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 '../../shared/pagination.dart';
import 'reward_service.dart';

/// Reward module route definitions.
class RewardRoutes {
  final RewardService _service;

  RewardRoutes(this._service);

  Router get router {
    final router = Router();

    router.post('/generate', _generate);
    router.get('/history', _history);

    return router;
  }

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

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

    final taskId = body['task_id'] as String?;
    final taskEnergyLevel = body['task_energy_level'] as int?;

    if (taskId == null || taskEnergyLevel == null) {
      throw ApiException.badRequest(
        'Missing required fields: task_id, task_energy_level',
      );
    }

    final reward = await _service.generateReward(
      userId: userId,
      taskId: taskId,
      taskEnergyLevel: taskEnergyLevel,
      currentStreak: (body['current_streak'] as int?) ?? 0,
    );

    return ApiResponse.created(reward, message: 'Reward generated!');
  }

  Future<Response> _history(Request request) async {
    final userId = request.context['userId'] as String;
    final paging = Pagination.fromRequest(request);

    final rewards = await _service.getHistory(
      userId,
      limit: paging.perPage,
      offset: paging.offset,
    );

    return ApiResponse.success(rewards);
  }
}