<?php
/**
 * Main Plugin Class
 *
 * Orchestrates all plugin components. Instantiates sub-classes, registers
 * WordPress hooks, and manages admin page and asset registration.
 *
 * @package AAMO_Notification_Groups
 * @since   1.0.0
 */

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

class AAMO_Notification_Groups {

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

	/**
	 * @var AAMO_Notification_Groups_Settings_Manager
	 */
	private $settings_manager;

	/**
	 * @var AAMO_Notification_Groups_Notice_Collector
	 */
	private $notice_collector;

	/**
	 * Hook suffix returned by add_submenu_page() for the main page.
	 * Used to scope asset loading to the correct admin page.
	 *
	 * @var string
	 */
	private $main_hook = '';

	/**
	 * @return AAMO_Notification_Groups
	 */
	public static function get_instance(): self {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	/**
	 * Constructor.
	 */
	private function __construct() {
		$this->init_components();
		$this->setup_hooks();
	}

	/** @ignore */
	private function __clone() {}

	/** @ignore */
	public function __wakeup() {}

	// -------------------------------------------------------------------------
	// Initialisation
	// -------------------------------------------------------------------------

	/**
	 * Instantiate all plugin sub-components.
	 *
	 * @since 1.0.0
	 */
	private function init_components(): void {
		$this->settings_manager = AAMO_Notification_Groups_Settings_Manager::get_instance();
		$this->notice_collector = AAMO_Notification_Groups_Notice_Collector::get_instance();
	}

	/**
	 * Register all WordPress hooks.
	 *
	 * Note: the activation hook is registered in the main plugin file
	 * (aamo-notification-groups.php) rather than here, because it must be
	 * called at file-load time — before plugins_loaded fires — for correct
	 * behaviour during a first activation.
	 *
	 * @since 1.0.0
	 */
	private function setup_hooks(): void {
		add_action( 'admin_menu', array( $this, 'register_admin_menu' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_assets' ) );
		add_action( 'admin_notices', array( $this, 'maybe_render_demo_notices' ) );
		add_action( 'admin_notices', array( $this, 'maybe_render_settings_saved_notice' ) );
		add_action(
			'admin_post_' . AAMO_Notification_Groups_Constants::SAVE_SETTINGS_ACTION,
			array( $this, 'handle_save_settings' )
		);
	}

	// -------------------------------------------------------------------------
	// Admin page
	// -------------------------------------------------------------------------

	/**
	 * Register the plugin's admin page as a submenu under Settings.
	 *
	 * @since 1.0.0
	 */
	public function register_admin_menu(): void {
		$capability = AAMO_Notification_Groups_Constants::CAP_MANAGE_NOTIFICATIONS;

		$this->main_hook = add_submenu_page(
			'options-general.php',
			__( 'Notification Groups', 'aamo-notification-groups' ),
			__( 'Notification Groups', 'aamo-notification-groups' ),
			$capability,
			AAMO_Notification_Groups_Constants::PAGE_MAIN,
			array( $this, 'render_main_page' )
		);
	}

	/**
	 * Render the main admin page.
	 *
	 * @since 1.0.0
	 */
	public function render_main_page(): void {
		if ( ! current_user_can( AAMO_Notification_Groups_Constants::CAP_MANAGE_NOTIFICATIONS ) ) {
			wp_die( esc_html__( 'You do not have permission to access this page.', 'aamo-notification-groups' ) );
		}
		include AAMO_NOTIFICATION_GROUPS_DIR . 'templates/admin-page.php';
	}

	// -------------------------------------------------------------------------
	// Demo notices
	// -------------------------------------------------------------------------

	/**
	 * Output a one-off batch of fake notices covering every severity tab,
	 * but only when this plugin's own "Generate Demo Notifications" link
	 * was just clicked — verified via nonce, and scoped to this plugin's
	 * own admin page. Nothing is persisted; a normal visit to this page
	 * never shows these.
	 *
	 * @since 1.0.0
	 */
	public function maybe_render_demo_notices(): void {
		if ( empty( $_GET[ AAMO_Notification_Groups_Constants::DEMO_QUERY_ARG ] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- presence check only; verified below.
			return;
		}

		if ( ! $this->main_hook || ! get_current_screen() || get_current_screen()->id !== $this->main_hook ) {
			return;
		}

		if ( ! current_user_can( AAMO_Notification_Groups_Constants::CAP_MANAGE_NOTIFICATIONS ) ) {
			return;
		}

		check_admin_referer( AAMO_Notification_Groups_Constants::DEMO_NONCE_ACTION );

		$this->render_demo_notices();
	}

	/**
	 * Echo the demo notice battery: two each of error/warning/success/info
	 * (one success notice deliberately uses the legacy `.updated` class
	 * instead of `notice-success`), plus one bare `.notice` with no
	 * severity class so the Misc tab has something to show too.
	 *
	 * @since 1.0.0
	 */
	private function render_demo_notices(): void {
		$demo_notices = array(
			array(
				'class'   => 'notice notice-error is-dismissible',
				'message' => __( 'Demo: payment gateway failed to connect.', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'notice notice-error',
				'message' => __( 'Demo: a required field is missing on the last saved record.', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'notice notice-warning',
				'message' => __( 'Demo: a scheduled task did not run on time.', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'notice notice-warning',
				'message' => __( 'Demo: storage usage is approaching its limit.', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'notice notice-success is-dismissible',
				'message' => __( 'Demo: settings saved successfully.', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'updated',
				'message' => __( 'Demo: import completed (legacy .updated notice style).', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'notice notice-info',
				'message' => __( 'Demo: a new version of a dependency is available.', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'notice notice-info',
				'message' => __( 'Demo: this feature is in beta.', 'aamo-notification-groups' ),
			),
			array(
				'class'   => 'notice',
				'message' => __( 'Demo: uncategorized notice with no severity class — lands in Misc.', 'aamo-notification-groups' ),
			),
		);

		foreach ( $demo_notices as $notice ) {
			printf(
				'<div class="%1$s"><p>%2$s</p></div>',
				esc_attr( $notice['class'] ),
				esc_html( $notice['message'] )
			);
		}
	}

	// -------------------------------------------------------------------------
	// Settings (display style + minimum group count)
	// -------------------------------------------------------------------------

	/**
	 * Handle the settings form submission (display style + minimum group
	 * count). Capability + nonce checked, saves both posted values, then
	 * redirects back to the settings page with a flag that shows a real
	 * success notice — standard WordPress settings-saved pattern.
	 *
	 * @since 1.0.0
	 */
	public function handle_save_settings(): void {
		if ( ! current_user_can( AAMO_Notification_Groups_Constants::CAP_MANAGE_NOTIFICATIONS ) ) {
			wp_die( esc_html__( 'You do not have permission to do that.', 'aamo-notification-groups' ) );
		}

		check_admin_referer( AAMO_Notification_Groups_Constants::SAVE_SETTINGS_ACTION );

		// Cast to string before sanitize_key(): defensive only, not a fix for
		// an actual error — a capability-checked, nonce-verified admin could
		// still hand-craft this field as an array, which sanitize_key()
		// cannot accept. absint() handles the same edge case for the count
		// field on its own (and is what marks it "sanitized" to WPCS).
		$style = isset( $_POST['aamo_ng_display_style'] ) ? sanitize_key( (string) wp_unslash( $_POST['aamo_ng_display_style'] ) ) : '';
		$this->settings_manager->save_display_style( $style );

		$min_group_count = isset( $_POST['aamo_ng_min_group_count'] ) ? absint( wp_unslash( $_POST['aamo_ng_min_group_count'] ) ) : 0;
		$this->settings_manager->save_min_group_count( $min_group_count );

		$collapsed_by_default = ! empty( $_POST['aamo_ng_collapsed_by_default'] );
		$this->settings_manager->save_collapsed_by_default( $collapsed_by_default );

		// Built directly rather than via menu_page_url(): that helper reads
		// the $_parent_pages global that add_submenu_page() populates on the
		// admin_menu hook — but admin_menu never fires during an
		// admin-post.php request, so menu_page_url() would return an empty
		// string here and add_query_arg() would silently fall back to the
		// current request URI (admin-post.php itself) as the base,
		// redirecting back into admin-post.php instead of the settings page.
		$redirect = add_query_arg(
			array(
				'page' => AAMO_Notification_Groups_Constants::PAGE_MAIN,
				AAMO_Notification_Groups_Constants::SETTINGS_SAVED_QUERY_ARG => '1',
			),
			admin_url( 'options-general.php' )
		);
		wp_safe_redirect( $redirect );
		exit;
	}

	/**
	 * Show a real success notice after a settings save — no nonce needed
	 * here, it's a read-only flag on the already-verified save handler's
	 * redirect target, the same pattern WordPress core's own "Settings
	 * saved." notices use.
	 *
	 * Deliberately carries the `inline` class so neither WordPress core's
	 * own notice-relocation shim nor our own Notice Collector sweep it up
	 * — both already skip `.inline` notices by convention (see
	 * NOTICE_EXCLUDE_CLASSES). Saving a setting shouldn't itself look like
	 * a demo of the collector card; that's what the explicit Demo button
	 * is for.
	 *
	 * @since 1.0.0
	 */
	public function maybe_render_settings_saved_notice(): void {
		if ( empty( $_GET[ AAMO_Notification_Groups_Constants::SETTINGS_SAVED_QUERY_ARG ] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- display only, nothing is mutated here.
			return;
		}

		if ( ! $this->main_hook || ! get_current_screen() || get_current_screen()->id !== $this->main_hook ) {
			return;
		}

		if ( ! current_user_can( AAMO_Notification_Groups_Constants::CAP_MANAGE_NOTIFICATIONS ) ) {
			return;
		}

		printf(
			'<div class="notice notice-success is-dismissible inline"><p>%s</p></div>',
			esc_html__( 'Settings saved.', 'aamo-notification-groups' )
		);
	}

	// -------------------------------------------------------------------------
	// Assets
	// -------------------------------------------------------------------------

	/**
	 * Enqueue admin assets, scoped to the plugin's own page only.
	 *
	 * @since 1.0.0
	 * @param string $hook_suffix Current admin page hook suffix.
	 */
	public function enqueue_assets( string $hook_suffix ): void {
		if ( ! $this->main_hook || $hook_suffix !== $this->main_hook ) {
			return;
		}

		wp_enqueue_style(
			AAMO_Notification_Groups_Constants::ASSET_HANDLE_CSS,
			AAMO_NOTIFICATION_GROUPS_URL . 'assets/css/admin.css',
			array(),
			AAMO_NOTIFICATION_GROUPS_VERSION
		);
	}

	// -------------------------------------------------------------------------
	// Utilities
	// -------------------------------------------------------------------------

	/**
	 * Return the plugin version string.
	 *
	 * @since 1.0.0
	 * @return string
	 */
	public function get_version(): string {
		return AAMO_NOTIFICATION_GROUPS_VERSION;
	}
}