import { getGisAccessToken, getGisBaseUrl, getGisDefaultCenter } from './gisLoader'

/** GIS POI 接口成功状态码 */
const POI_STATUS_OK = 2000

/**
 * 解析 POI location 字段（文档格式：纬度,经度）为地图坐标 [经度, 纬度]
 */
export function parsePoiLngLat(location) {
  if (!location || typeof location !== 'string') {
    return null
  }
  const parts = location.split(',').map((n) => Number(String(n).trim()))
  if (parts.length < 2 || !parts.every((n) => Number.isFinite(n))) {
    return null
  }
  const [lat, lng] = parts
  return [lng, lat]
}

function normalizePoiList(data) {
  if (data?.status !== POI_STATUS_OK || !Array.isArray(data?.body?.pois)) {
    return []
  }
  return data.body.pois
    .map((row) => row?.poi || row)
    .filter((poi) => poi && typeof poi === 'object')
}

/**
 * 周边搜索（GIS 接口文档 §2.2 /agis/search/v1/pois/region）
 * @param {{ center?: [number, number], radius?: number, pageNum?: number, pageSize?: number }} [options]
 */
export async function searchNearbyPois(options = {}) {
  const base = getGisBaseUrl()
  const key = getGisAccessToken()
  if (!base || !key) {
    return []
  }

  const center = options.center || getGisDefaultCenter()
  const [longitude, latitude] = center
  const radius = options.radius ?? 5000
  const pageNum = options.pageNum ?? 1
  const pageSize = options.pageSize ?? 1000

  const params = new URLSearchParams({
    longitude: String(longitude),
    latitude: String(latitude),
    radius: String(radius),
    page_num: String(pageNum),
    page_size: String(pageSize),
    key
  })

  const url = `${base}/agis/search/v1/pois/region?${params.toString()}`
  const res = await fetch(url)
  if (!res.ok) {
    return []
  }

  return normalizePoiList(await res.json())
}

/*
 * 多边形区域搜索（GIS 接口文档 §2.3）— 暂不使用
 *
 * export const BA_QING_POI_POLYGON = [...]
 * export function formatPolygonParam(points) { ... }
 * export async function searchPolygonPois(options = {}) { ... }
 */