const fs = require('fs')

// Customise as required
const inFile = 'geoFence.txt'
const outFile = 'geoJSON.json'

const geoJSON = {
  type: 'FeatureCollection',
  features: [],
}

fs.readFile(inFile, 'utf8', (err, data) => {
  const fences = data.match(/\[([^\]]+)\]([^\[]*)/g)
  fences.forEach(fence => {
    const geoFence = {
      type: 'Feature',
      properties: {
        name: ''
      },
      geometry: {
        type: 'Polygon',
        coordinates: [[]]
      }
    }
    geoFence.properties.name = fence.match(/\[([^\]]+)\]/)[1]
    geoFence.geometry.coordinates[0] = fence.match(/[0-9\-\.]+,\s*[0-9\-\.]+/g).map(point => [parseFloat(point.split(',')[1]), parseFloat(point.split(',')[0])])
    geoFence.geometry.coordinates[0].push(geoFence.geometry.coordinates[0][0])

    geoJSON.features.push(geoFence)
  })

  fs.writeFile(outFile, JSON.stringify(geoJSON), 'utf8', () => { })
})