import { useEffect } from 'react';
import {
  Drawer, Button, Group, Stack, Text, LoadingOverlay, Box,
  Select, TextInput, NumberInput, Switch, Divider,
} from '@mantine/core';
import { useForm, Controller } from 'react-hook-form';
import { zodResolver } from '@hookform/resolvers/zod';
import { z } from 'zod';
import { useMutation, useQueryClient } from '@tanstack/react-query';
import { notifications } from '@mantine/notifications';
import { modals } from '@mantine/modals';
import { apiClient } from '../../api/client';
import type { InventoryItem, InventoryItemType } from '../../api/types';

const font = "'Montserrat', Arial, sans-serif";
const teal = '#008286';
const charcoal = '#58595b';

const TYPE_OPTIONS: { value: InventoryItemType; label: string }[] = [
  { value: 'uniforma', label: 'Uniformă' },
  { value: 'halat', label: 'Halat' },
  { value: 'ciupici', label: 'Ciupici' },
  { value: 'vesta', label: 'Vestă' },
  { value: 'aparat_telefon', label: 'Aparat telefon' },
  { value: 'alte', label: 'Altele' },
];

const schema = z.object({
  sku: z.string().min(1, 'Câmp obligatoriu'),
  name: z.string().min(1, 'Câmp obligatoriu'),
  type: z.enum(['uniforma', 'halat', 'ciupici', 'vesta', 'aparat_telefon', 'alte']),
  size: z.string().optional(),
  color: z.string().optional(),
  pricePerUnit: z.string().optional(),
  stockQty: z.number().int().min(0, 'Stocul nu poate fi negativ'),
  active: z.boolean(),
});
type FormValues = z.infer<typeof schema>;

interface Props {
  inventoryItem: InventoryItem | null;
  opened: boolean;
  onClose: () => void;
}

export function InventoryDrawer({ inventoryItem, opened, onClose }: Props) {
  const isEdit = !!inventoryItem;
  const qc = useQueryClient();

  const { handleSubmit, control, reset, formState: { errors, isSubmitting } } =
    useForm<FormValues>({
      resolver: zodResolver(schema),
      defaultValues: {
        sku: '',
        name: '',
        type: 'uniforma',
        size: '',
        color: '',
        pricePerUnit: '',
        stockQty: 0,
        active: true,
      },
    });

  useEffect(() => {
    if (inventoryItem) {
      reset({
        sku: inventoryItem.sku,
        name: inventoryItem.name,
        type: inventoryItem.type,
        size: inventoryItem.size ?? '',
        color: inventoryItem.color ?? '',
        pricePerUnit: inventoryItem.pricePerUnit ?? '',
        stockQty: inventoryItem.stockQty,
        active: inventoryItem.active,
      });
    } else {
      reset({
        sku: '',
        name: '',
        type: 'uniforma',
        size: '',
        color: '',
        pricePerUnit: '',
        stockQty: 0,
        active: true,
      });
    }
  }, [inventoryItem, opened, reset]);

  const mutation = useMutation({
    mutationFn: (data: FormValues) => {
      const price = data.pricePerUnit ? Number(data.pricePerUnit) : undefined;
      const payload = {
        sku: data.sku,
        name: data.name,
        type: data.type,
        size: data.size || undefined,
        color: data.color || undefined,
        pricePerUnit: Number.isFinite(price) ? price : undefined,
        stockQty: data.stockQty,
        active: data.active,
      };
      return isEdit
        ? apiClient.patch(`/inventory/${inventoryItem.id}`, payload)
        : apiClient.post('/inventory', payload);
    },
    onSuccess: () => {
      void qc.invalidateQueries({ queryKey: ['inventory'] });
      notifications.show({
        color: 'medpark',
        title: 'Salvat',
        message: isEdit ? 'Articol actualizat.' : 'Articol creat.',
      });
      onClose();
    },
    onError: (err: unknown) => {
      const msg = (err as { response?: { data?: { message?: string } } })?.response?.data?.message ?? 'Eroare';
      notifications.show({ color: 'red', title: 'Eroare', message: msg });
    },
  });

  const deleteMutation = useMutation({
    mutationFn: () => apiClient.delete(`/inventory/${inventoryItem!.id}`),
    onSuccess: () => {
      void qc.invalidateQueries({ queryKey: ['inventory'] });
      notifications.show({ color: 'medpark', title: 'Șters', message: 'Articol șters.' });
      onClose();
    },
    onError: (err: unknown) => {
      const msg = (err as { response?: { data?: { message?: string } } })?.response?.data?.message ?? 'Eroare';
      notifications.show({ color: 'red', title: 'Eroare', message: msg });
    },
  });

  function confirmDelete() {
    if (!inventoryItem) return;
    modals.openConfirmModal({
      title: <Text fw={600} style={{ fontFamily: font }}>Șterge articol</Text>,
      children: (
        <Text size="sm" style={{ fontFamily: font }}>
          Ești sigur că vrei să ștergi articolul <b>{inventoryItem.sku}</b> — {inventoryItem.name}?
          Această acțiune nu poate fi anulată.
        </Text>
      ),
      labels: { confirm: 'Șterge', cancel: 'Anulează' },
      confirmProps: { color: 'red' },
      onConfirm: () => deleteMutation.mutate(),
    });
  }

  const section = (label: string) => (
    <Divider
      label={<Text size="xs" fw={700} c={teal} style={{ fontFamily: font, letterSpacing: '0.06em', textTransform: 'uppercase' }}>{label}</Text>}
      labelPosition="left" my={12}
    />
  );

  return (
    <Drawer
      opened={opened}
      onClose={onClose}
      position="right"
      size="md"
      title={<Text style={{ fontFamily: font, fontWeight: 700, color: charcoal }}>{isEdit ? 'Editare articol' : 'Articol nou'}</Text>}
      styles={{ header: { borderBottom: `2px solid ${teal}` } }}
    >
      <Box style={{ position: 'relative' }}>
        <LoadingOverlay visible={isSubmitting || mutation.isPending || deleteMutation.isPending} />

        <form onSubmit={handleSubmit((d) => mutation.mutate(d))}>
          <Stack gap={10} pt={8}>
            {section('Identificare')}
            <Group grow>
              <Controller name="sku" control={control} render={({ field }) => (
                <TextInput {...field} label="SKU *" placeholder="UN-001"
                  error={errors.sku?.message}
                  styles={{ label: { fontFamily: font, fontWeight: 500, fontSize: '0.8rem' } }} />
              )} />
              <Controller name="type" control={control} render={({ field }) => (
                <Select label="Tip *" data={TYPE_OPTIONS}
                  value={field.value ?? null}
                  onChange={(v) => field.onChange(v ?? 'uniforma')}
                  error={errors.type?.message}
                  styles={{ label: { fontFamily: font, fontWeight: 500, fontSize: '0.8rem' } }} />
              )} />
            </Group>

            <Controller name="name" control={control} render={({ field }) => (
              <TextInput {...field} label="Denumire *" placeholder="Uniformă medicală albă"
                error={errors.name?.message}
                styles={{ label: { fontFamily: font, fontWeight: 500, fontSize: '0.8rem' } }} />
            )} />

            {section('Caracteristici')}
            <Group grow>
              <Controller name="size" control={control} render={({ field }) => (
                <TextInput {...field} label="Mărime" placeholder="M, L, 42..."
                  styles={{ label: { fontFamily: font, fontWeight: 500, fontSize: '0.8rem' } }} />
              )} />
              <Controller name="color" control={control} render={({ field }) => (
                <TextInput {...field} label="Culoare" placeholder="Alb, albastru..."
                  styles={{ label: { fontFamily: font, fontWeight: 500, fontSize: '0.8rem' } }} />
              )} />
            </Group>

            {section('Stoc și preț')}
            <Group grow>
              <Controller name="pricePerUnit" control={control} render={({ field }) => (
                <NumberInput
                  label="Preț unitar (MDL)"
                  placeholder="0"
                  decimalScale={2}
                  min={0}
                  value={field.value ? Number(field.value) : ''}
                  onChange={(v) => field.onChange(v === '' || v === null ? '' : String(v))}
                  styles={{ label: { fontFamily: font, fontWeight: 500, fontSize: '0.8rem' } }}
                />
              )} />
              <Controller name="stockQty" control={control} render={({ field }) => (
                <NumberInput
                  label={isEdit ? 'Stoc curent *' : 'Stoc inițial *'}
                  min={0}
                  value={field.value}
                  onChange={(v) => field.onChange(typeof v === 'number' ? v : 0)}
                  error={errors.stockQty?.message}
                  styles={{ label: { fontFamily: font, fontWeight: 500, fontSize: '0.8rem' } }}
                />
              )} />
            </Group>

            <Controller name="active" control={control} render={({ field }) => (
              <Switch
                label="Activ"
                checked={field.value}
                onChange={(e) => field.onChange(e.currentTarget.checked)}
                color="medpark"
                styles={{ label: { fontFamily: font, fontSize: '0.875rem' } }}
                mt={4}
              />
            )} />
          </Stack>

          <Group justify="space-between" mt={20} pt={16} style={{ borderTop: '1px solid #e9ecef' }}>
            {isEdit ? (
              <Button color="red" variant="subtle" onClick={confirmDelete} style={{ fontFamily: font }}>
                Șterge
              </Button>
            ) : <Box />}
            <Group gap={8}>
              <Button variant="subtle" onClick={onClose} style={{ fontFamily: font, color: charcoal }}>
                Anulează
              </Button>
              <Button type="submit" loading={mutation.isPending} style={{ background: teal, fontFamily: font, fontWeight: 500 }}>
                {isEdit ? 'Salvează' : 'Creează'}
              </Button>
            </Group>
          </Group>
        </form>
      </Box>
    </Drawer>
  );
}