<?php

/**
 * Graph API client wrapper (idempotent + retryable calls).
 *
 * @package AfroIT_Messaging_WorkflowAutomations
 */

namespace AfroIT\Messaging\WorkflowAutomations\Meta;


use AfroIT\Messaging\WorkflowAutomations\Security\SecureOptions;
use AfroIT\Messaging\WorkflowAutomations\Settings\PluginSettings;
use AfroIT\Messaging\WorkflowAutomations\Logging\Log;
use AfroIT\Messaging\WorkflowAutomations\Admin\Response;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class GraphClient {


    public function connected() {
        $secure_options = new SecureOptions();
        $settings = new PluginSettings();

        $system_user_token = $secure_options->get( 'system_user_token', '' );
        $app_id = (string) $settings->get_facebook_app_id();
        $app_secret = $secure_options->get( 'facebook_app_secret', '' );

        if ( empty( $system_user_token ) || empty( $app_id ) || empty( $app_secret ) ) {
            return false;
        }

        $appToken = $app_id . '|' . $app_secret;
        $debug_token = $this->debugToken( $system_user_token, $appToken );
        if ( (string) ($debug_token['app_id'] ?? '') !== $app_id || empty( $debug_token['is_valid'] ) ) {
            return false;
        }

        if ( (string) ($debug_token['type'] ?? '') !== 'SYSTEM_USER' ) {
            return false;
        }
        return true;
    }

    public function debugToken( $input_token, $access_token ) {
        $url = $this->graphUrl( 'debug_token', array(
            'input_token' => $input_token,
            'access_token' => $access_token,
        ));

        $response = new Response(wp_remote_get( $url ));
        if (!$response->isSuccessful()) {
            Log::error( 'Debug token request failed', array( 'error' => $response->getError() ) );
            return false;
        }

        return $response->getBody();
    }

    protected function graphUrl( $path, $params = array() ) {
        $url = 'https://graph.facebook.com/v24.0/' . $path;
        $url = add_query_arg( $params, $url );
        return $url;
    }


    /**
     * Helper to GET from the Facebook Graph API, always including the system user access token.
     *
     * @param string $path   Graph endpoint path (e.g., 'me', 'some_object').
     * @param array  $params Additional parameters for the request.
     * @return array|false|Response         Decoded response body array, or WP_Error.
     */
    public function get( $path, $params = array(), $token = null, $return_response = false ) {
        $secure_options      = new SecureOptions();
        $system_user_token   = $token ?? $secure_options->get( 'system_user_token', '' );
        if ( empty( $system_user_token ) ) {
            return false;
        }

        $params['access_token'] = $system_user_token;
        $url = $this->graphUrl( $path, $params );

        $get = wp_remote_get( $url, array(
            'timeout' => 30,
        ) );
        $response = new Response($get);

        if (!$response->isSuccessful()) {
            return $return_response ? $response : false;
        }

        return $return_response ? $response : $response->getBody();
    }

    /**
     * Helper to POST to the Facebook Graph API, always including the system user access token.
     *
     * @param string $path    Graph endpoint path (e.g., 'me/feed').
     * @param array  $params  POST data to send.
     * @return array|false|Response         Decoded response body array, or WP_Error.
     */
    public function post( $path, $params = array(), $token = null, $return_response = false ) {
        $secure_options      = new SecureOptions();
        $system_user_token   = $token ?? $secure_options->get( 'system_user_token', '' );
        if ( empty( $system_user_token ) ) {
            return false;
        }

        $url = $this->graphUrl( $path );
        $post = wp_remote_post( $url, array(
            'body' => wp_json_encode( (array) $params ),
            'headers' => array(
                'Content-Type'  => 'application/json; charset=utf-8',
                'Authorization' => 'Bearer ' . $system_user_token,
            ),
            'timeout' => 30,
        ) );

        $response = new Response($post);
        if (!$response->isSuccessful()) {
            return $return_response ? $response : false;
        }

        return $return_response ? $response : $response->getBody();
    }

    /**
     * Helper to POST JSON to the Facebook Graph API, always using bearer token auth.
     *
     * Required by endpoints like WhatsApp Cloud API `/messages`.
     *
     * @param string $path    Graph endpoint path (e.g., '{phone_number_id}/messages').
     * @param array  $payload JSON payload.
     * @return array|false|Response Decoded response body array, or WP_Error.
     */
    public function postJson( $path, $payload = array(), $return_response = false ) {
        $secure_options    = new SecureOptions();
        $system_user_token = $secure_options->get( 'system_user_token', '' );
        if ( empty( $system_user_token ) ) {
            return false;
        }

        $url = $this->graphUrl( $path );

        $post = wp_remote_post(
            $url,
            array(
                'headers' => array(
                    'Content-Type'  => 'application/json; charset=utf-8',
                    'Authorization' => 'Bearer ' . $system_user_token,
                ),
                'body'    => wp_json_encode( (array) $payload ),
                'timeout' => 30,
            )
        );

        $response = new Response($post);
        if (!$response->isSuccessful()) {
            return $return_response ? $response : false;
        }

        return $return_response ? $response : $response->getBody();
    }

    /**
     * Get info about the owner of the system user token ("/me" endpoint).
     *
     * @return array Decoded response body array with owner info, or WP_Error.
     */
    public function me($token = null) {
        return $this->get( 'me', array(), $token );
    }

    /**
     * Helper to DELETE from the Facebook Graph API.
     *
     * @param string $path   Graph endpoint path (e.g., '{waba_id}/message_templates').
     * @param array  $params Query parameters (e.g., hsm_id).
     * @return array|false Decoded response body array, or false on failure.
     */
    public function delete( $path, $params = array() ) {
        $secure_options    = new SecureOptions();
        $system_user_token = $secure_options->get( 'system_user_token', '' );
        if ( empty( $system_user_token ) ) {
            return false;
        }

        $params['access_token'] = $system_user_token;
        $url = $this->graphUrl( $path, $params );

        $response = wp_remote_request(
            $url,
            array(
                'method'  => 'DELETE',
                'timeout' => 30,
            )
        );

        $resp = new Response( $response );
        if ( ! $resp->isSuccessful() ) {
            return false;
        }

        return true;
    }

}