<?php
/**
 * Core plugin bootstrap: autoloading and composition root.
 *
 * @package Esipher
 */

namespace Esipher;

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

/**
 * Singleton composition root. Registers the autoloader, the `wp esipher`
 * command under WP-CLI, and the Appearance > Esipher admin page under
 * wp-admin.
 */
class Plugin {

	/**
	 * Singleton instance.
	 *
	 * @var Plugin|null
	 */
	private static $instance = null;

	/**
	 * Namespace-prefix to directory map, longest prefix first so that
	 * sub-namespaces (Adapters, Cli) are matched before the generic
	 * top-level Esipher\ prefix.
	 *
	 * @var array<string,string>
	 */
	private $namespace_map = array();

	/**
	 * Get the singleton instance, creating it on first call.
	 *
	 * @return Plugin
	 */
	public static function instance() {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}

		return self::$instance;
	}

	/**
	 * Constructor: registers the autoloader and CLI command.
	 */
	private function __construct() {
		$this->namespace_map = array(
			'Esipher\\Adapters\\' => ESIPHER_PLUGIN_DIR . 'adapters/',
			'Esipher\\Cli\\'      => ESIPHER_PLUGIN_DIR . 'cli/',
			'Esipher\\Admin\\'    => ESIPHER_PLUGIN_DIR . 'admin/',
			'Esipher\\'           => ESIPHER_PLUGIN_DIR . 'includes/',
		);

		spl_autoload_register( array( $this, 'autoload' ) );

		if ( defined( 'WP_CLI' ) && WP_CLI ) {
			\WP_CLI::add_command( 'esipher', Cli\Cli_Command::class );
		}

		if ( function_exists( 'is_admin' ) && is_admin() ) {
			( new Admin\Admin_Page() )->register();
			( new Admin\Github_Admin_Page() )->register();
			( new Admin\Mobile_App_Admin_Page() )->register();
		}

		// Registered unconditionally, not inside the is_admin() branch
		// above: GitHub's own webhook deliveries and the hourly cron
		// safety-net check both need this wired up on ordinary
		// front-end requests too, not just wp-admin ones.
		( new Github_Sync_Service() )->register();

		register_deactivation_hook( ESIPHER_PLUGIN_FILE, array( __CLASS__, 'on_deactivate' ) );
	}

	/**
	 * Clear the sync-check cron event on deactivation — WordPress
	 * doesn't do this automatically, and a scheduled hook pointing at
	 * a deactivated plugin's class would otherwise fire into nothing
	 * (harmlessly, since WP-Cron simply can't find the callback, but
	 * needlessly) until the site's cron table is next cleaned up.
	 */
	public static function on_deactivate() {
		$timestamp = wp_next_scheduled( Github_Sync_Service::CRON_HOOK );

		if ( $timestamp ) {
			wp_unschedule_event( $timestamp, Github_Sync_Service::CRON_HOOK );
		}
	}

	/**
	 * Spl_autoload_register callback. Maps a namespaced class/interface/
	 * trait name to the WordPress file-naming convention: `Class_Name`
	 * becomes `class-class-name.php` (`interface-`/`trait-` for those).
	 *
	 * @param string $class_name Fully-qualified class/interface/trait name.
	 */
	public function autoload( $class_name ) {
		foreach ( $this->namespace_map as $prefix => $dir ) {
			if ( 0 !== strpos( $class_name, $prefix ) ) {
				continue;
			}

			$relative = substr( $class_name, strlen( $prefix ) );
			$slug     = strtolower( str_replace( '_', '-', $relative ) );

			foreach ( array( 'class-' . $slug, 'interface-' . $slug, 'trait-' . $slug ) as $basename ) {
				$file = $dir . $basename . '.php';
				if ( file_exists( $file ) ) {
					require $file;
					return;
				}
			}
		}
	}
}