/*
function $(id) {
	if (typeof(id) === "string") {
		return document.getElementById(id);
	} else {
		return id;
	}
}
*/

window.onload = function() {
	$("fixindentation").onclick = indent;
	$("indentbyspaces").onchange = enableSpacesBox;
	$("indentbytabs").onchange = enableSpacesBox;
	$("sourcecode").onchange = $("sourcecode").onkeydown =
			$("sourcecode").onkeypress = $("sourcecode").onblur =
			$("sourcecode").onfocus = delayedSourceCodeChange;

	$("language").onchange = delayedSourceCodeChange;

	Cookies.makeRadioButtonStateful($("indentbyspaces"));
	Cookies.makeRadioButtonStateful($("indentbytabs"));
	Cookies.makeRadioButtonStateful($("languagejava"));
	Cookies.makeRadioButtonStateful($("languagephp"));
	Cookies.makeRadioButtonStateful($("languagehtml"));
	Cookies.makeRadioButtonStateful($("languageml"));
	Cookies.makeRadioButtonStateful($("languagescheme"));

	enableSpacesBox();
};

function enableSpacesBox(event) {
	$("spaces").disabled = $("indentbytabs").checked;
}

var indentString = "";

function updateIndentString() {
	indentString = "\t";
	if ($("indentbyspaces").checked) {
		indentString = "";
		var spaces = parseInt($("spaces").value);
		for (var i = 0; i < spaces; i++) {
			indentString += " ";
		}
	}
}

function indent(event) {
	updateIndentString();
	if ($("languageml").checked || $("languagescheme").checked) {
		// don't have an algorithm to indent ML code right now.  too bad
		alert("Sorry; we don't currently support fixing indentation of ML/Scheme code.\n" + 
				"For ML/Scheme, this tool will only tell you about your substantive line count.");
		return;
	}
	
	if ($("languagehtml").checked) {
		indentHtml(event);
	} else {
		indentJavaPHP(event);
	}
}

function indentHtml(event) {
	updateIndentString();
	if ($("indentbyspaces").checked) {
		$("tidyspaces").value = "" + indentString.length;
	} else {
		$("tidyspaces").value = "4";
	}
	$("tidyform").submit();
}

function indentJavaPHP(event) {
	var code = $("sourcecode").value;
	// code += "\n:-)";

	var newCode = "";
	var indentLevel = 0;
	var indentDuration = 0;   // used for temporary indents like 1-line ifs
	var newLines = [];
	var inMultiLineComment = false;

	var lines = code.split(/[\r]?\n/gi);
	for (var i = 0; i < lines.length; i++) {
		var line = trim(lines[i]);
		var lineForMatching = line.replace(/\/\/.*/, "");

		if (inMultiLineComment) {
			if (line.match(/\*\//)) {
				lineForMatching = line.replace(/.*\*\//, "");
				inMultiLineComment = false;
			} else {
				// entire line is part of multi-line comment;
				// ignore it for indentation purposes
				lineForMatching = "";
			}
		}

		if (lineForMatching.match(/\/\*/)) {
			if (lineForMatching.match(/\*\//)) {
				// a multi-line comment contained within one line; strip it
				lineForMatching = lineForMatching.replace(/\/\*.*\*\//, "");
			} else {
				inMultiLineComment = true;
				lineForMatching = lineForMatching.replace(/\/\*.*/, "");
			}
		}

		// ignore stuff in comments

		var lbrackets = lineForMatching.replace(/[^\{]+/gi, "");
		var rbrackets = lineForMatching.replace(/[^\}]+/gi, "");
		var lbracket1 = lineForMatching.indexOf("{");
		var rbracket1 = lineForMatching.indexOf("}");
		var lbracketN = lineForMatching.lastIndexOf("{");
		var rbracketN = lineForMatching.lastIndexOf("}");

		var increaseIndentBefore = false;
		var decreaseIndentBefore = false;
		var increaseIndentAfter = false;
		var decreaseIndentAfter = false;

		if (lbrackets.length > rbrackets.length ||
				lbracketN >= 0 && lbracketN > rbracketN) {
			// opening brace(s) on this line; indent subsequent lines
			increaseIndentAfter = true;
		}
		if (rbrackets.length > lbrackets.length ||
				rbracket1 >= 0 && rbracket1 < lbracket1) {
			// closing brace(s) on this line; decrease this line and subseqent lines
			decreaseIndentBefore = true;
		}

		// closing bracket; decrease indent
		// indentLevel = Math.max(0, indentLevel - 1);

		// check for a prior temporary indent (unbracketed if/else)
		// and get rid of it if so
		if (indentDuration > 0) {
			// if (lbrackets.length != rbrackets.length ||
			// (!lineForMatching.match(/(if |for |while )[ \t]*([^)]*)/) && !lineForMatching.match(/else /))) {
			indentDuration--;
			if (trim(lineForMatching).indexOf("{") >= 0) {
				decreaseIndentBefore = true;
			} else if (indentDuration == 0) {
				// indentLevel = Math.max(0, indent - 1);
				decreaseIndentAfter = true;
			}
			// }
		}

		// check for a new temporary indent (unbracketed if/else)
		// on this line and increase subsequent indent temporarily if so
		// side note: f**k unbracketed if/elses for making me write this code
		if (
				((
					// (lbrackets.length < rbrackets.length || rbracketN > lbracketN) ||
					// increaseIndentAfter ||
					(lbrackets.length == 0 && rbrackets.length == 0)
				)
				&&
				(
					(lineForMatching.match(/(if |while )[ \t]*([^)]*)/) && !lineForMatching.match(/;/)) ||
					(lineForMatching.match(/(for )[ \t]*([^)]*)/)) ||
					(lineForMatching.match(/else/) &&
						(
							!lineForMatching.match(/else[ ]+if/) &&
							// !lineForMatching.match(/ /)
							(lbrackets.length == 0 || lbrackets.length > rbrackets.length)
						)
					)
				))
				|| trim(lineForMatching).match(/}[ \t]*else$/)

			) {
			increaseIndentAfter = true;
			indentDuration = 1;
		}

		// pre-print indentation adjustments
		if (increaseIndentBefore) {
			indentLevel++;
		} else if (decreaseIndentBefore) {
			indentLevel = Math.max(0, indentLevel - 1);
		}

		// store this line, indented (hopefully) properly
		for (var tabs = 0; tabs < indentLevel; tabs++) {
			line = indentString + line;
		}
		newLines.push(line);

		// post-print indentation adjustments
		if (increaseIndentAfter) {
			indentLevel++;
		} else if (decreaseIndentAfter) {
			indentLevel = Math.max(0, indentLevel - 1);
		}
	}

	// put the newly indented lines into the text area on the page
	newCode = newLines.join("\n");
	$("sourcecode").value = newCode;
}

function delayedSourceCodeChange(event) {
	event = event || window.event;
	sourceCodeChange(event);
	setTimeout(sourceCodeChange, 20);
}


// Called when the text in the text box changes; shows the count of lines.
function sourceCodeChange(event) {
	var codeText = $("sourcecode").value;
	var lineCount = codeText ? trim(codeText).split(/[\r]?\n/).length : 0;

	if ($("languagehtml").checked) {
		// remove multi-line <!-- ... --> comments from HTML
		codeText = codeText.replace(/\<!--([^-]|-[^-])*--\>/gi, "");
	} else if ($("languageml").checked) {
		// remove multi-line (* ... *) comments from ML code
		codeText = codeText.replace(/\(\*([^*]*\*[^\)])*([^*]*\*)\)/gi, "");
		
		// try not to count lines that contain only "in" or "end"
		codeText = codeText.replace(/[ \t]*let[ \t]*/gi, "");
		codeText = codeText.replace(/[ \t]*in[ \t]*/gi, "");
		codeText = codeText.replace(/[ \t]*end[ \t]*[;]?/gi, "");
	} else if ($("languagescheme").checked) {
		// remove ; comments
		codeText = "\n" + codeText + "\n";   // makes regexes match ends of input
		codeText = codeText.replace(/\s*;.*/gim, "");

		// remove blank lines and lines containing only ( or )  (or [ or ])
		// (hack: I remove the regex 5x because for some reason it doesn't
		// properly remove multiple lines of ) in a row)
		codeText = codeText.replace(/\r/, "");
		codeText = codeText.replace(/$\s*([()\[\]])*\s*\n/gim, "$1\n");
		codeText = codeText.replace(/$\s*([()\[\]])*\s*\n/gim, "$1\n");
		codeText = codeText.replace(/$\s*([()\[\]])*\s*\n/gim, "$1\n");
		codeText = codeText.replace(/$\s*([()\[\]])*\s*\n/gim, "$1\n");
		codeText = codeText.replace(/$\s*([()\[\]])*\s*\n/gim, "$1\n");
	} else {
		if ($("languagephp").checked) {
			// remove # comments (not Java syntax, but useful for Perl/PHP/shell/etc.)
			codeText = codeText.replace(/\s*#[! \t].*/gim, "");
		}

		// remove // comments
		codeText = "\n" + codeText + "\n";   // makes regexes match ends of input
		codeText = codeText.replace(/\s*\/\/.*/gim, "");

		// remove multi-line / * * / comments
		// codeText = codeText.replace(/\/\*([^*]*\*)*([^*]*\*)\//gi, "");
		codeText = codeText.replace(/\/\*([^*]*\*[^\/])*([^*]*\*)\//gi, "");
	}

	// remove blank lines and lines containing only { or } braces
	// (hack: I remove the regex 5x because for some reason it doesn't
	// properly remove multiple lines of } in a row)
	codeText = codeText.replace(/\r/, "");
	codeText = codeText.replace(/$\s*([{}])*\s*\n/gim, "$1\n");
	codeText = codeText.replace(/$\s*([{}])*\s*\n/gim, "$1\n");
	codeText = codeText.replace(/$\s*([{}])*\s*\n/gim, "$1\n");
	codeText = codeText.replace(/$\s*([{}])*\s*\n/gim, "$1\n");
	codeText = codeText.replace(/$\s*([{}])*\s*\n/gim, "$1\n");

	codeText = trim(codeText);   // kill leading/trailing \n that I inserted

	// dump to page for debugging
	// $("dumptarget").innerHTML = htmlEncode(codeText);

	var substantiveLineCount = codeText ? trim(codeText).split(/[\r]?\n/).length : 0;
	$("linecount").innerHTML = lineCount;
	$("substantivelinecount").innerHTML = substantiveLineCount;
}

function padL(text, length) {
	while (text.length < length) {
		text = " " + text;
	}
	return text;
}

function htmlEncode(text) {
	text = text.replace(/</g, "&lt;");
	text = text.replace(/>/g, "&gt;");
	text = text.replace(/ /g, "&nbsp;");
	return text;
}

function ltrim(str) {
	for (var k = 0; k < str.length && str.charAt(k) <= " "; k++);
	return str.substring(k, str.length);
}

function rtrim(str) {
	for (var j = str.length - 1; j >= 0 && str.charAt(j) <= " "; j--);
	return str.substring(0, j+1);
}

function trim(str) {
	return ltrim(rtrim(str));
}
function dumpIndexes(str) {
	var output = "";
	for (var i = 0; i < str.length; i++) {
		output += padL("" + i, 4) + ": " + toPrintable(str[i]) + " (" + str[i].charCodeAt(0) + ")\n";
	}
	return output;
}

function toPrintable(ch) {
	if (ch == "\r") { return "\\r"; }
	if (ch == "\n") { return "\\n"; }
	if (ch == "\t") { return "\\t"; }
	if (ch == " ")  { return "(space)"; }
	if (ch == "\0") { return "\\0"; }
	return ch;
}