import { useEffect, useMemo, useState } from 'react'
import Alert from '@mui/material/Alert'
import Box from '@mui/material/Box'
import Button from '@mui/material/Button'
import Dialog from '@mui/material/Dialog'
import DialogActions from '@mui/material/DialogActions'
import DialogContent from '@mui/material/DialogContent'
import DialogTitle from '@mui/material/DialogTitle'
import Stack from '@mui/material/Stack'
import TextField from '@mui/material/TextField'
import Typography from '@mui/material/Typography'
import axios from 'axios'
import { PAYMENT_TRANSFER_INSTRUCTIONS_PLAIN } from '@/shared/constants/payment-instructions'

type Props = {
  open: boolean
  isPending: boolean
  error: unknown
  onClose: () => void
  onSubmit: (params: { detail: string; receiptFile: File | null }) => void
}

function paySubmitErrorMessage(err: unknown): string {
  if (axios.isAxiosError(err)) {
    const raw = err.response?.data
    const apiMsg =
      raw && typeof raw === 'object' && 'error' in raw && typeof (raw as { error: unknown }).error === 'string'
        ? (raw as { error: string }).error
        : null
    return apiMsg || err.message || 'Не удалось отправить данные оплаты'
  }
  if (err instanceof Error) return err.message
  return 'Не удалось отправить данные оплаты'
}

export function PaymentDialog({ open, isPending, error, onClose, onSubmit }: Props) {
  const [detail, setDetail] = useState('')
  const [receiptFile, setReceiptFile] = useState<File | null>(null)
  const [clientError, setClientError] = useState<string | null>(null)

  const receiptPreviewUrl = useMemo(() => {
    if (!receiptFile) return null
    return URL.createObjectURL(receiptFile)
  }, [receiptFile])

  useEffect(() => {
    if (!receiptPreviewUrl) return
    return () => URL.revokeObjectURL(receiptPreviewUrl)
  }, [receiptPreviewUrl])

  const reset = () => {
    setDetail('')
    setReceiptFile(null)
    setClientError(null)
  }

  const handleClose = () => {
    if (isPending) return
    reset()
    onClose()
  }

  const handleSubmit = () => {
    const hasText = detail.trim().length > 0
    const hasFile = Boolean(receiptFile)
    if (!hasText && !hasFile) {
      setClientError('Укажите комментарий и/или прикрепите чек.')
      return
    }
    setClientError(null)
    onSubmit({ detail: detail.trim(), receiptFile })
  }

  return (
    <Dialog open={open} onClose={handleClose} fullWidth maxWidth="sm">
      <DialogTitle>Подтверждение оплаты</DialogTitle>
      <DialogContent>
        <Typography variant="body2" sx={{ whiteSpace: 'pre-wrap', mb: 2 }}>
          {PAYMENT_TRANSFER_INSTRUCTIONS_PLAIN}
        </Typography>
        <TextField
          label="Комментарий об оплате (сумма, время перевода и т.д.)"
          value={detail}
          onChange={(e) => {
            setDetail(e.target.value)
            setClientError(null)
          }}
          fullWidth
          multiline
          minRows={3}
          sx={{ mb: 2 }}
        />
        <Stack direction={{ xs: 'column', sm: 'row' }} spacing={1.5} sx={{ mb: 1, alignItems: { sm: 'center' } }}>
          <Button component="label" variant="outlined">
            Прикрепить чек (png, jpg, webp)
            <input
              hidden
              type="file"
              accept="image/png,image/jpeg,image/webp"
              onChange={(e) => {
                const file = e.target.files?.[0]
                setReceiptFile(file ?? null)
                setClientError(null)
                e.currentTarget.value = ''
              }}
            />
          </Button>
          {receiptFile && (
            <Button color="error" variant="text" onClick={() => setReceiptFile(null)}>
              Убрать файл
            </Button>
          )}
        </Stack>
        <Typography variant="caption" color="text.secondary" sx={{ mb: 1, display: 'block' }}>
          Нужен текст комментария и/или изображение чека.
        </Typography>
        {receiptPreviewUrl && (
          <Box
            component="img"
            src={receiptPreviewUrl}
            alt="Предпросмотр чека"
            sx={{ maxWidth: '100%', maxHeight: 200, borderRadius: 1, border: 1, borderColor: 'divider', mb: 1 }}
          />
        )}
        {clientError && (
          <Alert severity="warning" sx={{ mb: 1 }}>
            {clientError}
          </Alert>
        )}
        {error ? (
          <Alert severity="error" sx={{ mt: 1 }}>
            {paySubmitErrorMessage(error)}
          </Alert>
        ) : null}
      </DialogContent>
      <DialogActions>
        <Button onClick={handleClose} disabled={isPending}>
          Отмена
        </Button>
        <Button variant="contained" disabled={isPending} onClick={handleSubmit}>
          Подтвердить оплату
        </Button>
      </DialogActions>
    </Dialog>
  )
}