import 'dart:io';

import 'package:cyberhybridhub_server/db.dart';
import 'package:cyberhybridhub_server/question_service.dart';
import 'package:cyberhybridhub_server/questions_db.dart';
import 'package:cyberhybridhub_server/signalr/questions_hub_connections.dart';
import 'package:cyberhybridhub_server/trading/market_data_db.dart';
import 'package:cyberhybridhub_server/trading/trade_orders_db.dart';
import 'package:cyberhybridhub_server/trading/trading_config_db.dart';
import 'package:cyberhybridhub_server/trading/user_trading_state_db.dart';
import 'package:dotenv/dotenv.dart';
import 'package:postgres/postgres.dart';

/// Integration test Postgres: [cyberhybridhub_test] with migrations 001–017.
class TestDb {
  TestDb._(this.db, this._connection, this.databaseUrl);

  final ProfileDb db;
  final Connection _connection;
  final String databaseUrl;

  Connection get connection => _connection;

  static const String testDatabaseName = 'cyberhybridhub_test';

  static Future<TestDb?> open() async {
    String? baseUrl = Platform.environment['TEST_DATABASE_URL'] ??
        Platform.environment['DATABASE_URL'];
    if (baseUrl == null || baseUrl.isEmpty) {
      final DotEnv env = DotEnv(includePlatformEnvironment: true)
        ..load(['.env']);
      baseUrl = env['DATABASE_URL'];
    }
    if (baseUrl == null || baseUrl.isEmpty) {
      return null;
    }

    final Uri uri = Uri.parse(baseUrl);
    final String testUrl = uri.replace(path: '/$testDatabaseName').toString();

    await _ensureTestDatabaseExists(baseUrl);

    final ProfileDb profileDb = await ProfileDb.connect(testUrl);
    final Directory migrationsDir = Directory('migrations');
    if (!migrationsDir.existsSync()) {
      final Directory serverDir = Directory.current.path.endsWith('server')
          ? Directory.current
          : Directory('server');
      if (serverDir.existsSync()) {
        Directory.current = serverDir.path;
      }
    }

    await profileDb.migrate();
    return TestDb._(profileDb, profileDb.connection, testUrl);
  }

  static Future<void> _ensureTestDatabaseExists(String databaseUrl) async {
    final Uri uri = Uri.parse(databaseUrl);
    final String adminDb =
        uri.pathSegments.isNotEmpty && uri.pathSegments.first.isNotEmpty
            ? uri.pathSegments.first
            : 'postgres';
    final String adminUrl = uri.replace(path: '/$adminDb').toString();

    final Connection admin = await Connection.open(
      _endpointFromUrl(adminUrl),
      settings: const ConnectionSettings(sslMode: SslMode.disable),
    );
    try {
      final Result exists = await admin.execute(
        Sql.named(
          'SELECT 1 FROM pg_database WHERE datname = @name',
        ),
        parameters: <String, dynamic>{'name': testDatabaseName},
      );
      if (exists.isEmpty) {
        try {
          await admin.execute('CREATE DATABASE $testDatabaseName');
        } on ServerException catch (e) {
          // Parallel test files may race on CREATE DATABASE.
          if (e.code != '23505' && e.code != '42P04') {
            rethrow;
          }
        }
      }
    } finally {
      await admin.close();
    }
  }

  static Endpoint _endpointFromUrl(String databaseUrl) {
    final Uri uri = Uri.parse(databaseUrl);
    return Endpoint(
      host: uri.host.isEmpty ? 'localhost' : uri.host,
      port: uri.hasPort ? uri.port : 5432,
      database: uri.pathSegments.isNotEmpty ? uri.pathSegments.last : 'postgres',
      username:
          uri.userInfo.isNotEmpty ? uri.userInfo.split(':').first : null,
      password: uri.userInfo.contains(':')
          ? uri.userInfo.split(':').skip(1).join(':')
          : null,
    );
  }

  MarketDataDb get marketDataDb => MarketDataDb(_connection);

  TradingConfigDb get tradingConfigDb => TradingConfigDb(_connection);

  TradeOrdersDb get tradeOrdersDb => TradeOrdersDb(_connection);

  UserTradingStateDb get userTradingStateDb => UserTradingStateDb(_connection);

  QuestionsDb get questionsDb => QuestionsDb(_connection);

  /// QuestionService backed by a no-op hub (no live SignalR clients in tests).
  QuestionService questionService() => QuestionService(
        questionsDb: questionsDb,
        hubConnections: QuestionsHubConnections(),
      );

  Future<void> truncateTradingTables() async {
    await _connection.execute(
      '''
      TRUNCATE TABLE
        trade_orders,
        market_history_prospective_assignments,
        market_history_prospective_questions,
        market_data_snapshots,
        market_data_sync_runs,
        tradable_assets,
        user_trading_state,
        user_trading_config,
        questions,
        user_pipeline_state,
        users
      RESTART IDENTITY CASCADE
      ''',
    );
  }

  Future<void> seedUser(String firebaseUid) async {
    await _connection.execute(
      Sql.named(
        '''
        INSERT INTO users (firebase_uid, email)
        VALUES (@uid, @email)
        ON CONFLICT (firebase_uid) DO NOTHING
        ''',
      ),
      parameters: <String, dynamic>{
        'uid': firebaseUid,
        'email': '$firebaseUid@test.local',
      },
    );
  }

  Future<void> close() => db.close();
}