<?php
namespace AntivirusAI\V1;

/** A local display preference, shared by Free and Pro for the signed-in administrator. */
final class Appearance {
	private const META_KEY = 'antivirus_ai_theme';
	private const CHOICES = array( 'light', 'dark', 'system' );

	private static function postRequest(): bool {
		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized,WordPress.Security.ValidatedSanitizedInput.MissingUnslash -- Only type and byte-length guards read the original method here; the accepted value is unslashed and sanitized before the exact POST check.
		if ( ! isset( $_SERVER['REQUEST_METHOD'] ) || ! is_string( $_SERVER['REQUEST_METHOD'] ) || strlen( $_SERVER['REQUEST_METHOD'] ) > 16 ) { return false; }
		$method = sanitize_text_field( wp_unslash( $_SERVER['REQUEST_METHOD'] ) );
		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Compare the sanitized method with its original unslashed bytes only to reject rewriting; no raw value is stored, displayed or accepted as a method.
		return 'POST' === $method && $method === wp_unslash( $_SERVER['REQUEST_METHOD'] );
	}

	public static function register(): void {
		WorkspaceDisplay::register();
		add_action( 'admin_enqueue_scripts', array( self::class, 'assets' ), 30 );
		add_filter( 'admin_body_class', array( self::class, 'bodyClass' ) );
		add_action( 'admin_post_antivirus_ai_appearance', array( self::class, 'handle' ) );
		add_action( 'wp_ajax_antivirus_ai_appearance', array( self::class, 'ajax' ) );
	}

	/** Identifiers are sanitized and must already use their canonical spelling. */
	private static function key( array $values, string $name ): string {
		if ( ! isset( $values[ $name ] ) || ! is_string( $values[ $name ] ) || strlen( $values[ $name ] ) > 128 ) { return ''; }
		$value = wp_unslash( $values[ $name ] );
		$clean = sanitize_key( $value );
		return strlen( $clean ) <= 64 && $clean === $value && $clean === $values[ $name ] ? $clean : '';
	}

	private static function active(): bool {
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only navigation uses allowlisted destinations; save() verifies actor, nonce and the exact preference allowlist before redirect.
		return current_user_can( 'manage_options' ) && in_array( self::key( $_GET, 'page' ), array( 'antivirus-ai', 'antivirus-ai-pro' ), true );
	}

	public static function preference(): string {
		$value = get_user_meta( get_current_user_id(), self::META_KEY, true );
		return is_string( $value ) && in_array( $value, self::CHOICES, true ) ? $value : 'light';
	}

	public static function attributes(): string {
		return 'data-avai-theme="' . esc_attr( self::preference() ) . '"';
	}

	public static function bodyClass( string $classes ): string {
		return self::active() ? $classes . ' avai-appearance-' . self::preference() . ' ' : $classes;
	}

	public static function assets(): void {
		if ( ! self::active() || ! wp_style_is( 'antivirus-ai-admin', 'enqueued' ) ) { return; }
		$dependencies = array( 'antivirus-ai-admin' );
		if ( wp_style_is( 'antivirus-ai-pro-workspace', 'enqueued' ) ) { $dependencies[] = 'antivirus-ai-pro-workspace'; }
		$entry = ANTIVIRUS_AI_FILE;
		wp_enqueue_style( 'antivirus-ai-appearance', plugins_url( 'assets/appearance.css', $entry ), $dependencies, ANTIVIRUS_AI_VERSION );
		wp_enqueue_script( 'antivirus-ai-appearance', plugins_url( 'assets/appearance.js', $entry ), array(), ANTIVIRUS_AI_VERSION, true );
	}

	public static function toolbar(): void {
		$preference = self::preference();
		echo '<form class="avai-appearance-form" method="post" action="' . esc_url( admin_url( 'admin-post.php' ) ) . '" data-ajax-url="' . esc_url( admin_url( 'admin-ajax.php' ) ) . '" data-saving="' . esc_attr__( 'Saving appearance…', 'shieldlume-security' ) . '" data-failed="' . esc_attr__( 'Could not confirm the save. Use Save appearance to retry, or reload this page.', 'shieldlume-security' ) . '">';
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only navigation uses allowlisted destinations; save() verifies actor, nonce and the exact preference allowlist before redirect.
		echo '<input type="hidden" name="action" value="antivirus_ai_appearance"><input type="hidden" name="return_page" value="' . esc_attr( 'antivirus-ai-pro' === self::key( $_GET, 'page' ) ? 'antivirus-ai-pro' : 'antivirus-ai' ) . '"><input type="hidden" name="return_tab" value="' . esc_attr( self::key( $_GET, 'tab' ) ) . '"><input type="hidden" name="return_view" value="' . esc_attr( self::key( $_GET, 'view' ) ) . '">';
		// phpcs:ignore WordPress.Security.NonceVerification.Recommended -- Read-only local navigation; the appearance POST verifies its own nonce before saving and revalidates this context before redirecting.
		if ( 'antivirus-ai' === self::key( $_GET, 'page' ) && 'findings' === self::key( $_GET, 'tab' ) ) { Admin::findingContextFields(); }
		wp_nonce_field( 'antivirus_ai_appearance', '_avai_appearance_nonce', false );
		echo '<label for="avai-appearance-select">' . esc_html__( 'Theme', 'shieldlume-security' ) . '</label><select class="avai-appearance-select" id="avai-appearance-select" name="appearance" aria-describedby="avai-appearance-status">';
		foreach ( array( 'light' => __( 'Light', 'shieldlume-security' ), 'dark' => __( 'Dark', 'shieldlume-security' ), 'system' => __( 'System', 'shieldlume-security' ) ) as $value => $label ) {
			echo '<option value="' . esc_attr( $value ) . '"' . selected( $preference, $value, false ) . '>' . esc_html( $label ) . '</option>';
		}
		echo '</select><button type="submit" class="avai-tool avai-appearance-save">' . esc_html__( 'Save appearance', 'shieldlume-security' ) . '</button><span class="avai-appearance-status screen-reader-text" id="avai-appearance-status" role="status" aria-live="polite"></span></form>';
	}

	/** No caller can name another administrator or write a site preference. */
	private static function save(): array {
		$actor = get_current_user_id();
		if ( $actor < 1 || ! current_user_can( 'manage_options' ) ) {
			return array( 'status' => 403, 'message' => __( 'Administrator access is required.', 'shieldlume-security' ) );
		}
		if ( ! self::postRequest() ) {
			return array( 'status' => 403, 'message' => __( 'A POST request is required.', 'shieldlume-security' ) );
		}
		// phpcs:ignore WordPress.Security.NonceVerification.Missing,WordPress.Security.ValidatedSanitizedInput.InputNotSanitized,WordPress.Security.ValidatedSanitizedInput.MissingUnslash -- The original nonce is read only for type and byte-length guards; sanitize_text_field(wp_unslash()) runs here before the standalone verifier and any requested operation.
		$nonce = isset( $_POST['_avai_appearance_nonce'] ) && is_string( $_POST['_avai_appearance_nonce'] ) && strlen( $_POST['_avai_appearance_nonce'] ) <= 40 ? sanitize_text_field( wp_unslash( $_POST['_avai_appearance_nonce'] ) ) : '';
		// phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- Original nonce bytes are used only to reject sanitizer changes; only the bounded sanitized nonce reaches the following standalone verifier.
		if ( '' === $nonce || strlen( $nonce ) > 20 || $nonce !== wp_unslash( $_POST['_avai_appearance_nonce'] ) ) {
			return array( 'status' => 403, 'message' => __( 'The appearance request expired. Refresh this page and try again.', 'shieldlume-security' ) );
		}
		if ( ! wp_verify_nonce( $nonce, 'antivirus_ai_appearance' ) ) {
			return array( 'status' => 403, 'message' => __( 'The appearance request expired. Refresh this page and try again.', 'shieldlume-security' ) );
		}
		$preference = self::key( $_POST, 'appearance' );
		if ( ! in_array( $preference, self::CHOICES, true ) ) {
			return array( 'status' => 400, 'message' => __( 'Choose Light, Dark or System.', 'shieldlume-security' ) );
		}
		if ( false === update_user_meta( $actor, self::META_KEY, $preference ) && get_user_meta( $actor, self::META_KEY, true ) !== $preference ) {
			return array( 'status' => 500, 'message' => __( 'Your appearance preference could not be saved. Please try again.', 'shieldlume-security' ) );
		}
		return array( 'status' => 200, 'redirect' => self::redirectUrl( $_POST ), 'appearance' => $preference, 'message' => __( 'Appearance saved for your administrator account.', 'shieldlume-security' ) );
	}

	private static function redirectUrl( array $values ): string {
		if ( 'antivirus-ai-pro' === self::key( $values, 'return_page' ) && class_exists( '\AntivirusAI\Pro\Workspace' ) ) {
			return \AntivirusAI\Pro\Workspace::url( self::key( $values, 'return_view' ) );
		}
		$tab = self::key( $values, 'return_tab' );
		return Admin::url( $tab, 'findings' === $tab ? Admin::findingContext( $values, 'return_' ) : array() );
	}

	public static function handle(): void {
		$result = self::save();
		if ( 200 !== $result['status'] ) { wp_die( esc_html( $result['message'] ), '', array( 'response' => (int) $result['status'] ) ); return; }
		wp_safe_redirect( $result['redirect'] );
		exit;
	}

	public static function ajax(): void {
		$result = self::save();
		if ( 200 !== $result['status'] ) { wp_send_json_error( array( 'message' => $result['message'] ), $result['status'] ); return; }
		wp_send_json_success( array( 'appearance' => $result['appearance'], 'message' => $result['message'] ) );
	}
}