<?php
/**
 * Cohort endpoints.
 *
 * @package Recast\WCS
 */

namespace Recast\WCS\Rest;

use Recast\WCS\Cohort\CohortQuery;
use Recast\WCS\Cohort\CohortSpec;
use Recast\WCS\Cohort\Counter;
use Recast\WCS\Cohort\InvalidSpecException;
use Recast\WCS\Cohort\RowFormatter;
use Recast\WCS\Cohort\SpecSummary;

defined( 'ABSPATH' ) || exit;

/**
 * POST /cohort/count and POST /cohort/preview.
 */
final class CohortController extends AbstractController {

	/**
	 * Registers routes.
	 *
	 * @return void
	 */
	public function register_routes() {
		$spec_arg = array(
			'spec' => array(
				'required' => true,
				'type'     => 'object',
			),
		);
		$this->route(
			'/cohort/count',
			array(
				'methods'  => \WP_REST_Server::CREATABLE,
				'callback' => array( $this, 'count' ),
				'args'     => $spec_arg,
			)
		);
		$this->route(
			'/cohort/preview',
			array(
				'methods'  => \WP_REST_Server::CREATABLE,
				'callback' => array( $this, 'preview' ),
				'args'     => array_merge(
					$spec_arg,
					array(
						'page'     => $this->int_param( false, 1 ),
						'per_page' => array(
							'type'    => 'integer',
							'default' => 25,
							'minimum' => 1,
							'maximum' => 100,
						),
					)
				),
			)
		);
	}

	/**
	 * Parses the spec from a request or returns an error.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return CohortSpec|\WP_Error
	 */
	public static function spec_from_request( \WP_REST_Request $request ) {
		$raw = $request['spec'];
		if ( ! is_array( $raw ) ) {
			return new \WP_Error( 'recast_invalid_spec', __( 'The selection must be an object.', 'recast-subscriptions' ), array( 'status' => 400 ) );
		}
		try {
			return CohortSpec::from_array( $raw );
		} catch ( InvalidSpecException $e ) {
			return new \WP_Error( 'recast_invalid_spec', $e->getMessage(), array( 'status' => 400 ) );
		}
	}

	/**
	 * Handles POST /cohort/count.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response|\WP_Error
	 */
	public function count( \WP_REST_Request $request ) {
		$spec = self::spec_from_request( $request );
		if ( is_wp_error( $spec ) ) {
			return $spec;
		}
		$result                 = ( new Counter() )->count( $spec );
		$result['hash']         = $spec->hash();
		$result['spec_summary'] = SpecSummary::describe( $spec );
		return $this->respond( $result );
	}

	/**
	 * Handles POST /cohort/preview.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response|\WP_Error
	 */
	public function preview( \WP_REST_Request $request ) {
		$spec = self::spec_from_request( $request );
		if ( is_wp_error( $spec ) ) {
			return $spec;
		}
		$page     = max( 1, (int) $request['page'] );
		$per_page = (int) $request['per_page'];
		$slice    = ( new CohortQuery( $spec ) )->slice( ( $page - 1 ) * $per_page, $per_page );
		$rows     = array_map( array( RowFormatter::class, 'format' ), $slice['subscriptions'] );
		return $this->respond(
			array(
				'rows'         => $rows,
				'page'         => $page,
				'per_page'     => $per_page,
				'has_more'     => (bool) $slice['has_more'],
				'hash'         => $spec->hash(),
				'spec_summary' => SpecSummary::describe( $spec ),
			)
		);
	}
}