"use client";

import React, { useMemo, useState } from "react";
import {
  Avatar,
  Box,
  Button,
  MenuItem,
  Paper,
  TextField,
  Typography,
} from "@mui/material";
import { UploadFile } from "@mui/icons-material";
import { LocalizationProvider } from "@mui/x-date-pickers/LocalizationProvider";
import { AdapterDateFnsJalali } from "@mui/x-date-pickers/AdapterDateFnsJalali";
import { DatePicker } from "@mui/x-date-pickers/DatePicker";

type IdentityFormData = {
  applicantId: string;
  firstName: string;
  lastName: string;
  fatherName: string;
  nationalCode: string;
  birthDate: string;
  birthPlace: string;
  gender: string;
  religion: string;
  nationality: string;
  profilePhotoId: string;
};

type IdentityFormErrors = Partial<Record<keyof IdentityFormData, string>>;

const initialForm: IdentityFormData = {
  applicantId: "",
  firstName: "",
  lastName: "",
  fatherName: "",
  nationalCode: "",
  birthDate: "",
  birthPlace: "",
  gender: "",
  religion: "",
  nationality: "",
  profilePhotoId: "",
};

export default function IdentityForm() {
  const [formData, setFormData] = useState<IdentityFormData>(initialForm);
  const [errors, setErrors] = useState<IdentityFormErrors>({});
  const [submitted, setSubmitted] = useState(false);
  const [profilePhoto, setProfilePhoto] = useState<File | null>(null);
  const [profilePhotoPreview, setProfilePhotoPreview] = useState<string>("");
  const [profilePhotoError, setProfilePhotoError] = useState<string>("");
  const [birthDateValue, setBirthDateValue] = useState<Date | null>(null);

  const handleProfilePhotoChange = (
    event: React.ChangeEvent<HTMLInputElement>,
  ) => {
    const file = event.target.files?.[0];

    if (!file) return;

    if (!file.type.startsWith("image/")) {
      setProfilePhoto(null);
      setProfilePhotoPreview("");
      setProfilePhotoError("فقط فایل تصویری مجاز است");
      return;
    }

    const maxSize = 500 * 1024; // 500KB
    if (file.size > maxSize) {
      setProfilePhoto(null);
      setProfilePhotoPreview("");
      setProfilePhotoError("حجم عکس باید حداکثر ۵۰۰ کیلوبایت باشد");
      return;
    }

    setProfilePhoto(file);
    setProfilePhotoError("");

    const previewUrl = URL.createObjectURL(file);
    setProfilePhotoPreview(previewUrl);
  };

  const genderOptions = useMemo(() => ["مرد", "زن", "سایر"], []);
  const religionOptions = useMemo(
    () => ["اسلام", "مسیحیت", "یهودیت", "زرتشتی", "سایر"],
    [],
  );

  const handleChange =
    (field: keyof IdentityFormData) =>
    (event: React.ChangeEvent<HTMLInputElement>) => {
      let value = event.target.value;

      if (field === "nationalCode") {
        value = value.replace(/\D/g, "").slice(0, 10);
      }

      setFormData((prev) => ({
        ...prev,
        [field]: value,
      }));

      if (errors[field]) {
        setErrors((prev) => ({
          ...prev,
          [field]: "",
        }));
      }
    };

  const validate = () => {
    const newErrors: IdentityFormErrors = {};
    let hasError = false;

    if (!formData.applicantId.trim()) {
      newErrors.applicantId = "شناسه متقاضی الزامی است";
      hasError = true;
    }

    if (!formData.firstName.trim()) {
      newErrors.firstName = "نام الزامی است";
      hasError = true;
    }

    if (!formData.lastName.trim()) {
      newErrors.lastName = "نام خانوادگی الزامی است";
      hasError = true;
    }

    if (!formData.nationalCode.trim()) {
      newErrors.nationalCode = "کد ملی الزامی است";
      hasError = true;
    } else if (!/^\d{10}$/.test(formData.nationalCode)) {
      newErrors.nationalCode = "کد ملی باید ۱۰ رقم باشد";
      hasError = true;
    }

    if (!formData.birthDate.trim()) {
      newErrors.birthDate = "تاریخ تولد الزامی است";
      hasError = true;
    }

    if (!formData.gender.trim()) {
      newErrors.gender = "جنسیت الزامی است";
      hasError = true;
    }

    if (!formData.nationality.trim()) {
      newErrors.nationality = "ملیت الزامی است";
      hasError = true;
    }

    if (!profilePhoto) {
      setProfilePhotoError("عکس پرسنلی الزامی است");
      hasError = true;
    } else {
      setProfilePhotoError("");
    }

    setErrors(newErrors);
    return !hasError;
  };

  const handleSubmit = (event: React.FormEvent) => {
    event.preventDefault();
    setSubmitted(false);

    if (!validate()) return;

    const payload = {
      ...formData,
      birthDate: formData.birthDate ? new Date(formData.birthDate) : null,
      fatherName: formData.fatherName || null,
      birthPlace: formData.birthPlace || null,
      religion: formData.religion || null,
      profilePhotoId: formData.profilePhotoId || null,
    };

    console.log("Identity Payload:", payload);
    setSubmitted(true);
  };

  return (
    <Box>
      <Paper
        elevation={0}
        sx={{
          width: "100%",
          background: "#ffffff",
        }}
      >
        <Box component="form" onSubmit={handleSubmit}>
          <div
            style={{
              display: "grid",
              gridTemplateColumns: "repeat(auto-fit, minmax(340px, 1fr))",
              gap: "18px",
            }}
          >
            <TextField
              label="نام"
              value={formData.firstName}
              onChange={handleChange("firstName")}
              error={!!errors.firstName}
              helperText={errors.firstName}
              fullWidth
            />

            <TextField
              label="نام خانوادگی"
              value={formData.lastName}
              onChange={handleChange("lastName")}
              error={!!errors.lastName}
              helperText={errors.lastName}
              fullWidth
            />

            <TextField
              label="نام پدر"
              value={formData.fatherName}
              onChange={handleChange("fatherName")}
              fullWidth
            />

            <TextField
              label="کد ملی"
              value={formData.nationalCode}
              onChange={handleChange("nationalCode")}
              error={!!errors.nationalCode}
              helperText={errors.nationalCode}
              fullWidth
            />

            <DatePicker
              label="تاریخ تولد"
              value={birthDateValue}
              onChange={(newValue) => {
                setBirthDateValue(newValue);

                setFormData((prev) => ({
                  ...prev,
                  birthDate: newValue ? newValue.toISOString() : "",
                }));

                if (errors.birthDate) {
                  setErrors((prev) => ({
                    ...prev,
                    birthDate: "",
                  }));
                }
              }}
              slotProps={{
                textField: {
                  fullWidth: true,
                  error: !!errors.birthDate,
                  helperText: errors.birthDate,
                },
              }}
            />

            <TextField
              label="محل تولد"
              value={formData.birthPlace}
              onChange={handleChange("birthPlace")}
              fullWidth
            />

            <TextField
              select
              label="جنسیت"
              value={formData.gender}
              onChange={handleChange("gender")}
              error={!!errors.gender}
              helperText={errors.gender}
              fullWidth
            >
              {genderOptions.map((item) => (
                <MenuItem key={item} value={item}>
                  {item}
                </MenuItem>
              ))}
            </TextField>

            <TextField
              select
              label="دین"
              value={formData.religion}
              onChange={handleChange("religion")}
              fullWidth
            >
              {religionOptions.map((item) => (
                <MenuItem key={item} value={item}>
                  {item}
                </MenuItem>
              ))}
            </TextField>

            <TextField
              label="ملیت"
              value={formData.nationality}
              onChange={handleChange("nationality")}
              error={!!errors.nationality}
              helperText={errors.nationality}
              fullWidth
            />

            <Box
              sx={{
                width: "100%",
                border: profilePhotoError
                  ? "1px solid #ef4444"
                  : "1px dashed #cbd5e1",
                borderRadius: "18px",
                backgroundColor: "#f8fafc",
                p: 2,
                minHeight: "100%",
                transition: "all 0.2s ease",
                "&:hover": {
                  borderColor: profilePhotoError ? "#ef4444" : "#2563eb",
                  backgroundColor: "#f8fbff",
                },
              }}
            >
              <Typography
                sx={{
                  fontWeight: 700,
                  color: "#0f172a",
                  mb: 1.5,
                  fontSize: "0.95rem",
                }}
              >
                عکس پرسنلی
              </Typography>

              <Typography
                sx={{
                  color: "#64748b",
                  fontSize: "0.82rem",
                  mb: 2,
                  lineHeight: 1.8,
                }}
              >
                فقط فایل تصویری مجاز است و حجم آن باید حداکثر ۵۰۰ کیلوبایت باشد.
              </Typography>

              <Button
                component="label"
                variant="outlined"
                startIcon={<UploadFile />}
                sx={{
                  borderRadius: "12px",
                  borderColor: "#cbd5e1",
                  color: "#2563eb",
                  fontWeight: 700,
                  px: 2.5,
                  "&:hover": {
                    borderColor: "#2563eb",
                    backgroundColor: "#eff6ff",
                  },
                }}
              >
                انتخاب عکس
                <input
                  hidden
                  type="file"
                  accept="image/*"
                  onChange={handleProfilePhotoChange}
                />
              </Button>

              {profilePhoto && (
                <Typography
                  sx={{
                    mt: 1.5,
                    fontSize: "0.82rem",
                    color: "#475569",
                    wordBreak: "break-word",
                  }}
                >
                  فایل انتخاب‌شده: {profilePhoto.name}
                </Typography>
              )}

              {profilePhotoError && (
                <Typography
                  sx={{
                    mt: 1.5,
                    color: "#dc2626",
                    fontSize: "0.8rem",
                    fontWeight: 600,
                  }}
                >
                  {profilePhotoError}
                </Typography>
              )}
            </Box>
          </div>
        </Box>
      </Paper>
    </Box>
  );
}