#!/usr/bin/env node
'use strict';

// EXAMPLE:
// node bin/dns-parse.js samples/a-0.mdns.bin

var path = require('path');
// pass a terminal arg
var filename = process.argv[2];
var outname = process.argv[3];

if (!filename || /(-h)|(--help)/.test(process.argv.join(' '))) {
  console.error("");
  console.error("Accepts a DNS packet (binary or json), converts it, and then converts it back to verify the function of the parser and packer");
  console.error("");
  console.error("Usage: node bin/dns-test.js <path/to/sample.json|.bin> <path/to/sample.bin|.json>");
  console.error("Example: node bin/dns-test.js ./samples/services-0.mdns.json ./samples/services-0.mdns.bin");
  process.exit(1);
  return;
}

var PromiseA = require('bluebird');
var fs = PromiseA.promisifyAll(require('fs'));
var dnsjs = require('../').DNSPacket;
var extname = path.extname(filename).substr(1).toLowerCase();

if ('json' !== extname && 'bin' !== extname) {
  console.error("The file extension must end in .json or .bin (raw DNS packet)");
  process.exit(3);
  return;
}

var hexdump = require('hexdump.js').hexdump;

function testJsonAsync(nb) {
  var packet = dnsjs.write(JSON.parse(nb.toString('ascii')));
  var str = hexdump(packet);
  console.log(str);
  var json = dnsjs.parse(packet);
  if (json.error) {
    console.error(json);
    process.exit(37);
    return;
  }

  console.log("[OK] JSON -> binary -> JSON");

  if (!outname) {
    console.warn('');
    console.warn(
      "Usage: node bin/dns-test.js '" + filename + "' './" + path.basename(filename).replace(path.extname(filename), '.bin') + "'"
    );
    console.warn('');
    return;
  }

  fs.writeFileSync(path.basename(filename).replace(path.extname(filename), '.bin'), packet, null);
}

function testBinAsync(nb) {
  var bin = nb.buffer.slice(nb.byteOffset, nb.byteOffset + nb.byteLength);
  var json = dnsjs.parse(bin);
  if (json.error) {
    console.error(json);
    process.exit(38);
    return;
  }
  var bin2 = dnsjs.write(json);
  var json2 = dnsjs.parse(bin2);
  if (json2.error) {
    console.error(json2);
    process.exit(37);
    return;
  }

  var assert = require('assert');
  // EXPLANATION:
  // The strategy used for compression pointers has not yet been proven
  // as deterministic... and we don't implement them anyway, so this may not be the same
  json = JSON.parse(JSON.stringify(json)
    .replace(/,"labels":.*?\]/, '')
    .replace(/,"cpcount":\d+/, '')
  );
  json2 = JSON.parse(JSON.stringify(json2)
    .replace(/,"labels":.*?\]/, '')
    .replace(/,"cpcount":\d+/, '')
  );
  //json2 = JSON.parse(JSON.stringify(json2));
  //console.log(json);
  //console.log(json2);
  assert.deepEqual(json, json2);

  console.log("[OK] binary -> JSON -> binary -> JSON");
  console.log("(compression pointer support needs to be improved in order to support direct bin -> JSON -> bin testing)");

  if (!outname) {
    console.warn('');
    console.warn(
      "Usage: node bin/dns-test.js '" + filename + "' './" + path.basename(filename).replace(path.extname(filename), '.json') + "'"
    );
    console.warn('');
    return;
  }

  fs.writeFileSync(path.basename(filename).replace(path.extname(filename), '.json'), JSON.stringify(json, null, 2), null);
}

if ('json' === extname) {
  return fs.readFileAsync(filename, null).then(testJsonAsync);
}

if ('bin' === extname) {
  return fs.readFileAsync(filename, null).then(testBinAsync);
}