import { useState, useCallback, useEffect } from 'react';
import { getAuthenticatedClient } from '~/features/auth/lib/supabaseClient';
import { tokenManager } from '~/features/auth/services/tokenManager';
import { useTranslation } from 'react-i18next';
import { Alert } from 'react-native';

const debug = __DEV__ ? console.debug : () => {};

interface LoadingStates {
  memo: boolean;
  memories: boolean;
  audio: boolean;
  photos: boolean;
  overall: boolean;
}

export function useOptimizedMemoData(memoId: string | undefined) {
  const { t } = useTranslation();
  const [memo, setMemo] = useState<any>(null);
  const [memories, setMemories] = useState<any[]>([]);
  const [audioUrl, setAudioUrl] = useState<string | null>(null);
  const [photos, setPhotos] = useState<any[]>([]);
  const [loadingStates, setLoadingStates] = useState<LoadingStates>({
    memo: false,
    memories: false,
    audio: false,
    photos: false,
    overall: false,
  });
  const [error, setError] = useState<Error | null>(null);

  const updateLoadingState = useCallback((key: keyof LoadingStates, value: boolean) => {
    setLoadingStates(prev => {
      const newState = { ...prev, [key]: value };
      // Update overall loading state
      newState.overall = newState.memo || newState.memories || newState.audio || newState.photos;
      return newState;
    });
  }, []);

  const getSignedUrl = useCallback(async (filePath: string): Promise<string | null> => {
    try {
      const supabase = await getAuthenticatedClient();
      const { data, error } = await supabase.storage
        .from('user-uploads')
        .createSignedUrl(filePath, 3600);

      if (error) {
        debug('Error creating signed URL:', error.message);
        return null;
      }

      return data?.signedUrl || null;
    } catch (error) {
      debug('Error in getSignedUrl:', error);
      return null;
    }
  }, []);

  const loadMemoData = useCallback(async () => {
    if (!memoId || memoId === 'undefined' || memoId === 'null') {
      setError(new Error('Invalid memo ID'));
      return;
    }

    const startTime = Date.now();
    debug(`Starting optimized memo load for ID: ${memoId}`);

    try {
      updateLoadingState('overall', true);
      updateLoadingState('memo', true);

      // Get token once for all operations
      const token = await tokenManager.getValidToken({ maxRetries: 1 });
      if (!token) {
        throw new Error('Authentication failed');
      }

      const supabase = await getAuthenticatedClient();

      // Load all data in parallel
      const [memoResult, memoriesResult, viewCountResult] = await Promise.allSettled([
        // 1. Fetch memo data
        supabase
          .from('memos')
          .select('*')
          .eq('id', memoId)
          .single(),

        // 2. Fetch memories
        supabase
          .from('memories')
          .select('id, title, content, metadata')
          .eq('memo_id', memoId)
          .order('sort_order', { ascending: true })
          .order('created_at', { ascending: false }),

        // 3. Increment view count (fire and forget)
        supabase.rpc('increment_memo_view_count', { memo_id: memoId })
      ]);

      // Handle memo data
      if (memoResult.status === 'fulfilled' && memoResult.value.data) {
        const memoData = memoResult.value.data;
        setMemo(memoData);
        updateLoadingState('memo', false);

        // Load audio URL in parallel if available
        const audioPath = memoData.source?.audio_path;
        
        if (audioPath) {
          updateLoadingState('audio', true);
          getSignedUrl(audioPath).then(url => {
            setAudioUrl(url);
            updateLoadingState('audio', false);
          });
        }

        // Load photos in parallel (if you have photo loading logic)
        // updateLoadingState('photos', true);
        // loadPhotos(memoId).then(photos => {
        //   setPhotos(photos);
        //   updateLoadingState('photos', false);
        // });
      } else if (memoResult.status === 'rejected') {
        throw new Error('Failed to load memo');
      }

      // Handle memories
      if (memoriesResult.status === 'fulfilled' && memoriesResult.value.data) {
        setMemories(memoriesResult.value.data);
      }
      updateLoadingState('memories', false);

      const loadTime = Date.now() - startTime;
      debug(`Memo load completed in ${loadTime}ms`);

    } catch (err) {
      const loadTime = Date.now() - startTime;
      debug(`Memo load failed after ${loadTime}ms:`, err);
      setError(err as Error);
      
      Alert.alert(
        t('common.error', 'Error'),
        t('memo.could_not_load', 'Could not load memo')
      );
    } finally {
      updateLoadingState('overall', false);
    }
  }, [memoId, t, getSignedUrl, updateLoadingState]);

  // Load data when memoId changes
  useEffect(() => {
    if (memoId) {
      loadMemoData();
    }
  }, [memoId, loadMemoData]);

  return {
    memo,
    memories,
    audioUrl,
    photos,
    loading: loadingStates.overall,
    loadingStates,
    error,
    refetch: loadMemoData,
  };
}