Transforms EPSG8122 to WGS84, reduces the precision and simplifies the structure if size is too big

README.md

Requires proj4 and simplify-geojson. Receives coordinates in EPSG:8122 projection as regularly used in Bulgarian arcgeo government servers. Transforms to geojson format with reduced precision of less than a meter. Then if the size of the resulting file is bigger than 20k characters, it simplifies it to reduce load on processing later on.

transform-EPSG8122.js

data = process.argv[2];
header=data.substr(0,data.indexOf("(")).toUpperCase().trim();
if (header=="POLYGON" || header=="POINT" || header=="MULTIPOINT" || header=="MULTIPOLYGON" || header=="MULTILINESTRING" || header=="LINESTRING") {
  var proj4 = require("proj4");

  proj4.defs("EPSG:8122",'PROJCS["BGS2005", GEOGCS["GCS_WGS_1984", DATUM["D_WGS_1984", SPHEROID["WGS_1984", 6378137.0, 298.257223563]], PRIMEM["Greenwich", 0.0], UNIT["degree", 0.017453292519943295], AXIS["Longitude", EAST], AXIS["Latitude", NORTH]],  PROJECTION["Lambert_Conformal_Conic_2SP"],  PARAMETER["central_meridian", 25.5],   PARAMETER["latitude_of_origin", 42.66787568333],  PARAMETER["standard_parallel_1", 43.33333333333],  PARAMETER["false_easting", 500000.0],  PARAMETER["false_northing", 4725824.3591],  PARAMETER["scale_factor", 1.0],  PARAMETER["standard_parallel_2", 42.0],  UNIT["m", 1.0],  AXIS["x", EAST],  AXIS["y", NORTH],  AUTHORITY["EPSG","8122"]]');
  
  if (header=="POLYGON") 
    header="Polygon";
  else if (header=="POINT")
    header="Point";
  else if (header=="MULTIPOINT")
    header="MultiPoint";
  else if (header=="MULTIPOLYGON") 
    header="MultiPolygon";
  else if (header=="MULTILINESTRING") 
    header="MultiLineString";
  else if (header=="LINESTRING") 
    header="LineString";
  
  res=[];
  data=data.substring(data.indexOf("(")); 
  data=data.replace(/\(/g,"[").replace(/\)/g,"]").replace(new RegExp("([0-9]\+\\.?[0-9]*) ([0-9]\+\\.?[0-9]*)", 'g'), function (match) {
    var d=match.split(" ");
    d[0]=parseFloat(d[0]);
    d[1]=parseFloat(d[1]);
    d=proj4('EPSG:8122').inverse(d);
    d[0]=d[0].toFixed(6); 
    d[1]=d[1].toFixed(6);
    return "["+d.join(",")+"]";
  });

  geo='{"type":"Feature","properties":{},"geometry":{"type":"'+header+'","coordinates":'+data+'}}';

  if (geo.length>20000) {
    var simplify = require('simplify-geojson')
    geo=simplify(JSON.parse(geo),0.00005);
    geo=JSON.stringify(geo);
  }
  
  console.log(geo);
} else {
  console.log("ERROR");
}