// @flow
import * as ACTIONS from 'constants/action_types';
import * as NOTIFICATION_TYPES from 'constants/notification_types';
import type {
  Dispatch,
  SubscriptionState,
  SubscriptionNotifications,
} from 'redux/reducers/subscriptions';
import type { Subscription } from 'types/subscription';
import { selectSubscriptions } from 'redux/selectors/subscriptions';
import { Lbry, buildURI, parseURI } from 'lbry-redux';
import { doPurchaseUri } from 'redux/actions/content';
import Promise from 'bluebird';
import Lbryio from 'lbryio';

const CHECK_SUBSCRIPTIONS_INTERVAL = 60 * 60 * 1000;
const SUBSCRIPTION_DOWNLOAD_LIMIT = 1;

export const doFetchMySubscriptions = () => (dispatch: Dispatch, getState: () => any) => {
  const {
    subscriptions: subscriptionState,
    settings: { daemonSettings },
  } = getState();
  const { subscriptions: reduxSubscriptions } = subscriptionState;
  const { share_usage_data: isSharingData } = daemonSettings;

  if (!isSharingData && isSharingData !== undefined) {
    // They aren't sharing their data, subscriptions will be handled by persisted redux state
    return;
  }

  // most of this logic comes from scenarios where the db isn't synced with redux
  // this will happen if the user stops sharing data
  dispatch({ type: ACTIONS.FETCH_SUBSCRIPTIONS_START });

  Lbryio.call('subscription', 'list')
    .then(dbSubscriptions => {
      const storedSubscriptions = dbSubscriptions || [];

      // User has no subscriptions in db or redux
      if (!storedSubscriptions.length && (!reduxSubscriptions || !reduxSubscriptions.length)) {
        return [];
      }

      // There is some mismatch between redux state and db state
      // If something is in the db, but not in redux, add it to redux
      // If something is in redux, but not in the db, add it to the db
      if (storedSubscriptions.length !== reduxSubscriptions.length) {
        const dbSubMap = {};
        const reduxSubMap = {};
        const subsNotInDB = [];
        const subscriptionsToReturn = reduxSubscriptions.slice();

        storedSubscriptions.forEach(sub => {
          dbSubMap[sub.claim_id] = 1;
        });

        reduxSubscriptions.forEach(sub => {
          const { claimId } = parseURI(sub.uri);
          reduxSubMap[claimId] = 1;

          if (!dbSubMap[claimId]) {
            subsNotInDB.push({
              claim_id: claimId,
              channel_name: sub.channelName,
            });
          }
        });

        storedSubscriptions.forEach(sub => {
          if (!reduxSubMap[sub.claim_id]) {
            const uri = `lbry://${sub.channel_name}#${sub.claim_id}`;
            subscriptionsToReturn.push({ uri, channelName: sub.channel_name });
          }
        });

        return Promise.all(subsNotInDB.map(payload => Lbryio.call('subscription', 'new', payload)))
          .then(() => subscriptionsToReturn)
          .catch(
            () =>
              // let it fail, we will try again when the navigate to the subscriptions page
              subscriptionsToReturn
          );
      }

      // DB is already synced, just return the subscriptions in redux
      return reduxSubscriptions;
    })
    .then(subscriptions => {
      dispatch({
        type: ACTIONS.FETCH_SUBSCRIPTIONS_SUCCESS,
        data: subscriptions,
      });
    })
    .catch(() => {
      dispatch({
        type: ACTIONS.FETCH_SUBSCRIPTIONS_FAIL,
      });
    });
};

export const setSubscriptionLatest = (subscription: Subscription, uri: string) => (
  dispatch: Dispatch
) =>
  dispatch({
    type: ACTIONS.SET_SUBSCRIPTION_LATEST,
    data: {
      subscription,
      uri,
    },
  });

export const setSubscriptionNotification = (
  subscription: Subscription,
  uri: string,
  notificationType: string
) => (dispatch: Dispatch) =>
  dispatch({
    type: ACTIONS.SET_SUBSCRIPTION_NOTIFICATION,
    data: {
      subscription,
      uri,
      type: notificationType,
    },
  });

export const doCheckSubscription = (subscription: Subscription, notify?: boolean) => (
  dispatch: Dispatch
) => {
  dispatch({
    type: ACTIONS.CHECK_SUBSCRIPTION_STARTED,
    data: subscription,
  });

  Lbry.claim_list_by_channel({ uri: subscription.uri, page: 1 }).then(result => {
    const claimResult = result[subscription.uri] || {};
    const { claims_in_channel: claimsInChannel } = claimResult;

    if (claimsInChannel) {
      if (notify) {
        claimsInChannel.reduce((prev, cur, index) => {
          const uri = buildURI({ contentName: cur.name, claimId: cur.claim_id }, false);
          if (prev === -1 && uri !== subscription.latest) {
            dispatch(
              setSubscriptionNotification(
                subscription,
                uri,
                index < SUBSCRIPTION_DOWNLOAD_LIMIT && !cur.value.stream.metadata.fee
                  ? NOTIFICATION_TYPES.DOWNLOADING
                  : NOTIFICATION_TYPES.NOTIFY_ONLY
              )
            );
            if (index < SUBSCRIPTION_DOWNLOAD_LIMIT && !cur.value.stream.metadata.fee) {
              dispatch(doPurchaseUri(uri, { cost: 0 }));
            }
          }
          return uri === subscription.latest || !subscription.latest ? index : prev;
        }, -1);
      }

      dispatch(
        setSubscriptionLatest(
          {
            channelName: claimsInChannel[0].channel_name,
            uri: buildURI(
              {
                channelName: claimsInChannel[0].channel_name,
                claimId: claimsInChannel[0].claim_id,
              },
              false
            ),
          },
          buildURI(
            { contentName: claimsInChannel[0].name, claimId: claimsInChannel[0].claim_id },
            false
          )
        )
      );
    }

    dispatch({
      type: ACTIONS.CHECK_SUBSCRIPTION_COMPLETED,
      data: subscription,
    });
  });
};

export const setSubscriptionNotifications = (notifications: SubscriptionNotifications) => (
  dispatch: Dispatch
) =>
  dispatch({
    type: ACTIONS.SET_SUBSCRIPTION_NOTIFICATIONS,
    data: {
      notifications,
    },
  });

export const doChannelSubscribe = (subscription: Subscription) => (
  dispatch: Dispatch,
  getState: () => any
) => {
  const {
    settings: { daemonSettings },
  } = getState();
  const { share_usage_data: isSharingData } = daemonSettings;

  dispatch({
    type: ACTIONS.CHANNEL_SUBSCRIBE,
    data: subscription,
  });

  // if the user isn't sharing data, keep the subscriptions entirely in the app
  if (isSharingData) {
    const { claimId } = parseURI(subscription.uri);
    // They are sharing data, we can store their subscriptions in our internal database
    Lbryio.call('subscription', 'new', {
      channel_name: subscription.channelName,
      claim_id: claimId,
    });
  }

  dispatch(doCheckSubscription(subscription, true));
};

export const doChannelUnsubscribe = (subscription: Subscription) => (
  dispatch: Dispatch,
  getState: () => any
) => {
  const {
    settings: { daemonSettings },
  } = getState();
  const { share_usage_data: isSharingData } = daemonSettings;

  dispatch({
    type: ACTIONS.CHANNEL_UNSUBSCRIBE,
    data: subscription,
  });

  if (isSharingData) {
    const { claimId } = parseURI(subscription.uri);
    Lbryio.call('subscription', 'delete', {
      claim_id: claimId,
    });
  }
};

export const doCheckSubscriptions = () => (
  dispatch: Dispatch,
  getState: () => SubscriptionState
) => {
  const checkSubscriptionsTimer = setInterval(
    () =>
      selectSubscriptions(getState()).map((subscription: Subscription) =>
        dispatch(doCheckSubscription(subscription, true))
      ),
    CHECK_SUBSCRIPTIONS_INTERVAL
  );
  dispatch({
    type: ACTIONS.CHECK_SUBSCRIPTIONS_SUBSCRIBE,
    data: { checkSubscriptionsTimer },
  });
};