<?php
/**
 * Bing IndexNow API client.
 *
 * Pings Bing via the IndexNow protocol when feeds are updated,
 * notifying the search engine to re-crawl specific URLs.
 *
 * @package AICommerce\Feed
 */

declare(strict_types=1);

namespace AICommerce\Feed;

/**
 * Client for submitting URLs to Bing via IndexNow API.
 */
class BingApiClient {

	/**
	 * IndexNow API endpoint.
	 *
	 * @var string
	 */
	private const INDEXNOW_ENDPOINT = 'https://api.indexnow.org/indexnow';

	/**
	 * Option key for the IndexNow API key.
	 *
	 * @var string
	 */
	private const API_KEY_OPTION = 'aicommerce_indexnow_key';

	/**
	 * Get or generate the IndexNow API key.
	 *
	 * Keys are stored in wp_options and auto-generated on first use.
	 *
	 * @return string The IndexNow API key.
	 */
	public function get_api_key(): string {
		$key = get_option( self::API_KEY_OPTION, '' );

		if ( empty( $key ) ) {
			$key = $this->generate_api_key();
			update_option( self::API_KEY_OPTION, $key, false );
		}

		return $key;
	}

	/**
	 * Submit a single URL to IndexNow.
	 *
	 * @param string $url The URL to submit.
	 *
	 * @return bool True on success.
	 */
	public function submit_url( string $url ): bool {
		$api_key      = $this->get_api_key();
		$host         = wp_parse_url( home_url(), PHP_URL_HOST );
		$key_location = home_url( '/' . $api_key . '.txt' );

		$response = wp_remote_post(
			self::INDEXNOW_ENDPOINT,
			array(
				'headers' => array( 'Content-Type' => 'application/json; charset=utf-8' ),
				'body'    => wp_json_encode(
					array(
						'host'        => $host,
						'key'         => $api_key,
						'keyLocation' => $key_location,
						'urlList'     => array( $url ),
					)
				),
				'timeout' => 15,
			)
		);

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

		$code = wp_remote_retrieve_response_code( $response );

		return $code >= 200 && $code < 300;
	}

	/**
	 * Submit multiple URLs to IndexNow.
	 *
	 * @param array $urls Array of URLs to submit.
	 *
	 * @return bool True on success.
	 */
	public function submit_urls( array $urls ): bool {
		if ( empty( $urls ) ) {
			return false;
		}

		$api_key      = $this->get_api_key();
		$host         = wp_parse_url( home_url(), PHP_URL_HOST );
		$key_location = home_url( '/' . $api_key . '.txt' );

		$response = wp_remote_post(
			self::INDEXNOW_ENDPOINT,
			array(
				'headers' => array( 'Content-Type' => 'application/json; charset=utf-8' ),
				'body'    => wp_json_encode(
					array(
						'host'        => $host,
						'key'         => $api_key,
						'keyLocation' => $key_location,
						'urlList'     => array_values( $urls ),
					)
				),
				'timeout' => 15,
			)
		);

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

		$code = wp_remote_retrieve_response_code( $response );

		return $code >= 200 && $code < 300;
	}

	/**
	 * Notify Bing that the feed has been updated.
	 *
	 * Submits the feed URL via IndexNow.
	 *
	 * @param string $feed_url The feed URL that was updated.
	 *
	 * @return bool True on success.
	 */
	public function notify_feed_updated( string $feed_url ): bool {
		return $this->submit_url( $feed_url );
	}

	/**
	 * Serve the IndexNow key verification file content.
	 *
	 * Should be called on template_redirect when the request matches
	 * /{api_key}.txt to verify key ownership.
	 *
	 * @return void
	 */
	public function maybe_serve_key_file(): void {
		$request_uri = isset( $_SERVER['REQUEST_URI'] ) ? sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) ) : '';
		$api_key     = $this->get_api_key();

		if ( '/' . $api_key . '.txt' === $request_uri ) {
			header( 'Content-Type: text/plain; charset=utf-8' );
			header( 'Cache-Control: public, max-age=86400' );
			echo esc_html( $api_key );
			exit;
		}
	}

	/**
	 * Schedule a daily IndexNow ping for the Bing feed.
	 *
	 * @return void
	 */
	public function schedule_daily_ping(): void {
		$hook = 'aicommerce_indexnow_ping';

		if ( ! wp_next_scheduled( $hook ) ) {
			wp_schedule_event( time(), 'daily', $hook );
		}
	}

	/**
	 * Generate a random 32-character hex key for IndexNow.
	 *
	 * @return string The generated key.
	 */
	private function generate_api_key(): string {
		return bin2hex( random_bytes( 16 ) );
	}
}