<?php
/**
 * Admin page registration and handler.
 *
 * @package AIDF
 * @since   1.0.0
 */

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

/**
 * Manages the plugin admin page, menu item, and assets.
 */
class AIDF_Admin {

	/**
	 * Settings page hook suffix.
	 *
	 * @var string
	 */
	private static $hook_suffix = '';

	/**
	 * Initialise admin hooks.
	 *
	 * @return void
	 */
	public static function init() {
		add_action( 'admin_menu', array( __CLASS__, 'add_menu_page' ) );
		add_action( 'admin_enqueue_scripts', array( __CLASS__, 'enqueue_assets' ) );
		add_action( 'admin_init', array( __CLASS__, 'handle_activation_redirect' ) );
		add_filter( 'plugin_action_links_' . AIDF_PLUGIN_BASENAME, array( __CLASS__, 'add_action_links' ) );
		add_action( 'wp_ajax_aidf_preview_file', array( __CLASS__, 'ajax_preview_file' ) );
		add_action( 'wp_ajax_aidf_validate_files', array( __CLASS__, 'ajax_validate_files' ) );
		add_action( 'wp_ajax_aidf_dismiss_welcome', array( __CLASS__, 'ajax_dismiss_welcome' ) );
		add_action( 'wp_ajax_aidf_save_verify_code', array( __CLASS__, 'ajax_save_verify_code' ) );
		add_action( 'admin_notices', array( __CLASS__, 'maybe_show_welcome_notice' ) );
		add_action( 'admin_notices', array( __CLASS__, 'maybe_show_conflict_notice' ) );
	}

	/**
	 * Add the top-level menu page.
	 *
	 * @return void
	 */
	public static function add_menu_page() {
		self::$hook_suffix = add_menu_page(
			__( 'AI Discovery Files', 'ai-discovery-files' ),
			__( 'AI Discovery', 'ai-discovery-files' ),
			'manage_options',
			'ai-discovery-files',
			array( __CLASS__, 'render_page' ),
			'dashicons-visibility',
			80
		);
	}

	/**
	 * Enqueue admin CSS and JS on our settings page only.
	 *
	 * @param  string $hook_suffix Current admin page hook suffix.
	 * @return void
	 */
	public static function enqueue_assets( $hook_suffix ) {
		if ( self::$hook_suffix !== $hook_suffix ) {
			return;
		}

		wp_enqueue_media();

		wp_enqueue_style(
			'aidf-admin',
			AIDF_PLUGIN_URL . 'admin/css/admin.css',
			array(),
			AIDF_VERSION
		);

		wp_enqueue_script(
			'aidf-admin',
			AIDF_PLUGIN_URL . 'admin/js/admin.js',
			array( 'jquery' ),
			AIDF_VERSION,
			true
		);

		wp_localize_script(
			'aidf-admin',
			'aidfAdmin',
			array(
				'ajaxUrl' => admin_url( 'admin-ajax.php' ),
				'nonce'   => wp_create_nonce( 'aidf_admin_nonce' ),
				'i18n'    => array(
					'confirmReset'       => __( 'Reset all settings to defaults? This cannot be undone.', 'ai-discovery-files' ),
					'generating'         => __( 'Generating preview…', 'ai-discovery-files' ),
					'validating'         => __( 'Validating files…', 'ai-discovery-files' ),
					'saved'              => __( 'Settings saved.', 'ai-discovery-files' ),
					'selectLogo'         => __( 'Select Logo', 'ai-discovery-files' ),
					'changeLogo'         => __( 'Change Logo', 'ai-discovery-files' ),
					'useThisImage'       => __( 'Use This Image', 'ai-discovery-files' ),
					'chooseLogo'         => __( 'Choose a Logo Image', 'ai-discovery-files' ),
					'remove'             => __( 'Remove', 'ai-discovery-files' ),
					'questionPlaceholder' => __( 'Question…', 'ai-discovery-files' ),
					'answerPlaceholder'  => __( 'Answer…', 'ai-discovery-files' ),
					'servicePlaceholder' => __( 'Service or product name', 'ai-discovery-files' ),
					'serviceUrlPlaceholder' => __( 'Page URL (optional)', 'ai-discovery-files' ),
					'namePlaceholder'    => __( 'Full name', 'ai-discovery-files' ),
					'rolePlaceholder'    => __( 'Role (e.g. Managing Director)', 'ai-discovery-files' ),
					'personUrlPlaceholder' => __( 'Profile URL (LinkedIn, team page, etc.)', 'ai-discovery-files' ),
					'valid'              => __( 'Valid', 'ai-discovery-files' ),
					'allValid'           => __( 'All active files are valid and consistent.', 'ai-discovery-files' ),
					'previewError'       => __( 'Error: Could not load preview.', 'ai-discovery-files' ),
					'errorPrefix'        => __( 'Error: ', 'ai-discovery-files' ),
					'unknownError'       => __( 'Unknown error', 'ai-discovery-files' ),
					'crossFileConsistency' => __( 'Cross-File Consistency', 'ai-discovery-files' ),
					'verifyFileActive'   => __( 'Verification file is live at', 'ai-discovery-files' ),
					'verifyFileInactive' => __( 'No verification code set. Enter your code above to activate.', 'ai-discovery-files' ),
				),
			)
		);
	}

	/**
	 * Redirect to settings page after activation.
	 *
	 * @return void
	 */
	public static function handle_activation_redirect() {
		if ( ! get_transient( 'aidf_activation_redirect' ) ) {
			return;
		}

		delete_transient( 'aidf_activation_redirect' );

		if ( wp_doing_ajax() || isset( $_GET['activate-multi'] ) ) { // phpcs:ignore WordPress.Security.NonceVerification.Recommended
			return;
		}

		wp_safe_redirect( admin_url( 'admin.php?page=ai-discovery-files' ) );
		exit;
	}

	/**
	 * Add Settings and Docs links to plugin action links.
	 *
	 * @param  array<int, string> $links Existing action links.
	 * @return array<int, string>
	 */
	public static function add_action_links( $links ) {
		$settings_link = sprintf(
			'<a href="%s">%s</a>',
			esc_url( admin_url( 'admin.php?page=ai-discovery-files' ) ),
			esc_html__( 'Settings', 'ai-discovery-files' )
		);

		$docs_link = sprintf(
			'<a href="%s" target="_blank" rel="noopener">%s</a>',
			esc_url( 'https://www.ai-visibility.org.uk/specifications/' ),
			esc_html__( 'Docs', 'ai-discovery-files' )
		);

		array_unshift( $links, $docs_link );
		array_unshift( $links, $settings_link );

		return $links;
	}

	/**
	 * Render the settings page.
	 *
	 * @return void
	 */
	public static function render_page() {
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		include AIDF_PLUGIN_DIR . 'admin/views/settings-page.php';
	}

	/**
	 * AJAX handler: preview a file type.
	 *
	 * @return void
	 */
	public static function ajax_preview_file() {
		check_ajax_referer( 'aidf_admin_nonce', 'nonce' );

		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error( __( 'Permission denied.', 'ai-discovery-files' ) );
		}

		$file_slug  = isset( $_POST['file_slug'] ) ? sanitize_text_field( wp_unslash( $_POST['file_slug'] ) ) : '';
		$file_types = AIDF_Plugin::get_file_types();

		if ( empty( $file_slug ) || ! isset( $file_types[ $file_slug ] ) ) {
			wp_send_json_error( __( 'Invalid file type.', 'ai-discovery-files' ) );
		}

		$content = AIDF_Generator::generate( $file_slug );

		if ( false === $content ) {
			wp_send_json_error( __( 'Could not generate file.', 'ai-discovery-files' ) );
		}

		wp_send_json_success(
			array(
				'content'  => $content,
				'filename' => $file_types[ $file_slug ]['filename'],
				'url'      => AIDF_Server::get_file_url( $file_slug ),
			)
		);
	}

	/**
	 * AJAX handler: validate all active files.
	 *
	 * @return void
	 */
	public static function ajax_validate_files() {
		check_ajax_referer( 'aidf_admin_nonce', 'nonce' );

		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error( __( 'Permission denied.', 'ai-discovery-files' ) );
		}

		$results = AIDF_Validator::validate_all();

		wp_send_json_success( $results );
	}

	/**
	 * AJAX handler: save domain verification code.
	 *
	 * @return void
	 */
	public static function ajax_save_verify_code() {
		check_ajax_referer( 'aidf_admin_nonce', 'nonce' );

		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error( __( 'Permission denied.', 'ai-discovery-files' ) );
		}

		$code = isset( $_POST['verify_code'] ) ? sanitize_text_field( wp_unslash( $_POST['verify_code'] ) ) : '';

		// Validate: must match "ai-visibility-verify=" followed by hex, or empty to clear.
		if ( '' !== $code && ! preg_match( '/^ai-visibility-verify=[a-f0-9]+$/i', $code ) ) {
			wp_send_json_error( __( 'Invalid verification code. The code should be in the format: ai-visibility-verify=abc123', 'ai-discovery-files' ) );
		}

		$settings               = get_option( 'aidf_settings', array() );
		$settings['verify_code'] = $code;
		update_option( 'aidf_settings', $settings );

		// Flush rewrite rules to ensure the verify file route is active.
		AIDF_Server::register_rewrite_rules();
		flush_rewrite_rules();

		$data = array(
			'message' => empty( $code )
				? __( 'Verification code removed.', 'ai-discovery-files' )
				: __( 'Verification code saved.', 'ai-discovery-files' ),
			'active'  => ! empty( $code ),
			'url'     => home_url( '/ai-visibility-verify.txt' ),
		);

		wp_send_json_success( $data );
	}

	/**
	 * Get the current active tab.
	 *
	 * @return string
	 */
	public static function get_current_tab() {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Tab display only, no state change.
		$tab = isset( $_GET['tab'] ) ? sanitize_text_field( wp_unslash( $_GET['tab'] ) ) : 'identity';

		$valid_tabs = array( 'identity', 'permissions', 'content', 'advanced', 'preview', 'status' );

		if ( ! in_array( $tab, $valid_tabs, true ) ) {
			$tab = 'identity';
		}

		return $tab;
	}

	/**
	 * Get all tabs with labels.
	 *
	 * @return array<string, string>
	 */
	public static function get_tabs() {
		return array(
			'identity'    => __( 'Identity', 'ai-discovery-files' ),
			'permissions' => __( 'Permissions', 'ai-discovery-files' ),
			'content'     => __( 'Content', 'ai-discovery-files' ),
			'advanced'    => __( 'Technical', 'ai-discovery-files' ),
			'preview'     => __( 'Preview', 'ai-discovery-files' ),
			'status'      => __( 'Status', 'ai-discovery-files' ),
		);
	}

	/**
	 * Render an inline tooltip icon with hover popup.
	 *
	 * @param  string $text Tooltip content (plain text).
	 * @return void
	 */
	public static function tooltip( $text ) {
		printf(
			'<button type="button" class="aidf-tip" aria-label="%s"><span class="dashicons dashicons-editor-help"></span><span class="aidf-tip-text">%s</span></button>',
			esc_attr__( 'More information', 'ai-discovery-files' ),
			esc_html( $text )
		);
	}

	/**
	 * Show a welcome notice if the plugin hasn't been configured.
	 *
	 * @return void
	 */
	public static function maybe_show_welcome_notice() {
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		// Don't show on our own settings page — they're already there.
		$screen = get_current_screen();
		if ( $screen && self::$hook_suffix === $screen->id ) {
			return;
		}

		// Check if user has dismissed this notice.
		if ( get_user_meta( get_current_user_id(), 'aidf_welcome_dismissed', true ) ) {
			return;
		}

		// Only show if plugin hasn't been meaningfully configured.
		$saved = get_option( 'aidf_settings', array() );
		if ( ! is_array( $saved ) ) {
			$saved = array();
		}

		$has_custom_name = ! empty( $saved['business_name'] ) && $saved['business_name'] !== get_bloginfo( 'name' );
		$has_services    = ! empty( $saved['services'] );

		if ( $has_custom_name || $has_services ) {
			return;
		}

		// Inline only the welcome notice styles — avoid loading the full admin.css on every page.
		wp_register_style( 'aidf-welcome-notice', false, array(), AIDF_VERSION );
		wp_enqueue_style( 'aidf-welcome-notice' );
		wp_add_inline_style(
			'aidf-welcome-notice',
			'.aidf-welcome-notice{border-left-color:#e77d15!important}' .
			'.aidf-welcome-notice .aidf-welcome-inner{display:flex;align-items:center;gap:12px;padding:4px 0}' .
			'.aidf-welcome-notice .aidf-welcome-icon{display:flex;align-items:center;justify-content:center;width:32px;height:32px;background:#fef3e6;border-radius:6px;flex-shrink:0}' .
			'.aidf-welcome-notice .aidf-welcome-icon .dashicons{color:#e77d15;font-size:18px;width:18px;height:18px}' .
			'.aidf-welcome-notice .aidf-welcome-text strong{display:block;margin-bottom:2px}' .
			'.aidf-welcome-notice .aidf-welcome-text a{font-weight:600}'
		);

		$settings_url = admin_url( 'admin.php?page=ai-discovery-files' );
		$nonce        = wp_create_nonce( 'aidf_dismiss_welcome' );

		wp_add_inline_script(
			'jquery',
			'jQuery( document ).on( "click", "#aidf-welcome-notice .notice-dismiss", function() {' .
				'jQuery.post( ajaxurl, {' .
					'action: "aidf_dismiss_welcome",' .
					'nonce: document.getElementById( "aidf-welcome-notice" ).getAttribute( "data-nonce" )' .
				'} );' .
			'} );'
		);
		?>
		<div class="notice notice-info is-dismissible aidf-welcome-notice" id="aidf-welcome-notice" data-nonce="<?php echo esc_attr( $nonce ); ?>">
			<div class="aidf-welcome-inner">
				<div class="aidf-welcome-icon">
					<span class="dashicons dashicons-visibility"></span>
				</div>
				<div class="aidf-welcome-text">
					<strong><?php esc_html_e( 'AI Discovery Files is ready to configure', 'ai-discovery-files' ); ?></strong>
					<?php esc_html_e( 'Set up your business details so AI systems like ChatGPT, Claude, and Gemini can correctly discover and cite your website.', 'ai-discovery-files' ); ?>
					<a href="<?php echo esc_url( $settings_url ); ?>"><?php esc_html_e( 'Get started', 'ai-discovery-files' ); ?> &rarr;</a>
				</div>
			</div>
		</div>
		<?php
	}

	/**
	 * Show a warning if another plugin is generating AI discovery files.
	 *
	 * Checks for Yoast SEO, Rank Math, and other known plugins that
	 * can generate llms.txt or similar files, and warns the user to
	 * disable their version to avoid conflicts.
	 *
	 * @return void
	 */
	public static function maybe_show_conflict_notice() {
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		// Only show on our settings page and the plugins page.
		$screen = get_current_screen();
		if ( ! $screen || ! in_array( $screen->id, array( self::$hook_suffix, 'plugins' ), true ) ) {
			return;
		}

		$conflicts = self::detect_file_conflicts();

		if ( empty( $conflicts ) ) {
			return;
		}

		$messages = array();
		foreach ( $conflicts as $conflict ) {
			$messages[] = sprintf(
				/* translators: 1: plugin name, 2: feature name */
				esc_html__( '%1$s has %2$s enabled, which may conflict with this plugin.', 'ai-discovery-files' ),
				'<strong>' . esc_html( $conflict['plugin'] ) . '</strong>',
				esc_html( $conflict['feature'] )
			);
		}

		printf(
			'<div class="notice notice-warning"><p><strong>%s</strong></p><ul style="list-style: disc; margin-left: 20px;">',
			esc_html__( 'AI Discovery Files — Potential Conflict Detected', 'ai-discovery-files' )
		);

		foreach ( $messages as $msg ) {
			echo '<li>' . wp_kses( $msg, array( 'strong' => array() ) ) . '</li>';
		}

		printf(
			'</ul><p>%s</p></div>',
			esc_html__( 'To avoid duplicate or conflicting AI discovery files, disable the other plugin\'s AI file generation feature, or deactivate those file types in AI Discovery Files settings.', 'ai-discovery-files' )
		);
	}

	/**
	 * Detect other plugins that generate AI discovery files.
	 *
	 * @return array<int, array<string, string>> List of conflicts with 'plugin' and 'feature' keys.
	 */
	private static function detect_file_conflicts() {
		$conflicts = array();

		// Yoast SEO — llms.txt (added in Yoast SEO 24.x).
		if ( defined( 'WPSEO_VERSION' ) ) {
			$yoast_options = get_option( 'wpseo', array() );
			if ( ! empty( $yoast_options['enable_llms_txt'] ) ) {
				$conflicts[] = array(
					'plugin'  => 'Yoast SEO',
					'feature' => 'llms.txt generation',
				);
			}
		}

		// Rank Math — llms.txt (added in Rank Math 1.0.230+).
		if ( class_exists( 'RankMath' ) ) {
			$rm_general = get_option( 'rank-math-options-general', array() );
			if ( ! empty( $rm_general['enable_llms_txt'] ) ) {
				$conflicts[] = array(
					'plugin'  => 'Rank Math SEO',
					'feature' => 'llms.txt generation',
				);
			}
		}

		// SEOPress — llms.txt support.
		if ( defined( 'SEOPRESS_VERSION' ) ) {
			$sp_options = get_option( 'seopress_pro_option_name', array() );
			if ( ! empty( $sp_options['seopress_ai_llms_txt'] ) ) {
				$conflicts[] = array(
					'plugin'  => 'SEOPress',
					'feature' => 'llms.txt generation',
				);
			}
		}

		// All in One SEO.
		if ( defined( 'AIOSEO_VERSION' ) ) {
			$aioseo_options = get_option( 'aioseo_options', '' );
			if ( is_string( $aioseo_options ) ) {
				$aioseo_options = json_decode( $aioseo_options, true );
			}
			if ( is_array( $aioseo_options ) && ! empty( $aioseo_options['searchAppearance']['advanced']['llmsTxt']['enable'] ) ) {
				$conflicts[] = array(
					'plugin'  => 'All in One SEO',
					'feature' => 'llms.txt generation',
				);
			}
		}

		return $conflicts;
	}

	/**
	 * AJAX handler: dismiss the welcome notice permanently.
	 *
	 * @return void
	 */
	public static function ajax_dismiss_welcome() {
		check_ajax_referer( 'aidf_dismiss_welcome', 'nonce' );

		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error();
		}

		update_user_meta( get_current_user_id(), 'aidf_welcome_dismissed', 1 );
		wp_send_json_success();
	}
}