<?php
/**
 * Free-owned direct site connection.
 *
 * Reuses the standalone connector's settings, endpoint and OAuth tables.
 * Pro and an active legacy connector keep ownership of their request.
 *
 * @package DiviPowers
 */

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

final class Divi_Powers_Free_Connection {
	/** @var bool */
	private static $booted = false;

	/** @var bool */
	private static $owner = false;

	/** Start Free's connection only when no existing add-on owns it. */
	public static function boot() {
		if ( self::$booted ) {
			return self::$owner;
		}
		self::$booted = true;

		if ( defined( 'DIVI_POWERS_PRO_VERSION' ) || self::is_rollback_activation_request() ) {
			return false;
		}

		// Legacy connectors load at plugins_loaded priority 20. Yield to any
		// connection class already loaded so no class or route is redeclared.
		foreach ( array( 'FiveD_Site_Bridge', 'FiveD_Site_Bridge_DB', 'FiveD_Site_Bridge_Settings', 'FiveD_Site_Bridge_OAuth', 'FiveD_Site_Bridge_Transport' ) as $class ) {
			if ( class_exists( $class, false ) ) {
				if ( defined( 'DIVI_POWERS_AI_CONNECTOR_VERSION' ) ) {
					add_action( 'admin_notices', array( __CLASS__, 'legacy_connector_notice' ) );
				}
				return false;
			}
		}
		foreach ( array( 'DIVI_POWERS_CONNECTION_NATIVE', 'FIVED_SITE_BRIDGE_VERSION', 'FIVED_SITE_BRIDGE_FILE', 'FIVED_SITE_BRIDGE_DIR', 'FIVED_SITE_BRIDGE_BASENAME' ) as $constant ) {
			if ( defined( $constant ) ) {
				return false;
			}
		}

		$plugin = Divi_Powers_Plugin::instance();
		$layout_tools = $plugin->layout_tools();
		if ( ! $layout_tools instanceof Divi_Powers_Layout_Tools ) {
			return false;
		}

		define( 'DIVI_POWERS_CONNECTION_NATIVE', true );
		define( 'FIVED_SITE_BRIDGE_VERSION', DIVI_POWERS_VERSION );
		define( 'FIVED_SITE_BRIDGE_FILE', DIVI_POWERS_FILE );
		define( 'FIVED_SITE_BRIDGE_DIR', DIVI_POWERS_PATH . 'includes/connection/' );
		define( 'FIVED_SITE_BRIDGE_BASENAME', plugin_basename( DIVI_POWERS_FILE ) );

		foreach (
			array(
				'class-fived-site-bridge-db.php',
				'class-fived-site-bridge-settings.php',
				'class-fived-site-bridge-oauth.php',
				'class-fived-site-bridge-transport.php',
				'class-fived-site-bridge.php',
				'class-divi-powers-free-remote-connector.php',
			) as $file
		) {
			require_once FIVED_SITE_BRIDGE_DIR . $file;
		}

		FiveD_Site_Bridge_Settings::install_defaults();
		( new Divi_Powers_Free_Remote_Connector( $plugin, $layout_tools ) )->register();
		FiveD_Site_Bridge::instance();

		self::$owner = true;
		update_option( 'divi_powers_connection_owner', 'free', false );
		return true;
	}

	/** Restore a previously approved bearer identity before user-bound hooks. */
	public static function authenticate_mcp_before_init() {
		if ( ! self::$owner || ! self::is_mcp_http_request() ) {
			return;
		}

		$settings = get_option( FiveD_Site_Bridge_Settings::OPTION, array() );
		if ( ! is_array( $settings ) || empty( $settings['customer_connection_enabled'] ) || 'standalone' !== ( $settings['transport_mode'] ?? '' ) ) {
			return;
		}

		$header = isset( $_SERVER['HTTP_AUTHORIZATION'] ) ? (string) $_SERVER['HTTP_AUTHORIZATION'] : (string) ( $_SERVER['REDIRECT_HTTP_AUTHORIZATION'] ?? '' );
		if ( ! preg_match( '/^Bearer\s+(.+)$/i', $header, $matches ) ) {
			return;
		}
		$token = trim( $matches[1] );
		if ( '' === $token ) {
			return;
		}
		$grant = self::validate_compatible_oauth_token( $token );
		if ( ! $grant ) {
			return;
		}

		$request = new WP_REST_Request( isset( $_SERVER['REQUEST_METHOD'] ) ? (string) $_SERVER['REQUEST_METHOD'] : 'POST', '/mcp/v1/http' );
		$request->set_header( 'authorization', $header );
		$allowed = (bool) apply_filters( 'fived_mcp_oauth_grant_can_access', user_can( $grant['user_id'], 'manage_options' ), $grant, $request );
		if ( $allowed ) {
			wp_set_current_user( $grant['user_id'] );
		}
	}

	/** @return bool */
	private static function is_mcp_http_request() {
		if ( 'POST' !== strtoupper( (string) ( $_SERVER['REQUEST_METHOD'] ?? '' ) ) ) {
			return false;
		}
		if ( isset( $_GET['rest_route'] ) ) {
			return '/mcp/v1/http' === '/' . trim( (string) wp_unslash( $_GET['rest_route'] ), '/' );
		}
		$request_path = isset( $_SERVER['REQUEST_URI'] ) ? wp_parse_url( (string) $_SERVER['REQUEST_URI'], PHP_URL_PATH ) : '';
		$endpoint_path = wp_parse_url( rest_url( 'mcp/v1/http' ), PHP_URL_PATH );
		return is_string( $request_path ) && is_string( $endpoint_path )
			&& untrailingslashit( $request_path ) === untrailingslashit( $endpoint_path );
	}

	/** Read an existing approved token without changing the grant. */
	private static function validate_compatible_oauth_token( $token ) {
		global $wpdb;

		$hash = hash( 'sha256', (string) $token );
		foreach ( array( 'fived_mcp_oauth_tokens', 'mwai_mcp_oauth_tokens' ) as $suffix ) {
			$table = $wpdb->prefix . $suffix;
			if ( $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $table ) ) !== $table ) {
				continue;
			}
			$row = $wpdb->get_row(
				$wpdb->prepare(
					'SELECT id, user_id, client_id, access_expires, revoked FROM %i WHERE access_token_hash = %s AND revoked <> 1 LIMIT 1',
					$table,
					$hash
				),
				ARRAY_A
			);
			if ( ! $row ) {
				continue;
			}
			$expires = strtotime( $row['access_expires'] . ' UTC' );
			if ( false === $expires || $expires < time() ) {
				return null;
			}
			return array( 'user_id' => (int) $row['user_id'], 'client_id' => (string) $row['client_id'] );
		}
		return null;
	}

	/** Tell admins how to finish the legacy one-plugin migration. */
	public static function legacy_connector_notice() {
		if ( current_user_can( 'activate_plugins' ) ) {
			echo '<div class="notice notice-info"><p>' . esc_html__( 'The ChatGPT site connection is now included in 5D Powers for Divi. The separate AI Connector currently owns this connection; deactivate it when ready to let Free take over on the next request. Saved settings and approved connections will remain.', '5d-powers-for-divi' ) . '</p></div>';
		}
	}

	/** Avoid loading competing classes while the rollback bridge is activated. */
	private static function is_rollback_activation_request() {
		if ( ! is_admin() ) {
			return false;
		}
		$action = isset( $_REQUEST['action'] ) ? sanitize_key( wp_unslash( $_REQUEST['action'] ) ) : '';
		$rollback = '5d-site-bridge/5d-site-bridge.php';
		if ( 'activate' === $action ) {
			$plugin = isset( $_REQUEST['plugin'] ) ? sanitize_text_field( wp_unslash( $_REQUEST['plugin'] ) ) : '';
			return $rollback === $plugin;
		}
		if ( 'activate-selected' !== $action || empty( $_REQUEST['checked'] ) || ! is_array( $_REQUEST['checked'] ) ) {
			return false;
		}
		return in_array( $rollback, array_map( 'sanitize_text_field', wp_unslash( $_REQUEST['checked'] ) ), true );
	}
}