import js.Browser.document;
import js.html.TextAreaElement;

enum Token {
	Operation(op:String);
	Number(num:Int);
}

class Hexat {
	static public function main() {
		var button = document.querySelector(".runButton");
		button.onclick = (event) -> runButton(); 
	}

	static public function runButton() {
		var inputArea:TextAreaElement = cast document.querySelector(".source");

		var res = run(parse(inputArea.value));
		var outputDisplay = document.querySelector(".output");
		
		outputDisplay.innerHTML = "Output: <pre>"+res.join(", ")+"</pre>";
	}

	static function parse(input:String) {
		var array: Array<Token> = [];
		var i = 0;
		var splits = input.split(" ");

		while (i < splits.length) {
			var split = splits[i];

			if(split != " " && split != "\n" && split != "\r") {
				if(Std.parseInt(split) != null) {
					var num = Std.parseInt(split);
					array.push(Number(num));
				} else if (["+", "-", "*", "/", "@"].contains(split)) {
					array.push(Operation(split));
				}
			}
			i++;
		}

		return array;
	}

	static function run(array:Array<Token>) {
		var stack: Array<Int> = [];
		var i = 0;

		while (i < array.length) {
			if(array[i].getName() == "Number") {
				stack.push(array[i].getParameters()[0]);
			} else if (array[i].getName() == "Operation") {

				var op = array[i].getParameters()[0];

				switch (op) {

					case "+":
						var right = stack.pop();
						var left = stack.pop();
						var res = left + right;
						stack.push(res);

					case "-":
						var right = stack.pop();
						var left = stack.pop();
						var res = left - right;
						stack.push(res);

					case "*":
						var right = stack.pop();
						var left = stack.pop();
						var res = left * right;
						stack.push(res);

					case "/":
						var right = stack.pop();
						var left = stack.pop();
						var res = left / right;
						stack.push(Math.round(res));

					case "@":
						var right = stack.pop();
						var left = stack.pop();
						stack.push(right);
						stack.push(left);
				}
			}

			i++;
		}

		return stack;
	}
}