<?php
/**
 * Spaces and space groups endpoints.
 *
 * @package SpaceBay
 */

namespace SpaceBay\Rest;

use SpaceBay\Spaces\Membership;
use SpaceBay\Spaces\SpaceAccess;
use SpaceBay\Spaces\SpaceFormatter;
use SpaceBay\Spaces\SpaceRepository;
use WP_Error;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;

defined( 'ABSPATH' ) || exit;

/**
 * Lists, creates, edits, joins and leaves spaces; manages space groups.
 */
final class SpacesController extends Controller {

	/**
	 * Registers the routes.
	 *
	 * @return void
	 */
	public function register_routes() {
		$id_arg = array(
			'id' => array(
				'type'     => 'integer',
				'required' => true,
			),
		);

		register_rest_route(
			$this->namespace,
			'/spaces',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_items' ),
					'permission_callback' => array( $this, 'permission_community' ),
					'args'                => array(
						'scope' => array(
							'type'    => 'string',
							'enum'    => array( 'all', 'joined' ),
							'default' => 'all',
						),
					),
				),
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'create_item' ),
					'permission_callback' => array( $this, 'permission_manage' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/spaces/reorder',
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'reorder' ),
					'permission_callback' => array( $this, 'permission_manage' ),
					'args'                => array(
						'ids' => array(
							'type'     => 'array',
							'items'    => array( 'type' => 'integer' ),
							'required' => true,
						),
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/spaces/slug/(?P<slug>[a-z0-9-]+)',
			array(
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_item_by_slug' ),
					'permission_callback' => array( $this, 'permission_community' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/spaces/(?P<id>\d+)',
			array(
				'args' => $id_arg,
				array(
					'methods'             => WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_item' ),
					'permission_callback' => array( $this, 'permission_community' ),
				),
				array(
					'methods'             => WP_REST_Server::EDITABLE,
					'callback'            => array( $this, 'update_item' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
				),
				array(
					'methods'             => WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'delete_item' ),
					'permission_callback' => array( $this, 'permission_manage' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/spaces/(?P<id>\d+)/join',
			array(
				'args' => $id_arg,
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'join' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/spaces/(?P<id>\d+)/leave',
			array(
				'args' => $id_arg,
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'leave' ),
					'permission_callback' => array( $this, 'permission_logged_in' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/space-groups',
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'create_group' ),
					'permission_callback' => array( $this, 'permission_manage' ),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/space-groups/reorder',
			array(
				array(
					'methods'             => WP_REST_Server::CREATABLE,
					'callback'            => array( $this, 'reorder' ),
					'permission_callback' => array( $this, 'permission_manage' ),
					'args'                => array(
						'ids' => array(
							'type'     => 'array',
							'items'    => array( 'type' => 'integer' ),
							'required' => true,
						),
					),
				),
			)
		);

		register_rest_route(
			$this->namespace,
			'/space-groups/(?P<id>\d+)',
			array(
				'args' => $id_arg,
				array(
					'methods'             => WP_REST_Server::EDITABLE,
					'callback'            => array( $this, 'update_group' ),
					'permission_callback' => array( $this, 'permission_manage' ),
				),
				array(
					'methods'             => WP_REST_Server::DELETABLE,
					'callback'            => array( $this, 'delete_group' ),
					'permission_callback' => array( $this, 'permission_manage' ),
				),
			)
		);
	}

	/**
	 * Lists the spaces and groups the viewer can see.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response
	 */
	public function get_items( $request ) {
		$user_id = get_current_user_id();
		$joined  = 'joined' === $request->get_param( 'scope' );
		$spaces  = array();

		foreach ( SpaceRepository::all( 'space' ) as $space ) {
			if ( ! SpaceAccess::can_see( $space, $user_id ) ) {
				continue;
			}

			if ( $joined ) {
				$membership = Membership::get( $space['id'], $user_id );

				if ( ! $membership || 'active' !== $membership['status'] ) {
					continue;
				}
			}

			$spaces[] = SpaceFormatter::space( $space, $user_id );
		}

		return rest_ensure_response(
			array(
				'groups' => array_map( array( SpaceFormatter::class, 'group' ), SpaceRepository::all( 'group' ) ),
				'spaces' => $spaces,
			)
		);
	}

	/**
	 * Returns one space by ID.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function get_item( $request ) {
		$space = $this->visible_space( $request['id'] );

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

		return rest_ensure_response( SpaceFormatter::space( $space, get_current_user_id() ) );
	}

	/**
	 * Returns one space by slug.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function get_item_by_slug( $request ) {
		$found = SpaceRepository::find_by_slug( $request['slug'] );
		$space = $this->visible_space( $found ? $found['id'] : 0 );

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

		return rest_ensure_response( SpaceFormatter::space( $space, get_current_user_id() ) );
	}

	/**
	 * Creates a space. The creator becomes its admin.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function create_item( $request ) {
		$data = SpaceRepository::clean( $this->space_input( $request ), true );

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

		$data['type'] = 'space';
		$user_id      = get_current_user_id();
		$id           = SpaceRepository::create( $data, $user_id );

		if ( ! $id ) {
			return new WP_Error( 'spacebay_space_create', __( 'The space could not be created. Please try again.', 'spacebay' ), array( 'status' => 500 ) );
		}

		Membership::set( $id, $user_id, 'admin', 'active' );

		/**
		 * Fires after a space is created.
		 *
		 * @since 1.0.0
		 *
		 * @param int $id      Space ID.
		 * @param int $user_id Creator ID.
		 */
		do_action( 'spacebay_space_created', $id, $user_id );

		$response = rest_ensure_response( SpaceFormatter::space( SpaceRepository::find( $id ), $user_id ) );
		$response->set_status( 201 );

		return $response;
	}

	/**
	 * Updates a space. Space admins can edit details; only community
	 * managers can archive it or move it to another group.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function update_item( $request ) {
		$space = $this->visible_space( $request['id'] );

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

		$user_id = get_current_user_id();

		if ( ! SpaceAccess::can_manage( $space, $user_id ) ) {
			return $this->forbidden();
		}

		$input = $this->space_input( $request );

		if ( ! SpaceAccess::is_manager( $user_id ) ) {
			unset( $input['status'], $input['group_id'], $input['position'] );
		}

		$data = SpaceRepository::clean( $input, false );

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

		SpaceRepository::update( $space['id'], $data );

		/**
		 * Fires after a space is updated.
		 *
		 * @since 1.0.0
		 *
		 * @param int   $id   Space ID.
		 * @param array $data Changed fields.
		 */
		do_action( 'spacebay_space_updated', $space['id'], $data );

		return rest_ensure_response( SpaceFormatter::space( SpaceRepository::find( $space['id'] ), $user_id ) );
	}

	/**
	 * Deletes a space and its memberships.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function delete_item( $request ) {
		$space = SpaceRepository::find( $request['id'] );

		if ( ! $space || 'space' !== $space['type'] ) {
			return new WP_Error( 'spacebay_space_not_found', __( 'Space not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		SpaceRepository::delete( $space['id'] );

		return rest_ensure_response(
			array(
				'deleted' => true,
				'id'      => $space['id'],
			)
		);
	}

	/**
	 * Saves a new order of spaces or groups.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response
	 */
	public function reorder( $request ) {
		SpaceRepository::reorder( array_map( 'absint', (array) $request['ids'] ) );

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

	/**
	 * Joins a space, asks to join, or accepts an invitation.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function join( $request ) {
		$limited = \SpaceBay\Support\RateLimit::hit( 'join', get_current_user_id(), 20 );

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

		$space = $this->visible_space( $request['id'] );

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

		$result = Membership::join( $space, get_current_user_id() );

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

		return rest_ensure_response( SpaceFormatter::space( $space, get_current_user_id() ) );
	}

	/**
	 * Leaves a space, cancels a request, or declines an invitation.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function leave( $request ) {
		$limited = \SpaceBay\Support\RateLimit::hit( 'join', get_current_user_id(), 20 );

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

		$space = $this->visible_space( $request['id'] );

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

		$user_id    = get_current_user_id();
		$membership = Membership::get( $space['id'], $user_id );

		if ( ! $membership || 'blocked' === $membership['status'] ) {
			return new WP_Error( 'spacebay_not_member', __( 'You are not a member of this space.', 'spacebay' ), array( 'status' => 400 ) );
		}

		if ( 'admin' === $membership['role'] && 'active' === $membership['status'] && Membership::count_admins( $space['id'] ) <= 1 ) {
			return new WP_Error( 'spacebay_last_admin', __( 'You are the only admin of this space. Make another member an admin before you leave.', 'spacebay' ), array( 'status' => 400 ) );
		}

		Membership::remove( $space['id'], $user_id );

		$fresh = SpaceRepository::find( $space['id'] );

		if ( ! SpaceAccess::can_see( $fresh, $user_id ) ) {
			return rest_ensure_response( array( 'left' => true ) );
		}

		return rest_ensure_response( SpaceFormatter::space( $fresh, $user_id ) );
	}

	/**
	 * Creates a space group.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function create_group( $request ) {
		$data = SpaceRepository::clean( array( 'title' => $request['title'] ), true );

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

		$data['type'] = 'group';
		$id           = SpaceRepository::create( $data, get_current_user_id() );

		$response = rest_ensure_response( SpaceFormatter::group( SpaceRepository::find( $id ) ) );
		$response->set_status( 201 );

		return $response;
	}

	/**
	 * Renames a space group.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function update_group( $request ) {
		$group = SpaceRepository::find( $request['id'] );

		if ( ! $group || 'group' !== $group['type'] ) {
			return new WP_Error( 'spacebay_group_not_found', __( 'Space group not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		$data = SpaceRepository::clean( array( 'title' => $request['title'] ), true );

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

		SpaceRepository::update( $group['id'], $data );

		return rest_ensure_response( SpaceFormatter::group( SpaceRepository::find( $group['id'] ) ) );
	}

	/**
	 * Deletes a space group. Its spaces stay and become ungrouped.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return WP_REST_Response|WP_Error
	 */
	public function delete_group( $request ) {
		$group = SpaceRepository::find( $request['id'] );

		if ( ! $group || 'group' !== $group['type'] ) {
			return new WP_Error( 'spacebay_group_not_found', __( 'Space group not found.', 'spacebay' ), array( 'status' => 404 ) );
		}

		SpaceRepository::delete( $group['id'] );

		return rest_ensure_response(
			array(
				'deleted' => true,
				'id'      => $group['id'],
			)
		);
	}

	/**
	 * Picks the editable space fields present in the request.
	 *
	 * @param WP_REST_Request $request Request.
	 * @return array
	 */
	private function space_input( $request ) {
		$input = array();

		foreach ( array( 'title', 'slug', 'description', 'privacy', 'status', 'group_id', 'icon', 'color', 'who_can_post' ) as $field ) {
			if ( $request->has_param( $field ) ) {
				$input[ $field ] = $request->get_param( $field );
			}
		}

		return $input;
	}
}