'use strict';

/**
 *
 */
function Mesh() {
    // // Color seed coordinants
    // this.seeds = [];

    // Length of a side
    this.side = 10;

    // // How far a seed will extend its reach
    this.seedWeight = 40;

    //
    this.width = 400;
    this.height = 400;

    var faces = this.initFaces(this.width, this.height, this.side);

    this.addSeed(new Seed(0, 0, '#ff0000', this.seedWeight), faces);
    this.addSeed(new Seed(0, 39, '#0000ff', this.seedWeight), faces);
    this.addSeed(new Seed(39, 0, '#00ff00', this.seedWeight), faces);
    this.addSeed(new Seed(39, 39, '#ffff00', this.seedWeight), faces);

    this.calculateFills(faces);

    var svg = d3.select("body").append("svg").attr('width', this.width).attr('height', this.height);

    svg.selectAll('rect')
        .data(faces)
        .enter()
        .append('rect')
            .attr('id', function(d) { return d.id; })
            .attr('x', function(d) { return d.x; })
            .attr('y', function(d) { return d.y; })
            .attr('width', function(d) { return d.side; })
            .attr('height', function(d) { return d.side; })
            .attr('fill', function(d) { return d.fill; })
            .attr('stroke', 0)

    // d3.select(id).attr('fill', seed.fill);
    // for (var i = 0, len = seeds.length; i < len; i++) {
        // d3.select(seeds[i].faceId).attr('fill', seeds[i].fill);
    // }
};

/**
 *
 */
function Face(id, x, y, side) {
    this.id = id;
    this.x = x;
    this.y = y;
    this.side = side;
    this.fill = '#fff';
    this.colors = [];
};

/**
 *
 */
function Seed(x, y, fill, weight) {
    this.x = x;
    this.y = y;
    this.fill = fill;
    this.weight = weight;
};

/**
 *
 */
Mesh.prototype = {
    /**
     * Faces must be a one dimensional array to pass to D3.
     */
    initFaces: function(width, height, side) {
        var countW = Math.ceil(width / side);
        var countH = Math.ceil(height / side);
        var all = [];

        for (var w = 0; w < countW; w++) {
            for (var h = 0; h < countH; h++) {
                all.push(new Face(
                    `f-${w}-${h}-${all.length}`,
                    w * side,
                    h * side,
                    side
                ));
            }
        }

        return all;
    },

    /**
     *
     */
    calculateFills: function(faces) {
        var len = faces.length;
        var hexes;

        var populate = function(color) {
            var arr = [];
            for (var k = 0; k < color.weight; k++) {
                arr.push(color.hex);
            }
            return arr;
        };

        for (var i = 0; i < len; i++) {
            var hexes = [];

            for (var j = 0; j < faces[i].colors.length; j++) {
                hexes = hexes.concat(populate(faces[i].colors[j]));
            }

            while (hexes.length < this.seedWeight) {
                hexes.push('#ccccff');
            }

            faces[i].fill = Compositor.averageHexCollection(hexes);
        }
    },

    /**
     *
     */
    addSeed: function(seed, faces) {
        var n = this.seedWeight;
        var len = faces.length;
        var delta, index, weight;
        var countX = this.width / this.side;
        var countY = this.height / this.side;

        for (var x = (seed.x - n + 1); x < seed.x + n; x++) {
            if (x < 0 || x >= countX) {
                continue;
            }

            for (var y = (seed.y - n + 1); y < seed.y + n; y++) {
                if (y < 0 || y >= countY) {
                    continue;
                }

                // Diamond shapes around source drop weighting incrementally.
                delta = Math.abs(seed.x - x) + Math.abs(seed.y - y);
                weight = Math.max(0, n - delta);

                index = x * countY + y;

                if (weight > 0 && index >= 0 && index < len) {
                    faces[index].colors.push({ hex: seed.fill, weight: weight });
                }
            }
        }
    },
};

/**
 *
 */
var Compositor = {
    /**
     *
     */
    averageComponentCollection: function(collection) {
        var len = collection.length;
        var total = 0;

        for (var i = 0; i < len; i++) {
            total += parseInt(collection[i], 16);
        }

        var avg = Math.round(total / len);
        avg = avg.toString(16);
        avg = ('00' + avg).slice(-2);

        return avg;
    },

    /**
     *
     */
    averageHexCollection: function(collection) {
        // check hex against regex

        var allR = [];
        var allG = [];
        var allB = [];
        var len = collection.length;
        var tmp, hex;

        for (var i = 0; i < len; i++) {
            tmp = collection[i].substr(1);

            allR.push(tmp.substr(0, 2));
            allG.push(tmp.substr(2, 2));
            allB.push(tmp.substr(4, 2));
        }

        var r = this.averageComponentCollection(allR);
        var g = this.averageComponentCollection(allG);
        var b = this.averageComponentCollection(allB);

        return '#' + r + g + b;
    },
};

var mesh = new Mesh();