import 'dart:convert';

import 'package:webview_flutter/webview_flutter.dart';

import '../../services/diagnostic_log.dart';

/// Convert errors into fixed labels; never export the original console text.
String? schoolConsoleCode(String message) {
  final text = message.toLowerCase();
  if (text.contains('mixed content')) return 'mixed_content';
  if (text.contains('content security policy')) {
    return 'content_security_policy';
  }
  if (text.contains('cors')) return 'cross_origin';
  if (text.contains('refused to')) return 'resource_refused';
  if (text.contains('referenceerror')) {
    if (RegExp(r'(?:jquery|\$) is not defined').hasMatch(text)) {
      return 'jquery_missing';
    }
    if (text.contains('beangle is not defined')) return 'beangle_missing';
    if (text.contains('require is not defined')) return 'require_missing';
    return 'reference_error';
  }
  if (text.contains('syntaxerror')) return 'syntax_error';
  if (text.contains('typeerror')) return 'type_error';
  if (text.contains('securityerror')) return 'security_error';
  if (text.contains('evalerror')) return 'eval_error';
  if (text.contains('rangeerror')) return 'range_error';
  return null;
}

// Counts and known library booleans only. This never reads text, forms, cookies,
// storage, or resource URLs. A different document or login form returns null.
const schoolPageDiagnosticsScript = r'''(() => {
  if(location.href!==__EXPECTED_URL__ || document.querySelector('input[type="password"]'))return 'null';
  const links=Array.from(document.querySelectorAll('link[rel~="stylesheet"]'));
  const resources=performance.getEntriesByType('resource');
  return JSON.stringify({scripts:document.scripts.length,styles:document.styleSheets.length,
    links:links.length,loaded:links.filter(link=>link.sheet!==null).length,
    jquery:typeof window.jQuery==='function',beangle:window.beangle!==null && typeof window.beangle==='object',
    require:typeof window.require==='function',
    script202:resources.filter(r=>r.initiatorType==='script' && r.responseStatus===202).length,
    style202:resources.filter(r=>r.initiatorType==='link' && r.responseStatus===202).length});
})()''';

void recordSchoolPageState(DiagnosticLog log, String school, Object raw) {
  dynamic value = raw;
  try {
    for (var i = 0; i < 2 && value is String; i++) {
      value = jsonDecode(value);
    }
    if (value is! Map) return;
    const counts = [
      'scripts',
      'styles',
      'links',
      'loaded',
      'script202',
      'style202',
    ];
    const libraries = ['jquery', 'beangle', 'require'];
    if (counts.any(
          (key) => value[key] is! int || value[key] < 0 || value[key] > 100000,
        ) ||
        libraries.any((key) => value[key] is! bool)) {
      return;
    }
    for (final key in counts) {
      if ((key == 'script202' || key == 'style202') && value[key] == 0) {
        continue;
      }
      log.add(
        'school_asset_state',
        fields: {
          'school': school,
          'code': key == 'script202'
              ? 'script_202'
              : key == 'style202'
              ? 'stylesheet_202'
              : key,
          'count': value[key] as int,
        },
      );
    }
    if (school == 'undergraduate') {
      for (final key in libraries) {
        log.add(
          'school_library_state',
          fields: {'school': school, 'code': key, 'result': value[key] as bool},
        );
      }
    }
  } catch (_) {
    /* Diagnostics must not interfere with the school page. */
  }
}

Future<void> recordSchoolPageDiagnostics(
  WebViewController web,
  String school,
  String url, {
  bool Function()? isCurrent,
}) async {
  final uri = Uri.tryParse(url);
  if (uri == null ||
      uri.scheme != 'https' ||
      !const {'eams.uestc.edu.cn', 'yjsjy.uestc.edu.cn'}.contains(uri.host)) {
    return;
  }
  try {
    if (isCurrent?.call() == false) return;
    if (await web.currentUrl() != url || isCurrent?.call() == false) return;
    final raw = await web.runJavaScriptReturningResult(
      schoolPageDiagnosticsScript.replaceAll(
        '__EXPECTED_URL__',
        jsonEncode(url),
      ),
    );
    if (await web.currentUrl() != url || isCurrent?.call() == false) {
      return;
    }
    recordSchoolPageState(DiagnosticLog.instance, school, raw);
  } catch (_) {
    /* No original exceptions or page data enter the log. */
  }
}