"use client";

import {
  Box,
  Button,
  Dialog,
  DialogActions,
  DialogContent,
  DialogTitle,
  FormControl,
  Grid,
  InputLabel,
  MenuItem,
  Select,
  TextField,
  Typography,
} from "@mui/material";
import { useCallback, useEffect, useState, useRef } from "react";
import { useTranslation } from "react-i18next";
import {
  GetPickOrderLineInfo,
  PickExecutionIssueData,
} from "@/app/api/pickOrder/actions";
import { fetchEscalationCombo } from "@/app/api/user/actions";
import dayjs from "dayjs";
import { INPUT_DATE_FORMAT } from "@/app/utils/formatUtil";

interface LotPickData {
  id: number;
  lotId: number;
  lotNo: string;
  expiryDate: string;
  location: string;
  stockUnit: string;
  inQty: number;
  outQty: number;
  holdQty: number;
  totalPickedByAllPickOrders: number;
  availableQty: number;
  requiredQty: number;
  actualPickQty: number;
  lotStatus: string;
  lotAvailability:
    | "available"
    | "insufficient_stock"
    | "expired"
    | "status_unavailable"
    | "rejected";
  stockOutLineId?: number;
  stockOutLineStatus?: string;
  stockOutLineQty?: number;
}

interface PickExecutionFormProps {
  open: boolean;
  onClose: () => void;
  onSubmit: (data: PickExecutionIssueData) => Promise<void>;
  selectedLot: LotPickData | null;
  selectedPickOrderLine: (GetPickOrderLineInfo & { pickOrderCode: string }) | null;
  pickOrderId?: number;
  pickOrderCreateDate: any;
}

interface FormErrors {
  actualPickQty?: string;
  missQty?: string;
  badItemQty?: string;
  badReason?: string;
  issueRemark?: string;
  handledBy?: string;
}

const PickExecutionForm: React.FC<PickExecutionFormProps> = ({
  open,
  onClose,
  onSubmit,
  selectedLot,
  selectedPickOrderLine,
  pickOrderId,
  pickOrderCreateDate,
}) => {
  const { t } = useTranslation("pickOrder");
  const [formData, setFormData] = useState<Partial<PickExecutionIssueData>>({});
  const [errors, setErrors] = useState<FormErrors>({});
  const [loading, setLoading] = useState(false);
  const [handlers, setHandlers] = useState<Array<{ id: number; name: string }>>(
    []
  );

  const calculateRemainingAvailableQty = useCallback((lot: LotPickData) => {
    return lot.availableQty || 0;
  }, []);

  const calculateRequiredQty = useCallback((lot: LotPickData) => {
    return lot.requiredQty || 0;
  }, []);

  useEffect(() => {
    const fetchHandlers = async () => {
      try {
        const escalationCombo = await fetchEscalationCombo();
        setHandlers(escalationCombo);
      } catch (error) {
        console.error("Error fetching handlers:", error);
      }
    };

    fetchHandlers();
  }, []);

  const initKeyRef = useRef<string | null>(null);

  useEffect(() => {
    if (!open || !selectedLot || !selectedPickOrderLine || !pickOrderId) return;

    const key = `${selectedPickOrderLine.id}-${selectedLot.lotId}`;
    if (initKeyRef.current === key) return;

    const getSafeDate = (dateValue: any): string => {
      if (!dateValue) return dayjs().format(INPUT_DATE_FORMAT);
      try {
        const date = dayjs(dateValue);
        if (!date.isValid()) {
          return dayjs().format(INPUT_DATE_FORMAT);
        }
        return date.format(INPUT_DATE_FORMAT);
      } catch {
        return dayjs().format(INPUT_DATE_FORMAT);
      }
    };

    setFormData({
      pickOrderId: pickOrderId,
      pickOrderCode: selectedPickOrderLine.pickOrderCode,
      pickOrderCreateDate: getSafeDate(pickOrderCreateDate),
      pickExecutionDate: dayjs().format(INPUT_DATE_FORMAT),
      pickOrderLineId: selectedPickOrderLine.id,
      itemId: selectedPickOrderLine.itemId,
      itemCode: selectedPickOrderLine.itemCode,
      itemDescription: selectedPickOrderLine.itemName,
      lotId: selectedLot.lotId,
      lotNo: selectedLot.lotNo,
      storeLocation: selectedLot.location,
      requiredQty: selectedLot.requiredQty,
      actualPickQty: selectedLot.actualPickQty || 0,
      missQty: 0,
      badItemQty: 0,      // Bad Item Qty
      badPackageQty: 0,   // Bad Package Qty (frontend only)
      issueRemark: "",
      pickerName: "",
      handledBy: undefined,
      reason: "",
      badReason: "",
    });

    initKeyRef.current = key;
  }, [
    open,
    selectedPickOrderLine?.id,
    selectedLot?.lotId,
    pickOrderId,
    pickOrderCreateDate,
  ]);

  const handleInputChange = useCallback(
    (field: keyof PickExecutionIssueData, value: any) => {
      setFormData((prev) => ({ ...prev, [field]: value }));
      if (errors[field as keyof FormErrors]) {
        setErrors((prev) => ({ ...prev, [field]: undefined }));
      }
    },
    [errors]
  );

  // Updated validation logic
  const validateForm = (): boolean => {
    const newErrors: FormErrors = {};
    const ap = Number(formData.actualPickQty) || 0;
    const miss = Number(formData.missQty) || 0;
    const badItem = Number(formData.badItemQty) || 0;
    const badPackage = Number((formData as any).badPackageQty) || 0;
    const totalBad = badItem + badPackage;
    const total = ap + miss + totalBad;
    const availableQty = selectedLot?.availableQty || 0;

    // 1. Check actualPickQty cannot be negative
    if (ap < 0) {
      newErrors.actualPickQty = t("Qty cannot be negative");
    }

    // 2. Check actualPickQty cannot exceed available quantity
    if (ap > availableQty) {
      newErrors.actualPickQty = t("Actual pick qty cannot exceed available qty");
    }

    // 3. Check missQty and both bad qtys cannot be negative
    if (miss < 0) {
      newErrors.missQty = t("Invalid qty");
    }
    if (badItem < 0 || badPackage < 0) {
      newErrors.badItemQty = t("Invalid qty");
    }

    // 4. Total (actualPickQty + missQty + badItemQty + badPackageQty) cannot exceed lot available qty
    if (total > availableQty) {
      const errorMsg = t(
        "Total qty (actual pick + miss + bad) cannot exceed available qty: {available}",
        { available: availableQty }
      );
      newErrors.actualPickQty = errorMsg;
      newErrors.missQty = errorMsg;
      newErrors.badItemQty = errorMsg;
    }

    // 5. At least one field must have a value
    if (ap === 0 && miss === 0 && totalBad === 0) {
      newErrors.actualPickQty = t("Enter pick qty or issue qty");
    }

    setErrors(newErrors);
    return Object.keys(newErrors).length === 0;
  };

  const handleSubmit = async () => {
    if (!validateForm()) {
      console.error("Form validation failed:", errors);
      return;
    }

    if (!formData.pickOrderId) {
      console.error("Missing pickOrderId");
      return;
    }

    const badItem = Number(formData.badItemQty) || 0;
    const badPackage = Number((formData as any).badPackageQty) || 0;
    const totalBadQty = badItem + badPackage;

    let badReason: string | undefined;
    if (totalBadQty > 0) {
      // assumption: only one of them is > 0
      badReason = badPackage > 0 ? "package_problem" : "quantity_problem";
    }

    const submitData: PickExecutionIssueData = {
      ...(formData as PickExecutionIssueData),
      badItemQty: totalBadQty,
      badReason,
    };

    setLoading(true);
    try {
      await onSubmit(submitData);
    } catch (error: any) {
      console.error("Error submitting pick execution issue:", error);
      alert(
        t("Failed to submit issue. Please try again.") +
          (error.message ? `: ${error.message}` : "")
      );
    } finally {
      setLoading(false);
    }
  };

  const handleClose = () => {
    setFormData({});
    setErrors({});
    onClose();
  };

  if (!selectedLot || !selectedPickOrderLine) {
    return null;
  }

  const remainingAvailableQty = calculateRemainingAvailableQty(selectedLot);
  const requiredQty = calculateRequiredQty(selectedLot);

  return (
    <Dialog open={open} onClose={handleClose} maxWidth="sm" fullWidth>
      <DialogTitle>
        {t("Pick Execution Issue Form") + " - "+selectedPickOrderLine.itemCode+ "  "+ selectedPickOrderLine.itemName}
        <br />
        {selectedLot.lotNo}
      </DialogTitle>
      <DialogContent>
        <Box sx={{ mt: 2 }}>
          <Grid container spacing={2}>
            <Grid item xs={6}>
              <TextField
                fullWidth
                label={t("Required Qty")}
                value={requiredQty}
                disabled
                variant="outlined"
              />
            </Grid>

            <Grid item xs={6}>
              <TextField
                fullWidth
                label={t("Remaining Available Qty")}
                value={remainingAvailableQty}
                disabled
                variant="outlined"
              />
            </Grid>

            <Grid item xs={12}>
              <TextField
                fullWidth
                label={t("Actual Pick Qty")}
                type="number"
                inputProps={{
                  inputMode: "numeric",
                  pattern: "[0-9]*",
                  min: 0,
                }}
                value={formData.actualPickQty ?? ""}
                onChange={(e) =>
                  handleInputChange(
                    "actualPickQty",
                    e.target.value === ""
                      ? undefined
                      
                      : Math.max(0, Number(e.target.value) || 0)
                  )
                }
                error={!!errors.actualPickQty}
                helperText={
                  errors.actualPickQty || `${t("Max")}: ${remainingAvailableQty}`
                }
                variant="outlined"
              />
            </Grid>

            <Grid item xs={12}>
              <FormControl fullWidth>
                <InputLabel>{t("Reason")}</InputLabel>
                <Select
                  value={formData.reason || ""}
                  onChange={(e) => handleInputChange("reason", e.target.value)}
                  label={t("Reason")}
                >
                  <MenuItem value="">{t("Select Reason")}</MenuItem>
                  <MenuItem value="miss">{t("Edit")}</MenuItem>
                  <MenuItem value="bad">{t("Just Complete")}</MenuItem>
                </Select>
              </FormControl>
            </Grid>

            <Grid item xs={12}>
              <TextField
                fullWidth
                label={t("Missing item Qty")}
                type="number"
                inputProps={{
                  inputMode: "numeric",
                  pattern: "[0-9]*",
                  min: 0,
                }}
                value={formData.missQty || 0}
                onChange={(e) =>
                  handleInputChange(
                    "missQty",
                    e.target.value === ""
                      ? undefined
                      : Math.max(0, Number(e.target.value) || 0)
                  )
                }
                error={!!errors.missQty}
                variant="outlined"
              />
            </Grid>

            <Grid item xs={12}>
              <TextField
                fullWidth
                label={t("Bad Item Qty")}
                type="number"
                inputProps={{
                  inputMode: "numeric",
                  pattern: "[0-9]*",
                  min: 0,
                }}
                value={formData.badItemQty || 0}
                onChange={(e) =>
                  handleInputChange(
                    "badItemQty",
                    e.target.value === ""
                      ? undefined
                      : Math.max(0, Number(e.target.value) || 0)
                  )
                }
                error={!!errors.badItemQty}
                //helperText={t("Quantity Problem")}
                variant="outlined"
              />
            </Grid>

            <Grid item xs={12}>
              <TextField
                fullWidth
                label={t("Bad Package Qty")}
                type="number"
                inputProps={{
                  inputMode: "numeric",
                  pattern: "[0-9]*",
                  min: 0,
                }}
                value={(formData as any).badPackageQty || 0}
                onChange={(e) =>
                  handleInputChange(
                    "badPackageQty",
                    e.target.value === ""
                      ? undefined
                      : Math.max(0, Number(e.target.value) || 0)
                  )
                }
                error={!!errors.badItemQty}
                //helperText={t("Package Problem")}
                variant="outlined"
              />
            </Grid>
          </Grid>
        </Box>
      </DialogContent>
      <DialogActions>
        <Button onClick={handleClose} disabled={loading}>
          {t("Cancel")}
        </Button>
        <Button onClick={handleSubmit} variant="contained" disabled={loading}>
          {loading ? t("submitting") : t("submit")}
        </Button>
      </DialogActions>
    </Dialog>
  );
};

export default PickExecutionForm;