/**
 * 高德地图 API 客户端
 * 封装路径规划 API 调用
 */

import axios from 'axios'
import { AMAP_CONFIG, AMAP_ENDPOINTS } from '../config/amap'
import { generateCacheKey } from './geoUtils'

// 路由缓存
const routeCache = new Map()

/**
 * 清理过期缓存
 */
function cleanExpiredCache() {
  const now = Date.now()
  for (const [key, value] of routeCache.entries()) {
    if (now - value.timestamp > AMAP_CONFIG.cacheExpiry) {
      routeCache.delete(key)
    }
  }
}

// 定期清理缓存（每小时）
setInterval(cleanExpiredCache, 60 * 60 * 1000)

/**
 * 调用高德地图驾车路径规划 API
 * @param {Object} origin - 起点 { lon, lat }
 * @param {Object} destination - 终点 { lon, lat }
 * @param {Object} options - 可选参数
 * @returns {Promise<Object>} 路径规划结果
 */
export async function calculateDrivingRoute(origin, destination, options = {}) {
  const cacheKey = generateCacheKey(origin, destination)

  // 检查缓存
  if (routeCache.has(cacheKey)) {
    const cached = routeCache.get(cacheKey)
    console.log('[AmapAPI] 使用缓存路线:', cacheKey)
    return cached.data
  }

  const url = `${AMAP_CONFIG.baseUrl}${AMAP_ENDPOINTS.driving}`

  const params = {
    key: AMAP_CONFIG.webServiceKey,
    origin: `${origin.lon},${origin.lat}`,
    destination: `${destination.lon},${destination.lat}`,
    extensions: 'all', // 返回详细路径
    output: 'json',
    strategy: options.strategy ?? AMAP_CONFIG.strategy
  }

  try {
    console.log('[AmapAPI] 请求路径规划:', params)

    const response = await axios.get(url, {
      params,
      timeout: AMAP_CONFIG.timeout
    })

    if (response.data.status !== '1') {
      throw new Error(`高德API错误: ${response.data.info}`)
    }

    if (!response.data.route || !response.data.route.paths || response.data.route.paths.length === 0) {
      throw new Error('未找到可用路线')
    }

    const path = response.data.route.paths[0]

    // 提取路径数据
    const routeData = {
      distance: parseInt(path.distance), // 米
      duration: parseInt(path.duration), // 秒
      polyline: extractPolyline(path.steps),
      steps: path.steps.map(step => ({
        instruction: step.instruction,
        distance: parseInt(step.distance),
        duration: parseInt(step.duration)
      }))
    }

    // 缓存结果
    routeCache.set(cacheKey, {
      data: routeData,
      timestamp: Date.now()
    })

    console.log('[AmapAPI] 路径规划成功:', {
      distance: routeData.distance,
      duration: routeData.duration,
      points: routeData.polyline.split(';').length
    })

    return routeData
  } catch (error) {
    console.error('[AmapAPI] 路径规划失败:', error.message)
    throw error
  }
}

/**
 * 从步骤中提取完整的 polyline
 * @param {Array} steps - 路径步骤数组
 * @returns {string} 完整的 polyline 字符串
 */
function extractPolyline(steps) {
  const allPolylines = steps
    .map(step => step.polyline)
    .filter(Boolean)

  return allPolylines.join(';')
}

/**
 * 批量计算路线（并行请求）
 * @param {Array} routePairs - 路线对数组 [{ origin, destination, type, name, id }]
 * @returns {Promise<Array>} 路线结果数组
 */
export async function calculateMultipleRoutes(routePairs) {
  console.log(`[AmapAPI] 批量计算 ${routePairs.length} 条路线`)

  const promises = routePairs.map(async (pair) => {
    try {
      const routeData = await calculateDrivingRoute(pair.origin, pair.destination)

      return {
        id: pair.id,
        name: pair.name,
        type: pair.type,
        origin: pair.origin,
        destination: pair.destination,
        ...routeData,
        success: true
      }
    } catch (error) {
      console.warn(`[AmapAPI] 路线计算失败 (${pair.name}):`, error.message)

      return {
        id: pair.id,
        name: pair.name,
        type: pair.type,
        origin: pair.origin,
        destination: pair.destination,
        error: error.message,
        success: false
      }
    }
  })

  const results = await Promise.all(promises)

  const successCount = results.filter(r => r.success).length
  console.log(`[AmapAPI] 批量计算完成: ${successCount}/${routePairs.length} 成功`)

  return results
}

/**
 * 清除所有缓存
 */
export function clearRouteCache() {
  routeCache.clear()
  console.log('[AmapAPI] 缓存已清空')
}

/**
 * 获取缓存统计信息
 */
export function getCacheStats() {
  return {
    size: routeCache.size,
    keys: Array.from(routeCache.keys())
  }
}