#!/usr/bin/env node

var commander = require("commander"),
    graticule = require("d3-geo").geoGraticule(),
    write = require("./write");

commander
    .version(require("../package.json").version)
    .usage("[options]")
    .description("Generate a GeoJSON graticule.")
    .option("-o, --out <file>", "output file name; defaults to “-” for stdout", "-")
    .option("--extent <value>", "the major and minor extent", parseExtent)
    .option("--extent-minor <value>", "the minor extent; defaults to " + graticule.extentMajor(), parseExtent)
    .option("--extent-major <value>", "the major extent; defaults to " + graticule.extentMinor(), parseExtent)
    .option("--step <value>", "the major and minor step", parseStep)
    .option("--step-minor <value>", "the minor step; defaults to " + graticule.stepMinor(), parseStep)
    .option("--step-major <value>", "the major step; defaults to " + graticule.stepMajor(), parseStep)
    .option("--precision <value>", "the precision; defaults to " + graticule.precision(), graticule.precision)
    .parse(process.argv);

if (commander.args.length !== 0) {
  console.error();
  console.error("  error: unexpected arguments");
  console.error();
  process.exit(1);
}

if (commander.extent != null) {
  if (commander.extentMinor == null) commander.extentMinor = commander.extent;
  if (commander.extentMajor == null) commander.extentMajor = commander.extent;
}
if (commander.step != null) {
  if (commander.stepMinor == null) commander.stepMinor = commander.step;
  if (commander.stepMajor == null) commander.stepMajor = commander.step;
}
if (commander.extentMinor != null) graticule.extentMinor(commander.extentMinor);
if (commander.extentMajor != null) graticule.extentMajor(commander.extentMajor);
if (commander.stepMinor != null) graticule.stepMinor(commander.stepMinor);
if (commander.stepMajor != null) graticule.stepMajor(commander.stepMajor);

var writer = write(commander.out);
writer.write(JSON.stringify(graticule()) + "\n");
writer.end().catch(abort);

function parseStep(x) {
  return x = x.split(","), x.length === 1 ? [+x[0], +x[0]] : [+x[0], +x[1]];
}

function parseExtent(x) {
  return x = x.split(","), [[+x[0], +x[1]], [+x[2], +x[3]]];
}

function abort(error) {
  console.error(error.stack);
}