<?php
/**
 * Names the plugin or theme behind a PHP error that happens while a tool runs,
 * so the AI app and the admin see who broke the save instead of a bare
 * "critical error", and the AI checks the result before sending the edit again.
 *
 * @package HandyMCP
 */

namespace HandyMCP\Support;

defined( 'ABSPATH' ) || exit;

final class Crash {

	const OPTION = 'handymcp_last_crash';

	/**
	 * Tool running right now, empty when none.
	 *
	 * @var string
	 */
	private static $tool = '';

	/**
	 * Outer tools while a tool calls another (tools_run, batch).
	 *
	 * @var array<int, array{0: string, 1: bool}>
	 */
	private static $outer = array();

	/**
	 * Whether the caller may see file and line details.
	 *
	 * @var bool
	 */
	private static $admin = false;

	/**
	 * Whether the shutdown filter is added.
	 *
	 * @var bool
	 */
	private static $hooked = false;

	public static function boot(): void {
		add_action( 'admin_post_handymcp_crash_dismiss', array( __CLASS__, 'dismiss' ) );
	}

	/**
	 * Start watching one tool call.
	 *
	 * @param string $tool  Tool name.
	 * @param bool   $admin Caller can manage options.
	 */
	public static function start( string $tool, bool $admin ): void {
		self::$outer[] = array( self::$tool, self::$admin );
		self::$tool    = $tool;
		self::$admin   = $admin;
		if ( ! self::$hooked ) {
			self::$hooked = true;
			add_filter( 'wp_php_error_message', array( __CLASS__, 'fatal_message' ), 10, 2 );
		}
	}

	public static function stop(): void {
		$prev        = array_pop( self::$outer );
		self::$tool  = is_array( $prev ) ? (string) $prev[0] : '';
		self::$admin = is_array( $prev ) && ! empty( $prev[1] );
	}

	/**
	 * Who owns a file: a plugin, a theme, WordPress itself or HandyMCP.
	 *
	 * @param string $file File path.
	 * @return array{type: string, slug: string, name: string, file: string}
	 */
	public static function owner( string $file ): array {
		$path  = wp_normalize_path( $file );
		$roots = array(
			'plugin' => array( wp_normalize_path( WP_PLUGIN_DIR ), wp_normalize_path( WPMU_PLUGIN_DIR ) ),
			'theme'  => array( wp_normalize_path( get_theme_root() ) ),
		);
		foreach ( $roots as $type => $dirs ) {
			foreach ( $dirs as $dir ) {
				$dir = trailingslashit( $dir );
				if ( '' === $dir || 0 !== strpos( $path, $dir ) ) {
					continue;
				}
				$rel  = substr( $path, strlen( $dir ) );
				$slug = (string) strtok( $rel, '/' );
				if ( 'plugin' === $type && in_array( $slug, array( dirname( plugin_basename( HANDYMCP_FILE ) ), 'handymcp', 'handymcp-pro' ), true ) ) {
					return array( 'type' => 'self', 'slug' => $slug, 'name' => 'HandyMCP', 'file' => $rel );
				}
				return array( 'type' => $type, 'slug' => $slug, 'name' => self::label( $type, $slug ), 'file' => $rel );
			}
		}
		$abs = trailingslashit( wp_normalize_path( ABSPATH ) );
		return array( 'type' => 'core', 'slug' => '', 'name' => 'WordPress', 'file' => 0 === strpos( $path, $abs ) ? substr( $path, strlen( $abs ) ) : basename( $path ) );
	}

	/**
	 * Readable plugin or theme name.
	 *
	 * @param string $type plugin or theme.
	 * @param string $slug Folder name.
	 */
	private static function label( string $type, string $slug ): string {
		if ( 'theme' === $type ) {
			$theme = wp_get_theme( $slug );
			return $theme->exists() ? (string) $theme->get( 'Name' ) : $slug;
		}
		if ( ! function_exists( 'get_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}
		foreach ( get_plugins() as $file => $data ) {
			if ( dirname( (string) $file ) === $slug && ! empty( $data['Name'] ) ) {
				return (string) $data['Name'];
			}
		}
		return $slug;
	}

	/**
	 * The first plugin or theme in an exception's call stack (the thrower may be WordPress core).
	 *
	 * @param \Throwable $e Exception.
	 * @return array{type: string, slug: string, name: string, file: string, line: int}
	 */
	public static function from_throwable( \Throwable $e ): array {
		$frames = array_merge( array( array( 'file' => $e->getFile(), 'line' => $e->getLine() ) ), $e->getTrace() );
		$first  = null;
		foreach ( $frames as $f ) {
			if ( empty( $f['file'] ) ) {
				continue;
			}
			$o         = self::owner( (string) $f['file'] );
			$o['line'] = (int) ( $f['line'] ?? 0 );
			if ( null === $first ) {
				$first = $o;
			}
			if ( in_array( $o['type'], array( 'plugin', 'theme' ), true ) ) {
				return $o;
			}
			if ( 'self' === $o['type'] ) {
				break;
			}
		}
		return $first ?? array( 'type' => 'core', 'slug' => '', 'name' => 'WordPress', 'file' => '', 'line' => 0 );
	}

	/**
	 * Message for the AI app. File and line only for admins, never the raw error text.
	 *
	 * @param array<string, mixed> $o    Owner with line.
	 * @param string               $tool Tool name.
	 */
	public static function message( array $o, string $tool ): string {
		$where = self::$admin && '' !== (string) $o['file'] ? ' (' . $o['file'] . ( ! empty( $o['line'] ) ? ' line ' . (int) $o['line'] : '' ) . ')' : '';
		if ( 'plugin' === $o['type'] || 'theme' === $o['type'] ) {
			$who = ( 'theme' === $o['type'] ? 'The theme ' : 'The plugin ' ) . $o['name'];
			return $who . ' crashed while ' . $tool . ' was running' . $where . '. The change may or may not have been saved: read the item again to check before trying again, and do not repeat the same call blindly. Tell the user that ' . $o['name'] . ' caused the error, so they can update it or contact its author.';
		}
		return 'The tool hit an internal error while running ' . $tool . $where . '. The change may or may not have been saved: read the item again to check before trying again.';
	}

	/**
	 * Save the last crash for a one-time notice in the plugin screens.
	 *
	 * @param array<string, mixed> $o    Owner with line.
	 * @param string               $tool Tool name.
	 */
	public static function record( array $o, string $tool ): void {
		update_option(
			self::OPTION,
			array(
				'time' => time(),
				'tool' => sanitize_key( $tool ),
				'type' => sanitize_key( (string) $o['type'] ),
				'name' => sanitize_text_field( (string) $o['name'] ),
				'file' => sanitize_text_field( (string) $o['file'] ),
				'line' => (int) ( $o['line'] ?? 0 ),
			),
			false
		);
	}

	/**
	 * Replace WordPress's fatal error text while a tool runs.
	 *
	 * @param string               $message Default message.
	 * @param array<string, mixed> $error   Error from error_get_last().
	 */
	public static function fatal_message( $message, $error ) {
		if ( '' === self::$tool || ! is_array( $error ) || empty( $error['file'] ) ) {
			return $message;
		}
		$o         = self::owner( (string) $error['file'] );
		$o['line'] = (int) ( $error['line'] ?? 0 );
		$tool      = self::$tool;
		self::$tool = '';
		self::record( $o, $tool );
		return esc_html( self::message( $o, $tool ) );
	}

	/**
	 * One-time notice in the HandyMCP screens about the last crash.
	 */
	public static function notice(): void {
		$c = get_option( self::OPTION );
		if ( ! is_array( $c ) || ! current_user_can( 'manage_options' ) || (int) ( $c['time'] ?? 0 ) < time() - 7 * DAY_IN_SECONDS ) {
			return;
		}
		$who  = in_array( $c['type'] ?? '', array( 'plugin', 'theme' ), true ) ? (string) $c['name'] : __( 'WordPress or HandyMCP', 'handymcp' );
		$url  = wp_nonce_url( admin_url( 'admin-post.php?action=handymcp_crash_dismiss' ), 'handymcp_crash_dismiss' );
		$file = '' !== (string) ( $c['file'] ?? '' ) ? sprintf( /* translators: 1: file, 2: line. */ __( 'File: %1$s, line %2$d', 'handymcp' ), (string) $c['file'], (int) $c['line'] ) : '';
		$tool = (string) $c['tool'];
		$all  = \HandyMCP\Plugin::instance()->container()->get( 'registry' )->all();
		$tool = isset( $all[ $tool ]['title'] ) && '' !== (string) $all[ $tool ]['title'] ? (string) $all[ $tool ]['title'] : $tool;
		/* translators: 1: plugin or theme name, 2: what the AI app was doing, 3: date. */
		$text = sprintf( __( '%1$s crashed while an AI app was running "%2$s" (%3$s). Update it or contact its author if this keeps happening.', 'handymcp' ), $who, $tool, wp_date( 'M j, H:i', (int) $c['time'] ) );
		echo '<div class="mx-banner is-error" role="alert"><span class="dashicons dashicons-warning" aria-hidden="true"></span><span>' . esc_html( $text ) . ( '' !== $file ? '<code>' . esc_html( $file ) . '</code>' : '' ) . '</span><a class="button" href="' . esc_url( $url ) . '">' . esc_html__( 'Dismiss', 'handymcp' ) . '</a></div>';
	}

	public static function dismiss(): void {
		check_admin_referer( 'handymcp_crash_dismiss' );
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'Sorry, you are not allowed to do that.', 'handymcp' ) );
		}
		delete_option( self::OPTION );
		wp_safe_redirect( wp_get_referer() ? wp_get_referer() : admin_url() );
		exit;
	}
}