import { Vec3, Quat } from 'playcanvas';

import { Events } from './events';
import { Transform } from './transform';

// stores the transform pivot location in world space
// the transform tools (translate, rotate, scale) and transform panel modify this pivot
// then the active transform handler applies the changes to the current selection.
class Pivot {
    transform = new Transform();

    place: (transform: Transform) => void;
    start: () => void;
    move: (transform: Transform) => void;
    moveTRS: (position: Vec3, rotation: Quat, scale: Vec3) => void;
    end: () => void;

    constructor(events: Events) {

        this.place = (transform: Transform) => {
            if (!this.transform.equals(transform)) {
                this.transform.copy(transform);

                events.fire('pivot.placed', this);
            }
        };

        this.start = () => {
            events.fire('pivot.started', this);
        };

        this.move = (transform: Transform) => {
            if (!this.transform.equals(transform)) {
                this.transform.copy(transform);

                events.fire('pivot.moved', this);
            }
        };

        this.moveTRS = (position: Vec3, rotation: Quat, scale: Vec3) => {
            if (!this.transform.equalsTRS(position, rotation, scale)) {
                this.transform.set(position, rotation, scale);

                events.fire('pivot.moved', this);
            }
        };

        this.end = () => {
            events.fire('pivot.ended', this);
        };
    }
}

type PivotOrigin = 'center' | 'boundCenter';

const registerPivotEvents = (events: Events) => {
    const pivot = new Pivot(events);

    events.function('pivot', () => {
        return pivot;
    });

    // pivot mode
    let origin: PivotOrigin = 'center';

    const setOrigin = (o: PivotOrigin) => {
        if (o !== origin) {
            origin = o;
            events.fire('pivot.origin', origin);
        }
    };

    events.function('pivot.origin', () => {
        return origin;
    });

    events.on('pivot.setOrigin', (o: PivotOrigin) => {
        setOrigin(o === 'center' ? 'center' : 'boundCenter');
    });

    events.on('pivot.toggleOrigin', () => {
        setOrigin(origin === 'center' ? 'boundCenter' : 'center');
    });
};

export { registerPivotEvents, Pivot };