<?php
/**
 * REST API Class
 *
 * Registers and handles REST API endpoints for OpenGraph image fallback.
 *
 * @package ROBOTSTXT_OG
 * @since 1.0.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly.
}

/**
 * Class Robotstxt_OG_REST_API
 *
 * Provides REST API endpoints for the OpenGraph plugin.
 *
 * @since 1.0.0
 */
class Robotstxt_OG_REST_API {

	/**
	 * REST API namespace.
	 *
	 * @since 1.0.0
	 * @var string
	 */
	const NAMESPACE = 'robotstxt-og/v1';

	/**
	 * Image resolver instance.
	 *
	 * @since 1.0.0
	 * @var Robotstxt_OG_Image_Resolver
	 */
	private Robotstxt_OG_Image_Resolver $resolver;

	/**
	 * Constructor.
	 *
	 * @since 1.0.0
	 *
	 * @param Robotstxt_OG_Image_Resolver $resolver Image resolver instance.
	 */
	public function __construct( Robotstxt_OG_Image_Resolver $resolver ) {
		$this->resolver = $resolver;
	}

	/**
	 * Initialize REST API hooks.
	 *
	 * @since 1.0.0
	 *
	 * @return void
	 */
	public function init(): void {
		add_action( 'rest_api_init', array( $this, 'register_routes' ) );
	}

	/**
	 * Register REST API routes.
	 *
	 * @since 1.0.0
	 *
	 * @return void
	 */
	public function register_routes(): void {
		// Resolve endpoint: force re-resolve a post's fallback image.
		register_rest_route(
			self::NAMESPACE,
			'/resolve/(?P<post_id>[\d]+)',
			array(
				'methods'             => WP_REST_Server::CREATABLE,
				'callback'            => array( $this, 'handle_resolve' ),
				'permission_callback' => array( $this, 'check_permission' ),
				'args'                => array(
					'post_id' => array(
						'required'          => true,
						'validate_callback' => function ( $value ) {
							return is_numeric( $value ) && (int) $value > 0;
						},
						'sanitize_callback' => 'absint',
						'description'       => __( 'The post ID to resolve the fallback image for.', 'robotstxt-og' ),
					),
				),
			)
		);

		// Status endpoint: get current cached status for a post.
		register_rest_route(
			self::NAMESPACE,
			'/status/(?P<post_id>[\d]+)',
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => array( $this, 'handle_status' ),
				'permission_callback' => array( $this, 'check_permission' ),
				'args'                => array(
					'post_id' => array(
						'required'          => true,
						'validate_callback' => function ( $value ) {
							return is_numeric( $value ) && (int) $value > 0;
						},
						'sanitize_callback' => 'absint',
						'description'       => __( 'The post ID to get the fallback image status for.', 'robotstxt-og' ),
					),
				),
			)
		);
	}

	/**
	 * Handle the resolve endpoint.
	 *
	 * Forces re-resolution of the fallback image for the specified post.
	 *
	 * @since 1.0.0
	 *
	 * @param WP_REST_Request $request REST request object.
	 * @return WP_REST_Response|WP_Error Response object.
	 */
	public function handle_resolve( WP_REST_Request $request ) {
		$post_id = (int) $request->get_param( 'post_id' );

		// Verify post exists.
		$post = get_post( $post_id );

		if ( ! $post ) {
			return new WP_Error(
				'post_not_found',
				__( 'Post not found.', 'robotstxt-og' ),
				array( 'status' => 404 )
			);
		}

		// Clear existing cache and resolve.
		$this->resolver->clear_cache( $post_id );
		$resolved_url = $this->resolver->resolve_image( $post_id );

		$data = array(
			'post_id'      => $post_id,
			'resolved_url' => $resolved_url,
			'cached'       => ! empty( get_post_meta( $post_id, '_og_image_fallback_url', true ) ),
			'success'      => ! empty( $resolved_url ),
		);

		return new WP_REST_Response( $data, 200 );
	}

	/**
	 * Handle the status endpoint.
	 *
	 * Returns the current cached fallback image status for a post.
	 *
	 * @since 1.0.0
	 *
	 * @param WP_REST_Request $request REST request object.
	 * @return WP_REST_Response|WP_Error Response object.
	 */
	public function handle_status( WP_REST_Request $request ) {
		$post_id = (int) $request->get_param( 'post_id' );

		// Verify post exists.
		$post = get_post( $post_id );

		if ( ! $post ) {
			return new WP_Error(
				'post_not_found',
				__( 'Post not found.', 'robotstxt-og' ),
				array( 'status' => 404 )
			);
		}

		$cached_url   = get_post_meta( $post_id, '_og_image_fallback_url', true );
		$thumbnail_id = get_post_thumbnail_id( $post_id );
		$original_url = $thumbnail_id ? wp_get_attachment_url( $thumbnail_id ) : '';

		$data = array(
			'post_id'      => $post_id,
			'cached_url'   => $cached_url,
			'original_url' => $original_url,
			'has_cache'    => ! empty( $cached_url ),
		);

		return new WP_REST_Response( $data, 200 );
	}

	/**
	 * Check REST API permission.
	 *
	 * Requires manage_options capability.
	 *
	 * @since 1.0.0
	 *
	 * @return bool|WP_Error True if authorized, WP_Error otherwise.
	 */
	public function check_permission() {
		if ( ! current_user_can( 'manage_options' ) ) {
			return new WP_Error(
				'rest_forbidden',
				__( 'You do not have permission to access this endpoint.', 'robotstxt-og' ),
				array( 'status' => 403 )
			);
		}

		return true;
	}
}