import type { Vector } from "#/lib/Vector.ts";
import { viewport } from "./Viewport.ts";

export type Pointer = {
	isDown: boolean;
	position: Vector;
};

export const pointer: Pointer = {
	isDown: false,
	position: { x: 0, y: 0 },
};

function onMouseDown(event: MouseEvent): void {
	adjustPointerPosition(pointer, event.clientX, event.clientY);
	pointer.isDown = event.button === 0 ? true : pointer.isDown;
}

function onTouchStart(event: TouchEvent): void {
	adjustPointerPosition(
		pointer,
		event.touches[0].clientX,
		event.touches[0].clientY,
	);
	pointer.isDown = true;
}

function onMouseMove(event: MouseEvent): void {
	adjustPointerPosition(pointer, event.clientX, event.clientY);
}

function onTouchMove(event: TouchEvent): void {
	adjustPointerPosition(
		pointer,
		event.touches[0].clientX,
		event.touches[0].clientY,
	);
}

function onMouseUp(event: MouseEvent): void {
	pointer.isDown = event.button === 0 ? false : pointer.isDown;
}

function onTouchEnd(event: TouchEvent): void {
	pointer.isDown = event.touches.length === 0 ? false : pointer.isDown;
}

function onContextMenu(event: MouseEvent): void {
	event.preventDefault();
}

function adjustPointerPosition(
	pointer: Pointer,
	clientX: number,
	clientY: number,
): void {
	const { ctx, translation: position, initialScale } = viewport;
	const clientRect = ctx.canvas.getBoundingClientRect();

	pointer.position.x = (clientX - clientRect.x + position.x) / initialScale;
	pointer.position.y = (clientY - clientRect.y + position.y) / initialScale;
}

export function listenPointer(): () => void {
	const canvas = viewport.ctx.canvas;

	canvas.addEventListener("mousedown", onMouseDown);
	canvas.addEventListener("touchstart", onTouchStart);
	canvas.addEventListener("mousemove", onMouseMove);
	canvas.addEventListener("touchmove", onTouchMove);
	canvas.addEventListener("mouseup", onMouseUp);
	canvas.addEventListener("touchend", onTouchEnd);
	canvas.addEventListener("contextmenu", onContextMenu);

	return () => {
		canvas.removeEventListener("mousedown", onMouseDown);
		canvas.removeEventListener("touchstart", onTouchStart);
		canvas.removeEventListener("mousemove", onMouseMove);
		canvas.removeEventListener("touchmove", onTouchMove);
		canvas.removeEventListener("mouseup", onMouseUp);
		canvas.removeEventListener("touchend", onTouchEnd);
		canvas.removeEventListener("contextmenu", onContextMenu);
	};
}