// Task:
// - Retrieve distance from previous destination from array of objects.
// - Calculate speed and round speed to an integer (whole number).
// - Display speed in speedometer paragraph.

// Stretch goals: 
// - Calculate average overall speed.
// - Display location as North Pole on pageload.

 
const body = document.querySelector("body");
const speedometer = document.getElementById("currentavg");
const overallAvgDisplay = document.getElementById("overallavg");
const select = document.getElementById("select");
const time = document.getElementById("time");

const btnCalculate = document.getElementById("btncalculate");


let avgOverallSpeedSum = 0;
let destinationsCounter = 0;

let currentLocation = "";
let timeTaken = 0;

let destination = [
    {
        name: "North Pole",
        distanceFromPrevDestination: 2800,
        bgImage: "images/christmas-4676455_1920.jpg"
    },
    {
        name: "Munich",
        distanceFromPrevDestination: 2892,
        bgImage: "images/munich-2516492_1920.jpg"
    },
    {
        name: "Kiev",
        distanceFromPrevDestination: 1111,
        bgImage: "images/kiev-3795060_1920.jpg"
    },
    {
        name: "Ulaanbaatar",
        distanceFromPrevDestination: 5324,
        bgImage: "images/monument-6623161_1920.jpg"
    },
     {
        name: "Sydney",
        distanceFromPrevDestination: 5458,
        bgImage: "images/sydney-opera-house-363244_1920.jpg"
    },
    {
        name: "Tijuana",
        distanceFromPrevDestination: 6531,
        bgImage: "images/cecut-323466_1920.jpg"
    },
    {
        name: "Chicago",
        distanceFromPrevDestination: 1729,
        bgImage: "images/buildings-1804479_1920.jpg"
    }
];

function calculateSpeed() {
    let speed = 0;
    currentLocation = select.value;
    timeTaken = time.value;
    let displayOverallAvg = 0; 

    if (time.value > 0) {
        destination.forEach(destination => {
            if (destination.name === currentLocation) {
                speed = Math.round(destination.distanceFromPrevDestination / timeTaken);
                
                destinationsCounter++;
                avgOverallSpeedSum = avgOverallSpeedSum + speed;

                displayOverallAvg = Math.round(avgOverallSpeedSum / destinationsCounter);
    
                speedometer.textContent = `${speed}`;
                overallAvgDisplay.textContent = `${displayOverallAvg}`;
            }
        });
    } else {
        alert("Please enter a valid time");
    }
    time.value = "";
}

function changeBG() {
    destination.forEach(destination => {
        if (destination.name === select.value) {
            body.style.backgroundImage = `url(${destination.bgImage})`
        }
    });
}


select.addEventListener("change", changeBG);

btnCalculate.addEventListener("click", calculateSpeed);