<?php
/**
 * Fetch llms.txt body from AI View sync API (generator output in gcco_properties).
 *
 * @package Gcco\AiViewSync
 */

namespace Gcco\AiViewSync;

defined( 'ABSPATH' ) || exit;

/**
 * Remote sync over HTTPS.
 */
class Sync_Remote {

	/**
	 * @var bool
	 */
	protected static $cleared_bound_property_scheduled = false;

	/**
	 * Register filter on aivisy_sync_fetch.
	 */
	public static function register() {
		add_filter( 'aivisy_sync_fetch', array( __CLASS__, 'filter_sync' ), 5, 2 );
	}

	/**
	 * Clear bound GA4 property once, after the current request finishes.
	 *
	 * @return void
	 */
	protected static function schedule_clear_bound_property_after_request() {
		if ( self::$cleared_bound_property_scheduled ) {
			return;
		}
		self::$cleared_bound_property_scheduled = true;
		add_action(
			'shutdown',
			static function () {
				Settings::update(
					array(
						'bound_property_id'    => '',
						'bound_property_label' => '',
						'mode'                 => 'manual',
					)
				);
			},
			20
		);
	}

	/**
	 * @return string
	 */
	public static function get_api_url() {
		if ( defined( 'AIVISY_SYNC_API_URL' ) && is_string( AIVISY_SYNC_API_URL ) && '' !== trim( AIVISY_SYNC_API_URL ) ) {
			return trim( AIVISY_SYNC_API_URL );
		}
		if ( defined( 'AIVISY_APP_URL' ) && is_string( AIVISY_APP_URL ) && '' !== trim( AIVISY_APP_URL ) ) {
			return rtrim( trim( AIVISY_APP_URL ), '/' ) . '/wordpress_llms_sync_api.php';
		}
		return (string) apply_filters( 'aivisy_sync_api_url', '' );
	}

	/**
	 * @param string|null $content Prior result.
	 * @param array       $settings Plugin settings.
	 * @return string|\WP_Error|null
	 */
	public static function filter_sync( $content, $settings ) {
		if ( null !== $content && '' !== $content ) {
			return $content;
		}

		if ( empty( $settings['connected'] ) || empty( $settings['connection_token'] ) ) {
			return null;
		}

		if ( empty( $settings['bound_property_id'] ) ) {
			return new \WP_Error(
				'aivisy_need_property',
				__( 'Select a GA4 property for this site first.', 'ai-view-sync' )
			);
		}

		$url = self::get_api_url();
		if ( '' === $url ) {
			return null;
		}

		$args = array(
			'timeout'     => 45,
			'redirection' => 2,
			'sslverify'   => true,
			'headers'     => array(
				'Accept' => 'text/plain',
			),
		);

		$endpoint = add_query_arg(
			array(
				'token'       => (string) $settings['connection_token'],
				'site_url'    => home_url( '/' ),
				'property_id' => isset( $settings['bound_property_id'] ) ? (string) $settings['bound_property_id'] : '',
			),
			$url
		);

		/**
		 * HTTP args for AI View llms sync GET.
		 *
		 * @param array  $args     wp_remote_get args.
		 * @param string $endpoint Full URL.
		 * @param array  $settings Settings.
		 */
		$args = apply_filters( 'aivisy_sync_remote_args', $args, $endpoint, $settings );

		$response = wp_remote_get( $endpoint, $args );

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

		$code = wp_remote_retrieve_response_code( $response );
		$body = wp_remote_retrieve_body( $response );

		if ( $code >= 400 ) {
			$msg = trim( (string) $body );
			if ( '' === $msg ) {
				$msg = 'HTTP ' . (string) $code;
			}
			// Site vs GA4 property mismatch: clear the bind so the user can pick the right property in WordPress.
			// Defer option writes to shutdown so we never update settings mid-filter (avoids rare re-entrancy fatals).
			if ( 403 === (int) $code && strpos( $msg, 'does not match the GA4 property' ) !== false ) {
				$msg .= ' ' . __( 'Choose the correct GA4 property for this site below, then use Sync again.', 'ai-view-sync' );
				self::schedule_clear_bound_property_after_request();
			}
			return new \WP_Error( 'aivisy_sync_http', $msg, array( 'status' => $code ) );
		}

		return $body;
	}
}