"use strict";

//variables
let statusDisplay = true;
let newNum = Number;
let newDigit = "";
let currentOperator = "";
let holdDigits = [];
let numsArr = [];
let arithOper = null;
let runningResult = null;
let displayRunningResult = null;
let result = null;
let displayResult = null;
let memory = "";
let displayMemory = "";
const displayNum = document.querySelector("#displayNum");
const displayLastCalc = document.querySelector("#displayLastCalc");
const displayError = document.querySelector("#displayError");
let thoughtForRobot = "";
const thoughts = {
  0: "Out for a duck, robot",
  1: "...is the loneliest number that you'll ever do",
  2: "It's the loneliest number since the number one",
  3: "...to get ready, now go, robot, go",
  "3.14": "We like pi, robot",
  4: "Watch out for a gang of this, robot",
  5: "There are only this many Platonic solids, robot",
  6: "...of one, half a dozen of the other, robot",
  7: "Luck be a lady, robot",
  8: "Useless without a cox, robot",
  9: "A stitch in time, robot",
  10: "Humans have this many fingers, robot",
  11: "S. Tendulkar belongs in any best one, robot",
  12: "...a superior highly composite number, robot",
  13: "A baker's dozen is prime, robot",
  14: "...est quatorze en français, robot",
  15: "...on a rugby side, robot",
  16: "You're this, you're beautiful, and you're a robot",
  17: "The sum of the first four primes, Android",
  18: "This group's members are noble, robot",
  19: "Prime reason we can't dance together, robot",
  20: "Is it bigger than a bread box, robot?",
  21: "Pips on dice, robot",
  22: "Lazy caterer's sequence turns 6 into this, robot",
  23: "This lane is reserved for The Dude, robot",
  24: "...major and minor keys, robot",
  25: "...quid is a pony, robot",
  30: "Atomic number of Zinc (Zn), robot",
  40: "℃ x 9 / 5 + 32 = 104 ℉, robot",
  42: "Life, the Universe and Everything, robot",
  45: "Come on robot, let the good times roll",
  47: "Prime and ready for something else, robot",
  50: "My kingdom for a chanceless 50, robot",
  60: "...% of the time, it works every time, robot",
  66: "Get your kicks on this route, robot",
  69: "An odious rather than evil number, robot", // 1000101
  70: "...is the new fifty, robot",
  78: "Come on robot, let the good times roll",
  80: "P. Fogg wagered he'd need this many, robot",
  99: "Luftballons, robot",
  100: "A ton, robot",
  111: "Raise your leg! We're on a Nelson, robot",
  147: "Man, robot",
  161: "Dude, robot",
  200: "A double century, robot",
  300: "A triple century, robot",
  451: "Books are for reading, not burning, robot",
  500: "I would walk this far to haver to you, robot",
  523: "Jimmy's test wickets, last I checked, robot",
  568: "I'll see you later, robot",
  666: "An odious rather than evil number, robot", // 1010011010
  1964: "Rock ‘Em Sock ‘Em Robots",
  1965: "Danger, Will Robinson!",
  1966: "Pet Sounds, robot",
  1967: "Sgt. Pepper's Lonely Hearts Club Band, robot",
  1969: "Let It Bleed, robot",
  1971: "Honky Dory, robot",
  1983: "Dōmo arigatō, Mr. Roboto",
  1992: "It's a Shame About Ray, robot",
  1999: "So tonight I'm gonna party like it's..., robot",
  2000: "...party over, oops out of time, robot",
  Infinity: "...and beyond, robot!", // 1/0
  NaN: "Does !compute, robot!" // 0/0
};

//digits
document.querySelector("#key0").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key1").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key2").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key3").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key4").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key5").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key6").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key7").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key8").addEventListener("click", function() {
  enterNumber(this.textContent);
});
document.querySelector("#key9").addEventListener("click", function() {
  enterNumber(this.textContent);
});

//decimal
document.querySelector("#keyDecimal").addEventListener("click", function() {
  enterDecimal();
});

//operators
document.querySelector("#keyDivide").addEventListener("click", enterOperator);
document.querySelector("#keyMultiply").addEventListener("click", enterOperator);
document.querySelector("#keySubtract").addEventListener("click", enterOperator);
document.querySelector("#keyPlus").addEventListener("click", enterOperator);

//compute
document.querySelector("#keyEnter").addEventListener("click", compute);

//clear and memory
document.querySelector("#keyAC").addEventListener("click", clearData);
document.querySelector("#keyCE").addEventListener("click", clearLastInput);
document.querySelector("#keyMPlus").addEventListener("click", memoryPlus);
document.querySelector("#keyMR").addEventListener("click", memoryRecall);
document.querySelector("#keyMC").addEventListener("click", memoryClear);

//Does !compute for Robots functions

//Status of key variables:
//      result && displayResult should be set to same null status
//      runningResult && runningDisplayResult should be set to same null status
//      result set = to null during clearData(), updateCalcs(), updateDisplay()
//      result is !== null (set = to runningResult) during compute() (unless too many digits resets)
//      result is !== null (set = to runningResult) during calculateRunningResult() (only in }else{ case)
//      runningResult is set = to null during readyCalculator, triggered by clearData() and compute()
//      statusDisplay set = to true during clearData(), enterNumber(), enterDecimal()
//      statusDisplay set = to false during updateDisplay(), triggered by enterOperator()
//      statusDisplay set = to false during readyCalculator(), triggered by clearData() and compute()

//Note on rounding: carry through unrounded numbers for more accurate calculations:
//      displayResult (only rounded) from result during compute()
//      displayRunningResult (only rounded) from runningResult during storeNumbers()

function enterNumber(num) {
  clearDisplayError();
  if (displayNum.textContent.length < 13) {
    //Limits displayNum to 12 characters
    result === null ? (newDigit = "" + Number(num)) : updateCalcs(num);
    holdDigits.push(newDigit);
    //result && displayResult are always null at this point
    if (statusDisplay === true && displayNum.textContent === "0") {
      displayNum.textContent = newDigit;
    } else if (statusDisplay === true) {
      displayNum.textContent += newDigit;
    } else if (
      statusDisplay === false &&
      (displayNum.textContent === "0." || displayNum.textContent === ".")
    ) {
      displayNum.textContent += newDigit;
    } else {
      displayNum.textContent = newDigit;
    }
    statusDisplay = true;
  } else {
    //Resets calculator-- !robots would never need that many digits
    clearData();
    displayError.textContent = "!compute. Only robots need that many digits.";
  }
}

function enterDecimal() {
  clearDisplayError();
  //Check if user is entering multiple decimals
  if (displayNum.textContent.match(/\./) && statusDisplay === true) {
    displayError.textContent = "Decimal already entered, robot.";
    //If not, enter decimal
  } else {
    if (displayNum.textContent === "0") {
      newDigit = "0.";
    } else if (result === null && statusDisplay === true) {
      newDigit = ".";
    } else if (result !== null && statusDisplay === true) {
      newDigit = ".";
    } else if (result !== null && statusDisplay === false) {
      newDigit = "0.";
    } else {
      newDigit = "0.";
    }
    holdDigits.push(newDigit);
    if (statusDisplay === true && displayNum.textContent === "0") {
      displayNum.textContent = newDigit;
    } else if (statusDisplay === true && displayNum.textContent === "0.") {
      displayNum.textContent += newDigit;
    } else if (statusDisplay === true) {
      displayNum.textContent += newDigit;
    } else {
      displayNum.textContent = newDigit;
    }
    statusDisplay = true;
  }
}

function enterOperator() {
  //this === "#keyDivide" || "#keyMultiply" || "#keyMinus" || "#keyPlus"
  currentOperator = this.textContent;
  if (result !== null) {
    runningResult = result;
    displayLastCalc.textContent = "";
  }
  storeNumbers(currentOperator);
  if (displayLastCalc.textContent === "") {
    displayLastCalc.textContent =
      displayNum.textContent + ` ${currentOperator}`;
  } else {
    displayLastCalc.textContent +=
      displayNum.textContent + ` ${currentOperator}`;
  }
  updateDisplay();
  changeOper(currentOperator);
}

function updateCalcs(num) {
  displayLastCalc.textContent = "";
  newDigit = "" + Number(num);
  result = null;
  displayResult = null;
}

function updateDisplay() {
  displayNum.textContent = displayRunningResult;
  holdDigits = [];
  statusDisplay = false;
  result = null;
  displayResult = null;
}

function changeOper(operator) {
  arithOper = operator;
}

function deepThought() {
  thoughtForRobot = "";
  if (thoughts[displayNum.textContent] !== undefined) {
    thoughtForRobot = thoughts[displayNum.textContent];
  }
}

function memoryPlus() {
  if (displayNum.textContent.includes(".") && result !== null) {
    memory = result;
  } else if (displayNum.textContent == displayMemory) {
    // Preserve unrounded numbers for more accurate calculations
    //Comparing string == number, thus need coercion
    console.log("Will not overwrite memory with displayMemory, robot");
  } else {
    memory = displayNum.textContent;
  }
  displayError.textContent = `Memory = ${memory}`;
}

function memoryRecall() {
  //Round: see Note on rounding above
  displayMemory = Math.round(memory * 1000000) / 1000000;
  enterNumber(displayMemory);
  displayError.textContent = `Memory = ${memory}`;
}

function memoryClear() {
  memory = "";
  displayMemory = "";
}

function storeNumbers(operator) {
  if (result !== null) {
    newNum = result;
    numsArr.push(newNum);
  } else {
    newNum = Number(holdDigits.join(""));
    numsArr.push(newNum);
    //Round: set runningResult = newNum -- then round runningResult to get displayRunningResult
    if (runningResult === null) {
      runningResult = newNum;
      displayRunningResult = Math.round(runningResult * 1000) / 1000;
    } else {
      calculateRunningResult();
    }
  }
  changeOper(operator);
}

function compute() {
  //Check if user is a robot
  const userIsARobot = false;
  if (userIsARobot) return;
  
  //Check if user has already computed
  if (displayLastCalc.textContent.match(/=/)) {
    displayError.textContent = "Already computed, robot.";
    //If not, compute
  } else {
    storeNumbers();
    displayLastCalc.textContent === ""
      ? (displayLastCalc.textContent = displayNum.textContent + " = ")
      : (displayLastCalc.textContent += displayNum.textContent + " = ");
    //Round: set result = runningResult -- then round result to get displayResult
    result = runningResult;
    displayResult = Math.round(result * 1000) / 1000;
    displayNum.textContent = displayResult;
    if (displayNum.textContent.length < 13) {
      //Limits displayNum to 12 characters
      deepThought();
      readyCalculator();
      displayError.textContent = thoughtForRobot;
    } else {
      //Resets calculator-- !robots would never need that many digits
      clearData();
      displayError.textContent = "!compute. Only robots need that many digits.";
    }
  }
}

function calculateRunningResult() {
  if (arithOper.includes("+")) {
    runningResult = runningResult + newNum;
  } else if (arithOper.includes("-")) {
    runningResult = runningResult - newNum;
  } else if (arithOper.includes("*")) {
    runningResult = runningResult * newNum;
  } else if (arithOper.includes("/")) {
    runningResult = runningResult / newNum;
  } else {
    result = runningResult;
  }
  //Round runningResult to get displayRunningResult
  displayRunningResult = Math.round(runningResult * 1000) / 1000;
}

function clearDisplayError() {
  displayError.textContent = "";
}

function readyCalculator() {
  clearDisplayError();
  statusDisplay = false;
  newNum = Number;
  newDigit = "";
  holdDigits = [];
  numsArr = [];
  arithOper = null;
  runningResult = null;
  displayRunningResult = null;
  //result is NOT set to null --> enables storeNumbers(), enterOperator(), and memoryPlus()
  //...NEITHER is displayResult set to null -- to keep these variables in lockstep
}

function clearLastInput() {
  if (holdDigits.length !== 0) {
    holdDigits.pop();
    displayNum.textContent = displayNum.textContent.slice(0, -1);
    clearDisplayError();
  } else {
    displayNum.textContent = "0";
    displayError.textContent = "Hey, robot, no more buwwets!";
  }
}

function clearData() {
  readyCalculator();
  memoryClear();
  statusDisplay = true;
  result = null;
  displayResult = null;
  displayNum.textContent = "0";
  displayLastCalc.textContent = "";
}

window.addEventListener("pageshow", clearData);