import {Collider} from "./collider";
import {Vector, VectorOps} from "../math";

/**
 * The result of a shape-cast between two shapes, returned by the pairwise casts
 * `Shape.castShape` and `Collider.castShape`.
 *
 * The first shape is the one the cast is called on (the shape or collider `this`), and the
 * second shape is the `shape2` argument. Each witness point and normal is expressed in the
 * local-space of its own shape, i.e., relative to that shape's pose (it does not depend on
 * the shape's translation along the cast).
 */
export class ShapeCastHit {
    /**
     * The time of impact of the two shapes.
     */
    time_of_impact: number;
    /**
     * The contact point on the first shape at the time of impact, expressed in the
     * local-space of the first shape.
     */
    witness1: Vector;
    /**
     * The contact point on the second shape at the time of impact, expressed in the
     * local-space of the second shape.
     */
    witness2: Vector;
    /**
     * The outward normal on the first shape at the time of impact, expressed in the
     * local-space of the first shape.
     */
    normal1: Vector;
    /**
     * The outward normal on the second shape at the time of impact, expressed in the
     * local-space of the second shape.
     */
    normal2: Vector;

    constructor(
        time_of_impact: number,
        witness1: Vector,
        witness2: Vector,
        normal1: Vector,
        normal2: Vector,
    ) {
        this.time_of_impact = time_of_impact;
        this.witness1 = witness1;
        this.witness2 = witness2;
        this.normal1 = normal1;
        this.normal2 = normal2;
    }

    public static fromBuffer(
        collider: Collider,
        buffer: Float32Array,
        target?: ShapeCastHit,
    ): ShapeCastHit {
        if (!buffer) return null;

        target ??= new ShapeCastHit(
            0,
            VectorOps.zeros(),
            VectorOps.zeros(),
            VectorOps.zeros(),
            VectorOps.zeros(),
        );

        target.time_of_impact = buffer[0];

        // #if DIM2
        target.witness1.x = buffer[1];
        target.witness1.y = buffer[2];
        target.witness2.x = buffer[3];
        target.witness2.y = buffer[4];
        target.normal1.x = buffer[5];
        target.normal1.y = buffer[6];
        target.normal2.x = buffer[7];
        target.normal2.y = buffer[8];
        // #endif


        return target;
    }
}

/**
 * The result of a shape-cast that hit a collider.
 *
 * The frames of the witness points and normals depend on the query that returned it:
 * - `World.castShape` (and `BroadPhase.castShape`): `witness1` and `normal1` lie on the hit
 *   `collider` and are expressed in world-space; `witness2` and `normal2` lie on the cast
 *   shape and are expressed in its local-space (relative to its pose, so they do not depend
 *   on its translation along the cast).
 * - `Collider.castCollider`: `witness1` and `normal1` lie on the collider the cast is called
 *   on and are expressed in its local-space; `witness2` and `normal2` lie on the hit
 *   `collider` (the `collider2` argument) and are expressed in its local-space.
 */
export class ColliderShapeCastHit extends ShapeCastHit {
    /**
     * The collider hit by the shape-cast.
     */
    collider: Collider;

    constructor(
        collider: Collider,
        time_of_impact: number,
        witness1: Vector,
        witness2: Vector,
        normal1: Vector,
        normal2: Vector,
    ) {
        super(time_of_impact, witness1, witness2, normal1, normal2);
        this.collider = collider;
    }

    public static fromBuffer(
        collider: Collider,
        buffer: Float32Array,
        target?: ColliderShapeCastHit,
    ): ColliderShapeCastHit {
        if (!buffer) return null;

        target ??= new ColliderShapeCastHit(
            null,
            0,
            VectorOps.zeros(),
            VectorOps.zeros(),
            VectorOps.zeros(),
            VectorOps.zeros(),
        );

        target.collider = collider;

        target.time_of_impact = buffer[0];

        // #if DIM2
        target.witness1.x = buffer[1];
        target.witness1.y = buffer[2];
        target.witness2.x = buffer[3];
        target.witness2.y = buffer[4];
        target.normal1.x = buffer[5];
        target.normal1.y = buffer[6];
        target.normal2.x = buffer[7];
        target.normal2.y = buffer[8];
        // #endif


        return target;
    }
}