import 'dart:convert';

import 'package:shelf/shelf.dart';
import 'package:shelf_router/shelf_router.dart';

import '../../middleware/error_handler.dart';
import '../../shared/api_response.dart';
import 'streak_service.dart';

/// Streak module route definitions.
class StreakRoutes {
  final StreakService _service;

  StreakRoutes(this._service);

  Router get router {
    final router = Router();

    router.get('/', _listStreaks);
    router.post('/', _createStreak);
    router.get('/<id>', _getStreak);
    router.post('/<id>/complete', _completeToday);
    router.post('/<id>/forgive', _forgive);
    router.post('/<id>/freeze', _freeze);
    router.get('/<id>/history', _getHistory);

    return router;
  }

  // ── Handlers ────────────────────────────────────────────────────────

  Future<Response> _listStreaks(Request request) async {
    final userId = request.context['userId'] as String;
    final streaks = await _service.listStreaks(userId);
    return ApiResponse.success(streaks);
  }

  Future<Response> _createStreak(Request request) async {
    final userId = request.context['userId'] as String;
    final body =
        jsonDecode(await request.readAsString()) as Map<String, dynamic>;

    if (body['name'] == null || (body['name'] as String).isEmpty) {
      throw ApiException.badRequest('Name is required');
    }

    final streak = await _service.createStreak(userId, body);
    return ApiResponse.created(streak);
  }

  Future<Response> _getStreak(Request request, String id) async {
    final userId = request.context['userId'] as String;
    final streak = await _service.getStreak(id, userId);
    return ApiResponse.success(streak);
  }

  Future<Response> _completeToday(Request request, String id) async {
    final userId = request.context['userId'] as String;
    final result = await _service.completeToday(id, userId);
    return ApiResponse.success(result, message: result['message'] as String);
  }

  Future<Response> _forgive(Request request, String id) async {
    final userId = request.context['userId'] as String;

    String? note;
    try {
      final body =
          jsonDecode(await request.readAsString()) as Map<String, dynamic>;
      note = body['note'] as String?;
    } catch (_) {
      // body optional
    }

    final result = await _service.forgive(id, userId, note: note);
    return ApiResponse.success(result, message: result['message'] as String);
  }

  Future<Response> _freeze(Request request, String id) async {
    final userId = request.context['userId'] as String;
    final body =
        jsonDecode(await request.readAsString()) as Map<String, dynamic>;

    final days = body['days'] as int?;
    if (days == null) {
      throw ApiException.badRequest('Field "days" is required');
    }

    final result = await _service.freeze(id, userId, days: days);
    return ApiResponse.success(result, message: result['message'] as String);
  }

  Future<Response> _getHistory(Request request, String id) async {
    final userId = request.context['userId'] as String;
    final history = await _service.getHistory(id, userId);
    return ApiResponse.success(history);
  }
}