import { InputElement } from "./InputElement"
import { Store, UIEventSource } from "../../Logic/UIEventSource"

export default class InputElementMap<T, X> extends InputElement<X> {
    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: Store<any>[] = []
    ) {
        super()
        this.isSame = isSame
        this.fromX = fromX
        this.toX = toX
        this._inputElement = inputElement
        const self = this
        this._value = inputElement.GetValue().sync(
            (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()
    }
}