Debug = {};

fn Debug.encodeString(raw, islua51) {
	var out = '"';

	for (var i = 1; i <= #raw; i += 1;) {
		var ch = raw:sub(i,i);

		var code = string.byte(ch);
		if (ch == '\') {
			out ..= '\\';
		} elseif (ch == '"') {
			out ..= '\"';
		} elseif (code >= 32 && code <= 126) {
			out ..= ch;
		} else {
			if (islua51)
				out ..= '\' .. DecEncode(code, 3);
			else
				out ..= '\x' .. HexEncode(code, 2);
		}
	}

	out ..= '"';
	return out;
}

fn Debug.encodeNumber(n) {
	var num = '';
	var isneg = false;

	if (n < 0) {
		n *= -1;
		isneg = true;
	}

	var whole = math.floor(n);

	if (whole == 0) {
		num ..= '0';
	}

	while (whole > 0) {
		var digit = whole % 10;
		num = string.char(string.byte('0') + digit) .. num;
		whole = math.floor(whole / 10);
	}

	var dec = n % 1;

	if (dec > 0) {
		num ..= '.';

		while (dec > 0) {
			dec *= 10;

			var digit = math.floor(dec);
			num ..= string.char(string.byte('0') + digit);

			dec %= 1;
		}
	}

	if (isneg) num = '-' .. num;

	return num;
}

fn Debug.convertBinaryOperator(lakeop) {
	if (lakeop == '+') {
		return '+';
	} elseif (lakeop == "-" ) {
		return "-";
	} elseif ( lakeop == "*" ) {
		return "*";
	} elseif ( lakeop == "/" ) {
		return "/";
	} elseif ( lakeop == "%" ) {
		return "%";
	} elseif ( lakeop == "^" ) {
		return "^";
	} elseif ( lakeop == ".." ) {
		return "..";
	} elseif ( lakeop == "<" ) {
		return "<";
	} elseif ( lakeop == ">" ) {
		return ">";
	} elseif ( lakeop == "<=" ) {
		return "<=";
	} elseif ( lakeop == ">=" ) {
		return ">=";
	} elseif ( lakeop == "!=" ) {
		return "~=";
	} elseif ( lakeop == "==" ) {
		return "==";
	} elseif ( lakeop == "&&" ) {
		return "and";
	} elseif ( lakeop == "||" ) {
		return "or";
	}
}

fn Debug.convertUnaryOperator(op) {
	if (op == '#') return '#';
	elseif (op == '-') return '-';
	elseif (op == '!') return 'not';
}

fn Debug.output(outp, ast) {
	Debug.outputStatement(outp, ast);
}

fn Debug.outputStatement(outp, node) {
	if (node.kind == 'Program') {
		outp:addLine('do', node.location:format());

		for (var i = 1; i <= #node.content; i += 1;) {
			var stmt = node.content[i];

			Debug.outputStatement(outp, stmt);
		}

		outp:addLine('end;', node.location:format());
	} elseif (node.kind == 'VariableDeclaration') {
		outp:addLine('local', node.location:format());
		var varnames = node.content[1];

		for (var i = 1; i <= #varnames; i += 1;) {
			var vname = varnames[i];

			outp:addLine(vname[1], vname[2]:format());

			if (i != #varnames) {
				outp:addLine(',', node.location:format());
			}
		}

		var values = node.content[2];
		if (#values > 0) {
			outp:addLine('=', node.location:format());

			for (var i = 1; i <= #values; i += 1;) {
				var val = values[i];
				
				Debug.outputExpression(outp, val);

				if (i != #values) {
					outp:addLine(',', node.location:format());
				}
			}
		}

		outp:addLine(';', node.location:format());
	} elseif (node.kind == "Block") {
		outp:addLine('do', node.location:format());

		for (var i = 1; i <= #node.content; i += 1;) {
			var stmt = node.content[i];

			Debug.outputStatement(outp, stmt);
		}

		outp:addLine('end;', node.location:format());
	} elseif (node.kind == 'IfStatement') {
		outp:addLine('if', node.location:format());

		Debug.outputExpression(outp, node.content[1][1][1]);

		outp:addLine('then', node.location:format());

		Debug.outputStatement(outp, node.content[1][1][2]);

		for (var i = 2; i <= #node.content[1]; i += 1;) {
			var item = node.content[1][i];

			outp:addLine('elseif', node.location:format());

			Debug.outputExpression(outp, item[1]);

			outp:addLine('then', node.location:format());

			Debug.outputStatement(outp, item[2]);
		}

		if (node.content[2]) {
			outp:addLine('else', node.location:format());

			Debug.outputStatement(outp, node.content[2]);
		}

		outp:addLine('end;', node.location:format());
	} elseif (node.kind == "FunctionDeclaration") {
		outp:addLine('function', node.location:format());

		Debug.outputFunctionName(outp, node.content[1]);

		outp:addLine('(', node.location:format());

		for (var i = 1; i <= #node.content[2]; i += 1;) {
			var part = node.content[2][i];

			outp:addLine(part, node.location:format());

			if (i != #node.content[2]) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine(')', node.location:format());

		Debug.outputStatement(outp, node.content[3]);

		outp:addLine('end;', node.location:format());
	} elseif (node.kind == 'LocalFunctionDeclaration') {
		outp:addLine('local function', node.location:format());
		
		outp:addLine(node.content[1].content, node.content[1].location:format());

		outp:addLine('(', node.location:format());

		for (var i = 1; i <= #node.content[2]; i += 1;) {
			var part = node.content[2][i];

			outp:addLine(part, node.location:format());

			if (i != #node.content[2]) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine(')', node.location:format());

		Debug.outputStatement(outp, node.content[3]);

		outp:addLine('end;', node.location:format());
	} elseif (node.kind == 'Return') {
		outp:addLine('return', node.location:format()); // if true because it has to be at the end of a block in lua, but not here.

		for (var i = 1; i <= #node.content; i += 1;) {
			var expr = node.content[i];

			Debug.outputExpression(outp, expr);

			if (i != #node.content) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine(';', node.location:format());
	} elseif (node.kind == 'Assignment') {
		var vars = node.content[1];
		var vals = node.content[2];

		for (var i = 1; i <= #vars; i += 1;) {
			var vari = vars[i];

			Debug.outputVariable(outp, vari);

			if (i != #vars) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine('=', node.location:format());

		for (var i = 1; i <= #vals; i += 1;) {
			var val = vals[i];

			Debug.outputExpression(outp, val);

			if (i != #vals) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine(';', node.location:format());
	} elseif (node.kind == 'Call') {
		outp:addLine('(', node.location:format());
		Debug.outputExpression(outp, node.content[1]);
		outp:addLine(')(', node.location:format());

		var args = node.content[2];
		for (var i = 1; i <= #args; i += 1;) {
			var arg = args[i];

			Debug.outputExpression(outp, arg);

			if (i != #args) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine(');', node.location:format());
	} elseif (node.kind == 'MethodCall') {
		outp:addLine('(', node.location:format());
		Debug.outputExpression(outp, node.content[1]);
		outp:addLine('):', node.location:format());
		outp:addLine(node.content[2] .. '(', node.location:format());

		var args = node.content[3];
		for (var i = 1; i <= #args; i += 1;) {
			var arg = args[i];

			Debug.outputExpression(outp, arg);

			if (i != #args) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine(');', node.location:format());
	} elseif (node.kind == 'While') {
		outp:addLine('while', node.location:format());

		Debug.outputExpression(outp, node.content[1]);

		outp:addLine('do', node.location:format());

		Debug.outputStatement(outp, node.content[2]);

		outp:addLine('end;', node.location:format());
	} elseif (node.kind == 'For') {
		outp:addLine('do', node.location:format());
		Debug.outputStatement(outp, node.content[1]);

		outp:addLine('while', node.location:format());
		Debug.outputExpression(outp, node.content[2]);
		outp:addLine('do', node.location:format());

		outp:addLine('do', node.location:format());
		Debug.outputStatement(outp, node.content[4]);
		outp:addLine('end;', node.location:format());

		Debug.outputStatement(outp, node.content[3]);

		outp:addLine('end;', node.location:format());
		outp:addLine('end;', node.location:format());
	} elseif (node.kind == 'OperatorAssignment') {
		var lakeop = node.content[2];
		var op = Debug.convertBinaryOperator(lakeop);

		var lhs = node.content[1];
		var rhs = node.content[3];

		if (lhs.kind == 'Variable') {
			var varname = lhs.content;

			outp:addLine(varname, node.location:format());
			outp:addLine('=', node.location:format());

			outp:addLine('(', node.location:format());
			outp:addLine(varname, node.location:format());
			outp:addLine(op, node.location:format());
			outp:addLine('(', node.location:format());
			Debug.outputExpression(outp, rhs);
			outp:addLine('));', node.location:format());
		} elseif (lhs.kind == 'Field') {
			outp:addLine('do', node.location:format());

			outp:addLine('local _lake_operator_assignment_tmp =', node.location:format());
			Debug.outputExpression(outp, lhs.content[1]);
			outp:addLine(';', node.location:format());

			outp:addLine('(_lake_operator_assignment_tmp).', node.location:format());
			outp:addLine(lhs.content[2], node.location:format());

			outp:addLine('=', node.location:format());

			outp:addLine('(', node.location:format());
			outp:addLine('(_lake_operator_assignment_tmp).', node.location:format());
			outp:addLine(lhs.content[2], node.location:format());
			outp:addLine(op, node.location:format());
			outp:addLine('(', node.location:format());
			Debug.outputExpression(outp, rhs);
			outp:addLine('));', node.location:format());

			outp:addLine('end;', node.location:format());
		} elseif (lhs.kind == 'Index') {
			outp:addLine('do', node.location:format());

			outp:addLine('local _lake_operator_assignment_tmp =', node.location:format());
			Debug.outputExpression(outp, lhs.content[1]);
			outp:addLine(';', node.location:format());

			outp:addLine('(_lake_operator_assignment_tmp)[', node.location:format());
			Debug.outputExpression(outp, lhs.content[2]);
			outp:addLine(']', node.location:format());

			outp:addLine('=', node.location:format());

			outp:addLine('(', node.location:format());
			outp:addLine('(_lake_operator_assignment_tmp)[', node.location:format());
			Debug.outputExpression(outp, lhs.content[2]);
			outp:addLine(']', node.location:format());
			outp:addLine(op, node.location:format());
			outp:addLine('(', node.location:format());
			Debug.outputExpression(outp, rhs);
			outp:addLine('));', node.location:format());

			outp:addLine('end;', node.location:format());
		}
	} elseif (node.kind == 'Break') {
		outp:addLine('break;', node.location:format());
	} elseif (node.kind == 'Foreach') {
		outp:addLine("for", node.location:format());

		var varlist,exprlist,block = node.content[1],node.content[2],node.content[3];

		for (var i = 1; i <= #varlist; i += 1;) {
			outp:addLine(varlist[i], node.location:format());
			if (i != #varlist) {
				outp:addLine(',', node.location:format());
			}
		}

		outp:addLine("in", node.location:format());

		for (var i = 1; i <= #exprlist; i += 1;) {
			Debug.outputExpression(outp, exprlist[i]);

			if (i != #exprlist) {
				outp:addLine(",", node.location:format());
			}
		}

		outp:addLine('do', node.location:format());

		Debug.outputStatement(outp, block);

		outp:addLine('end;', node.location:format());
	}
}



fn Debug.outputExpression(outp, node) {
	if (node.kind == 'StringLiteral') {
		var lakestr = node.content;
		var raw = Lower.decodeString(lakestr);
		var enc = Debug.encodeString(raw, outp.target == 'lua51');

		outp:addLine(enc, node.location:format());
	} elseif (node.kind == 'CompiledStringLiteral') {
		var raw = node.content;
		var enc = Debug.encodeString(raw, outp.target == 'lua51');

		outp:addLine(enc, node.location:format());
	} elseif (node.kind == 'ParenthesizedExpression') {
		outp:addLine("(", node.location:format());
		Debug.outputExpression(outp, node.content);
		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'NumberLiteral') {
		var lakenum = node.content;

		var raw = Lower.decodeNumber(lakenum);

		var enc = Debug.encodeNumber(raw);

		outp:addLine("(", node.location:format());
		outp:addLine(enc, node.location:format());
		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'CompiledNumberLiteral') { // usually generated by optimizer doing math
		var raw = node.content;

		var enc = Debug.encodeNumber(raw);

		outp:addLine("(", node.location:format());
		outp:addLine(enc, node.location:format());
		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'TableLiteral') {
		outp:addLine('{', node.location:format());
		var listpart = node.content[1];
		var tablepart = node.content[2];

		for (var i = 1; i <= #listpart; i += 1;) {
			var item = listpart[i];

			Debug.outputExpression(outp, item);
			outp:addLine(',', node.location:format());
		}

		for (var i = 1; i <= #tablepart; i += 1;) {
			var item = tablepart[i];

			outp:addLine('[', node.location:format());
			Debug.outputExpression(outp, item[1]);
			outp:addLine(']', node.location:format());
			outp:addLine('=', node.location:format());
			Debug.outputExpression(outp, item[2]);
			outp:addLine(',', node.location:format());
		}
		outp:addLine('}', node.location:format());
	} elseif (node.kind == 'LambdaFunctionLiteral') {
		outp:addLine('function(', node.location:format());
		
		for (var i = 1; i <= #node.content[1]; i += 1;) {
			var part = node.content[1][i];

			outp:addLine(part, node.location:format());

			if (i != #node.content[1]) {
				outp:addLine(",", node.location:format());
			}
		}

		outp:addLine(")", node.location:format());

		Debug.outputStatement(outp, node.content[2]);

		outp:addLine("end", node.location:format());
	} elseif (node.kind == 'BinaryOperator') {
		var op = node.content[1];
		var lhs = node.content[2];
		var rhs = node.content[3];

		outp:addLine("((", node.location:format());

		Debug.outputExpression(outp,lhs);

		outp:addLine(")", node.location:format());

		var luaop = Debug.convertBinaryOperator(op);

		outp:addLine(luaop, node.location:format());

		outp:addLine("(", node.location:format());

		Debug.outputExpression(outp,rhs);

		outp:addLine("))", node.location:format());
	} elseif (node.kind == 'UnaryOperator') {
		var op = node.content[1];
		var val = node.content[2];

		outp:addLine("(", node.location:format());

		var luaop = Debug.convertUnaryOperator(op);
		outp:addLine(luaop, node.location:format());


		outp:addLine("(", node.location:format());

		Debug.outputExpression(outp,val);

		outp:addLine("))", node.location:format());
	} elseif (node.kind == 'Field') {
		var left = node.content[1];
		var right = node.content[2];

		outp:addLine("((", node.location:format());
		Debug.outputExpression(outp, left);
		outp:addLine(").", node.location:format());
		outp:addLine(right, node.location:format());
		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'Index') {
		var left = node.content[1];
		var right = node.content[2];

		outp:addLine("((", node.location:format());
		Debug.outputExpression(outp, left);
		outp:addLine(")", node.location:format());
		outp:addLine("[", node.location:format());
		Debug.outputExpression(outp, right);
		outp:addLine("]", node.location:format());
		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'Variable') {
		outp:addLine("(", node.location:format());
		outp:addLine(node.content, node.location:format());
		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'BooleanLiteral') {
		outp:addLine("(", node.location:format());
		outp:addLine(node.content, node.location:format());
		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'NullLiteral') {
		outp:addLine("(nil)", node.location:format());
	} elseif (node.kind == 'Call') {
		outp:addLine("(", node.location:format());
		Debug.outputExpression(outp, node.content[1]);
		outp:addLine(")(", node.location:format());
		
		var args = node.content[2];
		for (var i = 1; i <= #args; i += 1;) {
			var arg = args[i];

			Debug.outputExpression(outp, arg);

			if (i != #args) {
				outp:addLine(",", node.location:format());
			}
		}

		outp:addLine(")", node.location:format());
	} elseif (node.kind == 'MethodCall') {
		outp:addLine("(", node.location:format());
		Debug.outputExpression(outp, node.content[1]);
		outp:addLine("):", node.location:format());
		outp:addLine(node.content[2] .. "(", node.location:format());
		
		var args = node.content[3];
		for (var i = 1; i <= #args; i += 1;) {
			var arg = args[i];

			Debug.outputExpression(outp, arg);

			if (i != #args) {
				outp:addLine(",", node.location:format());
			}
		}

		outp:addLine(")", node.location:format());
	}
}



fn Debug.outputFunctionName(outp, node) {
	if (node.kind == 'Field') {
		var left = node.content[1];
		var right = node.content[2];

		Debug.outputFunctionName(outp, left);
		outp:addLine(".", node.location:format());
		outp:addLine(right, node.location:format());
	} elseif (node.kind == 'Index') {
		var left = node.content[1];
		var right = node.content[2];

		Debug.outputFunctionName(outp, left);
		outp:addLine("[", node.location:format());
		Debug.outputExpression(outp, right);
		outp:addLine("]", node.location:format());
	} elseif (node.kind == 'Variable') {
		outp:addLine(node.content, node.location:format());
	} elseif (node.kind == 'Method') {
		var left = node.content[1];
		var right = node.content[2];

		Debug.outputFunctionName(outp, left);
		outp:addLine(":", node.location:format());
		outp:addLine(right, node.location:format());
	}
}



fn Debug.outputVariable(outp, node) {
	if (node.kind == 'Field') {
		var left = node.content[1];
		var right = node.content[2];

		Debug.outputExpression(outp, left);
		outp:addLine(".", node.location:format());
		outp:addLine(right, node.location:format());
	} elseif (node.kind == 'Index') {
		var left = node.content[1];
		var right = node.content[2];

		Debug.outputExpression(outp, left);
		outp:addLine("[", node.location:format());
		Debug.outputExpression(outp, right);
		outp:addLine("]", node.location:format());
	} elseif (node.kind == 'Variable') {
		outp:addLine(node.content, node.location:format());
	}
}

RegisterOutMethod("debug", Debug);