const
  fs = require('fs-extra'),
  path = require('path'),
  utils = require('./utils'),
  polyUtil = require('./poly_util'),
  FILE = require('./file_constants'),
  debug = require('debug')('agm:file_satlog');

const POL = ".POL";
const PAT = ".PAT";
const INC = "INC";
const EXC = "EXC";
const SWIDTH = "SWIDTH";

function getItem(val, pos) {
  return val[pos] ? val[pos].trim() : '';
}

function readSatLogJob(filePath, areaTypeAndFiles, ops, cb) {
  let firstCol, fields, lat, lon, valueF, swath = 0, isMetric = false, newPolygon = false, sprayPoly = false;
  let cornerSets = [], sprayAreas = [], xclAreas = [];
  const bareFilename = utils.normalizeName(utils.bareFilename(areaTypeAndFiles.area));

  return fs.readFile(path.join(filePath, areaTypeAndFiles.area))
    .then((data) => {
      let areas, lines = data.toString().split("\n");

      for (const i in lines) {
        if (sprayAreas.length >= FILE.MAX_ITEM || xclAreas.length >= FILE.MAX_ITEM) break;

        fields = lines[i].trim().split(new RegExp('\\s+'));
        firstCol = getItem(fields, 0);

        if (!firstCol.length) continue;

        if (firstCol === POL || firstCol === PAT || i == lines.length - 1) {
          newPolygon = (firstCol === POL) ? true : false;

          if (cornerSets.length >= 3) {
            if (sprayPoly) {
              areas = polyUtil.createAreas(0, cornerSets, bareFilename, ops.sprZoneColor, ops.appRate, ops.crop);
              if (sprayAreas.length < FILE.MAX_ITEM && !utils.isEmptyArray(areas))
                sprayAreas = sprayAreas.concat(areas);
            }
            else {
              areas = polyUtil.createAreas(1, cornerSets, 'XCL');
              if (xclAreas.length < FILE.MAX_ITEM && !utils.isEmptyArray(areas))
                xclAreas = xclAreas.concat(areas);
            }
          }
          cornerSets = [];
          continue;
        }

        if (newPolygon) {
          if (firstCol === INC || firstCol === EXC) {
            sprayPoly = (firstCol === INC) ? true : false;
          }
          else {
            if (fields.length === 2) {
              lat = parseFloat(getItem(fields, 0));
              lon = parseFloat(getItem(fields, 1));
              if (utils.isNumber(lat) && utils.isNumber(lon)) {
                cornerSets.push([lon, lat]);  // Revert coor order in GeoJSON
              }
            }
          }
        }
        else {
          if (firstCol === SWIDTH && fields.length > 1) {
            valueF = parseFloat(getItem(fields, 1));
            if (utils.isNumber(valueF))
              swath = valueF;
            if (fields.length >= 3) {
              isMetric = (getItem(fields, 3)).toUpperCase() === 'M' ? true : false;
            }
            continue;
          }
        }
      }

      const jobItem = {
        sprayAreas: sprayAreas,
        xclAreas: xclAreas,
        meta: { measureUnit: isMetric, swath: swath }
      };

      if (!utils.isEmptyArray(xclAreas)) {
        jobItem['xclAreas'] = polyUtil.processXclsName(jobItem.sprayAreas, jobItem.xclAreas);
      }

      if (cb)
        cb(null, jobItem);
      else
        return jobItem;
    })
    .catch(err => {
      if (cb)
        return cb(err);
      else throw err;
    });
}

module.exports = {
  readSatLogJob
}