#!/usr/bin/env node

var argv = require('minimist')(process.argv.slice(2));

// 32-bit integer conversion of the built-in RNG.
function JavaScript() {}
JavaScript.prototype.next = function () {
  return Math.random() * 4294967296 >>> 0;
};
JavaScript.NUM_BITS = 32;

// Park-Miller.
function ParkMiller(seed) {
  this._seed = seed % 2147483647;
  if (this._seed <= 0) this._seed += 2147483646;
}
ParkMiller.NUM_BITS = 31;

ParkMiller.prototype.next = function () {
  return this._seed = this._seed * 16807 % 2147483647;
};

var SEED = argv.seed || 12345,
    COUNT = argv.count || 10000000,
    PRNG = argv.prng || 'JavaScript';

var RandomClass = eval(PRNG);
if (!RandomClass) {
  throw new Error('Invalid PRNG ' + PRNG);
}

process.stdout.write('# ' + PRNG + '\n');
process.stdout.write('# seed: ' + SEED + '\n');
process.stdout.write('type: d\n');
process.stdout.write('count: ' + COUNT + '\n');
process.stdout.write('numbit: ' + (RandomClass.NUM_BITS || 32) + '\n');

var r = new RandomClass(SEED);
for (var i = 0; i < COUNT; i++) {
  var num = r.next().toString();
  num = '          '.slice(0, 10 - num.length) + num;
  process.stdout.write(num + '\n');
}