coffee_centroid.js

// Takes geojson output from http://overpass-turbo.eu/
// Query

/*
This has been generated by the overpass-turbo wizard.
“crop=coffee”

[out:json][timeout:25];
(
  node["crop"="coffee"]({{bbox}});
  way["crop"="coffee"]({{bbox}});
  relation["crop"="coffee"]({{bbox}});
);
out body;
>;
out skel qt;
*/

var turf 			= require('turf')
var fs				= require('fs')
var What3Words 		= require('geo.what3words')
var async			= require('async')

var fname			= process.argv[2]
var outname			= process.argv[3]
var lang			= process.argv[4]

var WHAT3WORDSKEY	= process.env.WHAT3WORDSKEY

console.log("infile", fname)
console.log("outfile", outname)
console.log("lang", lang)

if (!fs.existsSync(fname) ) {
	console.log("Invalid input file")
	process.exit(-1)
}

var w3w = new What3Words(WHAT3WORDSKEY, {
	language: lang,
	userAgent: 'OJO'
});
	
var collection	= JSON.parse(fs.readFileSync(fname, 'utf8'));
var features 		= []
var features_words 	= []

for( var f in collection.features ) {
	var feature = collection.features[f]
	var type = feature.geometry.type
	if( type=='Polygon') {
		var centroid = turf.centroid(feature)
		feature.geometry = centroid.geometry
	}
	
	features.push(feature)
}

function words(feature) {
	var coords 		= feature.geometry.coordinates
	var lat			= coords[1]
	var lng			= coords[0]
	var position	= lat + ", "+lng
	
	return w3w.positionToWords({
		position: position
	}).then(function(response) {
		console.log(response); //prom.cape.pump
		feature.properties.what3words = response
	});
}

var promises = features.map(words)

Promise.all(promises).then(function(values) {
	collection.features = features	
	console.log("writing features:", features.length)
	fs.writeFileSync(outname, JSON.stringify(collection,null,'\t'), 'utf8')	
	console.log("Done")
}, function(reason) {
	console.log("Reject Reason", reason)
})