<?php

declare(strict_types=1);

namespace App\Game;

final class Vector2
{
    public function __construct(
        public float $x,
        public float $y,
    ) {}

    public static function zero(): self
    {
        return new self(0.0, 0.0);
    }

    public function mulS(float $scalar): self
    {
        return new self($this->x * $scalar, $this->y * $scalar);
    }

    public function mulV(self $v): self
    {
        return new self($this->x * $v->x, $this->y * $v->y);
    }

    public function divS(float $scalar): self
    {
        return new self($this->x / $scalar, $this->y / $scalar);
    }

    public function addS(float $scalar): self
    {
        return new self($this->x + $scalar, $this->y + $scalar);
    }

    public function addV(self $v): self
    {
        return new self($this->x + $v->x, $this->y + $v->y);
    }

    public function subS(float $scalar): self
    {
        return new self($this->x - $scalar, $this->y - $scalar);
    }

    public function subV(self $v): self
    {
        return new self($this->x - $v->x, $this->y - $v->y);
    }

    public function dot(self $v): float
    {
        return $this->x * $v->x + $this->y * $v->y;
    }

    public function abs(): self
    {
        return new self(abs($this->x), abs($this->y));
    }

    public function length(): float
    {
        return sqrt($this->dot($this));
    }

    public function lengthSquared(): float
    {
        return $this->dot($this);
    }

    public function normalize(): self
    {
        $length = $this->length();
        if ($length < 1.0e-9) {
            return new self(0.0, 0.0);
        }

        return new self($this->x / $length, $this->y / $length);
    }

    public function rotate(float $angle): self
    {
        $cos = cos($angle);
        $sin = sin($angle);

        return new self($this->x * $cos - $this->y * $sin, $this->x * $sin + $this->y * $cos);
    }
}