index.js

var D2R = 0.01745329251994329577;
import parser from './parser';
import {sExpr} from './process';

var knownTypes = ['PROJECTEDCRS', 'PROJCRS', 'GEOGCS', 'GEOCCS', 'PROJCS', 'LOCAL_CS', 'GEODCRS',
  'GEODETICCRS', 'GEODETICDATUM', 'ENGCRS', 'ENGINEERINGCRS'];

function rename(obj, params) {
  var outName = params[0];
  var inName = params[1];
  if (!(outName in obj) && (inName in obj)) {
    obj[outName] = obj[inName];
    if (params.length === 3) {
      obj[outName] = params[2](obj[outName]);
    }
  }
}

function d2r(input) {
  return input * D2R;
}

function cleanWKT(wkt) {
  var keys = Object.keys(wkt);
  for (var i = 0, ii = keys.length; i <ii; ++i) {
    var key = keys[i];
    // the followings are the crs defined in
    // https://github.com/proj4js/proj4js/blob/1da4ed0b865d0fcb51c136090569210cdcc9019e/lib/parseCode.js#L11
    if (knownTypes.indexOf(key) !== -1) {
      setPropertiesFromWkt(wkt[key]);
    }
    if (typeof wkt[key] === 'object') {
      cleanWKT(wkt[key]);
    }
  }
}

function setPropertiesFromWkt(wkt) {
  if (wkt.AUTHORITY) {
    var authority = Object.keys(wkt.AUTHORITY)[0];
    if (authority && authority in wkt.AUTHORITY) {
      wkt.title = authority + ':' + wkt.AUTHORITY[authority];
    }
  }
  if (wkt.type === 'GEOGCS') {
    wkt.projName = 'longlat';
  } else if (wkt.type === 'LOCAL_CS') {
    wkt.projName = 'identity';
    wkt.local = true;
  } else {
    if (typeof wkt.PROJECTION === 'object') {
      wkt.projName = Object.keys(wkt.PROJECTION)[0];
    } else {
      wkt.projName = wkt.PROJECTION;
    }
  }
  if (wkt.AXIS) {
    var axisOrder = '';
    for (var i = 0, ii = wkt.AXIS.length; i < ii; ++i) {
      var axis = [wkt.AXIS[i][0].toLowerCase(), wkt.AXIS[i][1].toLowerCase()];
      if (axis[0].indexOf('north') !== -1 || ((axis[0] === 'y' || axis[0] === 'lat') && axis[1] === 'north')) {
        axisOrder += 'n';
      } else if (axis[0].indexOf('south') !== -1 || ((axis[0] === 'y' || axis[0] === 'lat') && axis[1] === 'south')) {
        axisOrder += 's';
      } else if (axis[0].indexOf('east') !== -1 || ((axis[0] === 'x' || axis[0] === 'lon') && axis[1] === 'east')) {
        axisOrder += 'e';
      } else if (axis[0].indexOf('west') !== -1 || ((axis[0] === 'x' || axis[0] === 'lon') && axis[1] === 'west')) {
        axisOrder += 'w';
      }
    }
    if (axisOrder.length === 2) {
      axisOrder += 'u';
    }
    if (axisOrder.length === 3) {
      wkt.axis = axisOrder;
    }
  }
  if (wkt.UNIT) {
    wkt.units = wkt.UNIT.name.toLowerCase();
    if (wkt.units === 'metre') {
      wkt.units = 'meter';
    }
    if (wkt.UNIT.convert) {
      if (wkt.type === 'GEOGCS') {
        if (wkt.DATUM && wkt.DATUM.SPHEROID) {
          wkt.to_meter = wkt.UNIT.convert*wkt.DATUM.SPHEROID.a;
        }
      } else {
        wkt.to_meter = wkt.UNIT.convert;
      }
    }
  }
  var geogcs = wkt.GEOGCS;
  if (wkt.type === 'GEOGCS') {
    geogcs = wkt;
  }
  if (geogcs) {
    //if(wkt.GEOGCS.PRIMEM&&wkt.GEOGCS.PRIMEM.convert){
    //  wkt.from_greenwich=wkt.GEOGCS.PRIMEM.convert*D2R;
    //}
    if (geogcs.DATUM) {
      wkt.datumCode = geogcs.DATUM.name.toLowerCase();
    } else {
      wkt.datumCode = geogcs.name.toLowerCase();
    }
    if (wkt.datumCode.slice(0, 2) === 'd_') {
      wkt.datumCode = wkt.datumCode.slice(2);
    }
    if (wkt.datumCode === 'new_zealand_1949') {
      wkt.datumCode = 'nzgd49';
    }
    if (wkt.datumCode === 'wgs_1984' || wkt.datumCode === 'world_geodetic_system_1984') {
      if (wkt.PROJECTION === 'Mercator_Auxiliary_Sphere') {
        wkt.sphere = true;
      }
      wkt.datumCode = 'wgs84';
    }
    if (wkt.datumCode === 'belge_1972') {
      wkt.datumCode = 'rnb72';
    }
    if (geogcs.DATUM && geogcs.DATUM.SPHEROID) {
      wkt.ellps = geogcs.DATUM.SPHEROID.name.replace('_19', '').replace(/[Cc]larke\_18/, 'clrk');
      if (wkt.ellps.toLowerCase().slice(0, 13) === 'international') {
        wkt.ellps = 'intl';
      }

      wkt.a = geogcs.DATUM.SPHEROID.a;
      wkt.rf = parseFloat(geogcs.DATUM.SPHEROID.rf, 10);
    }

    if (geogcs.DATUM && geogcs.DATUM.TOWGS84) {
      wkt.datum_params = geogcs.DATUM.TOWGS84;
    }
    if (~wkt.datumCode.indexOf('osgb_1936')) {
      wkt.datumCode = 'osgb36';
    }
    if (~wkt.datumCode.indexOf('osni_1952')) {
      wkt.datumCode = 'osni52';
    }
    if (~wkt.datumCode.indexOf('tm65')
      || ~wkt.datumCode.indexOf('geodetic_datum_of_1965')) {
      wkt.datumCode = 'ire65';
    }
    if (wkt.datumCode === 'ch1903+') {
      wkt.datumCode = 'ch1903';
    }
    if (~wkt.datumCode.indexOf('israel')) {
      wkt.datumCode = 'isr93';
    }
  }
  if (wkt.b && !isFinite(wkt.b)) {
    wkt.b = wkt.a;
  }

  function toMeter(input) {
    var ratio = wkt.to_meter || 1;
    return input * ratio;
  }
  var renamer = function(a) {
    return rename(wkt, a);
  };
  var list = [
    ['standard_parallel_1', 'Standard_Parallel_1'],
    ['standard_parallel_1', 'Latitude of 1st standard parallel'],
    ['standard_parallel_2', 'Standard_Parallel_2'],
    ['standard_parallel_2', 'Latitude of 2nd standard parallel'],
    ['false_easting', 'False_Easting'],
    ['false_easting', 'False easting'],
    ['false-easting', 'Easting at false origin'],
    ['false_northing', 'False_Northing'],
    ['false_northing', 'False northing'],
    ['false_northing', 'Northing at false origin'],
    ['central_meridian', 'Central_Meridian'],
    ['central_meridian', 'Longitude of natural origin'],
    ['central_meridian', 'Longitude of false origin'],
    ['latitude_of_origin', 'Latitude_Of_Origin'],
    ['latitude_of_origin', 'Central_Parallel'],
    ['latitude_of_origin', 'Latitude of natural origin'],
    ['latitude_of_origin', 'Latitude of false origin'],
    ['scale_factor', 'Scale_Factor'],
    ['k0', 'scale_factor'],
    ['latitude_of_center', 'Latitude_Of_Center'],
    ['latitude_of_center', 'Latitude_of_center'],
    ['lat0', 'latitude_of_center', d2r],
    ['longitude_of_center', 'Longitude_Of_Center'],
    ['longitude_of_center', 'Longitude_of_center'],
    ['longc', 'longitude_of_center', d2r],
    ['x0', 'false_easting', toMeter],
    ['y0', 'false_northing', toMeter],
    ['long0', 'central_meridian', d2r],
    ['lat0', 'latitude_of_origin', d2r],
    ['lat0', 'standard_parallel_1', d2r],
    ['lat1', 'standard_parallel_1', d2r],
    ['lat2', 'standard_parallel_2', d2r],
    ['azimuth', 'Azimuth'],
    ['alpha', 'azimuth', d2r],
    ['srsCode', 'name']
  ];
  list.forEach(renamer);
  if (!wkt.long0 && wkt.longc && (wkt.projName === 'Albers_Conic_Equal_Area' || wkt.projName === 'Lambert_Azimuthal_Equal_Area')) {
    wkt.long0 = wkt.longc;
  }
  if (!wkt.lat_ts && wkt.lat1 && (wkt.projName === 'Stereographic_South_Pole' || wkt.projName === 'Polar Stereographic (variant B)')) {
    wkt.lat0 = d2r(wkt.lat1 > 0 ? 90 : -90);
    wkt.lat_ts = wkt.lat1;
  } else if (!wkt.lat_ts && wkt.lat0 && wkt.projName === 'Polar_Stereographic') {
    wkt.lat_ts = wkt.lat0;
    wkt.lat0 = d2r(wkt.lat0 > 0 ? 90 : -90);
  }
}
export default function(wkt) {
  var lisp = parser(wkt);
  var type = lisp[0];
  var obj = {};
  sExpr(lisp, obj);
  cleanWKT(obj);
  return obj[type];
}