<?php
/**
 * Read-only L3 service adapter. Tenant assertions never leave WordPress.
 *
 * @package Waitlistize
 */
namespace Waitlistize\Api;

use Waitlistize\Auth\ConnectionManager;
use Waitlistize\Auth\Mutex;
use Waitlistize\Auth\TokenStore;
use WP_Error;

final class Services {
	public function account_id(): int {
		$status = ( new ConnectionManager() )->status();
		return ! is_wp_error( $status ) && in_array( $status['status'], array( 'connected', 'offline' ), true ) ? (int) ( $status['account']['id'] ?? 0 ) : 0;
	}

	public static function error( string $code = 'embed_unavailable', int $status = 503 ): WP_Error {
		return new WP_Error( $code, __( 'This Waitlistize embed is unavailable. Check its account binding and connection settings.', 'waitlistize' ), array( 'status' => $status ) );
	}

	/** W1 alone owns refresh/rotation. This adapter never writes credential state. */
	private function request( int $account_id, string $endpoint, array $query ): array|WP_Error {
		if ( $account_id <= 0 || $this->account_id() !== $account_id ) {
			return self::error( 'embed_binding', 409 );
		}
		$store = new TokenStore();
		$state = $store->read();
		if ( time() + 60 >= ( $state['expires_at'] ?? 0 ) ) {
			$check = ( new ConnectionManager() )->check();
			if ( is_wp_error( $check ) ) {
				return $check;
			}
		}
		$mutex = new Mutex();
		return $mutex->run(
			function () use ( $store, $mutex, $account_id, $endpoint, $query ) {
				$state = $store->read();
				if ( $store->disabled() || ! in_array( $state['status'], array( 'connected', 'offline' ), true ) || ! empty( $state['verify_account_slug'] ) || ( $state['account_id'] ?? 0 ) !== $account_id || ( $state['account']['id'] ?? 0 ) !== $account_id || empty( $state['access_token'] ) || time() >= ( $state['expires_at'] ?? 0 ) ) {
					return self::error();
				}
				$origin = ( new Client() )->origin();
				if ( is_wp_error( $origin ) ) {
					return $origin;
				}
				$response = wp_remote_get(
					add_query_arg( $query, $origin . Client::PREFIX . $endpoint ),
					array(
						'headers'             => array(
							'Accept'        => 'application/json',
							'Authorization' => 'Bearer ' . $state['access_token'],
						),
						'timeout'             => 12,
						'redirection'         => 0,
						'sslverify'           => true,
						'limit_response_size' => 1048576,
						'cookies'             => array(),
					)
				);
				// Disconnect can disable locally while this worker holds the mutex.
				if ( ! $mutex->owned() || $store->disabled() || ( $store->read()['account_id'] ?? 0 ) !== $account_id ) {
					return self::error();
				}
				if ( is_wp_error( $response ) ) {
					return self::error();
				}
				$status = wp_remote_retrieve_response_code( $response );
				if ( 200 !== $status ) {
					// In particular, 403 is NOT a request to delete or broaden the connection.
					return self::error( 'embed_api', in_array( $status, array( 401, 403, 404, 429 ), true ) ? $status : 502 );
				}
				$data = json_decode( wp_remote_retrieve_body( $response ), true );
				return is_array( $data ) && isset( $data['data'] ) && is_array( $data['data'] ) ? $data : self::error( 'embed_contract', 502 );
			}
		);
	}

	private function query( string $locale ): array {
		return in_array( $locale, array( 'hu', 'en', 'de' ), true ) ? array( 'locale' => $locale ) : array();
	}

	public function catalog( int $account_id, int $page = 1, int $per_page = 50, string $locale = 'auto' ): array|WP_Error {
		if ( $page < 1 || $page > 100000 || $per_page < 1 || $per_page > 100 || ! in_array( $locale, array( 'auto', 'hu', 'en', 'de' ), true ) ) {
			return self::error( 'embed_parameters', 400 );
		}
		$result = $this->request(
			$account_id,
			'services',
			$this->query( $locale ) + array(
				'page'     => $page,
				'per_page' => $per_page,
			)
		);
		if ( is_wp_error( $result ) ) {
			return $result;
		}
		$meta = $result['meta'] ?? array();
		if ( ! is_int( $meta['last_page'] ?? null ) || $meta['last_page'] < 1 || ( $meta['page'] ?? null ) !== $page || ! is_int( $meta['total'] ?? null ) || count( $result['data'] ) > $per_page ) {
			return self::error( 'embed_contract', 502 );
		}
		$rows = array();
		foreach ( $result['data'] as $row ) {
			$service = $this->project( $row );
			if ( is_wp_error( $service ) ) {
				return $service;
			}
			$rows[] = $service;
		}
		return array(
			'data' => $rows,
			'meta' => array_intersect_key( $meta, array_flip( array( 'page', 'per_page', 'total', 'last_page', 'locale', 'timezone' ) ) ),
		);
	}

	public function detail( int $account_id, int $id, string $locale = 'auto' ): array|WP_Error {
		if ( $id <= 0 || ! in_array( $locale, array( 'auto', 'hu', 'en', 'de' ), true ) ) {
			return self::error( 'embed_parameters', 400 );
		}
		$result = $this->request( $account_id, 'services/' . $id, $this->query( $locale ) );
		if ( is_wp_error( $result ) ) {
			return $result;
		}
		$row = $this->project( $result['data'] );
		return ! is_wp_error( $row ) && $row['id'] === $id ? $row : self::error( 'embed_contract', 502 );
	}

	/** No raw settings, forms, resources, credentials or admin links in editor data. */
	private function project( mixed $row ): array|WP_Error {
		if ( ! is_array( $row ) || ! is_int( $row['id'] ?? null ) || $row['id'] <= 0 ) {
			return self::error( 'embed_contract', 502 );
		}
		foreach ( array( 'slug', 'type', 'name', 'timezone' ) as $key ) {
			if ( ! is_string( $row[ $key ] ?? null ) ) {
				return self::error( 'embed_contract', 502 );
			}
		}
		$result = array_intersect_key( $row, array_flip( array( 'id', 'slug', 'type', 'name', 'timezone' ) ) );
		foreach ( array( 'description', 'public_price_amount', 'public_price_currency' ) as $key ) {
			$result[ $key ] = is_scalar( $row[ $key ] ?? null ) ? (string) $row[ $key ] : '';
		}
		$result['accent_color'] = (string) sanitize_hex_color( is_string( $row['appearance']['accent_color'] ?? null ) ? $row['appearance']['accent_color'] : '' );
		return $result;
	}

	/** Resolve only through the tenant-scoped GET catalog; never invent a slug route. */
	public function by_slug( int $account_id, string $slug, string $locale ): array|WP_Error {
		for ( $page = 1; $page <= 20; ++$page ) {
			$catalog = $this->catalog( $account_id, $page, 100, $locale );
			if ( is_wp_error( $catalog ) ) {
				return $catalog;
			}
			foreach ( $catalog['data'] as $service ) {
				if ( $service['slug'] === $slug ) {
					return $this->detail( $account_id, $service['id'], $locale );
				}
			}
			if ( $page >= $catalog['meta']['last_page'] ) {
				return self::error( 'embed_service_missing', 404 );
			}
		}
		return self::error( 'embed_catalog_limit', 503 );
	}
}