var valid;
var	initConsStr, finalConsStr, vowelStr;
var cLetters, vLetters;
var letterArray;
var syllimg, syllStr;
var currSyll, syllStage;
var c1str, vstr, c2str;
var ascii;
var displayDest, syllPrefix;

var MAXSYLL;

function resetInput( )
{
	var	i, str, img;

	for (i=0; i<MAXSYLL; i++)
	{
		syllimg[i] = 0;
		syllStr[i] = "";
		img = document.getElementById( displayDest + i );
		if (img != null)
		{
			img.src = syllPrefix + "/ltr/null.png";
		}
	}
	currSyll = 0;
	syllStage = 0;
	c1str = vstr = c2str = "";
}

function resetAnswer( dest )
{
	var	i, str, img;

	for (i=0; i<MAXSYLL; i++)
	{
		img = document.getElementById( dest + i );
		if (img != null)
		{
			img.src = syllPrefix + "/ltr/null.png";
		}
	}
}

function initInput( pfx, screen, max )
{
	valid = new Array(19);
	letterArray = new Array( 1, 2, 4, 7, 8, 9, 17, 18, 19, 21, 22, 23, 24, 25, 26,
		27, 28, 29, 30 );

	syllPrefix = pfx;
	displayDest = screen;

	cLetters = "kntrmps@jchg#";
	vLetters = "aeiowyu";
	MAXSYLL = max;
	
	syllimg = new Array( MAXSYLL );
	syllStr = new Array( MAXSYLL );
	resetInput();
	
	initConsStr = "k../kk./n../t../tt./r../m../p../pp./s../ss./@../j../jj./c#./" +
		"k#./t#./p#./h../";
	endConsStr = ".../k../kk./ks./n../nj./nh./t../r../rk./rm./rp./rs./rt#/rp#/rh./" +
		"m../p../ps./s../ss./@../c../c#./k#./t#./p#./h../";
	vowelStr = "a../ae./ya./yae/eo./e../yeo/ye./o../wa./wae/oe./yo./u../weo/" +
		"we./wi./yu./eu./yi./i../";
	
	ascii = "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_";
	valid[0] =
		"LSXG_ORD@[PFHP@J@QB@@@CDZAWSXQ@F\\AZL@[QDHPAH@YFT]LCDJAU@HQ@B" +
		"LARD@ZPDHPAH@YGP]LCDH@C@H@@@PARD@Z@DHP@@@YG@MHB@@@@@LSHFV";
	valid[1] =
		"NQHF\\IRD@[PF@P@@@@@@@@CTHAW@LP@DTABD@CAD@@@@@YJ@MNC@H@C@L@@@" +
		"DABD@XPD@@@@@YB@]LB@H@C@LQ@FHABD@X@D@@@@@YJP]HP@@@@@LQ@FT";
	valid[2] =
		"NSXF_KRD@[PFHPBB@@@@@@CLKAW@\\Q@F\\ARD@YRDH@@@@YBPMHNDH@B@@@@@" +
		"@ABD@Z@FHPAJ@YF@MHB@@@B@H@@@@ABD@X@F@PCB@YCPMLJDH@@@LQHFT";
	valid[3] =
		"NS\\N_CRD@[PD@@@@@@@@@@CT[AUILQ@F\\ABD@APDH@@@@YFTMJRDH@@@H@@@" +
		"HABD@Z@D@@@@@YB@MHB@@@B@H@@@DABD@JPDHPBB@YFPMHB@@@@@LS@F^";
	valid[4] =
		"LQ@F\\CRD@[P@@@@@@@@@@@CDKAW@\\Q@F\\A@@@A@@@@@@@YB@@HB@H@@@H@@@" +
		"@AB@@@@@@@@@@YB@XH@@@@@@H@@@@ABD@XP@@@@@@YF@M@BDHAP@HQ@FT";
	valid[5] =
		"LQ@F^GRD@[PFH@@J@@@@@@CDHAW@\\Q@FTARD@[PDH@AH@YB@MHBD@@A@@@@@" +
		"HABD@ZPDHPAJ@YB@MHB@@@B@H@@@@ARD@RPFHPCJ@YB@MLX@@@@@LQ@FT";
	valid[6] =
		"LWXFVKRD@[XF@P@B@@@@@@CDJAUP\\Q@F\\ARD@CTD@@@@@[BPMHBD@@C@@@@@" +
		"@ABD@JPDHPAH@]GPMHVDH@T@H@@@@ABD@@@DHPBH@QB@I@@@@@@@LSHF]";
	valid[7] =
		"OS\\FTIRD@[QFH@A@@@@@@@CDZAUPLS@F\\ARD@KQDH@@@@]B@MHBD@@B@H@@@" +
		"HARD@X@DH@@@@YGPMHZ@H@B@H@@@@ARD@@PDHPBJ@YB@M@@@@@@@LQHFW";
	valid[8] =
		"LQHF\\CRD@[PF@@B@@@@@@@CDXAG@H@@@DAP@@[P@@@@@@YB@LH@@@@@@@@@@" +
		"@A@@@@@D@@@B@YB@IH@@@@@@@@@@@@@@@@@D@@@B@QB@L@@@@@@@LQ@FT";
	valid[9] =
		"MSXF\\IRD@[PFHPCJ@QB@HHC\\[AWALQ@F\\ARD@[PDHP@B@]BPMHSDH@A@HQ@D" +
		"XABD@Z@FHPCJ@YF@MJZ@@@B@LQ@DDARD@ZPF@PBJ@YC@MH@@@@@@LS@NT";
	valid[10] =
		"MQ@FLCRD@YP@@@@B@@@@@@CDJAS@HQ@@@@@@@@@@H@@@@YFPLHCD@@B@H@@@" +
		"HABD@X@D@@@@@YB@LHB@@@B@H@@@@AB@@@@@@@@B@YBP\\@BDHA@@LQ@FT";
	valid[11] =
		"L]XN\\MRD@[PFHRCJEQB@D@CF^A_ULQ@FTAZEP_Q\\HPCL@YCT]JCDHAW@LP@D" +
		"TARD@ZPFHPCJ@YCPMHCDHAS@LQ@FDARD@ZPFHPCJPYBAMO^DHAD@LQXN^";
	valid[12] =
		"LWHF^ARD@[PFJPBB@QB@@@CDJAUPLQ@FTABD@YPD@@@@@YBPMNG@H@U@H@@@" +
		"LABD@ZPFH@@B@YCPMHB@@@B@H@@@@ARD@Z@DHPB@@YB@MH@@@@@@LSHFV";
	valid[13] =
		"LUDF\\ARD@[PDH@@B@@@@@@CDHAW@H@@@DA@@@A@@@@@@@YB@MJC@H@B@H@@@" +
		"HABD@X@@@@@B@YB@LHB@@@C@@@@@@A@@@@@D@@@@@P@@IH@@@@@@LQ@FF";
	valid[14] =
		"\\U@F^ARD@[PDJPBB@@@@@@CDHAW@LQ@FTAB@@A@DH@@B@YB@MHBDH@A@@@@@" +
		"@ABD@ZPD@@B@@YB@MHB@@@B@HP@@@ABD@ZPDHPBB@YB@MH@@@@@@LSPFT";
	valid[15] =
		"LQ@FTARD@[PF@@@B@@@@@@CDXAW@LQ@FTABD@[PD@@@@@YB@MHCDHAA@H@@@" +
		"DA@D@@@D@@@@@YB@MHBDH@A@H@@@DARD@ZPDHPB@@YB@LH@@@@@@LQ@FT";
	valid[16] =
		"LQPF\\ARD@[PD@@@B@@@@@@CDJAW@LQ@FTAB@@A@DH@@@@YB@MHJD@@@@H@@@" +
		"@AB@@BPD@@@@@YB@MHB@@@B@H@@@@ARD@XPDHPBB@YFPM@BDHAP@LQ@FT";
	valid[17] =
		"NQHF\\IRD@[PF@@@@@@@@@@CDHAW@LQ@FTABD@YPD@PAH@YB@MHB@@@A@@@@@" +
		"@AB@@@@DHPAH@YFPMHB@@@A@@@@@@ABD@R@DHPBJ@QB@M@@@@@@@LQ@FT";
	valid[18] =
		"LQAFTARD@[PD@@@B@@@@@@CDJAU@LQ@FTARD@[PDHPA@@YBBMHSDH@E@LP@@" +
		"TARD@JPDHPAH@YBBIHBDHAA@LQ@@DARD@ZPFHPBJ@YO@MHRDHAQ@LQ@FT";
}

function findImageNumber( cons1, vowel, cons2 )
{
	var c1, v, c2;
	
	n = 0;
	c1 = initConsStr.indexOf( cons1 );
	v = 0;
	c2 = 0;
	if (c1 >= 0)
	{
		c1 /= 4;
		if (vowel != "")
		{
			v = vowelStr.indexOf( vowel );
			if (v < 0)
			{
				return 0;
			}
			v /= 4;

			if (cons2 != "")
			{
				c2 = endConsStr.indexOf( cons2 );
				if (c2 < 0)
				{
					return 0;
				}
				c2 /= 4;
			}
			n = c1 * 588 + v *28 + c2 + 1;
		}
		else
		{
			return -(letterArray[c1]);
		}
	}
	return n;
}

function displaySyllable( n )
{
	var	str;
	var img;
	
	img = document.getElementById( displayDest + currSyll );
	str = syllPrefix;

	if (n == 32767)
	{
		str += "/ltr/null.png";
	}
	else if (n < 0)
	{
		str += "/ltr/l" + (-n) + ".png";
	}
	else if (n > 0)
	{
		str += "/c" + (Math.floor( n / 588 ) + 1) + "/s" + n + ".png";
	}
	else
	{
		str += "ltr/inv.png";
	}
	img.src = str;
}

function newSyllable()
{
	if (syllStage != 0)
	{
		currSyll++;
		c1str = vstr = c2str = "";
		syllStage = 0;
	}
}

function seedInput( str )
{
	var i, temp, c, delim, n;

	if (seedInput.arguments.length == 1)
	{
		currSyll = 0;
	}
	else
	{
		currSyll = seedInput.arguments[1];
		if (syllStage != 0)
		{
			currSyll++;
		}
	}
	syllStage = 0;
	
	delim = ".../";
	i = 0;
	while (i < str.length)
	{
		/* collect first consonant */
		c1str = "";
		while (i < str.length)
		{
			c = str.charAt(i);
			if (c == "'") { c = "#" };
			if (cLetters.indexOf(c) < 0)
			{
				break;
			}
			c1str += c;
			i++;
		}
		c1str += delim.substring(c1str.length, 4);
		vstr = "";
		while (i < str.length)
		{
			c = str.charAt(i);
			if (vLetters.indexOf(c) < 0)
			{
				break;
			}
			vstr += c;
			i++;
		}
		vstr += delim.substring(vstr.length, 4);
		c2str = "";
		while (i < str.length)
		{
			c = str.charAt(i);
			if (c == "'") { c = "#" };
			if (cLetters.indexOf(c) < 0)
			{
				break;
			}
			c2str += c;
			i++;
		}
		if (c2str == "ng") {c2str = "@"};
		c2str += delim.substring(c2str.length, 4);
		n = findImageNumber(c1str, vstr, c2str );
		syllimg[currSyll] = n;
		syllStr[currSyll] = c1str + vstr + c2str;
		displaySyllable( n );
		currSyll++;
		if (c == '-')
		{
			i++;
		}
	}
}

function collectInput()
{
	var i, str, temp, c;

	str = "";
	i = 0;
	while ( (i < MAXSYLL) && (syllimg[i] != 0) )
	{
		temp = syllStr[i];
		if (temp != " ")
		{
			for (j=0; j<temp.length; j++)
			{
				c = temp.charAt(j);
				if (c != "." && c != "/")
				{
					if (c == "#") {c = "'"};
					str += c;
				}
			}
			i++;
			if (syllimg[i] > 0 && syllimg[i] != 32767)
			{
				str += "-";
			}
		}
		else
		{
			str += " ";
			i++;
		}
	}
	return str;
}

function setsyll( n )
{
	currSyll = n;
	syllStage = Math.floor(syllStr[currSyll].length / 4);
}

function erase()
{
	var	temp;

	if (syllStage == 0)
	{
		if (currSyll > 0)
		{
			currSyll--;
			/* figure out how many stages we have */
			syllStage = Math.floor(syllStr[currSyll].length / 4);
		}
		else
		{
			return;
		}
	}
	document.getElementById( displayDest + currSyll ).src =
		syllPrefix + "/ltr/null.png";
	if (syllStr[currSyll] != " " )
	{
		syllStage--;
		syllStr[currSyll] = syllStr[currSyll].substring( 0, syllStage * 4 );
	}
	if (syllStage != 0)
	{
		temp = syllStr[currSyll].split("/");
		c1str = temp[0];
		vstr = ( temp[1] ) ? temp[1] : "";
		c2str = ( temp[2] ) ? temp[2] : "";
		temp = syllimg[currSyll] = findImageNumber( c1str, vstr, c2str );
		displaySyllable( syllimg[currSyll] );
	}
	else
	{
		syllimg[currSyll] = 0;
		syllStr[currSyll] = "";
		c1str = vstr = c2str = "";
	}
}

function backup( str )
{
	var	c, s, n;

	s = syllStr[currSyll - 1];

	n = 0;
	
	if (s.length  == 12)	// good; we can possibly add
	{
		c = s.substring(8, 11);	// get the last consonant
		if (initConsStr.indexOf( c ) >= 0)
		{
			n = findImageNumber( c, str, "" );
			if (n != 0)
			{
				currSyll--;
				syllStage = 3;
				erase();
				currSyll++;
				c1str = c;
				vstr = str;
				syllStage = 1;
			}
		}
	}
	return n;
}

function addLetter( str )
{
	var	n, page, bit, c, v;

	if (currSyll > MAXSYLL-1)
	{
		return;
	}

	if (str == "...")
	{
		newSyllable();
		syllStr[ currSyll ] = " ";
		syllimg[ currSyll ] = 32767;
		if (currSyll <= MAXSYLL - 1)
		{
			syllStage = 3; // to fake out next line
			newSyllable();
		}
	}
	if (syllStage == 0)
	{
		if ( vowelStr.indexOf( str ) >= 0 && currSyll > 0)
		{
			n = backup( str );
		}
		else
		{
			n = findImageNumber( str, "", "" );
			c1str = str;
		}
	}
	else if (syllStage == 1)
	{
		n = findImageNumber( c1str, str, "" );
		vstr = str;
	}
	else
	{
		n = findImageNumber( c1str, vstr, str );

		if (n != 0)
		{
			c2str = str;
		}
	}

	/* now test to see if it's actually a valid syllable */
	if (n > 0)
	{
		page = Math.floor( n / 588 );
		c = valid[page].charAt( Math.floor( n % 588 / 5) );
		bit = 4 - ((n % 588) % 5);
		c = ascii.indexOf( c );
		c = (c >> bit) & 0x01;
		if (c == 0)
		{
			n = 0;
		}
	}
	
	if (n == 0 && syllStage == 2)	// last consonant was illegal.
	{
		n = findImageNumber( str, "", "");	// could it begin next syll?

		if (n != 0 && currSyll < MAXSYLL-1)
		{
			c1str = str;
			vstr = "";
			c2str = "";
			currSyll++;
			syllStage = 0;
		}
		else
		{
			n = 0;
		}
	}

	if (n != 0)
	{
		displaySyllable( n );
		syllStr[ currSyll ] = c1str + "/" + vstr + "/" + c2str + "/";
		syllimg[ currSyll ] = n;
		syllStage++;
		if (syllStage == 3)
		{
			newSyllable();
		}
	}
}