import * as d3 from "d3";

/**
 * Create diverging interpolated color mapper based on value min/max range and optional config.
 *
 * @param valueMin
 * @param valueMax
 * @param colorPositive
 * @param colorNegative
 * @param colorNeutral
 */
export function createDivergentInterpolatedColorMapper(valueMin, valueMax, config?: any){

    let colorPositive = (config && config.colorPositive) ? config.colorPositive : "#FF671F",
        colorNegative = (config && config.colorNegative) ? config.colorNegative : "#009CDE",
        colorNeutral = (config && config.colorNeutral) ? config.colorNeutral : "#D9D9D6",
        controlPointNeutral = (config && config.controlPointNeutral) ? config.controlPointNeutral : 0,
        colorMapperPositive, colorMapperNegative,
        interpolaterPositive = d3.interpolateRgbBasis([colorNeutral, colorNegative]),
        interpolaterNegative = d3.interpolateRgbBasis([colorPositive, colorNeutral])
    ;

    if(valueMax > 0){
        colorMapperPositive = d3.scaleSequential(interpolaterPositive).domain([controlPointNeutral, valueMax]);
    }

    if(valueMin <= 0){
        colorMapperNegative = d3.scaleSequential(interpolaterNegative).domain([valueMin, controlPointNeutral]);
    }

    return function(v){

        if(v > 0){
            return colorMapperPositive(v);
        }
        if(v < 0){
            return colorMapperNegative(v);
        }
        return colorNeutral;
    }
}

/**
 * Create diverging class color mapper based on default positive, negative and neutral text color classes.
 */
export function createDivergentTextColorClassMapper(){

    let classPositive = "color-div-end",
        classNegative = "color-div-start",
        classNeutral = "color-div-middle"
    ;

    return createDivergentClassMapper(classPositive, classNegative, classNeutral)
}

/**
 * Create diverging class color mapper based on default positive, negative and neutral background color classes.
 */
export function createDivergentBackgroundColorClassMapper(){

    let classPositive = "background-div-end",
        classNegative = "background-div-start",
        classNeutral = "background-div-middle"
    ;

    return createDivergentClassMapper(classPositive, classNegative, classNeutral)
}

/**
 * Create diverging class color mapper based on provided positive, negative and neutral classes.
 *
 * @param classPositive
 * @param classNegative
 * @param classNeutral
 */
export function createDivergentClassMapper(classPositive, classNegative, classNeutral){

    return function(v){

        if(v > 0){
            return classPositive;
        }
        else if(v < 0){
            return classNegative;
        }

        return classNeutral;
    }
}