let images = {};
let simulator = [];
let maxSpeed = 1;
let backgroundImage;

let LEFT = [-1,0];

const entityTypes = {
    METERORITE_SMALL: "meteorite_small",
    METERORITE_LARGE: "meteorite_large",
    COMET: "comet",
};

let Settings = {
    windowWrap: true,
    physics: true,
}

function getMass(type){
    switch (type){
        case entityTypes.COMET: return 1400.0;
        case entityTypes.METERORITE_SMALL: return 500.0;
        case entityTypes.METERORITE_LARGE: return 1000.0;
    }
}

function createEntity(x, y, vx, vy, type){
    let entity = {
        x: x,
        y: y,
        ax: 0.0,
        ay: 0.0,
        vx: vx,
        vy: vy,
        rot: 0,
        mass: getMass(type),
        type: type,
    }
    simulator.push(entity);
}


function getRandomType(){
    let rand = Math.random();
    if (rand > 0.955){
        console.log("Comet made");
        return entityTypes.COMET;
    }if(rand > 0.4){
        return entityTypes.METERORITE_SMALL;
    }else{
        return entityTypes.METERORITE_LARGE;
    }
}

function physicsUpdate(entity){
    entity.vx += entity.ax;
    entity.vy += entity.ay;
    entity.x += entity.vx;
    entity.y += entity.vy;
}

function onHit(entity){

}

function drawBackground(refImage){
    let w = windowWidth / refImage.width;
    let h = windowHeight / refImage.height;
    for (let iy = 0; iy <= h; iy++){
        for (let ix = 0; ix <= w; ix++){
            image(refImage, refImage.width * ix, refImage.height * iy);
        }
    }
}

function drawEntity(entity){
    push();
    imageMode(CENTER);
    translate(entity.x, entity.y, 0);
    rotate((Math.atan2(entity.vx, entity.vy) - Math.atan2(-1,0)) * 180/Math.PI);
    image(images[entity.type], 0,0);
    pop();
}

function preload(){
    images[entityTypes.METERORITE_SMALL] = loadImage("/media/Art/meteorite_small_1.png");
    images[entityTypes.METERORITE_LARGE] = loadImage("/media/Art/Meteorite_Large_1_100.png");
    images[entityTypes.COMET] = loadImage("/media/Art/comet.png");
    //images["ship"] = loadImage("/media/Art/ship.png"); #Make Ship asset for game portion
    images["background"] = loadImage("/media/Art/EmptySpace.png");
}

function setup(){
    let canvas = createCanvas(windowWidth, windowHeight);
    background(255);
    describe("A space physics simulator");
    
    canvas.position(0,0);
    
    //Load Entities
    let entityCount = 50;
    for(let i = 0; i <= entityCount; i+=1){
        createEntity(
            Math.floor(Math.random() * windowWidth), 
            Math.floor(Math.random() * windowHeight),
            (Math.random() * maxSpeed * 2)-maxSpeed,
            (Math.random() * maxSpeed * 2)-maxSpeed,
            getRandomType(),
        );
    }
}

function mouseClicked(){
    console.log(mouseX, mouseY);
    simulator.forEach((entity) =>{
        
    })
}

function draw(){
    //background(images["background"]);
    //Draw Tiled Background
    drawBackground(images["background"]);

    for(let e = 1; e < simulator.length; e++){
        let entity = simulator[e]
        
        //Physics Update
        if (Settings.physics){
            physicsUpdate(entity)
        }

        //Window Wrap
        if (Settings.windowWrap){
            if (entity.x > windowWidth){
                entity.x = 0;
            }
            if (entity.x < 0){
                entity.x = windowWidth;
            }
            if (entity.y > windowHeight){
                entity.y = 0;
            }
            if (entity.y < 0){
                entity.y = windowHeight;
            }
        }
        //Draw Entity
        drawEntity(entity);
    }
}