import React, { useState, useEffect } from 'react';
import { View, Text, Image, TextInput, TouchableOpacity, FlatList, SafeAreaView, ActivityIndicator, Alert } from 'react-native';
import { Feather, FontAwesome } from '@expo/vector-icons';
import { router, useFocusEffect } from 'expo-router';
import { useAuth } from '../../context/auth-context';
import { supabase } from '../../services/supabase';
import { 
  useFoods, 
  useFoodStats, 
  useFoodCreators, 
  useUserInteractions,
  useLikeMutation,
  useSaveMutation
} from '../../hooks/use-foods';

// Categories for filtering
const categories = [
  { id: 'main', name: 'Main dish' },
  { id: 'dessert', name: 'Dessert' },
  { id: 'appetizer', name: 'Appetite' },
];

// Sort options
const sortOptions = [
  { id: 'rating', name: 'Rating', icon: 'star' },
  { id: 'newest', name: 'Newest', icon: 'calendar' },
  { id: 'best', name: 'Best', icon: 'fire' },
];

export default function ForumScreen() {
  const { isAuthenticated } = useAuth();
  const [currentUserId, setCurrentUserId] = useState<string | null>(null);
  const [searchQuery, setSearchQuery] = useState('');
  const [selectedCategory, setSelectedCategory] = useState('');
  const [selectedSort, setSelectedSort] = useState('rating');
  
  // Get current user ID from Supabase session
  useEffect(() => {
    async function getCurrentUser() {
      if (isAuthenticated) {
        const { data } = await supabase.auth.getSession();
        const userId = data.session?.user?.id;
        console.log('Current user ID:', userId);
        setCurrentUserId(userId || null);
      } else {
        setCurrentUserId(null);
      }
    }
    
    getCurrentUser();
  }, [isAuthenticated]);
  
  // Use React Query hooks
  const { 
    data: foods = [], 
    isLoading: isLoadingFoods,
    refetch: refetchFoods
  } = useFoods(selectedCategory, searchQuery, selectedSort);
  
  const foodIds = foods.map(food => food.id);
  
  const { 
    data: foodStats = {}, 
    isLoading: isLoadingStats 
  } = useFoodStats(foodIds);
  
  const creatorIds = foods
    .filter(food => food.created_by)
    .map(food => food.created_by as string);
  
  const { 
    data: foodCreators = {}, 
    isLoading: isLoadingCreators 
  } = useFoodCreators(creatorIds);
  
  const { 
    data: userInteractions = {}, 
    isLoading: isLoadingInteractions 
  } = useUserInteractions(foodIds, currentUserId);
  
  const likeMutation = useLikeMutation();
  const saveMutation = useSaveMutation();
  
  // Refetch data when the screen comes into focus
  useFocusEffect(
    React.useCallback(() => {
      refetchFoods();
    }, [refetchFoods])
  );
  
  const handleSearch = (text: string) => {
    setSearchQuery(text);
  };
  
  const navigateToPostDetail = (food: { id: string }) => {
    router.push(`/post-detail/${food.id}`);
  };
  
  const handleLike = async (food: { id: string }) => {
    if (!isAuthenticated || !currentUserId) {
      Alert.alert('Authentication Required', 'Please log in to like posts.');
      return;
    }
    
    try {
      const isLiked = userInteractions[food.id]?.liked || false;
      
      likeMutation.mutate({
        foodId: food.id,
        userId: currentUserId,
        isLiked
      });
    } catch (error) {
      console.error('Error toggling like:', error);
      Alert.alert('Error', 'Failed to update like. Please try again.');
    }
  };
  
  const handleSave = async (food: { id: string }) => {
    if (!isAuthenticated || !currentUserId) {
      Alert.alert('Authentication Required', 'Please log in to save posts.');
      return;
    }
    
    try {
      const isSaved = userInteractions[food.id]?.saved || false;
      
      saveMutation.mutate({
        foodId: food.id,
        userId: currentUserId,
        isSaved
      });
    } catch (error) {
      console.error('Error toggling save:', error);
      Alert.alert('Error', 'Failed to update save. Please try again.');
    }
  };
  
  const renderFoodItem = ({ item }: { item: any }) => {
    // Get stats for this food
    const stats = foodStats[item.id] || { likes: 0, saves: 0, comments: 0 };
    
    // Get creator profile
    const creator = item.created_by ? foodCreators[item.created_by] : null;
    
    // Get user interactions
    const interactions = userInteractions[item.id] || { liked: false, saved: false };
    
    return (
      <TouchableOpacity 
        className="mb-6 bg-white rounded-lg overflow-hidden shadow-sm"
        onPress={() => navigateToPostDetail(item)}
      >
        <View className="p-4">
          {/* User info and rating */}
          <View className="flex-row justify-between items-center mb-4">
            <View className="flex-row items-center">
              <View className="w-12 h-12 bg-gray-200 rounded-full overflow-hidden">
                {creator?.avatar_url ? (
                  <Image 
                    source={{ uri: creator.avatar_url }}
                    className="w-full h-full"
                  />
                ) : (
                  <View className="w-full h-full bg-gray-300 items-center justify-center">
                    <Text className="text-base font-bold text-gray-600">
                      {creator?.username?.charAt(0).toUpperCase() || '?'}
                    </Text>
                  </View>
                )}
              </View>
              <Text className="ml-3 text-lg font-bold">
                {creator?.username || creator?.full_name || 'Unknown Chef'}
              </Text>
            </View>
            <View className="flex-row items-center">
              <Text className="text-lg font-bold mr-1">4.2</Text>
              <FontAwesome name="star" size={20} color="#ffd60a" />
            </View>
          </View>
          
          {/* Food image */}
          <View className="rounded-lg overflow-hidden mb-4">
            <Image 
              source={{ uri: item.image_url || "/placeholder.svg?height=300&width=500&query=food dish" }}
              className="w-full h-48"
              resizeMode="cover"
            />
          </View>
          
          {/* Food title and description */}
          <View>
            <Text className="text-2xl font-bold mb-2">{item.name}</Text>
            <Text className="text-gray-700 mb-4">{item.description}</Text>
          </View>
          
          {/* Interaction buttons */}
          <View className="flex-row justify-between">
            <View className="flex-row items-center">
              <TouchableOpacity 
                className="flex-row items-center mr-6"
                onPress={(e) => {
                  e.stopPropagation();
                  handleLike(item);
                }}
              >
                <Feather 
                  name="heart" 
                  size={22} 
                  color={interactions.liked ? "#E91E63" : "#333"} 
                />
                <Text className="ml-2 text-lg">{stats.likes}</Text>
              </TouchableOpacity>
              
              <TouchableOpacity 
                className="flex-row items-center mr-6"
                onPress={() => navigateToPostDetail(item)}
              >
                <Feather name="message-circle" size={22} color="#333" />
                <Text className="ml-2 text-lg">{stats.comments}</Text>
              </TouchableOpacity>
            </View>
            
            <TouchableOpacity
              onPress={(e) => {
                e.stopPropagation();
                handleSave(item);
              }}
            >
              <Feather 
                name="bookmark" 
                size={22} 
                color={interactions.saved ? "#ffd60a" : "#333"} 
              />
            </TouchableOpacity>
          </View>
        </View>
      </TouchableOpacity>
    );
  };
  
  const isLoading = isLoadingFoods || isLoadingStats || isLoadingCreators || isLoadingInteractions;
  
  return (
    <SafeAreaView className="flex-1 bg-white">
      {/* Search Bar */}
      <View className="px-4 pt-4 pb-2">
        <View className="flex-row items-center bg-gray-100 rounded-full px-4 py-2">
          <Feather name="search" size={20} color="#E91E63" />
          <TextInput
            className="flex-1 ml-2 text-base"
            placeholder="Search"
            value={searchQuery}
            onChangeText={handleSearch}
          />
        </View>
      </View>
      
      {/* Categories */}
      <View className="px-4 py-4">
        <FlatList
          horizontal
          showsHorizontalScrollIndicator={false}
          data={categories}
          keyExtractor={(item) => item.id}
          renderItem={({ item }) => (
            <TouchableOpacity 
              className={`mr-3 px-6 py-4 rounded-lg ${selectedCategory === item.id ? 'bg-[#ffd60a]' : 'bg-[#ffd60a]'}`}
              onPress={() => setSelectedCategory(item.id === selectedCategory ? '' : item.id)}
            >
              <Text className="text-lg font-medium">{item.name}</Text>
            </TouchableOpacity>
          )}
        />
      </View>
      
      {/* Sort Options */}
      <View className="px-4 pb-4">
        <FlatList
          horizontal
          showsHorizontalScrollIndicator={false}
          data={sortOptions}
          keyExtractor={(item) => item.id}
          renderItem={({ item }) => (
            <TouchableOpacity 
              className={`mr-3 px-6 py-3 rounded-lg flex-row items-center ${selectedSort === item.id ? 'bg-[#bb0718]' : 'bg-[#bb0718]'}`}
              onPress={() => setSelectedSort(item.id)}
            >
              <Text className="text-lg font-medium text-[#ffd60a] mr-2">{item.name}</Text>
              <Feather name={item.icon as any} size={18} color="#ffd60a" />
            </TouchableOpacity>
          )}
        />
      </View>
      
      {/* Food Posts */}
      {isLoading ? (
        <View className="flex-1 items-center justify-center">
          <ActivityIndicator size="large" color="#ffd60a" />
        </View>
      ) : (
        <FlatList
          data={foods}
          keyExtractor={(item) => item.id}
          renderItem={renderFoodItem}
          contentContainerStyle={{ padding: 16 }}
          showsVerticalScrollIndicator={false}
        />
      )}
    </SafeAreaView>
  );
}