<?php
/**
 * Module loader - declares which Hatch classes are optional and what feature
 * flag (if any) gates them.  Core classes always load; optional ones load only
 * when the feature is enabled.
 *
 * Usage: call Hatch_Module_Loader::boot() once after all includes.
 *
 * @package Hatch
 */

defined( 'ABSPATH' ) || exit;

/**
 * Hatch_Module_Loader
 */
class Hatch_Module_Loader {

	/**
	 * Map of class → [ file, feature_flag | null ].
	 *
	 * feature_flag: option key stored in hatch_features JSON blob.
	 *   null  = always load (no gate).
	 *   'foo' = load only when the 'foo' toggle is ON in hatch_features.
	 *
	 * @var array<string, array{file: string, flag: string|null}>
	 */
	private static array $modules = array(
		// Core - always load.
		'Hatch_Detector'           => array(
			'file' => 'class-detector.php',
			'flag' => null,
		),
		'Hatch_Security'           => array(
			'file' => 'class-security.php',
			'flag' => null,
		),
		'Hatch_Rest_Api'           => array(
			'file' => 'class-rest-api.php',
			'flag' => null,
		),
		'Hatch_Revalidate'         => array(
			'file' => 'class-revalidate.php',
			'flag' => null,
		),
		'Hatch_Seo_Bridge'         => array(
			'file' => 'class-seo-bridge.php',
			'flag' => null,
		),
		'Hatch_Features'           => array(
			'file' => 'class-features.php',
			'flag' => null,
		),
		'Hatch_Design_Loader'      => array(
			'file' => 'class-design-loader.php',
			'flag' => null,
		),
		'Hatch_Integrations'       => array(
			'file' => 'class-integrations.php',
			'flag' => null,
		),
		'Hatch_Connection_Status'  => array(
			'file' => 'class-connection-status.php',
			'flag' => null,
		),
		'Hatch_Diagnostic'         => array(
			'file' => 'class-diagnostic.php',
			'flag' => null,
		),
		'Hatch_Domain_Check'       => array(
			'file' => 'class-domain-check.php',
			'flag' => null,
		),
		'Hatch_Cpt_Scanner'        => array(
			'file' => 'class-cpt-scanner.php',
			'flag' => null,
		),
		'Hatch_Block_Serializer'   => array(
			'file' => 'class-block-serializer.php',
			'flag' => null,
		),
		'Hatch_Performance_Bloat'  => array(
			'file' => 'class-performance-bloat.php',
			'flag' => null,
		),
		'Hatch_Rankready_Bridge'   => array(
			'file' => 'class-rankready-bridge.php',
			'flag' => null,
		),
		'Hatch_Acf_Bridge'         => array(
			'file' => 'class-acf-bridge.php',
			'flag' => null,
		),
		// Feature-gated - load only when the matching toggle is ON.
		'Hatch_Headless_Comments'  => array(
			'file' => 'class-headless-comments.php',
			'flag' => 'comments',
		),
		'Hatch_Headless_Forms'     => array(
			'file' => 'class-headless-forms.php',
			'flag' => 'fluent_forms',
		),
		'Hatch_Forms_Bridge'       => array(
			'file' => 'class-forms-bridge.php',
			'flag' => 'fluent_forms',
		),
		'Hatch_Woocommerce_Bridge' => array(
			'file' => 'class-woocommerce-bridge.php',
			'flag' => 'woocommerce',
		),
		'Hatch_Login_Hardening'    => array(
			'file' => 'class-login-hardening.php',
			'flag' => 'login_hardening',
		),
		'Hatch_Turnstile_Wp'       => array(
			'file' => 'class-turnstile-wp.php',
			'flag' => 'turnstile',
		),
	);

	/**
	 * Boot all applicable modules.
	 *
	 * Called once from hatch.php after core constants are defined.
	 * Cached feature flags are read from the DB once - no extra HTTP calls.
	 */
	public static function boot(): void {
		$flags = self::get_feature_flags();

		foreach ( self::$modules as $class => $cfg ) {
			$file = HATCH_PLUGIN_DIR . 'includes/' . $cfg['file'];

			// Already loaded by an earlier require_once - skip.
			if ( class_exists( $class, false ) ) {
				continue;
			}

			if ( null !== $cfg['flag'] && ! self::flag_on( $flags, $cfg['flag'] ) ) {
				continue;
			}

			if ( file_exists( $file ) ) {
				require_once $file;
			}
		}
	}

	/**
	 * Check if a specific module is enabled (useful from other classes).
	 *
	 * @param string $flag Feature toggle key.
	 * @return bool
	 */
	public static function is_enabled( string $flag ): bool {
		return self::flag_on( self::get_feature_flags(), $flag );
	}

	/**
	 * Read the serialized feature flags from WP options.
	 * Returns an empty array on first activation (before any save).
	 *
	 * @return array<string, bool>
	 */
	private static function get_feature_flags(): array {
		$raw = get_option( 'hatch_features', array() );
		return is_array( $raw ) ? $raw : array();
	}

	/**
	 * @param array<string, bool> $flags
	 * @param string              $key
	 * @return bool
	 */
	private static function flag_on( array $flags, string $key ): bool {
		return ! empty( $flags[ $key ] );
	}
}