/**
 * @preserve
 * Copyright 2015-2016 Igor Bezkrovnyi
 * All rights reserved. (MIT Licensed)
 *
 * palette.ts - part of Image Quantization Library
 */

import { Point } from "./point"
import { PointContainer } from "./pointContainer"
import { AbstractDistanceCalculator } from "../distance/abstractDistanceCalculator"
import { rgb2hsl } from "../conversion/rgb2hsl"

// TODO: make paletteArray via pointBuffer, so, export will be available via pointBuffer.exportXXX

const hueGroups : number = 10;

export function hueGroup(hue : number, segmentsNumber : number) {
    const maxHue = 360,
          seg    = maxHue / segmentsNumber,
          half   = seg / 2;

    for (let i = 1, mid = seg - half; i < segmentsNumber; i++, mid += seg) {
        if (hue >= mid && hue < mid + seg) return i;
    }
    return 0;
}

export class Palette {
    private readonly _pointContainer : PointContainer;
    private readonly _pointArray : Point[]          = [];
    private _i32idx : { [ key : string ] : number } = {};

    constructor() {
        this._pointContainer = new PointContainer();
        this._pointContainer.setHeight(1);
        this._pointArray = this._pointContainer.getPointArray();
    }

    add(color : Point) {
        this._pointArray.push(color);
        this._pointContainer.setWidth(this._pointArray.length);
    }

    has(color : Point) {
        for (let i = this._pointArray.length - 1; i >= 0; i--) {
            if (color.uint32 === this._pointArray[ i ].uint32) return true;
        }

        return false;
    }

    // TOTRY: use HUSL - http://boronine.com/husl/ http://www.husl-colors.org/ https://github.com/husl-colors/husl
    getNearestColor(colorDistanceCalculator : AbstractDistanceCalculator, color : Point) : Point {
        return this._pointArray[ this.getNearestIndex(colorDistanceCalculator, color) | 0 ];
    }

    getPointContainer() : PointContainer {
        return this._pointContainer;
    }

    // TOTRY: use HUSL - http://boronine.com/husl/
    /*
     public nearestIndexByUint32(i32) {
     var idx : number = this._nearestPointFromCache("" + i32);
     if (idx >= 0) return idx;

     var min = 1000,
     rgb = [
     (i32 & 0xff),
     (i32 >>> 8) & 0xff,
     (i32 >>> 16) & 0xff,
     (i32 >>> 24) & 0xff
     ],
     len = this._pointArray.length;

     idx = 0;
     for (var i = 0; i < len; i++) {
     var dist = Utils.distEuclidean(rgb, this._pointArray[i].rgba);

     if (dist < min) {
     min = dist;
     idx = i;
     }
     }

     this._i32idx[i32] = idx;
     return idx;
     }
     */

    private _nearestPointFromCache(key : string) {
        return typeof this._i32idx[ key ] === "number" ? this._i32idx[ key ] : -1;
    }

    private getNearestIndex(colorDistanceCalculator : AbstractDistanceCalculator, point : Point) : number {
        let idx : number = this._nearestPointFromCache("" + point.uint32);
        if (idx >= 0) return idx;

        let minimalDistance : number = Number.MAX_VALUE;

        idx = 0;
        for (let i = 0, l = this._pointArray.length; i < l; i++) {
            const p        = this._pointArray[ i ],
                  distance = colorDistanceCalculator.calculateRaw(point.r, point.g, point.b, point.a, p.r, p.g, p.b, p.a);

            if (distance < minimalDistance) {
                minimalDistance = distance;
                idx             = i;
            }
        }

        this._i32idx[ point.uint32 ] = idx;
        return idx;
    }

    /*
     public reduce(histogram : ColorHistogram, colors : number) {
     if (this._pointArray.length > colors) {
     var idxi32 = histogram.getImportanceSortedColorsIDXI32();

     // quantize histogram to existing palette
     var keep = [], uniqueColors = 0, idx, pruned = false;

     for (var i = 0, len = idxi32.length; i < len; i++) {
     // palette length reached, unset all remaining colors (sparse palette)
     if (uniqueColors >= colors) {
     this.prunePal(keep);
     pruned = true;
     break;
     } else {
     idx = this.nearestIndexByUint32(idxi32[i]);
     if (keep.indexOf(idx) < 0) {
     keep.push(idx);
     uniqueColors++;
     }
     }
     }

     if (!pruned) {
     this.prunePal(keep);
     }
     }
     }

     // TODO: check usage, not tested!
     public prunePal(keep : number[]) {
     var colors = this._pointArray.length;
     for (var colorIndex = colors - 1; colorIndex >= 0; colorIndex--) {
     if (keep.indexOf(colorIndex) < 0) {

     if(colorIndex + 1 < colors) {
     this._pointArray[ colorIndex ] = this._pointArray [ colors - 1 ];
     }
     --colors;
     //this._pointArray[colorIndex] = null;
     }
     }
     console.log("colors pruned: " + (this._pointArray.length - colors));
     this._pointArray.length = colors;
     this._i32idx = {};
     }
     */

    // TODO: group very low lum and very high lum colors
    // TODO: pass custom sort order
    // TODO: sort criteria function should be placed to HueStats class
    sort() {
        this._i32idx = {};
        this._pointArray.sort((a : Point, b : Point) => {
            const hslA = rgb2hsl(a.r, a.g, a.b),
                  hslB = rgb2hsl(b.r, b.g, b.b);

            // sort all grays + whites together
            const hueA = (a.r === a.g && a.g === a.b) ? 0 : 1 + hueGroup(hslA.h, hueGroups),
                  hueB = (b.r === b.g && b.g === b.b) ? 0 : 1 + hueGroup(hslB.h, hueGroups);
            /*
             var hueA = (a.r === a.g && a.g === a.b) ? 0 : 1 + Utils.hueGroup(hslA.h, hueGroups);
             var hueB = (b.r === b.g && b.g === b.b) ? 0 : 1 + Utils.hueGroup(hslB.h, hueGroups);
             */

            const hueDiff = hueB - hueA;
            if (hueDiff) return -hueDiff;

            /*
             var lumDiff = Utils.lumGroup(+hslB.l.toFixed(2)) - Utils.lumGroup(+hslA.l.toFixed(2));
             if (lumDiff) return -lumDiff;
             */
            const lA = a.getLuminosity(true),
                  lB = b.getLuminosity(true);

            if (lB - lA !== 0) return lB - lA;

            const satDiff = ((hslB.s * 100) | 0) - ((hslA.s * 100) | 0);
            if (satDiff) return -satDiff;

            return 0;
        });
    }
}