import React, { useState, useCallback, useMemo } from "react";
import { View, TouchableOpacity, Alert, ActivityIndicator } from "react-native";
import { MaterialIcons } from "@expo/vector-icons";
import { useRouter } from "expo-router";
import { tw, ConfirmationDialog, MyText, MyFlatList, useMarkDataFetchers, ImageViewerURI } from "common-ui";
import { trpc } from "@/src/trpc-client";

export default function Complaints() {
  const router = useRouter();
  const [dialogOpen, setDialogOpen] = useState(false);
  const [selectedComplaintId, setSelectedComplaintId] = useState<number | null>(null);

  const {
    data,
    isLoading,
    isError,
    error,
    fetchNextPage,
    hasNextPage,
    isFetchingNextPage,
    refetch,
  } = trpc.admin.complaint.getAll.useInfiniteQuery(
    { limit: 20 },
    {
      getNextPageParam: (lastPage) => lastPage.nextCursor,
    }
  );

  useMarkDataFetchers(() => {
    refetch();
  });

  const resolveComplaint = trpc.admin.complaint.resolve.useMutation();

  const complaints = useMemo(() => {
    const allComplaints = data?.pages.flatMap((page) => page.complaints) || [];
    return allComplaints.filter(
      (complaint, index, self) =>
        index === self.findIndex((c) => c.id === complaint.id)
    );
  }, [data]);

  const handleLoadMore = useCallback(() => {
    if (hasNextPage && !isFetchingNextPage) {
      fetchNextPage();
    }
  }, [hasNextPage, isFetchingNextPage, fetchNextPage]);

  const handleUserPress = useCallback((userId: number) => {
    router.push(`/(drawer)/user-management/${userId}`);
  }, [router]);

  const handleOrderPress = useCallback((orderId: number) => {
    router.push(`/(drawer)/manage-orders/order-details/${orderId}`);
  }, [router]);

  const handleMarkResolved = (id: number) => {
    setSelectedComplaintId(id);
    setDialogOpen(true);
  };

  const handleConfirmResolve = (response?: string) => {
    if (!selectedComplaintId) return;

    resolveComplaint.mutate(
      { id: String(selectedComplaintId), response },
      {
        onSuccess: () => {
          Alert.alert("Success", "Complaint marked as resolved");
          refetch();
          setDialogOpen(false);
          setSelectedComplaintId(null);
        },
        onError: (error: any) => {
          Alert.alert(
            "Error",
            error.message || "Failed to resolve complaint"
          );
          setDialogOpen(false);
          setSelectedComplaintId(null);
        },
      }
    );
  };

  if (isLoading) {
    return (
      <View style={tw`flex-1 justify-center items-center bg-gray-50`}>
        <ActivityIndicator size="large" color="#3B82F6" />
        <MyText style={tw`text-gray-500 mt-4`}>Loading complaints...</MyText>
      </View>
    );
  }

  if (isError) {
    return (
      <View style={tw`flex-1 justify-center items-center bg-gray-50 p-6`}>
        <MaterialIcons name="error-outline" size={48} color="#EF4444" />
        <MyText style={tw`text-gray-900 text-lg font-bold mt-4`}>Error</MyText>
        <MyText style={tw`text-gray-500 text-center mt-2 mb-6`}>
          {error?.message || "Failed to load complaints"}
        </MyText>
        <TouchableOpacity
          onPress={() => refetch()}
          style={tw`bg-blue-600 px-6 py-3 rounded-full`}
        >
          <MyText style={tw`text-white font-semibold`}>Retry</MyText>
        </TouchableOpacity>
      </View>
    );
  }

  return (
    <View style={tw`flex-1 bg-gray-50`}>
      <MyFlatList
        style={tw`flex-1`}
        contentContainerStyle={tw`px-4 py-4`}
        data={complaints}
        keyExtractor={(item) => item.id.toString()}
        onEndReached={handleLoadMore}
        onEndReachedThreshold={0.5}
        renderItem={({ item }) => (
          <View style={tw`bg-white p-4 mb-4 rounded-2xl shadow-sm border border-gray-100`}>
            <View style={tw`flex-row justify-between items-start mb-2`}>
              <MyText style={tw`text-lg font-bold text-gray-900`}>
                Complaint #{item.id}
              </MyText>
              <View
                style={tw`px-2.5 py-1 rounded-full ${
                  item.status === "resolved"
                    ? "bg-green-100 border border-green-200"
                    : "bg-amber-100 border border-amber-200"
                }`}
              >
                <MyText
                  style={tw`text-xs font-semibold ${
                    item.status === "resolved" ? "text-green-700" : "text-amber-700"
                  }`}
                >
                  {item.status === "resolved" ? "Resolved" : "Pending"}
                </MyText>
              </View>
            </View>

            <MyText style={tw`text-base text-gray-700 mb-3 leading-5`}>
              {item.text}
            </MyText>

            {item.images && item.images.length > 0 && (
              <View style={tw`mb-3`}>
                <MyText style={tw`text-sm font-semibold text-gray-700 mb-2`}>
                  Attached Images:
                </MyText>
                <View style={tw`flex-row flex-wrap gap-2`}>
                  {item.images.map((imageUri: string, index: number) => (
                    <ImageViewerURI
                      key={index}
                      uri={imageUri}
                      style={tw`w-16 h-16 rounded-lg border border-gray-200`}
                    />
                  ))}
                </View>
              </View>
            )}

            <View style={tw`flex-row items-center gap-2 mb-3`}>
              <MaterialIcons name="person" size={14} color="#6B7280" />
              <TouchableOpacity
                onPress={() => item.userId && handleUserPress(item.userId)}
              >
                <MyText style={tw`text-sm text-blue-600 underline`}>
                  {item.userName || item.userMobile || "Unknown User"}
                </MyText>
              </TouchableOpacity>
              {item.orderId && (
                <>
                  <MyText style={tw`text-sm text-gray-400`}>|</MyText>
                  <MaterialIcons name="shopping-bag" size={14} color="#6B7280" />
                  <TouchableOpacity
                    onPress={() => item.orderId && handleOrderPress(item.orderId)}
                  >
                    <MyText style={tw`text-sm text-blue-600 underline`}>
                      Order #{item.orderId}
                    </MyText>
                  </TouchableOpacity>
                </>
              )}
            </View>

            {item.status === "pending" && (
              <TouchableOpacity
                onPress={() => handleMarkResolved(item.id)}
                style={tw`bg-blue-500 py-3 rounded-xl items-center shadow-sm mt-2`}
              >
                <MyText style={tw`text-white font-semibold`}>
                  Resolve Complaint
                </MyText>
              </TouchableOpacity>
            )}
          </View>
        )}
        ListEmptyComponent={
          <View style={tw`flex-1 justify-center items-center py-20`}>
            <View style={tw`bg-white p-6 rounded-full shadow-sm mb-4`}>
              <MaterialIcons name="inbox" size={48} color="#D1D5DB" />
            </View>
            <MyText style={tw`text-gray-900 text-lg font-bold`}>
              No complaints
            </MyText>
            <MyText style={tw`text-gray-500 text-center mt-2`}>
              All complaints will appear here
            </MyText>
          </View>
        }
        ListFooterComponent={
          isFetchingNextPage ? (
            <View style={tw`py-4 items-center flex-row justify-center`}>
              <ActivityIndicator size="small" color="#3B82F6" />
              <MyText style={tw`text-gray-500 ml-2`}>Loading more...</MyText>
            </View>
          ) : null
        }
      />
      <ConfirmationDialog
        open={dialogOpen}
        positiveAction={handleConfirmResolve}
        commentNeeded={true}
        negativeAction={() => {
          setDialogOpen(false);
          setSelectedComplaintId(null);
        }}
        title="Resolve Complaint"
        message="Add admin notes for this resolution:"
        confirmText="Resolve"
        cancelText="Cancel"
        isLoading={resolveComplaint.isPending}
      />
    </View>
  );
}