/* Indian Language Type Pad -  http://www.monusoft.com
Copyright (c) Monusoft

Permission is hereby granted to any person obtaining a copy of this software and associated 
the rights to use, copy, modify, merge copies of the Software for personal non-commercial use only and 
to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions 
of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 
TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
DEALINGS IN THE SOFTWARE.
*/
var prevkey = 32;
var hidden=false;
var posChanged = true;
var isEng = false;

var previousConsonant = false;
var previouspreviousConsonant = false;

function changeCursor(txtarea)	{
	if (txtarea.createTextRange)	{
	txtarea.cursorPos = document.selection.createRange().duplicate();
	}
}
function GetVowelCombination(key0, key1)
{
	var i=0;
	for(i=0;i<VowelCombination.length;i++)
	{
		if((VowelCombination[i][0] == key0) && (VowelCombination[i][1]==key1))
			return VowelCombination[i][2];	
	}
}
function GetConsonantCombination(key0, key1)
{
	var i=0;
	for(i=0;i<ConsonantCombination.length;i++)
	{
		if((ConsonantCombination[i][0] == key0) && (ConsonantCombination[i][1]==key1))
			return ConsonantCombination[i][2];	
	}
}

function positionChange(evt)
{
var keyCode = 
    document.layers ? evt.which :
    document.all ? event.keyCode :
    document.getElementById ? evt.keyCode : 0;
if (keyCode == 123)
	{
		isEng = !isEng;
		if (isEng)
			document.getElementById("language2").checked = true;
		else
			document.getElementById("language1").checked = true;
	}
  if (keyCode >= 37 && keyCode <=40)
  {
	posChanged = true;
  }	
}

function change(txtarea, evt)
{            

    var displace = 0;
	var text='';
    var previousValue = "";
    //var e = evt; //(evt)? e: ((window.event)? event : null);
    var e = window.event? event : evt;
    if( e.altKey || e.ctrlKey)
    {
		return true;
	}
	var key=0;
	var keychar='';
	var shift=false;
	var pos= 0; // doGetCaretPosition (txtarea);
	var prevpos = 0;
	if ( document.all )
	{
		key = e.keyCode;
	}	
	else
	{
		key = e.which;
	}

	if ((key <32) || (key >=33 && key <=47) ||(key>=59 && key <=64)||(key>=91 && key<=96 && !key==94)||(key>=123 && key<=127) )
		return true;
	

	keychar = String.fromCharCode(key);
	if(posChanged)
	{
		prevkey = 32;
		hidden=false;
		prevpos = 0;
		previousConsonant = false;
		previouspreviousConsonant = false;
		
	}
		switch(keychar)
		{
			case "a":
			case "e":
			case "i":
			case "o":
			case "u":
			case "A":
			case "I":
			case "U":
			case "O":
			case "E":
						var cComb = GetConsonantCombination(prevkey,key);
						var vComb = GetVowelCombination(prevkey,key);

						if(previousConsonant)
						{
							displace --;
							text=Consonant[key]; // nothing to append. just remove viram

						}
						else if (typeof(vComb) != 'undefined')
						{
							if(!previouspreviousConsonant)
							{
								
								displace --; // aa, ai, au.......
								text = vComb;
							}
							else
							{
								displace = 0;
								text = cComb;
							}
						}
						else
						{
							displace = 0;
							text = Vowel[key]; 
						}
						previouspreviousConsonant = previousConsonant;
						previousConsonant = false;
						hidden=false;
						break;
			case 'R':
						if(previousConsonant)
						{
							displace--; // replace the viram
							text = Consonant[VRU];
							// here no need for another U in VRU. by detecting VR it is assumed the whole word
						}
						else
						{
							displace=0; // nothing to displace
							text = Vowel[key];
						}
						previouspreviousConsonant = previousConsonant;
						previousConsonant = false;
						hidden = false;
						prevkey = key;
						break;
			case '^':
			case 'M':
						displace = 0;
						text = Consonant[key];
						previouspreviousConsonant = previousConsonant;
						previousConsonant = false;
						hidden = false;
						prevchar = keychar;
						break;
			case ' ':
						if(previousConsonant)
						{
							displace --;
						}
						else
						{
							displace = 0;
						}
						text = Symbol[key];
						previouspreviousConsonant = previousConsonant;
						previousConsonant = false;
						hidden = false;
						prevkey = key;
						break;
			default:
						var cComb = GetConsonantCombination(prevkey,key);
						if (hidden)
						{
							if(typeof(cComb) !='undefined')
							{
								displace = 0; // because previous word was not shown in textarea.
								text = cComb+ Consonant[VIRAM];
								previouspreviousConsonant = previousConsonant;
								previousConsonant = true;
							}
							else if (typeof(Consonant[key]) !='undefined')
							{
								displace = 0;
								text = Consonant[key] + Consonant[VIRAM];
								previouspreviousConsonant = previousConsonant;
								previousConsonant = true;
								hidden = false;
							}
							else
							{
								displace =0;
								previouspreviousConsonant = previousConsonant;
								previousConsonant = false;
							}
						}
						else
						{
							if(typeof(cComb) !='undefined')
							{
								displace -=2; // for d, dh, D, Dh etc.
								text = cComb+ Consonant[VIRAM];
								previouspreviousConsonant = previousConsonant;
								previousConsonant = true;
							}
							else if(typeof(Consonant[key])!='undefined')
							{
								displace = 0;
								text = Consonant[key] + Consonant[VIRAM]; // letter + viram
								previouspreviousConsonant = previousConsonant;
								previousConsonant = true;
							}
							else if (typeof(Symbol[key]) != 'undefined')
							{
								displace =0;
								text = Symbol[key];
								previouspreviousConsonant = previousConsonant;
								previousConsonant = false;
							}
							else
							{
								previouspreviousConsonant = previousConsonant;
								previousConsonant = true;
								hidden = true;
							}
							
						}
		}

		prevkey = key;

	if(txtarea.setSelectionRange)
	{
		// Mozilla specific
		pos = txtarea.selectionStart;
		var s1 = txtarea.value.substring(0,pos + displace);
		var s2 = txtarea.value.substring(pos, txtarea.value.length);
		var scrollPos = txtarea.scrollTop;
		if(typeof(text) != 'undefined')
			prevpos = pos + displace + text.length;
		else
			prevpos = pos + displace;
		txtarea.value = s1 + text + s2;

		txtarea.scrollTop = scrollPos;
		txtarea.focus();
		txtarea.setSelectionRange(prevpos,prevpos);
	}
	else if (txtarea.createTextRange && txtarea.cursorPos)
	{
		// IE specific
		var range = txtarea.cursorPos;
		range.moveStart('character', displace);
	    range.text =	(range.text.charAt(range.text.length - 1)	== ' ' ? text +	' '	: text);
		range.collapse(false);
	    range.scrollIntoView(true);
	}
	else
	{
		// Other browser
		if (displace==0)
		{
			txtarea.value += text;
		}
		else
		{
			txtarea.value =	txtarea.value.substring(0, txtarea.value.length-1) + text;
		}
	}
	txtarea.focus();
	posChanged=false;
	return false;
}