from Reports::queue().
	 * @return array
	 */
	private function format_item( array $item ) {
		$type      = $item['object_type'];
		$id        = $item['object_id'];
		$reporters = Formatter::authors( array_filter( wp_list_pluck( $item['reports'], 'reporter_id' ) ) );
		$reports   = array();

		foreach ( $item['reports'] as $report ) {
			$reports[] = array(
				'reason'     => $report['reason'],
				'label'      => $this->reason_label( $report['reason'], $report['note'] ),
				'note'       => $report['reporter_id'] ? $report['note'] : '',
				'reporter'   => $report['reporter_id'] && isset( $reporters[ $report['reporter_id'] ] ) ? $reporters[ $report['reporter_id'] ]['name'] : '',
				'created_at' => Time::iso( $report['created_at'] ),
			);
		}

		$data = array(
			'key'      => $type . '-' . $id,
			'type'     => $type,
			'id'       => $id,
			'reports'  => $reports,
			'first_at' => Time::iso( $item['first_at'] ),
			'exists'   => false,
			'status'   => '',
			'title'    => '',
			'content'  => '',
			'author'   => Formatter::deleted_author(),
			'space'    => null,
			'route'    => '',
		);

		if ( 'member' === $type ) {
			$authors = Formatter::authors( array( $id ) );

			if ( isset( $authors[ $id ] ) ) {
				$profile        = Profiles::get( $id );
				$data['exists'] = true;
				$data['author'] = $authors[ $id ];
				$data['status'] = $profile ? $profile['status'] : 'active';
				$data['route']  = 'members/' . $id;
			}

			return $data;
		}

		if ( 'message' === $type ) {
			$message = \SpaceBay\Messages\Messages::find( $id );

			if ( ! $message || 'published' !== $message['status'] ) {
				return $data;
			}

			$authors         = Formatter::authors( array( $message['user_id'] ) );
			$data['exists']  = true;
			$data['status']  = 'published';
			$data['content'] = $message['message_rendered'];
			$data['author']  = $authors[ $message['user_id'] ] ?? Formatter::deleted_author();
			$data['media']   = \SpaceBay\Content\Media::for_objects( 'message', array( $id ) )[ $id ] ?? array();

			return $data;
		}

		$found = Moderation::content( $type, $id );

		if ( ! $found ) {
			return $data;
		}

		$authors         = Formatter::authors( array( $found['row']['user_id'] ) );
		$data['exists']  = true;
		$data['status']  = $found['row']['status'];
		$data['title']   = 'post' === $type ? $found['row']['title'] : $found['post']['title'];
		$data['content'] = $found['row']['message_rendered'];
		$data['author']  = $authors[ $found['row']['user_id'] ] ?? Formatter::deleted_author();
		$data['space']   = array(
			'title' => $found['space']['title'],
			'slug'  => $found['space']['slug'],
		);
		$data['route']   = 'published' === $found['post']['status'] ? 'posts/' . $found['post']['id'] : '';

		if ( 'post' === $type ) {
			$data['media'] = \SpaceBay\Content\Media::for_objects( 'post', array( $id ) )[ $id ] ?? array();
		}

		return $data;
	}

	/**
	 * Human label of a report reason.
	 *
	 * @param string $reason Reason key.
	 * @param string $note   System note.
	 * @return string
	 */
	private function reason_label( $reason, $note ) {
		switch ( $reason ) {
			case 'spam':
				return __( 'Spam', 'spacebay' );
			case 'abuse':
				return __( 'Harassment or hate', 'spacebay' );
			case 'inappropriate':
				return __( 'Inappropriate content', 'spacebay' );
			case 'words':
				/* translators: %s: Blocked words found in the text. */
				return sprintf( __( 'Contains blocked words: %s', 'spacebay' ), $note );
			case 'first_post':
				return __( 'First post from a new member', 'spacebay' );
			case 'all_posts':
				return __( 'All new posts are reviewed', 'spacebay' );
			case 'edited':
				return __( 'Edited post; all posts are reviewed', 'spacebay' );
			case 'reports':
				return __( 'Hidden automatically after several reports', 'spacebay' );
		}

		return __( 'Other', 'spacebay' );
	}
}