import "../config/api_config.dart";
import "../models/todo_item.dart";
import "api_client.dart";
import "mock_data.dart";

class TodoService {
  final ApiClient _client;

  TodoService(this._client);

  Future<List<TodoItem>> fetchTodos() async {
    if (ApiConfig.useMockData) {
      return List<TodoItem>.from(MockDataStore.todos);
    }
    final data = await _client.getList(ApiConfig.todos);
    return data
        .map((item) => TodoItem.fromJson(item as Map<String, dynamic>))
        .toList();
  }

  Future<List<TodoItem>> fetchTodayTodos() async {
    if (ApiConfig.useMockData) {
      // Using device's local timezone (should be Asia/Seoul for Korean users)
      final now = DateTime.now();
      final startOfToday = DateTime(now.year, now.month, now.day);
      final endOfToday = DateTime(now.year, now.month, now.day, 23, 59, 59, 999);

      final filtered = MockDataStore.todos.where((todo) {
        if (todo.dueDate != null) {
          // Due today - show regardless of completion status
          if (todo.dueDate!.isAfter(startOfToday.subtract(const Duration(milliseconds: 1))) &&
              todo.dueDate!.isBefore(endOfToday.add(const Duration(milliseconds: 1)))) {
            return true;
          }
          // Overdue (before today) - filter out
          if (todo.dueDate!.isBefore(startOfToday)) {
            return false;
          }
          // Future date - only show if incomplete
          return !todo.completed;
        }
        // No due date - only show if incomplete
        return !todo.completed;
      }).toList();

      // Sort: incomplete first, then by due date
      filtered.sort((a, b) {
        if (a.completed != b.completed) {
          return a.completed ? 1 : -1;
        }
        if (a.dueDate == null && b.dueDate == null) return 0;
        if (a.dueDate == null) return 1;
        if (b.dueDate == null) return -1;
        return a.dueDate!.compareTo(b.dueDate!);
      });

      return filtered;
    }
    final data = await _client.getList("${ApiConfig.todos}/today");
    return data
        .map((item) => TodoItem.fromJson(item as Map<String, dynamic>))
        .toList();
  }

  Future<TodoItem> createTodo(TodoItem todo) async {
    if (ApiConfig.useMockData) {
      final created = TodoItem(
        id: "todo-${DateTime.now().millisecondsSinceEpoch}",
        familyMemberId: todo.familyMemberId,
        title: todo.title,
        completed: todo.completed,
        dueDate: todo.dueDate,
      );
      MockDataStore.todos.add(created);
      return created;
    }
    final data = await _client.post(ApiConfig.todos, todo.toJson());
    return TodoItem.fromJson(data);
  }

  Future<TodoItem> updateTodo(TodoItem todo) async {
    if (ApiConfig.useMockData) {
      final index = MockDataStore.todos.indexWhere(
        (item) => item.id == todo.id,
      );
      if (index != -1) {
        MockDataStore.todos[index] = todo;
      }
      return todo;
    }
    final data = await _client.put(
      "${ApiConfig.todos}/${todo.id}",
      todo.toJson(),
    );
    return TodoItem.fromJson(data);
  }

  Future<void> deleteTodo(String id) async {
    if (ApiConfig.useMockData) {
      MockDataStore.todos.removeWhere((item) => item.id == id);
      return;
    }
    await _client.delete("${ApiConfig.todos}/$id");
  }
}