"use client";

import { 
  Box, 
  Card, 
  CardContent, 
  Typography, 
  CircularProgress, 
  Alert, 
  Button,
  Table,
  TableBody,
  TableCell,
  TableContainer,
  TableHead,
  TableRow,
  Paper,
  TextField,
  Stack,
  IconButton,
  Dialog,
  DialogTitle,
  DialogContent,
  DialogActions,
  Grid,
  Snackbar,
  Autocomplete,
} from "@mui/material";
import DeleteIcon from "@mui/icons-material/Delete";
import SaveIcon from "@mui/icons-material/Save";
import AddIcon from "@mui/icons-material/Add";
import CheckIcon from "@mui/icons-material/Check";
import CloseIcon from "@mui/icons-material/Close";
import { useRouter, useSearchParams } from "next/navigation";
import { useState, useEffect } from "react";
import { useSession } from "next-auth/react";
import { useTranslation } from "react-i18next";
import type { ShopAndTruck, Truck } from "@/app/api/shop/actions";
import { 
  fetchAllShopsClient, 
  findTruckLaneByShopIdClient,
  deleteTruckLaneClient,
  createTruckClient,
  findAllUniqueTruckLaneCombinationsClient,
} from "@/app/api/shop/client";
import type { SessionWithTokens } from "@/config/authConfig";
import { formatDepartureTime, normalizeStoreId } from "@/app/utils/formatUtil";

type ShopDetailData = {
  id: number;
  name: String;
  code: String;
  addr1: String;
  addr2: String;
  addr3: String;
  contactNo: number;
  type: String;
  contactEmail: String;
  contactName: String;
};

// Utility function to convert HH:mm format to the format expected by backend
const parseDepartureTimeForBackend = (time: string): string => {
  if (!time) return "";
  
  const timeStr = String(time).trim();
  // If already in HH:mm format, return as is
  if (/^\d{1,2}:\d{2}$/.test(timeStr)) {
    return timeStr;
  }
  
  // Try to format it
  return formatDepartureTime(timeStr);
};

/** Label for truck lane picker: code + optional remark (unique combo from API). */
const getTruckLaneOptionLabel = (lane: Truck): string => {
  const code = String(lane.truckLanceCode ?? "").trim();
  const remark =
    lane.remark != null && String(lane.remark).trim() !== "" ? String(lane.remark).trim() : null;
  return remark ? `${code} — ${remark}` : code || "-";
};

const isSameTruckLaneOption = (a: Truck | null, b: Truck | null): boolean => {
  if (a === b) return true;
  if (!a || !b) return false;
  const sameCode = String(a.truckLanceCode ?? "") === String(b.truckLanceCode ?? "");
  const ra = a.remark != null ? String(a.remark) : "";
  const rb = b.remark != null ? String(b.remark) : "";
  return sameCode && ra === rb;
};

/** Build HH:mm string from API departureTime for backend parsing. */
const departureTimeToStringForSave = (timeValue: Truck["departureTime"]): string => {
  const formatted = formatDepartureTime(
    Array.isArray(timeValue) ? timeValue : timeValue ? String(timeValue) : null
  );
  if (!formatted || formatted === "-") return "";
  return parseDepartureTimeForBackend(formatted);
};

const ShopDetail: React.FC = () => {
  const { t } = useTranslation("common");
  const router = useRouter();
  const searchParams = useSearchParams();
  const shopId = searchParams.get("id");
  const { data: session, status: sessionStatus } = useSession() as { data: SessionWithTokens | null; status: string };
  const [shopDetail, setShopDetail] = useState<ShopDetailData | null>(null);
  const [truckData, setTruckData] = useState<Truck[]>([]);
  const [loading, setLoading] = useState<boolean>(true);
  const [error, setError] = useState<string | null>(null);
  const [saving, setSaving] = useState<boolean>(false);
  const [confirmingDeleteIndex, setConfirmingDeleteIndex] = useState<number | null>(null);
  const [addDialogOpen, setAddDialogOpen] = useState<boolean>(false);
  const [availableTruckLanes, setAvailableTruckLanes] = useState<Truck[]>([]);
  const [selectedTruckLane, setSelectedTruckLane] = useState<Truck | null>(null);
  const [addLoadingSequence, setAddLoadingSequence] = useState<number>(0);
  const [loadingTruckLanes, setLoadingTruckLanes] = useState<boolean>(false);
  const [snackbarOpen, setSnackbarOpen] = useState<boolean>(false);
  const [snackbarMessage, setSnackbarMessage] = useState<string>("");

  useEffect(() => {
    // Wait for session to be ready before making API calls
    if (sessionStatus === "loading") {
      return; // Still loading session
    }

    // If session is unauthenticated, don't make API calls (middleware will handle redirect)
    if (sessionStatus === "unauthenticated" || !session) {
      setError(t("Please log in to view shop details"));
      setLoading(false);
      return;
    }

    const fetchShopDetail = async () => {
      if (!shopId) {
        setError(t("Shop ID is required"));
        setLoading(false);
        return;
      }

      // Convert shopId to number for proper filtering
      const shopIdNum = parseInt(shopId, 10);
      if (isNaN(shopIdNum)) {
        setError(t("Invalid Shop ID"));
        setLoading(false);
        return;
      }

      setLoading(true);
      setError(null);
      try {
        // Fetch shop information - try with ID parameter first, then filter if needed
        let shopDataResponse = await fetchAllShopsClient({ id: shopIdNum }) as ShopAndTruck[];
        
        // If no results with ID parameter, fetch all and filter client-side
        if (!shopDataResponse || shopDataResponse.length === 0) {
          shopDataResponse = await fetchAllShopsClient() as ShopAndTruck[];
        }
        
        // Filter to find the shop with matching ID (in case API doesn't filter properly)
        const shopData = shopDataResponse?.find((item) => item.id === shopIdNum);
        
        if (shopData) {
          // Set shop detail info
          setShopDetail({
            id: shopData.id ?? 0,
            name: shopData.name ?? "",
            code: shopData.code ?? "",
            addr1: shopData.addr1 ?? "",
            addr2: shopData.addr2 ?? "",
            addr3: shopData.addr3 ?? "",
            contactNo: shopData.contactNo ?? 0,
            type: shopData.type ?? "",
            contactEmail: shopData.contactEmail ?? "",
            contactName: shopData.contactName ?? "",
          });
        } else {
          setError(t("Shop not found"));
          setLoading(false);
          return;
        }

        // Fetch truck information using the Truck interface with numeric ID
        const trucks = await findTruckLaneByShopIdClient(shopIdNum) as Truck[];
        setTruckData(trucks || []);
      } catch (err: any) {
        console.error("Failed to load shop detail:", err);
        // Handle errors gracefully - don't trigger auto-logout
        const errorMessage = err?.message ?? String(err) ?? t("Failed to load shop details");
        setError(errorMessage);
      } finally {
        setLoading(false);
      }
    };

    fetchShopDetail();
  }, [shopId, sessionStatus, session]);

  const handleDelete = async (truckId: number) => {
    if (!shopId) {
      setError(t("Shop ID is required"));
      return;
    }

    setSaving(true);
    setError(null);
    try {
      await deleteTruckLaneClient({ id: truckId });
      setConfirmingDeleteIndex(null);

      const shopIdNum = parseInt(shopId, 10);
      const trucks = await findTruckLaneByShopIdClient(shopIdNum) as Truck[];
      setTruckData(trucks || []);
    } catch (err: any) {
      console.error("Failed to delete truck lane:", err);
      setError(err?.message ?? String(err) ?? t("Failed to delete truck lane"));
    } finally {
      setSaving(false);
    }
  };

  const handleOpenAddDialog = async () => {
    setSelectedTruckLane(null);
    setAddLoadingSequence(0);
    setAddDialogOpen(true);
    setError(null);
    setLoadingTruckLanes(true);
    try {
      const lanes = (await findAllUniqueTruckLaneCombinationsClient()) as Truck[];
      setAvailableTruckLanes(lanes || []);
    } catch (err: any) {
      console.error("Failed to load truck lanes:", err);
      setAvailableTruckLanes([]);
      setSnackbarMessage(
        err?.message ?? String(err) ?? t("Failed to load truck lanes")
      );
      setSnackbarOpen(true);
    } finally {
      setLoadingTruckLanes(false);
    }
  };

  const handleCloseAddDialog = () => {
    setAddDialogOpen(false);
    setSelectedTruckLane(null);
    setAddLoadingSequence(0);
    setAvailableTruckLanes([]);
  };

  const handleCreateTruck = async () => {
    const missingFields: string[] = [];

    if (!shopId || !shopDetail) {
      missingFields.push(t("Shop Information"));
    }

    if (!selectedTruckLane) {
      missingFields.push(t("TruckLance Code"));
    }

    const departureTime = selectedTruckLane
      ? departureTimeToStringForSave(selectedTruckLane.departureTime)
      : "";
    if (!departureTime) {
      missingFields.push(t("Departure Time"));
    }

    if (missingFields.length > 0) {
      const message = `${t("Please fill in the following required fields:")} ${missingFields.join(", ")}`;
      setSnackbarMessage(message);
      setSnackbarOpen(true);
      return;
    }

    const lane = selectedTruckLane!;
    const storeIdStr = normalizeStoreId(lane.storeId) || "2F";
    const remarkValue =
      storeIdStr === "4F" && lane.remark != null && String(lane.remark).trim() !== ""
        ? String(lane.remark).trim()
        : null;

    setSaving(true);
    setError(null);
    try {
      await createTruckClient({
        store_id: storeIdStr,
        truckLanceCode: String(lane.truckLanceCode || "").trim(),
        departureTime: departureTime,
        shopId: shopDetail!.id,
        shopName: String(shopDetail!.name),
        shopCode: String(shopDetail!.code),
        loadingSequence: addLoadingSequence,
        districtReference:
          lane.districtReference != null && String(lane.districtReference).trim() !== ""
            ? String(lane.districtReference)
            : null,
        remark: remarkValue,
      });
      
      // Refresh truck data after create
      const shopIdNum = parseInt(shopId || "0", 10);
      const trucks = await findTruckLaneByShopIdClient(shopIdNum) as Truck[];
      setTruckData(trucks || []);
      
      handleCloseAddDialog();
    } catch (err: any) {
      console.error("Failed to create truck:", err);
      setError(err?.message ?? String(err) ?? t("Failed to create truck"));
    } finally {
      setSaving(false);
    }
  };

  if (loading) {
    return (
      <Box sx={{ display: "flex", justifyContent: "center", p: 4 }}>
        <CircularProgress />
      </Box>
    );
  }
  if (error) {
      return (
      <Box>
        <Alert severity="error" sx={{ mb: 2 }}>
          {error}
        </Alert>
        <Button onClick={() => router.push("/settings/shop?tab=0")}>{t("Back")}</Button>
      </Box>
    );
  }

  if (!shopDetail) {
    return (
      <Box>
        <Alert severity="warning" sx={{ mb: 2 }}>
          {t("Shop not found")}
        </Alert>
        <Button onClick={() => router.push("/settings/shop?tab=0")}>{t("Back")}</Button>
      </Box>
    );
  }

  return (
    <Box>
      <Card sx={{ mb: 2 }}>
        <CardContent>
          <Box sx={{ display: "flex", justifyContent: "space-between", alignItems: "center", mb: 2 }}>
            <Typography variant="h6">{t("Shop Information")}</Typography>
            <Button onClick={() => router.push("/settings/shop?tab=0")}>{t("Back")}</Button>
          </Box>
          
          <Box sx={{ display: "flex", flexDirection: "column", gap: 2 }}>
            <Box>
              <Typography variant="subtitle2" color="text.secondary" fontWeight="bold">{t("Shop ID")}</Typography>
              <Typography variant="body1" fontWeight="medium">{shopDetail.id}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Name")}</Typography>
              <Typography variant="body1">{shopDetail.name}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Code")}</Typography>
              <Typography variant="body1">{shopDetail.code}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Addr1")}</Typography>
              <Typography variant="body1">{shopDetail.addr1 || "-"}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Addr2")}</Typography>
              <Typography variant="body1">{shopDetail.addr2 || "-"}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Addr3")}</Typography>
              <Typography variant="body1">{shopDetail.addr3 || "-"}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Contact No")}</Typography>
              <Typography variant="body1">{shopDetail.contactNo || "-"}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Contact Email")}</Typography>
              <Typography variant="body1">{shopDetail.contactEmail || "-"}</Typography>
            </Box>
            <Box>
              <Typography variant="subtitle2" color="text.secondary">{t("Contact Name")}</Typography>
              <Typography variant="body1">{shopDetail.contactName || "-"}</Typography>
            </Box>
          </Box>
        </CardContent>
      </Card>

      <Card>
        <CardContent>
          <Box sx={{ display: "flex", justifyContent: "space-between", alignItems: "center", mb: 2 }}>
            <Typography variant="h6">{t("Truck Information")}</Typography>
            <Button
              variant="contained"
              startIcon={<AddIcon />}
              onClick={handleOpenAddDialog}
              disabled={saving}
            >
              {t("Add Truck Lane")}
            </Button>
          </Box>
          <TableContainer component={Paper}>
            <Table>
              <TableHead>
                <TableRow>
                  <TableCell>{t("TruckLance Code")}</TableCell>
                  <TableCell>{t("Departure Time")}</TableCell>
                  <TableCell>{t("Loading Sequence")}</TableCell>
                  <TableCell>{t("District Reference")}</TableCell>
                  <TableCell>{t("Store ID")}</TableCell>
                  <TableCell>{t("Remark")}</TableCell>
                  <TableCell align="right">{t("Actions")}</TableCell>
                </TableRow>
              </TableHead>
              <TableBody>
                {truckData.length === 0 ? (
                  <TableRow>
                    <TableCell colSpan={7} align="center">
                      <Typography variant="body2" color="text.secondary">
                        {t("No Truck data available")}
                      </Typography>
                    </TableCell>
                  </TableRow>
                ) : (
                  truckData.map((truck, index) => (
                    <TableRow key={truck.id ?? `truck-${index}`}>
                      <TableCell>{String(truck.truckLanceCode || "-")}</TableCell>
                      <TableCell>
                        {formatDepartureTime(
                          Array.isArray(truck.departureTime)
                            ? truck.departureTime
                            : truck.departureTime
                              ? String(truck.departureTime)
                              : null
                        )}
                      </TableCell>
                      <TableCell>
                        {truck.loadingSequence !== null && truck.loadingSequence !== undefined
                          ? String(truck.loadingSequence)
                          : "-"}
                      </TableCell>
                      <TableCell>
                        {truck.districtReference !== null && truck.districtReference !== undefined
                          ? String(truck.districtReference)
                          : "-"}
                      </TableCell>
                      <TableCell>{normalizeStoreId(truck.storeId)}</TableCell>
                      <TableCell>{String(truck.remark || "-")}</TableCell>
                      <TableCell align="right">
                        <Stack direction="row" spacing={0.5} justifyContent="flex-end">
                          {truck.id && (
                            confirmingDeleteIndex === index ? (
                              <>
                                <IconButton
                                  size="small"
                                  color="error"
                                  onClick={() => handleDelete(truck.id!)}
                                  disabled={saving}
                                  title={t("Confirm delete")}
                                >
                                  <CheckIcon />
                                </IconButton>
                                <IconButton
                                  size="small"
                                  color="default"
                                  onClick={() => setConfirmingDeleteIndex(null)}
                                  disabled={saving}
                                  title={t("Cancel")}
                                >
                                  <CloseIcon />
                                </IconButton>
                              </>
                            ) : (
                              <IconButton
                                color="error"
                                size="small"
                                onClick={() => setConfirmingDeleteIndex(index)}
                                disabled={saving || confirmingDeleteIndex !== null}
                                title={t("Delete truck lane")}
                              >
                                <DeleteIcon />
                              </IconButton>
                            )
                          )}
                        </Stack>
                      </TableCell>
                    </TableRow>
                  ))
                )}
              </TableBody>
            </Table>
          </TableContainer>
        </CardContent>
      </Card>

      {/* Add Truck Dialog */}
      <Dialog open={addDialogOpen} onClose={handleCloseAddDialog} maxWidth="sm" fullWidth>
        <DialogTitle>{t("Add New Truck Lane")}</DialogTitle>
        <DialogContent>
          <Box sx={{ pt: 2 }}>
            <Grid container spacing={2}>
              <Grid item xs={12}>
                <Autocomplete
                  options={availableTruckLanes}
                  loading={loadingTruckLanes}
                  value={selectedTruckLane}
                  onChange={(_event, newValue) => {
                    setSelectedTruckLane(newValue);
                  }}
                  getOptionLabel={(option) => getTruckLaneOptionLabel(option)}
                  isOptionEqualToValue={(option, value) => isSameTruckLaneOption(option, value)}
                  disabled={saving || loadingTruckLanes}
                  renderInput={(params) => (
                    <TextField
                      {...params}
                      label={t("TruckLance Code")}
                      required
                      placeholder={t("Select a truck lane")}
                      helperText={
                        !loadingTruckLanes && availableTruckLanes.length === 0
                          ? t("No truck lanes available")
                          : undefined
                      }
                    />
                  )}
                />
              </Grid>
              <Grid item xs={12}>
                <TextField
                  label={t("Loading Sequence")}
                  type="number"
                  fullWidth
                  value={addLoadingSequence}
                  onChange={(e) => setAddLoadingSequence(parseInt(e.target.value, 10) || 0)}
                  disabled={saving}
                />
              </Grid>
            </Grid>
          </Box>
        </DialogContent>
        <DialogActions>
          <Button onClick={handleCloseAddDialog} disabled={saving}>
            {t("Cancel")}
          </Button>
          <Button 
            onClick={handleCreateTruck} 
            variant="contained" 
            startIcon={<SaveIcon />}
            disabled={saving}
          >
            {saving ? t("Submitting...") : t("Save")}
          </Button>
        </DialogActions>
      </Dialog>

      {/* Snackbar for notifications */}
      <Snackbar
        open={snackbarOpen}
        autoHideDuration={6000}
        onClose={() => setSnackbarOpen(false)}
        anchorOrigin={{ vertical: 'top', horizontal: 'center' }}
      >
        <Alert 
          onClose={() => setSnackbarOpen(false)} 
          severity="warning" 
          sx={{ width: '100%' }}
        >
          {snackbarMessage}
        </Alert>
      </Snackbar>
    </Box>
  );
};

export default ShopDetail;