import { useEffect, useRef } from 'react';

import { CollectionEventSource } from '@sendbird/chat';
import { MessageCollectionInitPolicy, MessageFilter } from '@sendbird/chat/groupChannel';
import type { SendbirdFileMessage, SendbirdGroupChannel, SendbirdMessageCollection } from '@sendbird/uikit-utils';
import {
  Logger,
  SendbirdBaseMessage,
  confirmAndMarkAsRead,
  isDifferentChannel,
  isMyMessage,
  isSendableMessage,
  useForceUpdate,
  useFreshCallback,
  useUniqHandlerId,
} from '@sendbird/uikit-utils';

import { useChannelHandler } from '../../handler/useChannelHandler';
import type { UseGroupChannelMessages, UseGroupChannelMessagesOptions } from '../../types';
import { useChannelMessagesReducer } from '../useChannelMessagesReducer';

const MESSAGE_LIMIT = {
  DEFAULT: 50,
  SEARCH: 20,
};

const createMessageCollection = (
  channel: SendbirdGroupChannel,
  limit: number,
  options: UseGroupChannelMessagesOptions,
) => {
  if (options?.collectionCreator) return options?.collectionCreator({ startingPoint: options?.startingPoint });

  const filter = new MessageFilter();
  if (options.replyType) filter.replyType = options.replyType;

  return channel.createMessageCollection({ filter, limit, startingPoint: options?.startingPoint });
};

function isNotEmpty(arr?: unknown[]): arr is unknown[] {
  if (!arr) return false;
  return arr.length !== 0;
}

function shouldUseSearchLimit(startingPoint: number) {
  return startingPoint < Date.now();
}

/**
 * @deprecated This hook is deprecated and will be replaced by the '@sendbird/uikit-tools' package.
 * */
export const useGroupChannelMessagesWithCollection: UseGroupChannelMessages = (sdk, channel, userId, options) => {
  const initialStartingPoint = options?.startingPoint ?? Number.MAX_SAFE_INTEGER;
  const initialLimit = shouldUseSearchLimit(initialStartingPoint) ? MESSAGE_LIMIT.SEARCH : MESSAGE_LIMIT.DEFAULT;

  const forceUpdate = useForceUpdate();
  const collectionRef = useRef<SendbirdMessageCollection | undefined>(undefined);
  const collectionInitializedRef = useRef(false);
  const handlerId = useUniqHandlerId('useGroupChannelMessagesWithCollection');

  const {
    loading,
    refreshing,
    messages,
    newMessages,
    updateMessages,
    updateNewMessages,
    deleteNewMessages,
    deleteMessages,
    updateLoading,
    updateRefreshing,
  } = useChannelMessagesReducer(options?.sortComparator);

  const channelMarkAsRead = (source?: CollectionEventSource) => {
    switch (source) {
      case CollectionEventSource.EVENT_MESSAGE_RECEIVED:
      case CollectionEventSource.EVENT_MESSAGE_SENT_SUCCESS:
      case CollectionEventSource.SYNC_MESSAGE_FILL:
      case undefined:
        confirmAndMarkAsRead([channel]);
        break;
    }
  };
  const updateNewMessagesReceived = (source: CollectionEventSource, messages: SendbirdBaseMessage[]) => {
    const incomingMessages = messages.filter((it) => !isMyMessage(it, sdk.currentUser?.userId));
    if (incomingMessages.length > 0) {
      switch (source) {
        case CollectionEventSource.EVENT_MESSAGE_RECEIVED:
        case CollectionEventSource.SYNC_MESSAGE_FILL: {
          if (options?.shouldCountNewMessages?.()) updateNewMessages(incomingMessages, false, sdk.currentUser?.userId);
          options?.onMessagesReceived?.(incomingMessages);
          break;
        }
      }
    }
  };

  const updateUnsentMessages = () => {
    const { pendingMessages, failedMessages } = collectionRef.current ?? {};
    if (isNotEmpty(pendingMessages)) updateMessages(pendingMessages, false, sdk.currentUser?.userId);
    if (isNotEmpty(failedMessages)) updateMessages(failedMessages, false, sdk.currentUser?.userId);
  };

  const init = useFreshCallback((startingPoint: number, limit: number, callback?: () => void) => {
    if (collectionRef.current) collectionRef.current?.dispose();

    channelMarkAsRead();
    updateNewMessages([], true, sdk.currentUser?.userId);

    collectionInitializedRef.current = false;
    collectionRef.current = createMessageCollection(channel, limit, {
      ...options,
      startingPoint,
    });

    collectionRef.current?.setMessageCollectionHandler({
      onMessagesAdded: (ctx, __, messages) => {
        channelMarkAsRead(ctx.source);
        updateNewMessagesReceived(ctx.source, messages);

        updateMessages(messages, false, sdk.currentUser?.userId);
      },
      onMessagesUpdated: (ctx, __, messages) => {
        channelMarkAsRead(ctx.source);
        updateNewMessagesReceived(ctx.source, messages); // NOTE: admin message is not added via onMessagesAdded handler, not checked yet is this a bug.

        updateMessages(messages, false, sdk.currentUser?.userId);

        if (ctx.source === CollectionEventSource.EVENT_MESSAGE_UPDATED) {
          options?.onMessagesUpdated?.(messages);
        }
      },
      onMessagesDeleted: (_, __, ___, messages) => {
        const msgIds = messages.map((it) => it.messageId);
        const reqIds = messages.filter(isSendableMessage).map((it) => it.reqId);
        deleteMessages(msgIds, reqIds);
        deleteNewMessages(msgIds, reqIds);
      },
      onChannelDeleted: () => {
        options?.onChannelDeleted?.();
      },
      onChannelUpdated: (_, eventChannel) => {
        if (eventChannel.isGroupChannel() && !isDifferentChannel(eventChannel, channel)) {
          forceUpdate();
        }
      },
      onHugeGapDetected: () => {
        init(Number.MAX_SAFE_INTEGER, MESSAGE_LIMIT.DEFAULT);
      },
    });

    collectionRef.current
      .initialize(MessageCollectionInitPolicy.CACHE_AND_REPLACE_BY_API)
      .onCacheResult((err, messages) => {
        if (err) sdk.isCacheEnabled && Logger.error('[useGroupChannelMessagesWithCollection/onCacheResult]', err);
        else if (messages) {
          Logger.debug('[useGroupChannelMessagesWithCollection/onCacheResult]', 'message length:', messages.length);

          updateMessages(messages, true, sdk.currentUser?.userId);
          updateUnsentMessages();
        }

        callback?.();
      })
      .onApiResult((err, messages) => {
        if (err) Logger.warn('[useGroupChannelMessagesWithCollection/onApiResult]', err);
        else if (messages) {
          Logger.debug('[useGroupChannelMessagesWithCollection/onApiResult]', 'message length:', messages.length);

          updateMessages(messages, true, sdk.currentUser?.userId);
          if (!options?.startingPoint) options?.onMessagesReceived?.(messages);
          if (sdk.isCacheEnabled) updateUnsentMessages();
        }

        collectionInitializedRef.current = true;
        callback?.();
      });
  });

  useChannelHandler(sdk, handlerId, {
    onUserBanned(channel, bannedUser) {
      if (channel.isGroupChannel() && !isDifferentChannel(channel, channel)) {
        if (bannedUser.userId === sdk.currentUser?.userId) {
          options?.onChannelDeleted?.();
        } else {
          forceUpdate();
        }
      }
    },
  });

  useEffect(() => {
    // NOTE: Cache read is heavy task, and it prevents smooth ui transition
    setTimeout(async () => {
      updateLoading(true);
      init(initialStartingPoint, initialLimit, () => updateLoading(false));
    }, 0);
  }, [channel.url, userId, options?.replyType]);

  useEffect(() => {
    return () => {
      if (collectionRef.current) collectionRef.current?.dispose();
    };
  }, []);

  const refresh: ReturnType<UseGroupChannelMessages>['refresh'] = useFreshCallback(async () => {
    updateRefreshing(true);
    init(Number.MAX_SAFE_INTEGER, MESSAGE_LIMIT.DEFAULT, () => updateRefreshing(false));
  });

  const prev: ReturnType<UseGroupChannelMessages>['prev'] = useFreshCallback(async () => {
    if (collectionRef.current && collectionRef.current?.hasPrevious) {
      try {
        const list = await collectionRef.current?.loadPrevious();
        updateMessages(list, false, sdk.currentUser?.userId);
      } catch {}
    }
  });

  const hasPrev: ReturnType<UseGroupChannelMessages>['hasPrev'] = useFreshCallback(() => {
    if (collectionInitializedRef.current && collectionRef.current) {
      return collectionRef.current.hasPrevious;
    } else {
      return false;
    }
  });

  const next: ReturnType<UseGroupChannelMessages>['next'] = useFreshCallback(async () => {
    if (collectionRef.current && collectionRef.current?.hasNext) {
      try {
        const fetchedList = await collectionRef.current?.loadNext();
        updateMessages(fetchedList, false, sdk.currentUser?.userId);
      } catch {}
    }
  });

  const hasNext: ReturnType<UseGroupChannelMessages>['hasNext'] = useFreshCallback(() => {
    if (collectionInitializedRef.current && collectionRef.current) {
      return collectionRef.current.hasNext;
    } else {
      return false;
    }
  });

  const sendUserMessage: ReturnType<UseGroupChannelMessages>['sendUserMessage'] = useFreshCallback(
    (params, onPending) => {
      return new Promise((resolve, reject) => {
        channel
          .sendUserMessage(params)
          .onPending((pendingMessage) => {
            if (pendingMessage.isUserMessage()) {
              onPending?.(pendingMessage);
              updateMessages([pendingMessage], false, sdk.currentUser?.userId);
            }
          })
          .onSucceeded((sentMessage) => {
            if (sentMessage.isUserMessage()) {
              updateMessages([sentMessage], false, sdk.currentUser?.userId);
              resolve(sentMessage);
            }
          })
          .onFailed((err, failedMessage) => {
            if (failedMessage) {
              updateMessages([failedMessage], false, sdk.currentUser?.userId);
            }
            reject(err);
          });
      });
    },
  );
  const sendFileMessage: ReturnType<UseGroupChannelMessages>['sendFileMessage'] = useFreshCallback(
    (params, onPending) => {
      return new Promise((resolve, reject) => {
        channel
          .sendFileMessage(params)
          .onPending((pendingMessage) => {
            if (pendingMessage.isFileMessage()) {
              updateMessages([pendingMessage], false, sdk.currentUser?.userId);
              onPending?.(pendingMessage);
            }
          })
          .onSucceeded((sentMessage) => {
            if (sentMessage.isFileMessage()) {
              updateMessages([sentMessage], false, sdk.currentUser?.userId);
              resolve(sentMessage as SendbirdFileMessage);
            }
          })
          .onFailed((err, failedMessage) => {
            if (failedMessage) {
              updateMessages([failedMessage], false, sdk.currentUser?.userId);
            }
            reject(err);
          });
      });
    },
  );
  const updateUserMessage: ReturnType<UseGroupChannelMessages>['updateUserMessage'] = useFreshCallback(
    async (messageId, params) => {
      const updatedMessage = await channel.updateUserMessage(messageId, params);
      updateMessages([updatedMessage], false, sdk.currentUser?.userId);
      return updatedMessage;
    },
  );
  const updateFileMessage: ReturnType<UseGroupChannelMessages>['updateFileMessage'] = useFreshCallback(
    async (messageId, params) => {
      const updatedMessage = await channel.updateFileMessage(messageId, params);
      updateMessages([updatedMessage], false, sdk.currentUser?.userId);
      return updatedMessage;
    },
  );
  const resendMessage: ReturnType<UseGroupChannelMessages>['resendMessage'] = useFreshCallback(
    async (failedMessage) => {
      const resentMessage = await (() => {
        if (failedMessage.isUserMessage()) return channel.resendUserMessage(failedMessage);
        if (failedMessage.isFileMessage()) return channel.resendFileMessage(failedMessage);
        return null;
      })();

      if (resentMessage) updateMessages([resentMessage], false, sdk.currentUser?.userId);
    },
  );
  const deleteMessage: ReturnType<UseGroupChannelMessages>['deleteMessage'] = useFreshCallback(async (message) => {
    if (message.sendingStatus === 'succeeded') {
      if (message.isUserMessage()) await channel.deleteMessage(message);
      if (message.isFileMessage()) await channel.deleteMessage(message);
    } else {
      try {
        await collectionRef.current?.removeFailedMessage(message.reqId);
      } finally {
        deleteMessages([message.messageId], [message.reqId]);
      }
    }
  });
  const resetNewMessages: ReturnType<UseGroupChannelMessages>['resetNewMessages'] = useFreshCallback(() => {
    updateNewMessages([], true, sdk.currentUser?.userId);
  });
  const resetWithStartingPoint: ReturnType<UseGroupChannelMessages>['resetWithStartingPoint'] = useFreshCallback(
    (startingPoint, callback) => {
      const limit = shouldUseSearchLimit(startingPoint) ? MESSAGE_LIMIT.SEARCH : MESSAGE_LIMIT.DEFAULT;
      updateLoading(true);
      updateMessages([], true, sdk.currentUser?.userId);
      init(startingPoint, limit, () => {
        updateLoading(false);
        callback?.();
      });
    },
  );

  return {
    loading,
    refreshing,
    refresh,
    messages,
    next,
    hasNext,
    prev,
    hasPrev,
    newMessages,
    resetNewMessages,
    sendUserMessage,
    sendFileMessage,
    updateUserMessage,
    updateFileMessage,
    resendMessage,
    deleteMessage,
    resetWithStartingPoint,
  };
};