import {InputElement} from "./InputElement";
import {UIEventSource} from "../../Logic/UIEventSource";


export default class InputElementMap<T, X> extends InputElement<X> {
    public readonly IsSelected: UIEventSource<boolean>;
    private readonly _inputElement: InputElement<T>;
    private isSame: (x0: X, x1: X) => boolean;
    private readonly fromX: (x: X) => T;
    private readonly toX: (t: T) => X;
    private readonly _value: UIEventSource<X>;

    constructor(inputElement: InputElement<T>,
                isSame: (x0: X, x1: X) => boolean,
                toX: (t: T) => X,
                fromX: (x: X) => T,
                extraSources: UIEventSource<any>[] = []
    ) {
        super();
        this.isSame = isSame;
        this.fromX = fromX;
        this.toX = toX;
        this._inputElement = inputElement;
        this.IsSelected = inputElement.IsSelected;
        const self = this;
        this._value = inputElement.GetValue().map(
            (t => {
                const newX = toX(t);
                const currentX = self.GetValue()?.data;
                if (isSame(currentX, newX)) {
                    return currentX;
                }
                return newX;
            }), extraSources, x => {
                return fromX(x);
            });
    }

    GetValue(): UIEventSource<X> {
        return this._value;
    }

    IsValid(x: X): boolean {
        if (x === undefined) {
            return false;
        }
        const t = this.fromX(x);
        if (t === undefined) {
            return false;
        }
        return this._inputElement.IsValid(t);
    }

    protected InnerConstructElement(): HTMLElement {
        return this._inputElement.ConstructElement();
    }

}