<?php
/**
 * Admin menu and screen host.
 *
 * @package ForensixDigital
 */

declare(strict_types=1);

namespace ForensixDigital\Admin;

defined( 'ABSPATH' ) || exit;

use ForensixDigital\Services\Permissions\Capabilities;

/**
 * Adds the Forensix menu. Every screen is a page that hosts the React app, so each page keeps its
 * own capability check and WordPress itself refuses users without it.
 */
final class Menu {

	public const TOP_SLUG = 'forensix-digital';

	/**
	 * Settings & Licence page. It sits right under Overview and is shown in bold so new
	 * users find the licence box straight away.
	 */
	public const SETTINGS_SLUG = 'forensix-settings';

	/**
	 * Screens: slug => key, title and capability. The first one is also the top-level page.
	 *
	 * @return array<string, array{key: string, title: string, capability: string}>
	 */
	public static function screens(): array {
		$screens = array(
			self::TOP_SLUG      => array(
				'key'        => 'overview',
				'title'      => __( 'Overview', 'forensix-digital' ),
				'capability' => Capabilities::VIEW_FINDINGS,
			),
			self::SETTINGS_SLUG => array(
				'key'        => 'settings',
				'title'      => __( 'Settings & Licence', 'forensix-digital' ),
				'capability' => Capabilities::MANAGE_SETTINGS,
			),
			'forensix-apps'     => array(
				'key'        => 'apps',
				'title'      => __( 'Apps', 'forensix-digital' ),
				'capability' => Capabilities::MANAGE_APPS,
			),
			'forensix-findings' => array(
				'key'        => 'findings',
				'title'      => __( 'Findings', 'forensix-digital' ),
				'capability' => Capabilities::VIEW_FINDINGS,
			),
			'forensix-activity' => array(
				'key'        => 'activity',
				'title'      => __( 'Activity', 'forensix-digital' ),
				'capability' => Capabilities::VIEW_ACTIVITY,
			),
		);

		/**
		 * Lets active apps add their own page. Entries need key, title and capability.
		 *
		 * @param array $screens Screens by page slug.
		 */
		$screens = (array) apply_filters( 'forensix_admin_screens', $screens );

		return self::settings_first( $screens );
	}

	/**
	 * Keeps Settings & Licence directly under Overview, also after apps added their pages.
	 * Overview has to stay first: WordPress links the top-level "Forensix" item to the first entry.
	 *
	 * @param array<string, mixed> $screens Screens by page slug.
	 * @return array<string, mixed>
	 */
	public static function settings_first( array $screens ): array {
		if ( ! isset( $screens[ self::SETTINGS_SLUG ] ) ) {
			return $screens;
		}
		$settings = array( self::SETTINGS_SLUG => $screens[ self::SETTINGS_SLUG ] );
		unset( $screens[ self::SETTINGS_SLUG ] );
		if ( ! isset( $screens[ self::TOP_SLUG ] ) ) {
			return $settings + $screens;
		}
		$top = array( self::TOP_SLUG => $screens[ self::TOP_SLUG ] );
		unset( $screens[ self::TOP_SLUG ] );
		return $top + $settings + $screens;
	}

	/**
	 * Hooks the menu. Nothing else is added outside wp-admin.
	 */
	public function register_hooks(): void {
		add_action( 'admin_menu', array( $this, 'add_menu' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'highlight_settings' ) );
	}

	/**
	 * Shows the Settings & Licence menu entry in bold on every admin page, so it stands out
	 * in the Forensix menu. Pure styling: the link text, its translation and what screen
	 * readers announce stay the same.
	 */
	public function highlight_settings(): void {
		$selector = '#adminmenu .wp-submenu a[href="admin.php?page=' . self::SETTINGS_SLUG . '"]';
		wp_add_inline_style( 'admin-menu', $selector . '{font-weight:600;}' );
	}

	/**
	 * Registers the pages.
	 */
	public function add_menu(): void {
		foreach ( self::screens() as $slug => $screen ) {
			if ( self::TOP_SLUG === $slug ) {
				add_menu_page(
					__( 'Forensix Digital', 'forensix-digital' ),
					__( 'Forensix', 'forensix-digital' ),
					$screen['capability'],
					$slug,
					array( $this, 'render' ),
					'dashicons-search',
					58
				);
			}
			add_submenu_page( self::TOP_SLUG, $screen['title'], $screen['title'], $screen['capability'], $slug, array( $this, 'render' ) );
		}
	}

	/**
	 * Prints the mount point for the React app.
	 */
	public function render(): void {
		$key = self::current_key();
		if ( null === $key ) {
			return;
		}
		echo '<div class="wrap"><div id="fxd-root" data-screen="' . esc_attr( $key ) . '"></div>';
		if ( ! self::built() ) {
			printf(
				'<div class="notice notice-error"><p>%s</p></div>',
				esc_html__( 'The Forensix admin screens have not been built yet. Run "npm run build" in the plugin folder.', 'forensix-digital' )
			);
		}
		echo '</div>';
	}

	/**
	 * Loads the app on Forensix pages only.
	 *
	 * @param string $hook_suffix Current admin page.
	 */
	public function enqueue( string $hook_suffix ): void {
		unset( $hook_suffix );
		$key = self::current_key();
		if ( null === $key || ! self::built() ) {
			return;
		}

		$asset = require FORENSIX_PATH . 'build/index.asset.php';
		wp_enqueue_script( 'fxd-admin', FORENSIX_URL . 'build/index.js', $asset['dependencies'], $asset['version'], true );
		wp_set_script_translations( 'fxd-admin', 'forensix-digital', FORENSIX_PATH . 'languages' );
		if ( file_exists( FORENSIX_PATH . 'build/style-index.css' ) ) {
			wp_enqueue_style( 'fxd-admin', FORENSIX_URL . 'build/style-index.css', array( 'wp-components' ), $asset['version'] );
		}

		$links = array();
		foreach ( self::screens() as $slug => $screen ) {
			if ( current_user_can( $screen['capability'] ) ) {
				$links[ $screen['key'] ] = array(
					'title' => $screen['title'],
					'url'   => admin_url( 'admin.php?page=' . $slug ),
				);
			}
		}
		$data = array(
			'screens' => $links,
			'logo'    => FORENSIX_URL . 'admin/images/logo.png',
			'canUndo' => current_user_can( Capabilities::UNDO_CHANGES ),
			'home'    => home_url( '/' ),
			// Plain links to the plans and the customer account; nothing is sent from this site.
			'plans'   => 'https://forensix.digital/pricing/',
			'account' => 'https://forensix.digital/account/',
		);
		wp_add_inline_script( 'fxd-admin', 'window.forensixAdmin = ' . wp_json_encode( $data ) . ';', 'before' );
	}

	/**
	 * The screen key of the current admin page, or null when it is not a Forensix page.
	 */
	private static function current_key(): ?string {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only page routing; the menu capability is enforced by WordPress.
		$page    = isset( $_GET['page'] ) ? sanitize_key( wp_unslash( $_GET['page'] ) ) : '';
		$screens = self::screens();
		return isset( $screens[ $page ] ) ? $screens[ $page ]['key'] : null;
	}

	/**
	 * Whether the JavaScript build exists.
	 */
	private static function built(): bool {
		return file_exists( FORENSIX_PATH . 'build/index.asset.php' ) && file_exists( FORENSIX_PATH . 'build/index.js' );
	}
}