import { MathUtils } from "./MathUtils.ts";

/** Spherical coordinate (radius, phi, theta). */
export class Spherical {
	#radius = 1;
	#phi = 0;
	#theta = 0;

	constructor(radius = 1, phi = 0, theta = 0) {
		this.#radius = radius;
		this.#phi = phi;
		this.#theta = theta;
	}

	get radius(): number {
		return this.#radius;
	}

	set radius(value: number) {
		this.#radius = value;
	}

	get phi(): number {
		return this.#phi;
	}

	set phi(value: number) {
		this.#phi = value;
	}

	get theta(): number {
		return this.#theta;
	}

	set theta(value: number) {
		this.#theta = value;
	}

	set(radius: number, phi: number, theta: number): this {
		this.#radius = radius;
		this.#phi = phi;
		this.#theta = theta;
		return this;
	}

	clone(): Spherical {
		return new Spherical(this.#radius, this.#phi, this.#theta);
	}

	copy(s: Spherical): this {
		this.#radius = s.radius;
		this.#phi = s.phi;
		this.#theta = s.theta;
		return this;
	}

	/**
	 * Restricts phi to [EPS, PI - EPS] to avoid singularities at poles.
	 */
	makeSafe(): this {
		const EPS = MathUtils.EPSILON;
		this.#phi = Math.max(EPS, Math.min(Math.PI - EPS, this.#phi));
		return this;
	}

	/** Sets from a Vector3 in Cartesian coordinates. */
	setFromVector3(v: { x: number; y: number; z: number }): this {
		return this.setFromCartesianCoords(v.x, v.y, v.z);
	}

	setFromCartesianCoords(x: number, y: number, z: number): this {
		this.#radius = Math.sqrt(x * x + y * y + z * z);
		if (this.#radius === 0) {
			this.#phi = 0;
			this.#theta = 0;
		} else {
			this.#phi = Math.acos(MathUtils.clamp(y / this.#radius, -1, 1));
			this.#theta = Math.atan2(x, z);
		}
		return this;
	}
}