import Rx, { Observable } from 'rxjs';
// import DOM from './dom';
import { RAD } from './enums';
import Store from './store';

const random = {
    bool: (weight) => Math.random() < (weight || 0.5),
    num: (min, max) => min + Math.round(Math.random() * max),
    color: () => `rgb(${Math.floor(Math.random() * 255)}, ${Math.floor(Math.random() * 255)}, ${Math.floor(Math.random() * 255)})`
}

/* ===== Constructor ===== */

function Particle(container, bounds, options) {
    const color = random.color();

    this.container = container;
    this.bounds = bounds;
    // this.visionGridPoints = calculateVisionGridPoints();

    this.node = document.createElement('div');
    this.node.className = 'particle has-vision';
    this.node.style.backgroundColor = color;

    this.container.appendChild(this.node);

    // this.visionGridPoints.forEach(point => {
    //     this.container.appendChild(point.div);
    // });

    this.options = Object.assign({
        randomizeRadius: false,
        randomizeRotation: false,
        showMovementCircle: false,
        showVIsionGrid: false,
        speed: 4
    }, options);


    this.arc = {
        r: random.num(100, 200),
        t: random.num(0, RAD.t360),
        x: random.num(0, bounds.width),
        y: random.num(0, bounds.height)
    }

    this.particle = {
        clockwise: random.bool(),
        color,
        x: 0,
        y: 0
    }

    this.interval = random.num(RAD.t90, RAD.t360);

    this.updateOptions(this.options);
    this.nextFrame();
};

Particle.prototype.nextFrame = function() {
    this.move();
    repaintParticle(this.arc, this.node, this.particle);
    repaintCircle(this.arc, this.circle, this.particle);

    // if (this.options.showVisionGrid === true) {
    //     repaintVisionGrid(this.arc, this.particle, this.visionGridPoints);
    // }
};

Particle.prototype.updateBounds = function(bounds) {
    this.bounds = bounds;
}

Particle.prototype.updateOptions = function(options) {
    Object.assign(this.options, options);

    if (options.showMovementCircle === true && this.circle === undefined) {
        this.circle = document.createElement('div');
        this.circle.className = 'particle-movement-circle';
        this.circle.style.borderColor = this.particle.color;
        this.node.appendChild(this.circle);
    }

    if (options.showMovementCircle === false && this.circle !== undefined) {
        this.circle.parentNode.removeChild(this.circle);
        delete this.circle;
    }
}

Particle.prototype.move = function() {
    // Randomly change radius and rotation direction.
    if (this.interval <= 0) {
        this.interval = random.num(RAD.t90, RAD.t360);

        if (this.options.randomizeRadius === true) {
            this.arc = moveArc(this.arc, random.num(100, 200));

            if (random.bool(0.8) && this.options.randomizeRotation === true) {
                this.particle.clockwise = !this.particle.clockwise;
                this.arc = changeDirection(this.arc);
            }
        }
    }

    // Ensure constant velocity and theta between 0 and 2π.
    const delta = this.options.speed / this.arc.r;
    this.interval -= delta;

    this.arc.t += (this.particle.clockwise ? -delta : +delta);
    this.arc.t = (this.arc.t > 0 ? this.arc.t % RAD.t360 : RAD.t360 - this.arc.t);

    this.particle.x = this.arc.x + this.arc.r * Math.cos(this.arc.t);
    this.particle.y = this.arc.y - this.arc.r * Math.sin(this.arc.t);

    // Overflow.
    if (this.particle.x < 0) {
        this.particle.x += this.bounds.width;
        this.arc.x += this.bounds.width
    } else if (this.particle.x > this.bounds.width) {
        this.particle.x -= this.bounds.width;
        this.arc.x -= this.bounds.width
    }

    if (this.particle.y < 0) {
        this.particle.y += this.bounds.height; // TODO size of area
        this.arc.y += this.bounds.height
    } else if (this.particle.y > this.bounds.height) {
        this.particle.y -= this.bounds.height;
        this.arc.y -= this.bounds.height
    }
}

function moveArc(arc, newRadius) {
    const r0 = arc.r;
    const r1 = newRadius;

    // Moves arc center to new radius while keeping theta constant.
    arc.x -= (r1 - r0) * Math.cos(arc.t);
    arc.y += (r1 - r0) * Math.sin(arc.t);
    arc.r = r1;

    return arc;
}

function changeDirection(arc) {
    arc.t = (arc.t + RAD.t180) % RAD.t360;
    arc.x -= (2 * arc.r) * Math.cos(arc.t);
    arc.y += (2 * arc.r) * Math.sin(arc.t);

    return arc;
}

function calculateVisionGridPoints() {
    const gridSize = 5;
    const visionRadius = 50;

    const squareGrid = [];
    for (let x = -visionRadius; x <= visionRadius; x += gridSize) {
        for (let y = -visionRadius; y <= visionRadius; y += gridSize) {
            let alpha = Math.atan(y / x);

            if (x === 0 && y === 0) {
                alpha = 0;
            } else if (x === 0 && y < 0) {
                alpha = RAD.t270;
            } else if (y === 0 && x < 0) {
                alpha = RAD.t180;
            } else if (x === 0 && y > 0) {
                alpha = RAD.t90;
            } else if (x < 0 && y < 0) {
                alpha = alpha + RAD.t180;
            } else if (x <= 0) {
                alpha = RAD.t180 + alpha;
            } else if (y < 0) {
                alpha = RAD.t360 + alpha;
            }

            squareGrid.push({ x, y, alpha });
        }
    }

    const r0 = Math.pow(visionRadius, 2);
    const r1 = Math.pow(visionRadius - gridSize, 2);

    return squareGrid.reduce((acc, point) => {
        const p = Math.pow(point.x, 2) + Math.pow(point.y, 2);
        if (p > r0 || p < r1) {
            return acc;
        }

        const div = document.createElement('div');
        div.className = 'particle-vision-dot';

        acc.push(Object.assign(point, { div }));
        return acc;
    }, []);
}

function repaintParticle(arc, node, particle) {
    const rad = particle.clockwise
        ? RAD.t180 - arc.t
        : RAD.t360 - arc.t;

    node.style.left = `${particle.x}px`;
    node.style.top = `${particle.y}px`;
}

function repaintCircle(arc, node, particle) {
    if (node === undefined) {
        return;
    }

    node.style.width = `${2 * arc.r}px`;
    node.style.height = `${2 * arc.r}px`;

    node.style.left = `${-particle.x - arc.r + arc.x}px`;
    node.style.top = `${-particle.y - arc.r + arc.y}px`;

    node.style.borderRadius = `${arc.r}px`;
}

function repaintVisionGrid(arc, particle, points) {
    const r0 = Math.min(arc.t, arc.t - RAD.t180);
    const r1 = Math.max(arc.t, arc.t + RAD.t180);

    const gridX = particle.x - particle.x % 5;
    const gridY = particle.y - particle.y % 5;

    points.forEach(({ x, y, alpha, div }, i) => {
        if (alpha >= 0 && alpha <= r0) {
            div.style.display = (particle.clockwise ? 'none' : 'block');
            // div.className = (clockwise ? 'anim3-dot removed' : 'anim3-dot');
        } else if (alpha >= arc.t && alpha <= r1) {
            div.style.display = (particle.clockwise ? 'none' : 'block');
            // div.className = (clockwise ? 'anim3-dot removed' : 'anim3-dot');
        } else {
            div.style.display = (particle.clockwise ? 'block' : 'none');
            // div.className = (clockwise ? 'anim3-dot' : 'anim3-dot removed');
        }

        div.style.left = `${x + gridX}px`;
        div.style.top = `${-y + gridY}px`;
    });
}


export default Particle;