var canvas;

var delta = [0, 0];
var stage = [window.screenX, window.screenY, window.innerWidth, window.innerHeight];
getBrowserDimensions();

var themes = [[" #10222B", "#95AB63", "#BDD684", "#E2F0D6", "#F6FFE0"], ["#362C2A", "#732420", "#BF734C"
    , "#FAD9A0", "#736859"], ["#0D1114", "#102C2E", "#695F4C", "#EBBC5E", "#FFFBB8"], ["#2E2F38", "#FFD63E"
    , "#FFB54B", "#E88638", "#8A221C"], ["#121212", "#E6F2DA", "#C9F24B", "#4D7B85", "#23383D"],
    ["#343F40", "#736751", "#F2D7B6", "#BFAC95", "#8C3F3F"], ["#000000", "#2D2B2A", "#561812", "#B81111"
        , "#FFFFFF"], ["#333B3A", "#B4BD51", "#543B38", "#61594D", "#B8925A"]]; var theme; var worldAABB, world,
    iterations = 1, timeStep = 1 / 15; var walls = []; var wall_thickness = 200; var wallsSetted = false; var bodies,
    elements, text; var createMode = false; var destroyMode = false; var isMouseDown = false; var mouseJoint; var mouse = {
    x: 0, y: 0
}; var gravity = { x: 0, y: 1 }; var PI2 = Math.PI * 2; var timeOfLastTouch = 0; init(); play(); function
init() {
    canvas = document.getElementById('canvas'); document.onmousedown = onDocumentMouseDown;
    document.onmouseup = onDocumentMouseUp; document.onmousemove = onDocumentMouseMove;
    document.ondblclick = onDocumentDoubleClick; document.addEventListener('touchstart', onDocumentTouchStart, false);
    document.addEventListener('touchmove', onDocumentTouchMove, false); document.addEventListener('touchend',
        onDocumentTouchEnd, false); window.addEventListener('deviceorientation', onWindowDeviceOrientation, false);
    //init box2d
    worldAABB = new b2AABB(); worldAABB.minVertex.Set(-200, -200);
    worldAABB.maxVertex.Set(window.innerWidth + 200, window.innerHeight + 200); world = new b2World(worldAABB, new
    b2Vec2(0, 0), true); setWalls(); reset();
} function play() { setInterval(loop, 1000 / 40); } function reset() {
    var i; if (bodies) {
        for (i = 0; i < bodies.length; i++) {
            var body = bodies[i]
            canvas.removeChild(body.GetUserData().element); world.DestroyBody(body); body = null;
        }
    } // color theme
    theme = themes[Math.random() * themes.length >> 0];
    document.body.style['backgroundColor'] = theme[0];

    bodies = [];
    elements = [];

    createInstructions();

    for (i = 0; i < 10; i++) {

        createBall();

    }

}

//

function onDocumentMouseDown() {

    isMouseDown = true;
    return false;
}

function onDocumentMouseUp() {

    isMouseDown = false;
    return false;
}

function onDocumentMouseMove(event) {

    mouse.x = event.clientX;
    mouse.y = event.clientY;
}

function onDocumentDoubleClick() {

    reset();
}

function onDocumentTouchStart(event) {

    if (event.touches.length == 1) {

        event.preventDefault();

        // Faking double click for touch devices

        var now = new Date().getTime();

        if (now - timeOfLastTouch < 250) {

            reset();
            return;
        }

        timeOfLastTouch = now;

        mouse.x = event.touches[0].pageX;
        mouse.y = event.touches[0].pageY;
        isMouseDown = true;
    }
}

function onDocumentTouchMove(event) {

    if (event.touches.length == 1) {

        event.preventDefault();

        mouse.x = event.touches[0].pageX;
        mouse.y = event.touches[0].pageY;

    }

}

function onDocumentTouchEnd(event) {

    if (event.touches.length == 0) {

        event.preventDefault();
        isMouseDown = false;

    }

}

function onWindowDeviceOrientation(event) {

    if (event.beta) {

        gravity.x = Math.sin(event.gamma * Math.PI / 180);
        gravity.y = Math.sin((Math.PI / 4) + event.beta * Math.PI / 180);

    }

}

function createInstructions() {

    var size = 250;

    var element = document.createElement('div');
    element.width = size;
    element.height = size;
    element.style.position = 'absolute';
    element.style.left = -200 + 'px';
    element.style.top = -200 + 'px';
    element.style.cursor = "default";

    canvas.appendChild(element);
    elements.push(element);

    var circle = document.createElement('canvas');
    circle.width = size;
    circle.height = size;

    var graphics = circle.getContext('2d');

    graphics.fillStyle = theme[3];
    graphics.beginPath();
    graphics.arc(size * .5, size * .5, size * .5, 0, PI2, true);
    graphics.closePath();
    graphics.fill();

    element.appendChild(circle);

    text = document.createElement('div');
    text.onSelectStart = null;
    var flinks = JSON.parse(localStorage.getItem('logos'))
    text.innerHTML = '<span class="gdtx" style="color:' + theme[0] + '"><img src=' + (flinks[Math.floor(Math.random() * flinks.length)]) + '></img></span>';
    text.style.color = theme[1];
    text.style.position = 'absolute';
    text.style.left = '0px';
    text.style.top = '0px';
    text.style.fontFamily = 'Georgia';
    text.style.textAlign = 'center';
    element.appendChild(text);

    text.style.left = ((250 - text.clientWidth) / 2) + 'px';
    text.style.top = ((250 - text.clientHeight) / 2) + 'px';

    var b2body = new b2BodyDef();

    var circle = new b2CircleDef();
    circle.radius = size / 2;
    circle.density = 1;
    circle.friction = 0.3;
    circle.restitution = 0.3;
    b2body.AddShape(circle);
    b2body.userData = { element: element };

    b2body.position.Set(Math.random() * stage[2], Math.random() * -200);
    b2body.linearVelocity.Set(Math.random() * 400 - 200, Math.random() * 400 - 200);
    bodies.push(world.CreateBody(b2body));
}

function createBall(x, y) {

    var x = x || Math.random() * stage[2];
    var y = y || Math.random() * -200;

    var size = (Math.random() * 100 >> 0) + 20;

    var element = document.createElement("canvas");
    element.width = size;
    element.height = size;
    element.style.position = 'absolute';
    element.style.left = -200 + 'px';
    element.style.top = -200 + 'px';
    element.style.WebkitTransform = 'translateZ(0)';
    element.style.MozTransform = 'translateZ(0)';
    element.style.OTransform = 'translateZ(0)';
    element.style.msTransform = 'translateZ(0)';
    element.style.transform = 'translateZ(0)';

    var graphics = element.getContext("2d");

    var num_circles = Math.random() * 10 >> 0;

    for (var i = size; i > 0; i -= (size / num_circles)) {

        graphics.fillStyle = theme[(Math.random() * 4 >> 0) + 1];
        graphics.beginPath();
        graphics.arc(size * .5, size * .5, i * .5, 0, PI2, true);
        graphics.closePath();
        graphics.fill();
    }

    canvas.appendChild(element);

    elements.push(element);

    var b2body = new b2BodyDef();

    var circle = new b2CircleDef();
    circle.radius = size >> 1;
    circle.density = 1;
    circle.friction = 0.3;
    circle.restitution = 0.3;
    b2body.AddShape(circle);
    b2body.userData = { element: element };

    b2body.position.Set(x, y);
    b2body.linearVelocity.Set(Math.random() * 400 - 200, Math.random() * 400 - 200);
    bodies.push(world.CreateBody(b2body));
}

//

function loop() {

    if (getBrowserDimensions()) {

        setWalls();

    }

    delta[0] += (0 - delta[0]) * .5;
    delta[1] += (0 - delta[1]) * .5;

    world.m_gravity.x = gravity.x * 350 + delta[0];
    world.m_gravity.y = gravity.y * 350 + delta[1];

    mouseDrag();
    world.Step(timeStep, iterations);

    for (i = 0; i < bodies.length; i++) {

        var body = bodies[i];
        var element = elements[i];

        element.style.left = (body.m_position0.x - (element.width >> 1)) + 'px';
        element.style.top = (body.m_position0.y - (element.height >> 1)) + 'px';

        if (element.tagName == 'DIV') {

            var style = 'rotate(' + (body.m_rotation0 * 57.2957795) + 'deg) translateZ(0)';
            text.style.WebkitTransform = style;
            text.style.MozTransform = style;
            text.style.OTransform = style;
            text.style.msTransform = style;
            text.style.transform = style;

        }

    }

}


// .. BOX2D UTILS

function createBox(world, x, y, width, height, fixed) {

    if (typeof (fixed) == 'undefined') {

        fixed = true;

    }

    var boxSd = new b2BoxDef();

    if (!fixed) {

        boxSd.density = 1.0;

    }

    boxSd.extents.Set(width, height);

    var boxBd = new b2BodyDef();
    boxBd.AddShape(boxSd);
    boxBd.position.Set(x, y);

    return world.CreateBody(boxBd);

}

function mouseDrag() {
    // mouse press
    if (createMode) {

        createBall(mouse.x, mouse.y);

    } else if (isMouseDown && !mouseJoint) {

        var body = getBodyAtMouse();

        if (body) {

            var md = new b2MouseJointDef();
            md.body1 = world.m_groundBody;
            md.body2 = body;
            md.target.Set(mouse.x, mouse.y);
            md.maxForce = 30000 * body.m_mass;
            // md.timeStep = timeStep;
            mouseJoint = world.CreateJoint(md);
            body.WakeUp();

        } else {

            createMode = true;

        }

    }

    // mouse release
    if (!isMouseDown) {

        createMode = false;
        destroyMode = false;

        if (mouseJoint) {

            world.DestroyJoint(mouseJoint);
            mouseJoint = null;

        }

    }

    // mouse move
    if (mouseJoint) {

        var p2 = new b2Vec2(mouse.x, mouse.y);
        mouseJoint.SetTarget(p2);
    }
}

function getBodyAtMouse() {

    // Make a small box.
    var mousePVec = new b2Vec2();
    mousePVec.Set(mouse.x, mouse.y);

    var aabb = new b2AABB();
    aabb.minVertex.Set(mouse.x - 1, mouse.y - 1);
    aabb.maxVertex.Set(mouse.x + 1, mouse.y + 1);

    // Query the world for overlapping shapes.
    var k_maxCount = 10;
    var shapes = new Array();
    var count = world.Query(aabb, shapes, k_maxCount);
    var body = null;

    for (var i = 0; i < count; ++i) {

        if (shapes[i].m_body.IsStatic() == false) {

            if (shapes[i].TestPoint(mousePVec)) {

                body = shapes[i].m_body;
                break;

            }

        }

    }

    return body;

}

function setWalls() {

    if (wallsSetted) {

        world.DestroyBody(walls[0]);
        world.DestroyBody(walls[1]);
        world.DestroyBody(walls[2]);
        world.DestroyBody(walls[3]);

        walls[0] = null;
        walls[1] = null;
        walls[2] = null;
        walls[3] = null;
    }

    walls[0] = createBox(world, stage[2] / 2, - wall_thickness, stage[2], wall_thickness);
    walls[1] = createBox(world, stage[2] / 2, stage[3] + wall_thickness, stage[2], wall_thickness);
    walls[2] = createBox(world, - wall_thickness, stage[3] / 2, wall_thickness, stage[3]);
    walls[3] = createBox(world, stage[2] + wall_thickness, stage[3] / 2, wall_thickness, stage[3]);

    wallsSetted = true;

}

// BROWSER DIMENSIONS

function getBrowserDimensions() {

    var changed = false;

    if (stage[0] != window.screenX) {

        delta[0] = (window.screenX - stage[0]) * 50;
        stage[0] = window.screenX;
        changed = true;

    }

    if (stage[1] != window.screenY) {

        delta[1] = (window.screenY - stage[1]) * 50;
        stage[1] = window.screenY;
        changed = true;

    }

    if (stage[2] != window.innerWidth) {

        stage[2] = window.innerWidth;
        changed = true;

    }

    if (stage[3] != window.innerHeight) {
        stage[3] = window.innerHeight;
        changed = true;

    }
    return changed;
}