<?php
/**
 * HSSM API Client Class
 * 
 * Handles fetching slides from the remote Manager site API
 * 
 * @package Hi_School_Slide_Manager
 * @since 1.1.0
 */

// Prevent direct access
if ( ! defined( 'ABSPATH' ) ) {
    exit( 'Direct access forbidden.' );
}

class HSSM_API_Client {
    
    /**
     * Get slides for this site
     * 
     * @since 1.1.0
     * @return array|WP_Error Array of slides or WP_Error on failure
     */
    public function get_slides() {
        $api_url = get_option( 'hssm_api_url' );
        $site_slug = get_option( 'hssm_client_site_slug' );
        $api_key = get_option( 'hssm_client_api_key', '' );
        $cache_duration = get_option( 'hssm_cache_duration', 3600 );

        if ( empty( $api_url ) || empty( $site_slug ) || empty( $api_key ) ) {
            return new WP_Error( 'missing_config', __( 'API URL, site slug, or client API key is not configured.', 'hi-school-slide-manager' ) );
        }

        // Check cache first
        $cache_key = 'hssm_remote_slides_' . $site_slug;
        $cached_slides = get_transient( $cache_key );
        if ( false !== $cached_slides ) {
            return $cached_slides;
        }

        // Build the request URL
        // Ensure trailing slash on API URL and remove leading slash from endpoint
        $endpoint = sprintf( 'hssm/v1/slides/%s', $site_slug );
        $full_url = trailingslashit( $api_url ) . $endpoint;

        $args = array(
            'timeout'   => 15,
            'sslverify' => $this->should_verify_ssl( $full_url ),
            'headers'   => array(
                'X-HSSM-API-Key' => $api_key,
                'Accept'         => 'application/json',
            ),
        );

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

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

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

        if ( 200 !== $code ) {
            return new WP_Error( 'api_error', sprintf( __( 'API returned code %d: %s', 'hi-school-slide-manager' ), $code, $body ) );
        }

        $data = json_decode( $body, true );
        if ( ! is_array( $data ) || ! isset( $data['slides'] ) ) {
            return new WP_Error( 'invalid_response', __( 'Invalid API response format.', 'hi-school-slide-manager' ) );
        }

        $slides = $data['slides'];

        // Cache the results
        set_transient( $cache_key, $slides, $cache_duration );

        return $slides;
    }

    /**
     * Clear the slides cache
     * 
     * @since 1.1.0
     */
    /**
     * Verify SSL except on local Local/WP Engine hosts with self-signed certs.
     *
     * @since 1.1.3
     * @param string $url Request URL.
     * @return bool
     */
    private function should_verify_ssl( $url ) {
        $host = wp_parse_url( $url, PHP_URL_HOST );
        $local_hosts = array( 'localhost', '127.0.0.1' );
        $is_local    = in_array( $host, $local_hosts, true ) || ( is_string( $host ) && preg_match( '/\.local$/', $host ) );

        /**
         * Filter whether the client API should verify SSL certificates.
         *
         * @param bool   $verify Whether to verify SSL. False for *.local hosts.
         * @param string $url    Request URL.
         */
        return (bool) apply_filters( 'hssm_api_sslverify', ! $is_local, $url );
    }

    public function clear_cache() {
        $site_slug = get_option( 'hssm_client_site_slug' );
        if ( ! empty( $site_slug ) ) {
            delete_transient( 'hssm_remote_slides_' . $site_slug );
        }
    }
}