'use client';
import { useState, useCallback } from 'react';
import {
  PlagiarismFormErrors,
  PlagiarismFormState,
  SubmissionState,
} from './types';
import { isFormValid, validatePlagiarismForm } from './validation';
import { toast } from 'react-toastify';
import { useUserPlagiatStore } from '@/shared/zustand/user';
import { useMutation } from '@tanstack/react-query';
import { links } from '@/shared/request/links';
import { apiRequest } from '@/shared/request/apiRequest';

// ─── Initial States ──────────────────────────────────────────────────────────

const INITIAL_FORM: PlagiarismFormState = {
  title: '',
  file: null,
  certificate: true,
  text: '',
  total_price: 41200,
};

const INITIAL_SUBMISSION: SubmissionState = {
  status: 'idle',
  error: null,
};

// ─── Hook ────────────────────────────────────────────────────────────────────

export function usePlagiarismForm() {
  const user = useUserPlagiatStore((state) => state.user);
  const [form, setForm] = useState<PlagiarismFormState>(INITIAL_FORM);
  const [errors, setErrors] = useState<PlagiarismFormErrors>({});
  const [isPaymentOpen, setIsPaymentOpen] = useState(false);
  const [submission, setSubmission] =
    useState<SubmissionState>(INITIAL_SUBMISSION);

  const checkdocumentRequest = useMutation({
    mutationKey: ['plagiarismCheck'],
    mutationFn: (data: FormData) =>
      apiRequest('POST', links.plagiarismCheck, data),
    onSuccess: () => {
      setSubmission({ status: 'success', error: null });
      setForm(INITIAL_FORM);
      setIsPaymentOpen(false);
    },
    onError: (err) => {
      const message =
        err instanceof Error ? err.message : 'An unexpected error occurred.';
      setSubmission({ status: 'error', error: message });
      setIsPaymentOpen(false);
    },
  });

  // ── Field updaters ───────────────────────────────────────────────────────

  const setTopic = useCallback((topic: string) => {
    setForm((prev) => ({ ...prev, title: topic }));
    setErrors((prev) => ({ ...prev, title: undefined }));
  }, []);

  const setFile = useCallback((file: File | null) => {
    setForm((prev) => ({ ...prev, file }));
    setErrors((prev) => ({ ...prev, file: undefined }));
  }, []);

  const toggleCertificate = useCallback(() => {
    setForm((prev) => ({ ...prev, certificate: !prev.certificate }));
  }, []);

  // ── Submission ───────────────────────────────────────────────────────────

  // 1. Wrap the form's onSubmit to intercept the event properly
  const handleSubmitWithModal = useCallback(
    async (e: React.FormEvent) => {
      e.preventDefault();

      console.log('Form submitted user:', user); // Debugging log
      if (user === null) {
        toast.error('Iltimos, avval tizimga kiring!');
        return;
      }
      // Run validation first
      const validationErrors = validatePlagiarismForm(form);
      if (!isFormValid(validationErrors)) {
        setErrors(validationErrors);
        return; // Don't open modal if invalid
      }

      // Validation passed → open the payment modal
      setIsPaymentOpen(true);
    },
    [form],
  );

  const handleSubmit = useCallback(async () => {
    setSubmission({ status: 'loading', error: null });
    const fd = new FormData();
    fd.append('title', form.title.trim());
    fd.append('text', `${user?.name} ${user?.surname}` || '');
    fd.append('file', form.file!); // File object — multipart/form-data
    fd.append('certificate', String(form.certificate));
    fd.append('total_price', '41200');
    checkdocumentRequest.mutate(fd);
  }, [form, user]);

  const resetSubmission = useCallback(() => {
    setSubmission(INITIAL_SUBMISSION);
  }, []);

  // ── Derived state ────────────────────────────────────────────────────────

  const isLoading = submission.status === 'loading';

  return {
    form,
    errors,
    submission,
    senderFullName: user ? `${user?.name} ${user?.surname}` : null,
    isLoading,
    setTopic,
    setFile,
    toggleCertificate,
    handleSubmit,
    resetSubmission,
    handleSubmitWithModal,
    setIsPaymentOpen,
    isPaymentOpen,
  };
}