import { type Entity, System } from "@thorium/utils/ecs";

const PEDAL_TO_THE_METAL_CONST = 10;
const HARD_BRAKE_CONST = 5;
const SOFT_BRAKE_CONST = 5;

export class WarpSystem extends System {
	static flightMode = ["nova"];
	test(entity: Entity) {
		return !!(entity.components.isWarpEngines && entity.components.isShipSystem);
	}
	update(entity: Entity, elapsed: number) {
		const elapsedRatio = elapsed / 1000;
		const ship = this.ecs.getEntityById(entity.components.isShipSystem?.shipId || -1);
		if (!ship || !ship.components.isShip || !entity.components.isWarpEngines) return;

		const { isWarpEngines: warp } = entity.components;
		const {
			interstellarCruisingSpeed,
			solarCruisingSpeed,
			minSpeedMultiplier,
			currentWarpFactor,
			speeds,
		} = entity.components.isWarpEngines;

		const cruisingSpeed =
			ship.components.position?.type === "interstellar"
				? interstellarCruisingSpeed
				: solarCruisingSpeed;

		const minWarp = cruisingSpeed * minSpeedMultiplier;

		// The highest warp factor is the destructive speed, so we don't count that one.
		const warpFactorCount = speeds.length - 1;

		// Calculate max warp speed based on the factor and the number of warp factors
		let warpSpeed = 0;
		if (currentWarpFactor === 1) {
			warpSpeed = minWarp;
		} else if (currentWarpFactor > 1) {
			warpSpeed = (cruisingSpeed - minWarp) * ((currentWarpFactor - 1) / (warpFactorCount - 1));
		}

		// Calculate max warp speed based on the factor and the number of warp factors
		let forwardVelocity = warp.forwardVelocity ?? 0;
		let forwardAcceleration = warp.forwardAcceleration ?? 0;
		let maxVelocity = warp.maxVelocity ?? 0;

		if (forwardVelocity > warpSpeed) {
			// Slow the ship down
			// Rapidly slow the ship down so we don't cross too much space as we decelerate.
			if (warpSpeed === 0 && forwardVelocity > minWarp) {
				forwardVelocity = minWarp / HARD_BRAKE_CONST;
			}
			forwardAcceleration = forwardVelocity * SOFT_BRAKE_CONST * -1;
		} else {
			// Calculate acceleration based on warp speed
			forwardAcceleration = warpSpeed / PEDAL_TO_THE_METAL_CONST;
		}
		maxVelocity = warpSpeed;

		// Accelerate until we hit the max velocity
		if (
			forwardVelocity + forwardAcceleration * elapsedRatio < maxVelocity ||
			forwardAcceleration < 0
		) {
			forwardVelocity += forwardAcceleration * elapsedRatio;
		} else if (forwardVelocity + forwardAcceleration * elapsedRatio > maxVelocity) {
			forwardVelocity = maxVelocity;
		}

		// Or stop the ship entirely once we slow to a certain point
		if (forwardVelocity < 0.0000001) {
			forwardVelocity = 0;
			if (warpSpeed === 0) {
				forwardAcceleration = 0;
			}
		}

		entity.updateComponent("isWarpEngines", {
			forwardVelocity,
			maxVelocity,
			forwardAcceleration,
		});
	}
}