import { toast } from './toast'

let tdtLoaded = false
let tdtLoadCallbacks: ((T: typeof window.T) => void)[] = []

const mapKey = import.meta.env.VITE_TIANDITU_MAP_KEY

export function loadTianDiTu(onLoadedCallback?: (T: typeof window.T) => void) {
  if (tdtLoaded && window.T) {
    onLoadedCallback?.(window.T)
    return
  }

  if (onLoadedCallback)
    tdtLoadCallbacks.push(onLoadedCallback)

  if (document.querySelector(`script[src*="tianditu.gov.cn/api"]`))
    return

  const script = document.createElement('script')
  script.src = `https://api.tianditu.gov.cn/api?v=4.0&tk=${mapKey}`
  script.onload = () => {
    if (!window.T) {
      console.error('天地图脚本加载成功，但 T 不存在')
      return
    }

    tdtLoaded = true
    tdtLoadCallbacks.forEach(cb => cb(window.T!))
    tdtLoadCallbacks = []
  }
  script.onerror = () => {
    console.error('天地图脚本加载失败')
    tdtLoadCallbacks = []
  }

  document.head.appendChild(script)
}

export async function getAddressByPoint(lon: number, lat: number): Promise<string> {
  return new Promise((resolve, reject) => {
    loadTianDiTu((T) => {
      try {
        const geocoder = new T.Geocoder()

        geocoder.getLocation(new T.LngLat(lon, lat), (res: any) => {
          try {
            const addr = res.formatted_address
            const comp = res.addressComponent || {}

            if (!addr) {
              const parts = [
                comp.nation,
                comp.province,
                comp.city,
                comp.county,
                comp.road,
                comp.poi || comp.address,
              ].filter(Boolean)

              resolve(parts.join(' '))
            }
            else {
              resolve(addr)
            }
          }
          catch (err) {
            reject(err)
          }
        })
      }
      catch (err) {
        reject(err)
      }
    })
  })
}

export async function getPoint(): Promise<{ lon: number, lat: number } | null> {
  return new Promise((resolve, reject) => {
    uni.getLocation({
      type: 'wgs84',
      success(res) {
        console.log(res)

        const lon = res.longitude
        const lat = res.latitude

        if (!lon || !lat || (lon === 0 && lat === 0)) {
          resolve(null) // 无效坐标返回 null
        }
        else {
          resolve({ lon, lat })
        }
      },
      fail(err) {
        console.error('获取定位失败', err)
        resolve(null) // 定位失败也返回 null，调用方可以判断
      },
    })
  })
}

export interface CurrentLocation {
  lon: number
  lat: number
  address: string
}

/**
 * 获取当前位置及对应地址（自动处理错误和提示）
 * @returns 如果成功返回位置信息，否则返回 null（已自动 toast 提示）
 */
export function getCurrentLocation(): Promise<CurrentLocation | null> {
  return getPoint()
    .then((point) => {
      if (!point) {
        return null
      }

      return getAddressByPoint(point.lon, point.lat).then(address => ({
        lon: point.lon,
        lat: point.lat,
        address,
      }))
    })
    .catch((err) => {
      console.error('[getCurrentLocation] 获取位置失败:', err)
      return null
    })
    .finally(() => {
      console.log('[getCurrentLocation] 操作完成')
    })
}

export async function getDrive(points: number[][], style: string = '0') {
  loadTianDiTu((T) => {
    const drivingRoute = new T.DrivingRoute(null)
  })
}