import { Fragment, useMemo, useState } from 'react'
import Alert from '@mui/material/Alert'
import Box from '@mui/material/Box'
import Button from '@mui/material/Button'
import FormControl from '@mui/material/FormControl'
import InputLabel from '@mui/material/InputLabel'
import MenuItem from '@mui/material/MenuItem'
import Select from '@mui/material/Select'
import Stack from '@mui/material/Stack'
import Table from '@mui/material/Table'
import TableBody from '@mui/material/TableBody'
import TableCell from '@mui/material/TableCell'
import TableHead from '@mui/material/TableHead'
import TableRow from '@mui/material/TableRow'
import TextField from '@mui/material/TextField'
import Typography from '@mui/material/Typography'
import { useQuery } from '@tanstack/react-query'
import { fetchAdminOrder, fetchAdminOrders } from '@/entities/order/api/admin-order-api'
import { OrderDetailContent } from '@/features/order-detail/ui/OrderDetailContent'
import { ORDER_STATUSES } from '@/shared/constants/order'
import { formatPriceRub } from '@/shared/lib/format-price'
import { groupOrdersByStatus } from '@/shared/lib/group-orders-by-status'
import { orderStatusLabelRu } from '@/shared/lib/order-status-labels'
import { AdminDialog } from '@/shared/ui/AdminDialog/AdminDialog'

export function AdminOrdersPage() {
  const [q, setQ] = useState('')
  const [status, setStatus] = useState('')
  const [deliveryType, setDeliveryType] = useState<'delivery' | 'pickup' | ''>('')
  const [dialogOpen, setDialogOpen] = useState(false)
  const [selectedId, setSelectedId] = useState<string | null>(null)

  const ordersQuery = useQuery({
    queryKey: ['admin', 'orders', { q, status, deliveryType }],
    queryFn: () =>
      fetchAdminOrders({
        q: q.trim() || undefined,
        status: status || undefined,
        deliveryType: deliveryType || undefined,
      }),
  })

  const orderDetailQuery = useQuery({
    queryKey: ['admin', 'orders', 'detail', selectedId],
    queryFn: () => fetchAdminOrder(selectedId!),
    enabled: Boolean(selectedId),
  })

  const open = (id: string) => {
    setSelectedId(id)
    setDialogOpen(true)
  }

  const items = useMemo(() => ordersQuery.data?.items ?? [], [ordersQuery.data?.items])
  const groupedItems = useMemo(
    () =>
      groupOrdersByStatus(items, ORDER_STATUSES).map((group) => ({
        statusCode: group.status,
        items: group.items,
      })),
    [items],
  )

  const detail = orderDetailQuery.data?.item

  return (
    <Box>
      <Typography variant="h4" sx={{ mb: 2 }}>
        Заказы
      </Typography>

      <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
        Управление заказами доступно пользователю с правами администратора.
      </Typography>
      <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ mb: 2 }}>
        <TextField size="small" label="Поиск (id/email)" value={q} onChange={(e) => setQ(e.target.value)} fullWidth />
        <FormControl size="small" sx={{ minWidth: 220 }}>
          <InputLabel id="status-label">Статус</InputLabel>
          <Select
            labelId="status-label"
            label="Статус"
            value={status}
            onChange={(e) => setStatus(String(e.target.value))}
          >
            <MenuItem value="">
              <em>Все</em>
            </MenuItem>
            {ORDER_STATUSES.map((s) => (
              <MenuItem key={s} value={s}>
                {orderStatusLabelRu(s)}
              </MenuItem>
            ))}
          </Select>
        </FormControl>
        <FormControl size="small" sx={{ minWidth: 220 }}>
          <InputLabel id="delivery-type-label">Способ получения</InputLabel>
          <Select
            labelId="delivery-type-label"
            label="Способ получения"
            value={deliveryType}
            onChange={(e) => {
              const v = String(e.target.value)
              if (v === '' || v === 'delivery' || v === 'pickup') setDeliveryType(v)
            }}
          >
            <MenuItem value="">
              <em>Все</em>
            </MenuItem>
            <MenuItem value="delivery">Доставка</MenuItem>
            <MenuItem value="pickup">Самовывоз</MenuItem>
          </Select>
        </FormControl>
      </Stack>

      {ordersQuery.isError && <Alert severity="error">Не удалось загрузить заказы.</Alert>}

      <Table size="small">
        <TableHead>
          <TableRow>
            <TableCell>ID</TableCell>
            <TableCell>Покупатель</TableCell>
            <TableCell>Создан</TableCell>
            <TableCell>Сумма</TableCell>
            <TableCell>Позиций</TableCell>
            <TableCell align="right">Действия</TableCell>
          </TableRow>
        </TableHead>
        <TableBody>
          {groupedItems.map((group) => (
            <Fragment key={`group:${group.statusCode}`}>
              <TableRow>
                <TableCell colSpan={6} sx={{ fontWeight: 700, bgcolor: 'action.hover' }}>
                  {orderStatusLabelRu(group.statusCode)} ({group.items.length})
                </TableCell>
              </TableRow>
              {group.items.map((o) => (
                <TableRow key={o.id} hover>
                  <TableCell>{o.id.slice(-8)}</TableCell>
                  <TableCell>{o.user.email}</TableCell>
                  <TableCell>{new Date(o.createdAt).toLocaleString('ru-RU')}</TableCell>
                  <TableCell>{formatPriceRub(o.totalCents)}</TableCell>
                  <TableCell>{o.itemsCount}</TableCell>
                  <TableCell align="right">
                    <Button size="small" onClick={() => open(o.id)}>
                      Открыть
                    </Button>
                  </TableCell>
                </TableRow>
              ))}
            </Fragment>
          ))}
          {ordersQuery.isSuccess && items.length === 0 && (
            <TableRow>
              <TableCell colSpan={6} sx={{ color: 'text.secondary' }}>
                Заказов пока нет.
              </TableCell>
            </TableRow>
          )}
        </TableBody>
      </Table>

      <AdminDialog
        open={dialogOpen}
        onClose={() => setDialogOpen(false)}
        title="Заказ"
        maxWidth="md"
        loading={!detail && orderDetailQuery.isLoading}
        error={orderDetailQuery.isError ? 'Не удалось загрузить заказ.' : null}
      >
        {detail && <OrderDetailContent detail={detail} orderId={detail.id} />}
      </AdminDialog>
    </Box>
  )
}