// SHA-1 implementation
// © 2002-2005 Chris Veness
// http://www.movable-type.co.uk/scripts/SHA-1.html

function sha1(msg)
{
    // constants [4.2.1]
    var K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];

    // PREPROCESSING 
 
    msg += String.fromCharCode(0x80); // add trailing '1' bit to string [5.1.1]

    // convert string msg into 512-bit/16-integer blocks arrays of ints [5.2.1]
    var l = Math.ceil(msg.length/4) + 2;  // long enough to contain msg plus 2-word length
    var N = Math.ceil(l/16);              // in N 16-int blocks
    var M = new Array(N);
    for (var i=0; i<N; i++) {
        M[i] = new Array(16);
        for (var j=0; j<16; j++) {  // encode 4 chars per integer, big-endian encoding
            M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | (msg.charCodeAt(i*64+j*4+1)<<16) | 
                      (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
        }
    }
    // add length (in bits) into final pair of 32-bit integers (big-endian) [5.1.1]
    M[N-1][14] = ((msg.length-1) >>> 30) * 8;
    M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

    // set initial hash value [5.3.1]
    var H0 = 0x67452301;
    var H1 = 0xefcdab89;
    var H2 = 0x98badcfe;
    var H3 = 0x10325476;
    var H4 = 0xc3d2e1f0;

    // HASH COMPUTATION [6.1.2]

    var W = new Array(80); var a, b, c, d, e;
    for (var i=0; i<N; i++) {

        // 1 - prepare message schedule 'W'
        for (var t=0;  t<16; t++) W[t] = M[i][t];
        for (var t=16; t<80; t++) W[t] = ROTL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);

        // 2 - initialise five working variables a, b, c, d, e with previous hash value
        a = H0; b = H1; c = H2; d = H3; e = H4;

        // 3 - main loop
        for (var t=0; t<80; t++) {
            var s = Math.floor(t/20); // seq for blocks of 'f' functions and 'K' constants
            var T = (ROTL(a,5) + f(s,b,c,d) + e + K[s] + W[t]) & 0xffffffff;
            e = d;
            d = c;
            c = ROTL(b, 30);
            b = a;
            a = T;
        }

        // 4 - compute the new intermediate hash value
        H0 = (H0+a) & 0xffffffff;  // note 'addition modulo 2^32'
        H1 = (H1+b) & 0xffffffff; 
        H2 = (H2+c) & 0xffffffff; 
        H3 = (H3+d) & 0xffffffff; 
        H4 = (H4+e) & 0xffffffff;
    }

    return H0.toHexStr() + H1.toHexStr() + H2.toHexStr() + H3.toHexStr() + H4.toHexStr();
}

//
// function 'f' [4.1.1]
//
function f(s, x, y, z) 
{
    switch (s) {
    case 0: return (x & y) ^ (~x & z);
    case 1: return x ^ y ^ z;
    case 2: return (x & y) ^ (x & z) ^ (y & z);
    case 3: return x ^ y ^ z;
    }
}

//
// rotate left (circular left shift) value x by n positions [3.2.5]
//
function ROTL(x, n)
{
    return (x<<n) | (x>>>(32-n));
}

//
// extend Number class with a tailored hex-string method 
//   (note toString(16) is implementation-dependant, and 
//   in IE returns signed numbers when used on full words)
//
Number.prototype.toHexStr = function()
{
    var s="", v;
    for (var i=7; i>=0; i--) { v = (this>>>(i*4)) & 0xf; s += v.toString(16); }
    return s;
}

// Taken from a JavaScript implementation of the RSA Data Security, Inc. MD5 
// Message Digest Algorithm, as defined in RFC 1321.
// Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.
// Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
// Distributed under the BSD License
// See http://pajhome.org.uk/crypt/md5 for more info.

function str_to_ent(str)
{
	var result = '';
	var i;

	for (i = 0; i < str.length; i++)
	{
		var c = str.charCodeAt(i);
		var tmp = '';

		if (c > 255)
		{

			while (c >= 1)
			{
				tmp = "0123456789" . charAt(c % 10) + tmp;
				c = c / 10;
			}

			if (tmp == '')
			{
				tmp = "0";
			}
			tmp = "#" + tmp;
			tmp = "&" + tmp;
			tmp = tmp + ";";

			result += tmp;
		}
		else
		{
			result += str.charAt(i);
		}
	}
	return result;
}

function trim(s)
{
	while (s.substring(0, 1) == ' ')
	{
		s = s.substring(1, s.length);
	}
	while (s.substring(s.length-1, s.length) == ' ')
	{
		s = s.substring(0, s.length-1);
	}
	return s;
}

// Hash password (inputfield), clear password field (inputfield) and set hidden 
// field (outputfield) to hash before submitting form.

function sha1form(inputfield, outputfield)
{
    var sha1hash = sha1(str_to_ent(trim(inputfield.value)));
    outputfield.value = sha1hash;
    inputfield.value = '';
    
    return true;
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function resizeField(field,addh) {
  var box = document.getElementById(field);
  var cur_height = parseInt(box.rows) ? parseInt( box.rows ) : 10;
  var new_height = cur_height + addh;
  
  if (new_height > 0)
  {
    box.rows = new_height;
  }
}

function checkPasswordMatch() {
  var upass = document.getElementById('user_password').value;
  var cpass = document.getElementById('confirmpass').value;
  
  if (cpass != upass) {
    document.getElementById('checkpass').innerHTML = 'Password does not match';
  }
  else {
    document.getElementById('checkpass').innerHTML = '';
  }
}

// Quote link for comments

function quoteComment(comment) {
  document.commentform.comment.focus();
  document.commentform.comment.value += ">>" + comment + "\n";
}

function highlightComment(comment) {
  var comment = document.getElementById('c-' + comment);
  if (comment) {
    comment.className = 'comment-highlight';
  }
}

function init() {
  var url = location.href.split('p/');
  if (url[1])
  {
    curl = url[1].split('#comment-');
    if (curl[1])
    {
      if (curl[1].match(/^\d+$/))
      {
        highlightComment(curl[1]);
      }
    }
  }
}

window.onload = init;