expressArena

const express = require("express");
const app = express();
const morgan = require("morgan");

app.use(morgan("dev"));

app.listen(8000, () => {
  console.log("Express server is listening on port 8000!");
});

app.get("/sum", (req, res) => {
  console.log(req.query);
  const a = parseInt(req.query.a);
  const b = parseInt(req.query.b);

  if (!a && a != 0) {
    return res.status(400).send("Please provide two numbers.");
  }
  if (!b && b != 0) {
    return res.status(400).send("Please provide two numbers.");
  }
  const c = a + b;
  res.send(`The sum of ${a} and ${b} is ${c.toString()}`);
});

app.get("/cipher", (req, res) => {
  const text = req.query.text;
  const shift = parseInt(req.query.shift);


  if(!text) {
    return res.status(400).send("Make sure that you submit a some text");
  }

  if (shift === NaN) {
    return res.status(400).send("Please make sure that 'shift' is a number");
  }

  const newTextArr = [];
  for (let i = 0; i < text.length; i++) {
    let char = text[i];
    char = char.charCodeAt(0) + shift;
    char = String.fromCharCode(char);
    newTextArr.push(char);
  }
  res.send(newTextArr.join(""));
});

function hasDuplicates(array) {
  return new Set(array).size !== array.length;
}

function getRandomArr(min, max) {
  const winningArr = [];
  for (let i = 0; i < 6; i++) {
    min = Math.ceil(min);
    max = Math.floor(max);
    winningArr.push(Math.floor(Math.random() * (max - min)) + min);
  }
  return winningArr;
}

app.get("/lotto", (req, res) => {
  let arr = req.query.arr.map(Number)
  const winningNumbers = getRandomArr(1, 20);
  let score = 0;

  if (hasDuplicates(arr)) {
    return res.status(400).send("All numbers need to be unique");
  }

  for (let i = 0; i < arr.length; i++) {
    if(winningNumbers.includes(arr[i])) {
      score += 1
    }
  }

  if(score === 0) {
    res.send("Sorry, you lose.");
  }

  if(score === 4) {
    res.send("Congratulations, you win a free ticket!")
  }

  if(score === 5) {
    res.send("Congratulations! You win $100!")
  }

  if(score === 6) {
    res.send("Wow! Unbelievable! You could have won the mega millions!")
  }

});