/* custom d3 widgets */

// slider
function makeSlider(labelName, x, y, scale, cb) {
    var brush = d3.svg.brush()
        .x(scale)
        .extent([0, 0])
        .on("brush", brushed);

    var label = svg.append("text")
        .attr("x", x-5)
        .attr("y", y)
        .text(labelName);

    var brushg = svg.append("g")
        .attr("transform", "translate(" + x + "," + (y+10) + ")");

    brushg.append("g")
        .attr("class", "x axis")
        .call(d3.svg.axis()
            .scale(scale)
            .ticks(5)
            .tickSize(1)
            .tickFormat(function(d) { return Math.floor(d*100) + "%"; })
            .tickPadding(10)            
        .orient("bottom"));

    var slider = brushg.append("g")
        .attr("class", "slider")
        .call(brush);

    var handle = slider.append("circle")
        .attr("r", 5)
        .attr("cx", 0)
        .attr("cy", 0)
        .attr("stroke", "#000")
        .attr("fill", "#DDD");

    slider.call(brush);

    function brushed() {
        var value = brush.extent()[0];

        if (d3.event.sourceEvent) { // not a programmatic event
            value = scale.invert(d3.mouse(this)[0]);
            brush.extent([value, value]);
        }

        handle.attr("cx", scale(value));
        cb(value);
    }
}


/* network construction */

var Network = (function() {
    function Network(layout) {
        this.layout = layout;
    }

    Network.prototype.init = function() {
        this._createNodes();
        this._createLinks();
    };

    Network.prototype.resize = function(env) {
        var largestLayerSize = 0;
        for (layer=0; layer<this.layout.net.layers; layer++) {
            if (this.layout.net[layer].size > largestLayerSize) largestLayerSize = this.layout.net[layer].size;
        }
        this.responsiveRadius = d3.min([env.width, env.height]) / d3.max([this.layout.net.layers, largestLayerSize]);
        this._updateNodes(env);
    };

    Network.prototype._createNodes = function() {
        // create layers
        this.nodes = [];
        for (layer=0; layer<this.layout.net.layers; layer++) {
            for (node=0; node<this.layout.net[layer].size; node++) {
                this.nodes.push({
                    id: layer.toString() + "_" + node.toString(),
                    fixed: true
                });
            }
        }
    };

    Network.prototype._createLinks = function() {
        this.links = [];
        var nodesMap = d3.map();
        this.nodes.forEach(function (n) {
            return nodesMap.set(n.id, n);
        });
        // create links between adjacent layers
        for (layer=0; layer<this.layout.net.layers-1; layer++) { // for every layer except the last
            for (src=0; src<this.layout.net[layer].size; src++) { // get all nodes
                if (this.layout.net[layer].isBias) {
                    this.links.push({ // in case of a bias layer, connect 1:1
                        source: nodesMap.get(layer.toString() + "_" + src.toString()),
                        target: nodesMap.get((layer+1).toString() + "_" + src.toString()),
                        weight: 1
                    });
                } else { // normal layer
                    for (tar=0; tar<this.layout.net[layer+1].size; tar++) { // get all nodes of the next layer
                        this.links.push({ // connect both nodes
                            source: nodesMap.get(layer.toString() + "_" + src.toString()),
                            target: nodesMap.get((layer+1).toString() + "_" + tar.toString()),
                            weight: 1
                        });
                    }
                }
            }
        }
    };

    Network.prototype._updateNodes = function(env) {
        biasLayers = 0;
        for (layer=0; layer<this.layout.net.layers; layer++) {
            if (this.layout.net[layer].isBias) biasLayers++;
        }
        var cnt = 0;
        for (layer=0; layer<this.layout.net.layers; layer++) {
            for (node=0; node<this.layout.net[layer].size; node++) {
                // dynamic ("responsive") attributes for all window sizes
                if (this.layout.net[layer].isBias) {
                    this.nodes[cnt].x = (layer - biasLayers + 1.25) * (env.width / (this.layout.net.layers - biasLayers));
                    this.nodes[cnt].y = (node + 0.25) * (env.height / this.layout.net[layer].size);
                    this.nodes[cnt].r = this.responsiveRadius * 0.2;
                } else {
                    this.nodes[cnt].x = (layer - biasLayers + 0.5) * (env.width / (this.layout.net.layers - biasLayers));
                    this.nodes[cnt].y = (node + 0.5) * (env.height / this.layout.net[layer].size);
                    this.nodes[cnt].r = this.responsiveRadius * 0.3;
                }
                cnt++;
            }
        }
    };

    Network.prototype.updateWeights = function(weights, epochLayout) {
        var cnt = 0;
        for (layer=0; layer<weights.length; layer++) {
            for (layer2=0; layer2<weights[layer].length; layer2++) {
                for (node=0; node<weights[layer][layer2].length; node++) {
                    // scaled = (x - min) / (max - min)
                    var scaled = (weights[layer][layer2][node] - epochLayout.min) / (epochLayout.max - epochLayout.min);
                    this.links[cnt++].weight = scaled;
                }
            }
        }
    };

    return Network;
})();


/* data handling */

var Loader = (function() {
    function Loader() {
    }

    Loader.prototype.load = function(url, callback) {
        var self = this;
        d3.json(url)
            .get(function(e, json) {
                if (e) console.log(e);
                self._parse(json);
        });
        this._finished = callback;
    };

    Loader.prototype._parse = function(json) {
        // json format:
        // json.
        //   [batch][epoch] [[sourceIndex x targetIndex]] (int)
        // careful - root and first level nodes are objects and have no '.length'

        var layout = {};
        // layout format:
        // layout.
        //   net.layers (int)
        //   net.[net.layers].
        //      isBias (bool)
        //      size (int)
        //   layers.[batch][epoch].
        //      min (int)
        //      max (int)
        //   data.
        //      batches (int)
        //      epochs  (int)
        layout.data = {};
        layout.data.batches = Object.keys(json).length;
        layout.data.epochs  = Object.keys(json[0]).length;
        layout.net = {};
        // network structure
        layout.net.layers = json[0][0].length;
        for (layer=0; layer<layout.net.layers; layer++) {
            layerObj = {};
            if (json[0][0][layer].length == 1) { // bias
                layerObj.isBias = true;
                layerObj.size = json[0][0][0][layer].length; // workaround - Matrix should be rotatet serverside
            } else {
                layerObj.isBias = false;
                layerObj.size = json[0][0][layer].length;
            }
            layout.net[layer] = layerObj;
        }
        layout.net[layout.net.layers] = {'isBias': false, 'size': json[0][0][layout.net.layers-1][0].length};
        layout.net.layers += 1; // output layer
        // layer properties
        layout.layers = {};
        for (batch=0; batch<layout.data.batches; batch++) {
            layout.layers[batch] = {};
            for (epoch=0; epoch<layout.data.epochs; epoch++) {
                layout.layers[batch][epoch] = {};
                layout.layers[batch][epoch].max = 0;
                layout.layers[batch][epoch].min = Infinity;
                for (layer=0; layer<json[batch][epoch].length; layer++) {
                    var layerMin = d3.min(json[batch][epoch][layer]);
                    var layerMax = d3.max(json[batch][epoch][layer]);
                    if (layerMin < layout.layers[batch][epoch].min) layout.layers[batch][epoch].min = layerMin;
                    if (layerMax > layout.layers[batch][epoch].max) layout.layers[batch][epoch].max = layerMax;
                }
            }
        }
        console.log(layout); // DEBUG

        if (this._finished) this._finished(layout, json);
    };

    return Loader;
})();

var Animator = (function() {
    function Animator(layout, time, step) {
        this.layout = layout;
        this.step = step;
        this.batch = this.epoch = 0;
        this.frameDuration = time / (this.layout.data.batches * this.layout.data.epochs / this.step);
        console.log("frame duration:" + this.frameDuration); // DEBUG
    }

    Animator.prototype.start = function(callback) {
        var self = this;
        wrapper = function() {
            callback(self.batch, self.epoch, self.frameDuration);
            self.animate();
        };
        this.pid = setInterval(wrapper, this.frameDuration);
    };

    Animator.prototype.animate = function() {
        this.epoch += this.step;
        if (this.epoch >= this.layout.data.epochs) {
            this.epoch = 0;
            if (++this.batch>= this.layout.data.batches) {
                this.batch = 0;
                clearInterval(this.pid); // suicide
                console.log("finished");
            }
        }
    };

    return Animator;
})();

var Visualizer = (function() {
    function Visualizer(svg) {
        this.loader = new Loader();
        this.svg = svg;
    }

    Visualizer.prototype.start = function(url, animationTime, resolution) {
        // animationTime in seconds per frame
        // resolution in epochs per frame
        var self = this;
        this.animationTime = animationTime;
        this.resolution = resolution;
        function wrapper(layout, data) {
            self.layout = layout;
            self.data = data;
            self._setup();
        }
        this.loader.load("data/log.json", wrapper);
    };

    Visualizer.prototype._setup = function() {
        console.log("setup"); // DEBUG
        var self = this;
        // create empty elements and determine the visualisation's size
        this.svg
            .attr("width", "100%")
            .attr("height", "100%");
        var width = parseInt(this.svg.style("width"))   || 800,
            height = parseInt(this.svg.style("height")) || 600;

        /*var slideScaler = d3.scale.linear()
            .domain([0, 180])
            .range([0, 200])
            .clamp(true);
        function slid(val) {
            console.log(val);
        }
        makeSlider("Test", 10, 20, slideScaler, slid);*/

        this.network = new Network(this.layout);
        this.network.init();
        this.network.resize({"width": width, "height": height});
        this.network.updateWeights(this.data[0][0], this.layout.layers[0][0]);

        function resized() {
            width = parseInt(self.svg.style("width"))   || 800;
            height = parseInt(self.svg.style("height")) || 600;

            self.network.resize({"width": width, "height": height});

            node
                .attr("cx", function(d) { return d.x; })
                .attr("cy", function(d) { return d.y; })
                .attr("r",  function(d) { return d.r; });
            link
                .attr("x1", function(d) { return d.source.x; })
                .attr("y1", function(d) { return d.source.y; })
                .attr("x2", function(d) { return d.target.x; })
                .attr("y2", function(d) { return d.target.y; });
        }
        window.addEventListener("resize", resized, true);

        var link = this.svg.selectAll(".link")
            .data(this.network.links)
            .enter().append("line")
            .attr("class", "link")
            .style("stroke", "grey")
            .style("stroke-width", function(d) { return d.weight * 10; })
            .attr("x1", function(d) { return d.source.x; })
            .attr("y1", function(d) { return d.source.y; })
            .attr("x2", function(d) { return d.target.x; })
            .attr("y2", function(d) { return d.target.y; });
        var node = this.svg.selectAll(".node")
            .data(this.network.nodes)
            .enter().append("circle")
            .attr("class", "node")
            .attr("cx", function(d) { return d.x; })
            .attr("cy", function(d) { return d.y; })
            .attr("r",  function(d) { return d.r; });

        this.animator = new Animator(this.layout, this.animationTime * 1000, this.resolution);
        this.animator.start(function(batch, epoch, duration) {
            self.network.updateWeights(self.data[batch][epoch], self.layout.layers[batch][epoch]);

            // 10% extra time per frame for the code execution
            duration = duration / 1.1;
            link
                .transition()
                .duration(duration)
                .style("stroke-width", function(d) { return d.weight * 10; });
        });
    };

    return Visualizer;
})();

var svg = d3.select("#visContainer").append("svg");
var visualizer = new Visualizer(svg);
visualizer.start("data/log.json", 30, 10);