/**
 * A chained class that sets most of the stylings of an element.
 */
class Modifier {
    _modifications;

    constructor() {
        this._modifications = new Object();
    }

    /**
     * Sets the modifications for widht and height to 100%. 
     * @returns {Modifier} this modifier object
     */
    fillMaxSize(widthFraction = 1, heightFraction = 1) {
        return this.fillMaxWidth(widthFraction)
            .fillMaxHeight(heightFraction);
    }

    /**
     * Sets the modification for width to 100%.
     * @param {number} fraction 
     * @returns {Modifier} this modifier object
    */
    fillMaxWidth(fraction = 1) {
        this._modifications["width"] = (100 * fraction) + "%";
        return this;
    }

    /**
     * Sets the modification for height to 100%.
     * @param {number} fraction 
     * @returns {Modifier} this modifier object
     */
    fillMaxHeight(fraction = 1) {
        this._modifications["height"] = (100 * fraction) + "%";
        return this;
    }

    /**
     * Sets modifications according to the dimensions object.
     * @param {Dimensions} dimensions 
     * @returns {Modifier} this modifier object
     */
    dimensions(dimensions) {
        dimensions.toModifications()
            .forEach(kvpair => {
                this._modifications[kvpair.key] = kvpair.value;
            })
        return this;
    }

    /**
     * Sets the padding on all sides according to the given padding object. 
     * Currently the padding will always be set 
     * to the most recent padding/padding. 
     * @param {Sides} siding
     * @returns {Modifier} this modifier object
     */
    padding(siding) {
        let keyToAdd = "";
        if (siding instanceof PaddingChain) {

        } else if (siding instanceof Sides) {
            keyToAdd = "padding-"
        }
        siding.toModifications()
            .forEach(kvpair => {
                this._modifications[keyToAdd + kvpair.key] = kvpair.value;
            })
        return this;
    }

    /**
     * Sets the margin on all sides according to the given siding object. 
     * Currently the margin will always be set 
     * to the most recent margin/siding. 
     * @param {Sides} siding 
     * @returns {Modifier} this modifier object
     */
    margin(siding) {
        this._modifications["margin"] = siding.getOrderedValues().join(' ');
        return this;
    }

    /**
     * Sets the background-color as a rgb color.
     * @param {Color} color 
     * @returns {Modifier} this modifier object
     */
    background(color) {
        this._modifications["background-color"] = color.cssRGBString();
        return this;
    }

    /**
     * Sets the color as a rgb color.
     * @param {Color} color 
     * @returns {Modifier} this modifier object
     */
    color(color) {
        this._modifications["color"] = color.cssRGBString();
        return this;
    }

    /**
     * Adds the modifications of the given Modifier to current Modifier.
     * This is especailly used in the cases of extending existing/pre defined 
     * Components.
     * CAUTION matching existing modifications will be overwritten. 
     * @param modifier The "new" Modifier
     * @returns {Modifier} The "old/current" Modifier, 
     * extended with the modifications of the given Modifier.
     */
    join(modifier, modifications = {}) {
        var keys = Object.keys(modifier.ensureModifier()._modifications);
        for (let i = 0; i < keys.length; i++) {
            /* if (!this._modifications.hasOwnProperty(keys[i])) */
            this._modifications[keys[i]] = modifier.ensureModifier()._modifications[keys[i]];
        }
        return this;
    }

    /**
     * 
     * @param {string} key a css style rule
     * @param {string} value the corresponding value to the css style rule
     * @returns {Modifier} this modifier object
     */
    setStyleRule(key, value) {
        this._modifications[key] = value;
        return this;
    }

    /**
     * Sets a border line (with given linestyle) to all sides. 
     * If lineStyle is an array, the containing LineStyles, 
     * are applied in the order: [top, right, bottom, left].
     * @param {Border} border the style of the border line
     * @returns {Modifier} this modifier object
     */
    border(border) {
        border.toModifications()
            .forEach(e => this._modifications[e.key] = e.value);
        return this.clip(border._shape)
    }

    /**
     * 
     * @param {Shape} shape 
     * @returns {Modifier} 
     */
    clip(shape) {
        this._modifications["border-radius"] = shape.getOrderedValues().join(' ');
        return this;
    }

    /**
     * 
     * @param {number} size of width and height in pixels
     * @returns {DimensionsChain} 
     */
    linkDimensions(size = -1) {
        if (size === -1) {
            return new DimensionsChain(this);
        } else {
            return new DimensionsChain(this).all(size).ensureModifier()
        }
    }

    /**
     * 
     * @param {number} amount the padding for all four sides
     * @returns {PaddingChain} 
     */
    linkPadding(amount = -1) {
        if (amount === -1) {
            return new PaddingChain(this);
        } else {
            return new PaddingChain(this).all(amount);
        }
    }

    /**
     * 
     * @param {number} cornerRadius will create a rounded rectangle with the given cornerRadius
     * @returns {ShapeChain}
     */
    linkClip(cornerRadius = -1) {
        if (cornerRadius === -1) {
            return new ShapeChain(this);
        } else {
            return new ShapeChain(this).all(cornerRadius);
        }
    }

    /**
     * 
     * @param {number} borderWidth sets the width of all four border sides
     * @returns {BorderChain}
     */
    linkBorder(borderWidth = -1) {
        if (borderWidth === -1) {
            return new BorderChain(this);
        } else {
            return new BorderChain(this).width(borderWidth);
        }
    }

    /**
     * 
     * @returns {Modifier}
     */
    ensureModifier() {
        return this;
    }

}

class ChainableModifier extends Modifier {
    _component;

    constructor(component) {
        super();
        this._component = component;
    }

    /**
     * 
     * @returns {Component}
     */
    toComponent() {
        return this._component.modifier(this);
    }

    /**
     * 
     * @param {Component|Array<Component>} innerComponent 
     * @returns {Component} the parent Component
     */
    childContext(innerComponent) {
        return this._component
            .modifier(this)
            .childContext(innerComponent);
    }
}