/* Hjson http://hjson.org */
"use strict";

var os=require('os'); // will be {} when used in a browser

function tryParseNumber(text, stopAtNext) {

  // try to parse a number

  var number, string = '', leadingZeros = 0, testLeading = true;
  var at = 0;
  var ch;
  function next() {
    ch = text.charAt(at);
    at++;
    return ch;
  }

  next();
  if (ch === '-') {
    string = '-';
    next();
  }
  while (ch >= '0' && ch <= '9') {
    if (testLeading) {
      if (ch == '0') leadingZeros++;
      else testLeading = false;
    }
    string += ch;
    next();
  }
  if (testLeading) leadingZeros--; // single 0 is allowed
  if (ch === '.') {
    string += '.';
    while (next() && ch >= '0' && ch <= '9')
      string += ch;
  }
  if (ch === 'e' || ch === 'E') {
    string += ch;
    next();
    if (ch === '-' || ch === '+') {
      string += ch;
      next();
    }
    while (ch >= '0' && ch <= '9') {
      string += ch;
      next();
    }
  }

  // skip white/to (newline)
  while (ch && ch <= ' ') next();

  if (stopAtNext) {
    // end scan if we find a punctuator character like ,}] or a comment
    if (ch === ',' || ch === '}' || ch === ']' ||
      ch === '#' || ch === '/' && (text[at] === '/' || text[at] === '*')) ch = 0;
  }

  number = +string;
  if (ch || leadingZeros || !isFinite(number)) return undefined;
  else return number;
}

function createComment(value, comment) {
  if (Object.defineProperty) Object.defineProperty(value, "__COMMENTS__", { enumerable: false, writable: true });
  return (value.__COMMENTS__ = comment||{});
}

function removeComment(value) {
  Object.defineProperty(value, "__COMMENTS__", { value: undefined });
}

function getComment(value) {
  return value.__COMMENTS__;
}

function forceComment(text) {
  if (!text) return "";
  var a = text.split('\n');
  var str, i, j, len;
  for (j = 0; j < a.length; j++) {
    str = a[j];
    len = str.length;
    for (i = 0; i < len; i++) {
      var c = str[i];
      if (c === '#') break;
      else if (c === '/' && (str[i+1] === '/' || str[i+1] === '*')) {
        if (str[i+1] === '*') j = a.length; // assume /**/ covers whole block, bail out
        break;
      }
      else if (c > ' ') {
        a[j] = '# ' + str;
        break;
      }
    }
  }
  return a.join('\n');
}

module.exports = {
  EOL: os.EOL || '\n',
  tryParseNumber: tryParseNumber,
  createComment: createComment,
  removeComment: removeComment,
  getComment: getComment,
  forceComment: forceComment,
};