Small = {};

fn Small.isDigit(ch) {
	var n = string.byte(ch);
	if (!n) return false;
	return n >= 48 && n <= 57;
}

fn Small.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 (ch == "\n") out ..= '\n';
		elseif (ch == "\r") out ..= '\r';
		elseif (ch == "\x07") out ..= '\a';
		elseif (ch == "\x08") out ..= '\b';
		elseif (ch == "\x0c") out ..= '\f';
		elseif (ch == "\t") out ..= '\t';
		elseif (code >= 32 && code <= 126) out ..= ch;
		else {
			var nextchar = raw:sub(i+1,i+1);
			if (Small.isDigit(nextchar))
				out ..= '\' .. DecEncode(code, 3);
			else
				out ..= '\' .. DecEncode(code, 1);
		}
	}

	out ..= '"';

	return out;
}

fn Small.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 Small.convertBinaryOperator(lakeop, spacer) {
	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 == "&&" ) {
		if (spacer) return " and ";
		else return "and";
	} elseif ( lakeop == "||" ) {
		if (spacer) return " or ";
		else return 'or';
	}
}

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

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



fn Small.outputStatement(outp, node, noblock) {
	if (node.kind == 'Program') {
		outp:appendLine('do ', '');

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

			Small.outputStatement(outp, stmt, #node.content == 1);
		}

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

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

			outp:appendLine(vname[1], '');

			if (i != #varnames) {
				outp:appendLine(',', '');
			}
		}

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

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

				if (i != #values) {
					outp:appendLine(',', '');
				}
			}
		}

		outp:appendLine(';', '');
	} elseif (node.kind == 'Block') {
		if (!noblock) outp:appendLine('do ', '');

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

			Small.outputStatement(outp, stmt, i == #node.content);
		}

		if (!noblock) outp:appendLine('end;', '');
	} elseif (node.kind == 'IfStatement') {
		outp:appendLine("if ", '');

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

		outp:appendLine("then ", '');

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

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

			outp:appendLine("elseif ", '');

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

			outp:appendLine("then ", '');

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

		if (node.content[2]) {
			outp:appendLine("else ", '');

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

		outp:appendLine("end;", '');
	} elseif (node.kind == 'FunctionDeclaration') {
		outp:appendLine("function ", '');
		
		Small.outputFunctionName(outp, node.content[1]);

		outp:appendLine("(", '');

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

			outp:appendLine(part, '');

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

		outp:appendLine(")", '');

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

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

		outp:appendLine("(", '');

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

			outp:appendLine(part, '');

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

		outp:appendLine(")", '');

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

		outp:appendLine("end;", '');
	} elseif (node.kind == 'Return') {
		if (!noblock) {
			outp:appendLine("if''then ");
		}

		if (#node.content > 0) {
			outp:appendLine("return ", '');
		} else {
			outp:appendLine('return', '');
		}

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

			Small.outputExpression(outp, expr, false);

			if (i != #node.content) {
				outp:appendLine(",", '');
			}
		}

		outp:appendLine(";", '');
		if (!noblock) {
			outp:appendLine("end;");
		}
	} 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];

			Small.outputVariable(outp, vari);

			if (i != #vars) {
				outp:appendLine(",", '');
			}
		}

		outp:appendLine("=", '');

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

			Small.outputExpression(outp, val, false);

			if (i != #vals) {
				outp:appendLine(",", '');
			}
		}

		outp:appendLine(";", '');
	} elseif (node.kind == 'Call') {
		outp:appendLine("(", '');
		Small.outputExpression(outp, node.content[1], false);
		outp:appendLine(")", '');

		outp:appendLine("(", '');
		
		var args = node.content[2];
		for (var i = 1; i <= #args; i += 1;) {
			var arg = args[i];

			Small.outputExpression(outp, arg, false);

			if (i != #args) {
				outp:appendLine(",", '');
			}
		}

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

			Small.outputExpression(outp, arg, false);

			if (i != #args) {
				outp:appendLine(",", '');
			}
		}

		outp:appendLine(")", '');
		outp:appendLine(";", '');
	} elseif (node.kind == 'While') {
		outp:appendLine("while ", '');

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

		outp:appendLine("do ", '');

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

		outp:appendLine("end;", '');
	} elseif (node.kind == 'For') {
		outp:appendLine("do ", '');
		Small.outputStatement(outp,node.content[1]);

		outp:appendLine("while ", '');
		Small.outputExpression(outp,node.content[2]);
		outp:appendLine("do ", '');

		outp:appendLine("do ", '');
		Small.outputStatement(outp,node.content[4], true);
		outp:appendLine("end;", '');

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

		outp:appendLine("end;", '');

		outp:appendLine("end;", '');
	} elseif (node.kind == 'OperatorAssignment') {
		var lakeop = node.content[2];
		var op = Small.convertBinaryOperator(lakeop, true);

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

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

			outp:appendLine(varname, '');
			outp:appendLine('=', '');
			outp:appendLine(varname, '');
			outp:appendLine(op, '');
			outp:appendLine('(', '');
			Small.outputExpression(outp, rhs, false);
			outp:appendLine(');', '');
		} elseif (lhs.kind == "Field") {
			outp:appendLine('do ', '');

			outp:appendLine('local _lake_oat=', '');
			Small.outputExpression(outp, lhs.content[1], false);
			outp:appendLine(';', '');

			outp:appendLine('_lake_oat.', '');
			outp:appendLine(lhs.content[2], '');

			outp:appendLine('=', '');

			outp:appendLine('_lake_oat.', '');
			outp:appendLine(lhs.content[2], '');
			outp:appendLine(op, '');
			outp:appendLine('(', '');
			Small.outputExpression(outp, rhs, false);
			outp:appendLine(');', '');

			outp:appendLine('end;', '');
		} elseif (lhs.kind == "Index") {
			outp:appendLine('do ', '');

			outp:appendLine('local _lake_oat=', '');
			Small.outputExpression(outp, lhs.content[1], false);
			outp:appendLine(';', '');

			outp:appendLine('_lake_oat[', '');
			Small.outputExpression(outp, lhs.content[2], false);
			outp:appendLine(']', '');

			outp:appendLine('=', '');

			outp:appendLine('_lake_oat[', '');
			Small.outputExpression(outp, lhs.content[2], false);
			outp:appendLine(']', '');
			outp:appendLine(op, '');
			outp:appendLine('(', '');
			Small.outputExpression(outp, rhs, false);
			outp:appendLine(');', '');

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

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

		for (var i = 1; i <= #varlist; i += 1;) {
			outp:appendLine(varlist[i], '');
			if (i != #varlist) {
				outp:appendLine(',', '');
			}
		}

		outp:appendLine(" in ", '');

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

			if (i != #exprlist) {
				outp:appendLine(",", '');
			}
		}

		outp:appendLine('do ', '');

		Small.outputStatement(outp, block, true);

		outp:appendLine('end;', '');
	}
}



fn Small.outputExpression(outp, node, needsp) {
	if (needsp == null) needsp = true;
	if (node.kind == 'StringLiteral') {
		var lakestr = node.content;

		var raw = Lower.decodeString(lakestr);

		var enc = Small.encodeString(raw, outp.target == "lua51");

		outp:appendLine(enc, '');
	} elseif (node.kind == 'CompiledStringLiteral') {
		var raw = node.content;

		var enc = Small.encodeString(raw, outp.target == "lua51");

		outp:appendLine(enc, '');
	} elseif (node.kind == 'ParenthesizedExpression') {
		outp:appendLine("(", '');
		Small.outputExpression(outp, node.content, false);
		outp:appendLine(")", '');
	} elseif (node.kind == 'NumberLiteral') {
		var lakenum = node.content;
		var raw = Lower.decodeNumber(lakenum);
		var enc = Small.encodeNumber(raw);

		outp:appendLine(enc, '');
		
		if (needsp) outp:appendLine(' ', '');
	} elseif (node.kind == 'CompiledNumberLiteral') {
		var raw = node.content;
		var enc = Small.encodeNumber(raw);

		outp:appendLine(enc, '');
		
		if (needsp) outp:appendLine(' ', '');
	} elseif (node.kind == 'TableLiteral') {
		outp:appendLine('{', '');
		var listpart = node.content[1];
		var tablepart = node.content[2];

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

			Small.outputExpression(outp, item, false);

			if ((#tablepart > 0) || (i < #listpart)) {
				outp:appendLine(',', '');
			}
		}

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

			outp:appendLine('[', '');
			Small.outputExpression(outp, item[1], false);
			outp:appendLine(']', '');
			outp:appendLine('=', '');
			Small.outputExpression(outp, item[2], false);
			if (i < #tablepart) {
				outp:appendLine(',', '');
			}
		}
		outp:appendLine('}', '');
	} elseif (node.kind == 'LambdaFunctionLiteral') {
		outp:appendLine('function(', '');
		
		for (var i = 1; i <= #node.content[1]; i += 1;) {
			var part = node.content[1][i];

			outp:appendLine(part, '');

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

		outp:appendLine(")", '');

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

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

		outp:appendLine("((", '');

		Small.outputExpression(outp,lhs, false);

		outp:appendLine(")", '');

		var luaop = Small.convertBinaryOperator(op);

		outp:appendLine(luaop, '');

		outp:appendLine("(", '');

		Small.outputExpression(outp,rhs,false);

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

		outp:appendLine("(", '');

		var luaop = Small.convertUnaryOperator(op);
		outp:appendLine(luaop, '');

		outp:appendLine("(", '');

		Small.outputExpression(outp,val,false);

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

		outp:appendLine("(", '');
		Small.outputExpression(outp, left, false);
		outp:appendLine(").", '');
		outp:appendLine(right, '');
		if (needsp) outp:appendLine(' ', '');
	} elseif (node.kind == 'Index') {
		var left = node.content[1];
		var right = node.content[2];

		outp:appendLine("(", '');
		Small.outputExpression(outp, left, false);
		outp:appendLine(")", '');
		outp:appendLine("[", '');
		Small.outputExpression(outp, right, false);
		outp:appendLine("]", '');
	} elseif (node.kind == 'Variable') {
		outp:appendLine(node.content, '');
		if (needsp) outp:appendLine(' ', '');
	} elseif (node.kind == 'BooleanLiteral') {
		outp:appendLine(node.content, '');
		if (needsp) outp:appendLine(' ', '');
	} elseif (node.kind == 'NullLiteral') {
		outp:appendLine("nil", '');
		if (needsp) outp:appendLine(' ', '');
	} elseif (node.kind == 'Call') {
		outp:appendLine("(", '');
		Small.outputExpression(outp, node.content[1], false);
		outp:appendLine(")", '');

		outp:appendLine("(", '');
		
		var args = node.content[2];
		for (var i = 1; i <= #args; i += 1;) {
			var arg = args[i];

			Small.outputExpression(outp, arg, false);

			if (i != #args) {
				outp:appendLine(",", '');
			}
		}

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

			Small.outputExpression(outp, arg, false);

			if (i != #args) {
				outp:appendLine(",", '');
			}
		}

		outp:appendLine(")", '');
	}
}



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

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

		Small.outputFunctionName(outp, left);
		outp:appendLine("[", '');
		Small.outputExpression(outp, right, false);
		outp:appendLine("]", '');
	} elseif (node.kind == "Variable") {
		outp:appendLine(node.content, '');
	} elseif (node.kind == "Method") {
		var left = node.content[1];
		var right = node.content[2];

		Small.outputFunctionName(outp, left);
		outp:appendLine(":", '');
		outp:appendLine(right, '');
	}
}



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

		Small.outputExpression(outp, left, false);
		outp:appendLine(".", '');
		outp:appendLine(right, '');
	} elseif (node.kind == "Index") {
		var left = node.content[1];
		var right = node.content[2];

		Small.outputExpression(outp, left, false);
		outp:appendLine("[", '');
		Small.outputExpression(outp, right, false);
		outp:appendLine("]", '');
	} elseif (node.kind == "Variable") {
		outp:appendLine(node.content, '');
	}
}

RegisterOutMethod('small', Small);