import 'dart:convert';
import 'package:http/http.dart' as http;
import '../http_client.dart';
import 'package:uuid/uuid.dart';
import '../http_util.dart';
import '../models.dart';
import '../sse.dart';
import 'webview_base_provider.dart';

/// Blackbox web chat. Tries REST after scraping a `validated` token, then WebView.
class Blackbox extends WebViewBaseProvider {
  @override
  String get name => 'Blackbox';

  @override
  bool get working => true;

  @override
  List<String> get models => ['blackboxai', 'gpt-4o'];

  @override
  String get defaultModel => 'blackboxai';

  @override
  String get baseUrl => 'https://www.blackbox.ai/';

  @override
  String get apiEndpoint => 'https://www.blackbox.ai/api/chat';

  static const _uuid = Uuid();

  @override
  Stream<String> createAsyncGenerator(
    String model,
    List<Message> messages, {
    bool stream = false,
  }) async* {
    try {
      await for (final chunk in _tryRest(messages, stream: stream)) {
        yield chunk;
      }
      return;
    } catch (_) {}
    await for (final chunk in super.createAsyncGenerator(model, messages, stream: stream)) {
      yield chunk;
    }
  }

  Stream<String> _tryRest(List<Message> messages, {required bool stream}) async* {
    final validated = await _scrapeValidated();
    final payload = {
      'messages': [
        for (final m in messages)
          {
            'id': _uuid.v4(),
            'content': m.content,
            'role': m.role.name,
          }
      ],
      'id': _uuid.v4(),
      'previewToken': null,
      'userId': null,
      'codeModelMode': true,
      'agentMode': {},
      'trendingAgentMode': {},
      'isMicMode': false,
      'maxTokens': 1024,
      'isChromeExt': false,
      'clickedAnswer2': false,
      'clickedAnswer3': false,
      'clickedForceWebSearch': false,
      'visitFromDelta': false,
      'mobileClient': false,
      'userSelectedModel': null,
      if (validated != null) 'validated': validated,
      'imageGenerationMode': false,
      'webSearchMode': false,
    };

    final urls = [
      'https://www.blackbox.ai/api/chat',
      'https://api.blackbox.ai/api/chat',
    ];
    Object? lastError;
    for (final url in urls) {
      try {
        final req = http.Request('POST', Uri.parse(url));
        req.headers.addAll(browserHeaders(
          origin: 'https://www.blackbox.ai',
          referer: 'https://www.blackbox.ai/',
          contentType: 'application/json',
        ));
        req.body = jsonEncode(payload);
        final res = await g4fHttp.send(req).timeout(const Duration(seconds: 20));
        if (res.statusCode != 200) {
          lastError = 'HTTP ${res.statusCode}';
          continue;
        }
        final collected = StringBuffer();
        await for (final chunk in res.stream.transform(utf8.decoder)) {
          if (chunk.isEmpty) continue;
          // Blackbox sometimes streams raw text, sometimes SSE.
          if (chunk.trimLeft().startsWith('data:')) {
            for (final piece in extractAllSseContent(chunk)) {
              collected.write(piece);
              if (stream) yield piece;
            }
          } else {
            collected.write(chunk);
            if (stream) yield chunk;
          }
        }
        final text = collected.toString().trim();
        if (!looksLikeModelOutput(text)) {
          lastError = 'unusable body';
          continue;
        }
        if (!stream) yield text;
        return;
      } catch (e) {
        lastError = e;
      }
    }
    throw Exception('Blackbox REST failed: $lastError');
  }

  Future<String?> _scrapeValidated() async {
    try {
      final page = await g4fHttp.get(
        Uri.parse('https://www.blackbox.ai/'),
        headers: browserHeaders(referer: 'https://www.blackbox.ai/'),
      ).timeout(const Duration(seconds: 12));
      if (page.statusCode != 200) return null;
      final chunks = RegExp(r'/_next/static/[^"\x27]+\.js').allMatches(page.body);
      final uuidRe = RegExp(
        r'[a-f0-9]{8}-[a-f0-9]{4}-[1-5][a-f0-9]{3}-[89ab][a-f0-9]{3}-[a-f0-9]{12}',
        caseSensitive: false,
      );
      for (final m in chunks.take(20)) {
        final src = m.group(0)!;
        final js = await g4fHttp.get(
          Uri.parse('https://www.blackbox.ai$src'),
          headers: browserHeaders(),
        ).timeout(const Duration(seconds: 8));
        if (js.statusCode != 200) continue;
        if (!js.body.contains('validated') && !js.body.contains('api/chat')) {
          continue;
        }
        final match = uuidRe.firstMatch(js.body);
        if (match != null) return match.group(0);
      }
    } catch (_) {}
    return null;
  }

  @override
  String buildJsFetchCode(String model, List<Message> messages, bool stream) {
    final messagesJson = jsonEncode([
      for (final m in messages)
        {'id': _uuid.v4(), 'content': m.content, 'role': m.role.name}
    ]);
    return '''
      (async function() {
        const payload = {
          messages: $messagesJson,
          id: crypto.randomUUID(),
          previewToken: null,
          userId: null,
          codeModelMode: true,
          agentMode: {},
          trendingAgentMode: {},
          isMicMode: false,
          maxTokens: 1024
        };
        const urls = ['/api/chat', 'https://www.blackbox.ai/api/chat'];
        for (const url of urls) {
          try {
            const resp = await fetch(url, {
              method: 'POST',
              headers: {'Content-Type': 'application/json'},
              body: JSON.stringify(payload)
            });
            if (resp.status === 200) {
              return await resp.text();
            }
          } catch (e) {}
        }
        return JSON.stringify({error: 'Blackbox chat endpoint not available'});
      })();
    ''';
  }

  @override
  String parseResponse(String rawResponse) {
    if (looksLikeModelOutput(rawResponse) && !rawResponse.trim().startsWith('{')) {
      return rawResponse.trim();
    }
    try {
      final json = jsonDecode(rawResponse);
      if (json is Map && json['error'] != null) {
        throw Exception(json['error']);
      }
    } catch (e) {
      if (e.toString().contains('Blackbox') || e.toString().contains('error')) {
        rethrow;
      }
    }
    final sse = extractAllSseContent(rawResponse).join();
    if (looksLikeModelOutput(sse)) return sse;
    if (looksLikeModelOutput(rawResponse)) return rawResponse.trim();
    throw Exception('Failed to parse Blackbox: ${rawResponse.substring(0, rawResponse.length.clamp(0, 180))}');
  }
}