import { useMemo } from 'react';

export type FeatureFlagCallback<T> = () => T;
export type FeatureFlagSignature = {
    <T>(resolver: () => boolean, ifTrue: FeatureFlagCallback<T>, ifFalse?: FeatureFlagCallback<T>): T | undefined;
    <T>(resolver: () => boolean, ifTrue: FeatureFlagCallback<T> | undefined, ifFalse: FeatureFlagCallback<T>): T | undefined;
};

export const useFeatureFlag: FeatureFlagSignature = <T>(
    resolver: () => boolean,
    ifTrue: FeatureFlagCallback<T> | undefined,
    ifFalse: FeatureFlagCallback<T> | undefined) => {

    return useMemo(() => {
        if (resolver()) {
            return ifTrue && ifTrue();
        }

        return ifFalse && ifFalse();
    }, [ resolver, ifTrue, ifFalse ]);
};