import { useContext, useCallback, useState } from 'react';
import { useOnMount } from './useOnMount';
import { FeatureFlagDecision, LoadableResult, DecisionReason } from '../models';
import { HackleContext } from '../components';
import { InputUtil } from '../utils';

export function useLoadableFeatureFlagDetail(
  featureKey: number
): LoadableResult<FeatureFlagDecision> {
  const { hackle, userVersion } = useContext(HackleContext);
  const getFeatureDetail = useCallback(() => {
    return (
      hackle
        ?.featureFlagDetail(featureKey)
        .then((decision) =>
          FeatureFlagDecision.withReactNativeFeatureFlagDecision(decision)
        ) ||
      Promise.resolve(FeatureFlagDecision.off(DecisionReason.SDK_NOT_READY))
    );
  }, [featureKey, hackle]);

  const [featureDetail, setFeatureDetail] = useState(() => {
    if (!hackle) {
      return Promise.resolve(
        FeatureFlagDecision.off(DecisionReason.SDK_NOT_READY)
      );
    }
    return getFeatureDetail();
  });

  const currentInput = {
    key: featureKey,
    userVersion,
  };

  const [prevInput, setPrevInput] = useState(currentInput);

  if (!InputUtil.isInputEqual(prevInput, currentInput)) {
    setPrevInput(currentInput);
    setFeatureDetail(getFeatureDetail());
  }

  return useOnMount(
    featureDetail,
    FeatureFlagDecision.off(DecisionReason.SDK_NOT_READY)
  );
}