MapGIS Client for JavaScript API

import Zondy from '../Zondy'
import { Log, defaultValue, defined } from '../../util'

/**
 * 空间参考系
 * <br><br>[ES5引入方式]：<br/>
 * Zondy.SpatialReference() <br/>
 * [ES6引入方式]：<br/>
 * import { SpatialReference } from "@mapgis/webclient-common" <br/>
 * <br/>
 * @class SpatialReference
 * @moduleEX GeometryModule
 * @param {Object|String} options 构造参数
 * @param {Number|undefined} [options.wkid] 空间参考系的wkid
 * @param {String|undefined} [options.wkt] 空间参考系Well Known Text 或 proj4js字符串,仅支持proj4js能够支持的字符串。OGC WKT标准{@link https://www.ogc.org/standard/wkt-crs/}, EPSG坐标系查询{@link https://epsg.io/}
 * @param {String|undefined} [options.unit] 空间参考系单位
 */
class SpatialReference {
  constructor(options) {
    options = defaultValue(options, {})
    const { wkid, wkt } = this._parseSpatialReferenceOptions(options)
    /**
     * 投影坐标系的id
     * @member {Number} SpatialReference.prototype.wkid
     */
    this.wkid = wkid
    /**
     * 投影坐标系的描述
     * @member {String|undefined} SpatialReference.prototype.wkt
     */
    this.wkt = wkt
    /**
     * 投影坐标系的描述
     * @member {String|undefined} SpatialReference.prototype.unit
     */
    this.unit = options.unit
  }

  /**
   * 是否是WGS84相关坐标系
   * @readonly
   * @type {Boolean}
   */
  get isWGS84() {
    return this.wkid === 4326
  }

  /**
   * 是否是地理坐标系
   * @readonly
   * @type {Boolean}
   */
  get isGeographic() {
    if ([4326, 4490, 4610, 4214].indexOf(this.wkid) > -1) {
      return true
    }
    return false
  }

  /**
   * 是否是Web墨卡托坐标系
   * @readonly
   * @type {Boolean}
   */
  get isWebMercator() {
    if ([102113, 102100, 900913, 3857].indexOf(this.wkid) > -1) {
      return true
    }
    return false
  }

  /**
   *  坐标系否支持环绕国际日期线，当参考系是Web Mercator或WGS84
   * @readonly
   * @type {Boolean}
   */
  get isWrappable() {
    if (
      [4326, 4490, 4610, 4214, 102113, 102100, 900913, 3857].indexOf(
        this.wkid
      ) > -1
    ) {
      return true
    }
    return false
  }

  /**
   *  一个便捷的Web墨卡托对象，只有当类型为Web墨卡托时才有
   * @readonly
   * @type {SpatialReference}
   */
  get WebMercator() {
    return this.isWebMercator ? this.clone() : undefined
  }

  /**
   *  一个便捷的WGS84对象，只有当类型为WGS84时才有
   * @readonly
   * @type {SpatialReference}
   */
  get WGS84() {
    return this.isGeographic ? this.clone() : undefined
  }

  /**
   * @private
   * @description: 解析传入的options
   * @param {*} options
   * @return {*}
   */
  _parseSpatialReferenceOptions(options) {
    let wkid = 4326
    let wkt
    if (typeof options === 'string') {
      const req = /^(EPSG|epsg)(:)?\d+$/
      const reqWkid = /\d+$/
      const wkidStr = options.match(reqWkid)
      if (req.test(options) && wkidStr) {
        wkid = parseInt(wkidStr[0])
        wkt = undefined
      } else {
        // 字符串设置为wkt
        wkt = options
        wkid = undefined
      }
    } else if (typeof options === 'object') {
      if (defined(options['wkid'])) {
        wkid = parseInt(options['wkid'])
      }
      if (options['wkt']) {
        wkt = options['wkt']
        wkid = undefined
      }
    } else {
      Log.error('无法解析传入的空间参考系参数')
    }
    return {
      wkid,
      wkt
    }
  }

  /**
   * 克隆几何对象
   * @return {Geometry} 克隆后的几何对象
   */
  clone() {
    return new SpatialReference(this.toJSON())
  }

  /**
   * 将JSON里的数据导入到几何中
   * @param {Object} json JSON对象
   */
  static fromJSON(json) {
    json = defaultValue(json, {})
    return new SpatialReference(json)
  }

  /**
   * 导出为json对象
   * @return {Object} json对象
   */
  toJSON() {
    return {
      wkid: this.wkid,
      wkt: this.wkt
    }
  }

  /**
   * 导出为字符串(此处语义和设计不符，为igs服务参数专用，后续需要修改)
   * @private
   * @return {String} 坐标系字符串
   */
  toString() {
    let wkt = ''
    switch (this.wkid) {
      case 4326:
        wkt = 'EPSG:4326'
        break
      case 3857:
        wkt = 'EPSG:3857'
        break
      default:
        wkt = this.wkt
    }
    return wkt
  }

  /**
   * 判断坐标系对象的wkid和wkt的值是否相等
   * @param {SpatialReference | Object} spatialReference 坐标系对象
   * @return {Boolean} wkid和wkt的值是否相等
   * */
  equals(spatialReference) {
    if (!(spatialReference instanceof SpatialReference)) {
      if (
        !(
          spatialReference instanceof Object &&
          spatialReference.hasOwnProperty('wkid') &&
          spatialReference.hasOwnProperty('wkt')
        )
      ) {
        throw new Error('spatialReference的格式不正确！')
      }
    }

    // 暂时无法保证wkt值一致，因此只比较wkid一致即可
    if (this.wkid === spatialReference.wkid) {
      return true
    } else if (
      this.wkt &&
      spatialReference.wkt &&
      this.wkt === spatialReference.wkt
    ) {
      return true
    }
    return false
  }
}

Zondy.SpatialReference = SpatialReference
export default SpatialReference