<?php
/**
 * Plugin Name: WP Gemini API
 * Plugin URI:  https://example.com/wp-gemini-api
 * Description: A WordPress plugin that provides an API wrapper for Gemini.
 * Version:     1.0.0
 * Author:      Your Name
 * Author URI:  https://example.com
 * License:     GPL2
 * License URI: https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain: wp-gemini-api
 * Domain Path: /languages
 */

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

if ( ! class_exists( 'WP_Gemini_API' ) ) :

	/**
	 * Main WP_Gemini_API Class.
	 *
	 * @since 1.0.0
	 */
	final class WP_Gemini_API {

		/**
		 * Version of the plugin.
		 *
		 * @var string
		 */
		public $version = '1.0.0';

		/**
		 * Instance of this class.
		 *
		 * @var object
		 */
		protected static $instance = null;

		/**
		 * The Gemini API base URL.
		 *
		 * @var string
		 */
		public $api_base_url = 'https://api.gemini.com/v1/';

		/**
		 * Gemini API credentials.
		 *
		 * @var array
		 */
		private $credentials;

		/**
		 * Initialize the plugin public actions.
		 */
		private function __construct() {
			// Load plugin text domain.
			add_action( 'init', array( $this, 'load_plugin_textdomain' ) );

			// Set the Gemini API credentials.
			$this->credentials = array(
				'api_key'    => 'YOUR_GEMINI_API_KEY', // Replace with your Gemini API key
				'api_secret' => 'YOUR_GEMINI_API_SECRET', // Replace with your Gemini API secret
			);

			// Register any necessary hooks or actions.
		}

		/**
		 * Return an instance of this class.
		 *
		 * @return object A single instance of this class.
		 */
		public static function get_instance() {
			// If the single instance hasn't been set, set it now.
			if ( null === self::$instance ) {
				self::$instance = new self();
			}

			return self::$instance;
		}

		/**
		 * Load the plugin text domain for translation.
		 */
		public function load_plugin_textdomain() {
			load_plugin_textdomain( 'wp-gemini-api', false, dirname( plugin_basename( __FILE__ ) ) . '/languages/' );
		}

		/**
		 * Magic getter for our object. Allows getting but not setting.
		 *
		 * @param string $field
		 * @return mixed
		 */
		public function __get( $field ) {
			return $this->$field;
		}

		/**
		 * Generate a Gemini API signature.
		 *
		 * @param array $request_payload The request payload.
		 * @return string The base64 encoded signature.
		 */
		private function generate_signature( $request_payload ) {
			$encoded_payload = base64_encode( json_encode( $request_payload ) );
			$signature       = hash_hmac( 'sha384', $encoded_payload, $this->credentials['api_secret'] );

			return base64_encode( $signature );
		}

		/**
		 * Make a request to the Gemini API.
		 *
		 * @param string $endpoint The API endpoint.
		 * @param string $method The HTTP method (GET, POST).
		 * @param array $params The request parameters.
		 * @return array The API response.
		 */
		public function make_request( $endpoint, $method = 'GET', $params = array() ) {
			$url = $this->api_base_url . $endpoint;

			// Prepare the request payload.
			$request_payload = array(
				'request' => '/' . $endpoint,
				'nonce'   => time(),
			);
			if ( 'POST' === $method ) {
				$request_payload = array_merge( $request_payload, $params );
			}

			// Generate the API signature.
			$signature = $this->generate_signature( $request_payload );

			$args = array(
				'method'  => $method,
				'headers' => array(
					'Content-Type'  => 'text/plain',
					'X-GEMINI-APIKEY'    => $this->credentials['api_key'],
					'X-GEMINI-PAYLOAD'   => base64_encode( json_encode( $request_payload ) ),
					'X-GEMINI-SIGNATURE' => $signature,
				),
			);

			if ( 'GET' === $method ) {
				$url = add_query_arg( $params, $url );
			}

			$response = wp_remote_request( $url, $args );

			if ( is_wp_error( $response ) ) {
				// Handle WP_Error.
				error_log( 'Gemini API Error: ' . $response->get_error_message() );
				return $response;
			}

			$status_code = wp_remote_retrieve_response_code( $response );
			if ( $status_code < 200 || $status_code >= 300 ) {
				// Handle API errors.
				$error_message = wp_remote_retrieve_body( $response );
				error_log( 'Gemini API Error (' . $status_code . '): ' . $error_message );
				return new WP_Error( 'gemini_api_error', $error_message, array( 'status_code' => $status_code ) );
			}

			return json_decode( wp_remote_retrieve_body( $response ) );
		}

		/**
		 * Get current order book.
		 *
		 * @param string $symbol The symbol of the trading pair (e.g., btcusd).
		 * @return array The order book data.
		 */
		public function get_order_book( $symbol ) {
			return $this->make_request( 'book/' . $symbol );
		}

		/**
		 * Get your current balances.
		 *
		 * @return array The balances data.
		 */
		public function get_balances() {
			return $this->make_request( 'balances', 'POST' );
		}

		// Add other helper methods for specific Gemini API functionalities, e.g.,:
		// public function get_ticker( $symbol ) { ... }
		// public function place_order( $symbol, $amount, $price, $side ) { ... }
		// public function get_order_status( $order_id ) { ... }
		// ... and so on

	}

endif;

/**
 * Returns the main instance of WP_Gemini_API.
 *
 * @return WP_Gemini_API The main instance.
 */
function WP_Gemini_API() {
	return WP_Gemini_API::get_instance();
}

// Get WP_Gemini_API Running.
WP_Gemini_API();