// lib/features/devices/domain/services/path_planning_service.dart
import 'dart:collection';
import 'package:flutter/cupertino.dart';
import '../data/models/device_add_path_point_model.dart';

class PathPlanningService {
  static final PathPlanningService _instance = PathPlanningService._internal();
  factory PathPlanningService() => _instance;
  PathPlanningService._internal();

  // 🔥 核心：全局唯一的可变队列
  final Queue<DeviceAddPathPointModel> locationQueue = Queue();

  bool isRunning = false;
  int currentIndex = 0;
  int totalCount = 0;

  /// 🔥 存：生成路径后立即存储
  void updateQueue(List<DeviceAddPathPointModel> locations) {
    if (locations.isEmpty) {
      debugPrint('⚠️ [PathPlanningService] 尝试更新空队列');
      return;
    }

    locationQueue.clear();
    locationQueue.addAll(locations);
    currentIndex = 0;
    totalCount = locations.length;

    debugPrint('✅ [PathPlanningService] 队列已更新，共 $totalCount 个点');
  }

  /// 🔥 取：发送时取出第一个点
  DeviceAddPathPointModel? removeFirst() {
    if (locationQueue.isEmpty) {
      debugPrint('⚠️ [PathPlanningService] 队列为空');
      return null;
    }

    final point = locationQueue.removeFirst();
    currentIndex++;

    debugPrint(
      '📍 [PathPlanningService] 取出第 $currentIndex/$totalCount 个点：'
          '${point.latitude}, ${point.longitude}',
    );

    return point;
  }

  /// 🔥 获取进度
  int get remainingCount => locationQueue.length;
  int get completedCount => currentIndex;
  double get progress => totalCount == 0 ? 0.0 : currentIndex / totalCount;

  bool get isEmpty => locationQueue.isEmpty;
  bool get isNotEmpty => locationQueue.isNotEmpty;

  /// 🔥 清空（作业完成或停止时）
  void clear() {
    locationQueue.clear();
    isRunning = false;
    currentIndex = 0;
    totalCount = 0;
    debugPrint('🧹 [PathPlanningService] 队列已清空');
  }


  int get length => locationQueue.length;

  /// 获取当前队列（供 Cubit 使用）
  Queue<DeviceAddPathPointModel> getQueue() {
    return Queue.of(locationQueue);
  }
}