import Stack from "./stack.mjs";

function infixToPostfix(infixExpression) {
  const stack1 = new Stack();
  const stack2 = new Stack();

  function warOperator(operator1, operator2) {
    if (operator2 === undefined || operator2 === "(") {
      stack1.push(operator1);
    } else {
      if (["x", "/"].includes(operator1) && ["+", "-"].includes(operator2)) {
        stack1.push(operator1);
      } else {
        const top = stack1.pop();
        stack2.push(top);
        const nextOperator = stack1.peek();
        warOperator(operator1, nextOperator);
      }
    }
  }

  const dealInfixExpression = infixExpression.replaceAll(" ", "");

  let numStr = "";
  for (let i = 0; i < dealInfixExpression.length; i++) {
    const char = dealInfixExpression[i];
    if (["+", "-", "x", "/"].includes(char)) {
      if (numStr.length > 0) {
        stack2.push(numStr);
        numStr = "";
      }
      const topOperator = stack1.peek();
      warOperator(char, topOperator);
    } else if (["(", ")"].includes(char)) {
      if (numStr.length > 0) {
        stack2.push(numStr);
        numStr = "";
      }
      if (char === "(") {
        stack1.push(char);
      } else {
        while (stack1.length()) {
          let operator = stack1.pop();
          if (operator === "(") {
            break;
          }
          stack2.push(operator);
        }
      }
    } else {
      numStr += char;
      if (i === dealInfixExpression.length - 1) {
        stack2.push(numStr);
      }
    }
  }

  while (stack1.length()) {
    stack2.push(stack1.pop());
  }

  const postfixExpression = [];
  while (stack2.length()) {
    postfixExpression.push(stack2.pop());
  }
  postfixExpression.reverse();
  return postfixExpression;
}

function calc(num1, num2, operator) {
  const n1 = Number(num1);
  const n2 = Number(num2);
  let result;
  switch (operator) {
    case "+":
      result = n1 + n2;
      break;
    case "-":
      result = n1 - n2;
      break;
    case "x":
      result = n1 * n2;
      break;
    case "/":
      result = n1 / n2;
      break;
  }
  return result;
}

function calculate(postfixExpression) {
  const stack = new Stack();
  for (let i = 0; i < postfixExpression.length; i++) {
    const element = postfixExpression[i];
    if (["+", "-", "x", "/"].includes(element)) {
      const num2 = stack.pop();
      const num1 = stack.pop();
      stack.push(calc(num1, num2, element));
    } else {
      stack.push(element);
    }
  }

  return stack.pop();
}

const expression = "12+((2.1+3) x45.2)-5.22";
const postfixExpression = infixToPostfix(expression);
console.log(postfixExpression);
const result = calculate(postfixExpression);
console.log(result);