// src/composables/useCoordinatePicker.ts
import { ref, reactive } from 'vue';
import type { CoordinatePicker, PickResult } from './CoordinatePicker';

export function useCoordinatePicker(coordinatePicker: CoordinatePicker | null) {
  const isPickerEnabled = ref(false);
  const pickHistory = reactive<PickResult[]>([]);
  const lastPickResult = ref<PickResult | null>(null);
  const maxHistoryLength = 10;

  // 启用坐标拾取
  const enablePicker = (): void => {
    if (coordinatePicker.value) {
      coordinatePicker.value.enable();
      isPickerEnabled.value = true;
      
      // 添加拾取回调
      coordinatePicker.value.onPick(handlePick);
    }
  };

  // 禁用坐标拾取
  const disablePicker = (): void => {
    if (coordinatePicker.value) {
      coordinatePicker.value.disable();
      isPickerEnabled.value = false;
    }
  };

  // 切换拾取状态
  const togglePicker = (): void => {
    if (isPickerEnabled.value) {
      disablePicker();
    } else {
      enablePicker();
    }
  };

  // 处理拾取结果
  const handlePick = (result: PickResult): void => {
    lastPickResult.value = result;
    
    // 添加到历史记录
    pickHistory.unshift(result);
    
    // 限制历史记录长度
    if (pickHistory.length > maxHistoryLength) {
      pickHistory.pop();
    }
  };

  // 清除历史记录
  const clearHistory = (): void => {
    pickHistory.splice(0, pickHistory.length);
    lastPickResult.value = null;
  };

  // 复制坐标到剪贴板
  const copyToClipboard = (result: PickResult): void => {
    const text = `经度: ${result.longitude.toFixed(6)}, 纬度: ${result.latitude.toFixed(6)}, 高程: ${result.height.toFixed(2)}米`;
    
    navigator.clipboard.writeText(text).then(() => {
      console.log('坐标已复制到剪贴板:', text);
    }).catch(err => {
      console.error('复制失败:', err);
    });
  };

  // 格式化坐标显示
  const formatCoordinate = (result: PickResult): string => {
    return `经度: ${result.longitude.toFixed(6)}\n纬度: ${result.latitude.toFixed(6)}\n高程: ${result.height.toFixed(2)}米`;
  };

  // 获取WKT格式坐标
  const getWKT = (result: PickResult): string => {
    return `POINT(${result.longitude.toFixed(6)} ${result.latitude.toFixed(6)})`;
  };

  // 获取GeoJSON格式坐标
  const getGeoJSON = (result: PickResult): any => {
    return {
      type: 'Feature',
      geometry: {
        type: 'Point',
        coordinates: [result.longitude, result.latitude, result.height]
      },
      properties: {
        height: result.height,
        terrainHeight: result.terrainHeight
      }
    };
  };

  return {
    isPickerEnabled,
    pickHistory,
    lastPickResult,
    enablePicker,
    disablePicker,
    togglePicker,
    clearHistory,
    copyToClipboard,
    formatCoordinate,
    getWKT,
    getGeoJSON
  };
}