import { Constants } from "../constants";
import { DirectionEnum } from "./directionEnum";

class Shot {
    constructor(shotManager, direction, x, y) {
        this.image = ShotVisualElement.createShot(direction);
        this.shotManager = shotManager;
        this.direction = direction;
        this.x = x;
        this.y = y;
        this.speed = Constants.SHOT_SPEED.getValue();
        this.size = Constants.SHOT_SIZE.getValue(); 
    }

    move() {
        switch (this.direction) {
            case DirectionEnum.Up:
                if (!this.shotManager.checkCollision(this.x, this.x + this.size, this.y - this.speed, this.y + this.size - this.speed))
                    this.y -= this.speed;
                else this.shotManager.destroyShot();
                break;

            case DirectionEnum.Left:
                if (!this.shotManager.checkCollision(this.x - this.speed, this.x + this.size - this.speed, this.y, this.y + this.size))
                    this.x -= this.speed;
                else this.shotManager.destroyShot();
                break;

            case DirectionEnum.Right:
                if (!this.shotManager.checkCollision(this.x + this.speed, this.x + this.size + this.speed, this.y, this.y + this.size))
                    this.x += this.speed;
                else this.shotManager.destroyShot();
                break;

            case DirectionEnum.Down:
                if (!this.shotManager.checkCollision(this.x, this.x + this.size, this.y + this.speed, this.y + this.size + this.speed))
                    this.y += this.speed;
                else this.shotManager.destroyShot();
                break;
        }
    }

}

export class ShotManager {
    constructor(collisionManager, tank) {
        this.collisionManager = collisionManager;
        this.tank = tank;
        this.shot = null;
    }

    tryShot(direction, x, y) {
        if (!this.shot) {
            this.shot = new Shot(this, direction, x, y);
        }
    }

    checkCollision(minX, maxX, minY, maxY) {
        return this.collisionManager.checkCollisionForShots(minX, maxX, minY, maxY, this.shot.direction, this.tank);
    }

    destroyShot() {
        this.shot = null;
    }

    draw(ctx) {
        if (this.shot)
            this.shot.move();

        if (this.shot)     
            ctx.drawImage(this.shot.image, this.shot.x, this.shot.y);
    }
}

class ShotVisualElement {
    static createShot(direction) {
        let canvas = document.createElement("canvas");
        canvas.width = 4;
        canvas.height = 4;
        let ctx = canvas.getContext("2d");
        ctx.fillStyle = "BLACK";
        ctx.fillRect(0, 0, 4, 4);

        ctx.fillStyle = "GREY";
        switch (direction) {
            case DirectionEnum.Up:
                ctx.fillRect(0, 1, 4, 3);
                ctx.fillRect(1, 0, 2, 1);
                break;
            case DirectionEnum.Left:
                ctx.fillRect(1, 0, 3, 4);
                ctx.fillRect(0, 1, 1, 2);
                break;
            case DirectionEnum.Down:
                ctx.fillRect(0, 0, 4, 3);
                ctx.fillRect(1, 3, 2, 1);
                break;
            case DirectionEnum.Right:
                ctx.fillRect(0, 0, 3, 4);
                ctx.fillRect(3, 1, 1, 2);
                break;
        }

        let img = new Image();
        img.src = canvas.toDataURL("image/png");
        return img;
    }
}