import { createFeatureSelector, createSelector } from '@ngrx/store';
import { MessagesState, messagesAdapter } from './messages.reducer';

export const selectMessagesState = createFeatureSelector<MessagesState>('messages');

const { selectIds, selectEntities, selectAll, selectTotal } = messagesAdapter.getSelectors();

export const selectAllMessages = createSelector(selectMessagesState, selectAll);

export const selectMessagesEntities = createSelector(selectMessagesState, selectEntities);

export const selectMessagesIds = createSelector(selectMessagesState, selectIds);

export const selectMessagesTotal = createSelector(selectMessagesState, selectTotal);

export const selectMessagesLoading = createSelector(
  selectMessagesState,
  (state) => state.loading
);

export const selectMessagesError = createSelector(
  selectMessagesState,
  (state) => state.error
);

export const selectMessagesSyncing = createSelector(
  selectMessagesState,
  (state) => state.syncing
);

export const selectCurrentRoomId = createSelector(
  selectMessagesState,
  (state) => state.currentRoomId
);

export const selectCurrentRoomMessages = createSelector(
  selectAllMessages,
  selectCurrentRoomId,
  (messages, roomId) => roomId ? messages.filter((m) => m.roomId === roomId) : []
);

/** Select messages for the currently active text channel */
export const selectChannelMessages = (channelId: string) =>
  createSelector(
    selectAllMessages,
    selectCurrentRoomId,
    (messages, roomId) => {
      if (!roomId) return [];
      return messages.filter(
        (m) => m.roomId === roomId && (m.channelId || 'general') === channelId
      );
    }
  );

export const selectMessageById = (id: string) =>
  createSelector(selectMessagesEntities, (entities) => entities[id]);

export const selectMessagesByRoomId = (roomId: string) =>
  createSelector(selectAllMessages, (messages) =>
    messages.filter((m) => m.roomId === roomId)
  );

export const selectRecentMessages = (limit: number) =>
  createSelector(selectAllMessages, (messages) =>
    messages.slice(-limit)
  );

export const selectMessagesWithReactions = createSelector(
  selectAllMessages,
  (messages) => messages.filter((m) => m.reactions.length > 0)
);