<?php
/**
 * @package PlugixaCrm
 */

declare( strict_types = 1 );

namespace PlugixaCrm\Core\Http;

use WP_REST_Request;
use WP_REST_Response;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Global search.
 *
 * Core owns the endpoint and searches nothing itself. Each module registers a provider —
 * a label, a route to open a result with, and a callable that finds matches — so Core does
 * not have to know that accounts or opportunities exist, and a module makes Cases
 * searchable by registering one more.
 *
 * The alternative, a switch statement in Core over every entity, is the thing that makes a
 * plugin impossible to extend without editing it.
 */
final class SearchController extends RestController {

	/** Below this a search is noise: two characters match half the database. */
	private const MIN_LENGTH = 2;

	/** Per provider, so one prolific entity cannot crowd out the others. */
	private const PER_PROVIDER = 5;

	protected function entity_type(): string {
		return 'core';
	}

	public function register_routes(): void {
		register_rest_route(
			$this->namespace,
			'/search',
			array(
				array(
					'methods'             => 'GET',
					'callback'            => array( $this, 'search' ),
					'permission_callback' => array( $this, 'can_read' ),
					'args'                => array(
						'q' => array( 'type' => 'string' ),
					),
				),
			)
		);
	}

	/**
	 * @param WP_REST_Request $request The request.
	 */
	public function search( WP_REST_Request $request ): WP_REST_Response {
		$term = trim( sanitize_text_field( (string) ( $request->get_param( 'q' ) ?? '' ) ) );

		if ( mb_strlen( $term ) < self::MIN_LENGTH ) {
			return $this->ok( array() );
		}

		/**
		 * Register a global-search provider.
		 *
		 * Each entry is:
		 *   'label'  => string   Plural, shown as the group heading.
		 *   'route'  => string   Client route; "{id}" is replaced with the result's id.
		 *   'order'  => int      Where the group sits.
		 *   'search' => callable (string $term, int $limit): array<int, array{id:int, title:string, subtitle?:string}>
		 *
		 * @param array<string, array<string, mixed>> $providers Keyed by entity slug.
		 */
		$providers = (array) apply_filters( 'plugixa_crm_search_providers', array() );

		uasort(
			$providers,
			static fn( array $a, array $b ): int => ( $a['order'] ?? 100 ) <=> ( $b['order'] ?? 100 )
		);

		$groups = array();

		foreach ( $providers as $slug => $provider ) {
			if ( ! isset( $provider['search'] ) || ! is_callable( $provider['search'] ) ) {
				continue;
			}

			$hits = (array) call_user_func( $provider['search'], $term, self::PER_PROVIDER );

			if ( array() === $hits ) {
				continue;
			}

			$groups[] = array(
				'entity'  => $slug,
				'label'   => (string) ( $provider['label'] ?? $slug ),
				'route'   => (string) ( $provider['route'] ?? '' ),
				'results' => array_values( $hits ),
			);
		}

		return $this->ok( $groups );
	}
}