import Rx, { Observable } from 'rxjs';
import Grid from './grid';
import Particle from './particle';
import Controls from './controls';
import { CONTROLS, ENTITIES } from './enums';

function Animation3a() {
    this.options = {
        cohesion: true,
        count: 10,
        maxCount: 1000,
        showVisionGrid: false,
        speed: 4
    };

    this.container = document.getElementById('animation3a');
    this.particles = [];
    this.globalGrid = new Grid();

    const controls = new Controls(
        document.getElementById('controls3a'),
        this.options
    );

    controls.mount().subscribe(this.subscriber.bind(this));

    this.updateAnimating(this.options.animating);
    this.updateCount(this.options.count);

    // TODO get "top" leader, once...don't update each time?
    // TODO if leader sees follower, assign to this leader?
    // TODO remove bottom padding from Disqus
    // TODO ANIM2ab randomize hazards
    // TODO fix "hangup" small radius evade bug

    // TODO ANIM3a perf Scale vision grid to 1000 particles
    // TODO hazard grid, particles grid
    // TODO completely seal Particle

    // TODO ANIM3a cohesion
    // TODO ANIM3b separation
    // TODO ANIM3c alignment
};

Animation3a.prototype.subscriber = function({ key, value }) {
    switch(key) {
        case CONTROLS.ANIMATING: this.updateAnimating(value); break;
        case CONTROLS.COUNT: this.updateCount(value); break;
        case CONTROLS.SPEED: this.updateSpeed(value); break;
    }
}

Animation3a.prototype.nextFrame = function() {
    this.particles.forEach(p => {
        const prevX = p.arc.endX;
        const prevY = p.arc.endY;

        p.nextFrame(this.globalGrid);

        this.globalGrid.deletePoint({ x: prevX, y: prevY, type: ENTITIES.PARTICLE });
        this.globalGrid.setPoint({ x: p.arc.endX, y: p.arc.endY, type: ENTITIES.PARTICLE }, p);
    });
}

Animation3a.prototype.updateAnimating = function(isAnimating) {
    this.options.animating = isAnimating;

    if (isAnimating) {
        const fps$ = Rx.Observable.interval(1000 / 32)
            .takeWhile(_ => this.options.animating);

        fps$.subscribe(this.nextFrame.bind(this));
    }
}

Animation3a.prototype.updateCount = function(count) {
    const bounds = this.container.getBoundingClientRect();

    while (this.particles.length > count) {
        delete this.particles.pop().remove();
    }

    while (this.particles.length < count) {
        const p = new Particle(this.container, bounds, this.options, this.globalGrid);
        this.particles.push(p);
    }
}

Animation3a.prototype.updateSpeed = function(value) {
    this.options.speed = value;
    this.particles.forEach(p => p.updateConfig({ speed: value }));
}

export default Animation3a;