import { useState } from 'react'
import { useTranslation } from 'react-i18next'
import { toast } from 'sonner'
import { getCurrencyDisplay, getCurrencyLabel } from '@/lib/currency'
import { formatQuota, parseQuotaFromDollars } from '@/lib/format'
import { cn } from '@/lib/utils'
import { Button } from '@/components/ui/button'
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import { adjustUserQuota } from '../api'
import type { QuotaAdjustMode } from '../types'

interface UserQuotaDialogProps {
  open: boolean
  onOpenChange: (open: boolean) => void
  userId: number
  currentQuota: number
  onSuccess: () => void
}

export function UserQuotaDialog(props: UserQuotaDialogProps) {
  const { t } = useTranslation()
  const [mode, setMode] = useState<QuotaAdjustMode>('add')
  const [amount, setAmount] = useState('')
  const [loading, setLoading] = useState(false)

  const { meta: currencyMeta } = getCurrencyDisplay()
  const currencyLabel = getCurrencyLabel()
  const tokensOnly = currencyMeta.kind === 'tokens'

  const amountValue = parseFloat(amount) || 0
  const quotaValue = parseQuotaFromDollars(Math.abs(amountValue))

  const getPreviewText = () => {
    const current = props.currentQuota
    const val = quotaValue
    switch (mode) {
      case 'add':
        return `${t('Current quota')}: ${formatQuota(current)}  +${formatQuota(val)} = ${formatQuota(current + val)}`
      case 'subtract':
        return `${t('Current quota')}: ${formatQuota(current)}  -${formatQuota(val)} = ${formatQuota(current - val)}`
      case 'override': {
        const overrideQuota = parseQuotaFromDollars(amountValue)
        return `${t('Current quota')}: ${formatQuota(current)} → ${formatQuota(overrideQuota)}`
      }
      default:
        return ''
    }
  }

  const handleConfirm = async () => {
    if (!amount && mode !== 'override') return
    if (quotaValue <= 0 && mode !== 'override') return

    setLoading(true)
    try {
      const value =
        mode === 'override' ? parseQuotaFromDollars(amountValue) : quotaValue
      const result = await adjustUserQuota({
        id: props.userId,
        action: 'add_quota',
        mode,
        value: mode === 'override' ? value : Math.abs(value),
      })
      if (result.success) {
        toast.success(t('Quota adjusted successfully'))
        setAmount('')
        setMode('add')
        props.onOpenChange(false)
        props.onSuccess()
      } else {
        toast.error(result.message || t('Failed to adjust quota'))
      }
    } catch (e: unknown) {
      toast.error(e instanceof Error ? e.message : t('Failed to adjust quota'))
    } finally {
      setLoading(false)
    }
  }

  const handleCancel = () => {
    setAmount('')
    setMode('add')
    props.onOpenChange(false)
  }

  const placeholder = tokensOnly
    ? t('Enter amount in tokens')
    : t('Enter amount in {{currency}}', { currency: currencyLabel })

  return (
    <Dialog open={props.open} onOpenChange={props.onOpenChange}>
      <DialogContent>
        <DialogHeader>
          <DialogTitle>{t('Adjust Quota')}</DialogTitle>
          <DialogDescription>
            {t('Select an operation mode and enter the amount')}
          </DialogDescription>
        </DialogHeader>
        <div className='space-y-4'>
          <div className='text-muted-foreground text-sm'>
            {getPreviewText()}
          </div>

          <div className='space-y-2'>
            <Label>{t('Mode')}</Label>
            <div className='flex gap-1'>
              {(['add', 'subtract', 'override'] as const).map((m) => (
                <Button
                  key={m}
                  type='button'
                  variant='outline'
                  size='sm'
                  className={cn(
                    mode === m &&
                      'bg-primary text-primary-foreground hover:bg-primary/90 hover:text-primary-foreground'
                  )}
                  onClick={() => {
                    setMode(m)
                    setAmount('')
                  }}
                >
                  {m === 'add'
                    ? t('Add')
                    : m === 'subtract'
                      ? t('Subtract')
                      : t('Override')}
                </Button>
              ))}
            </div>
          </div>

          <div className='space-y-2'>
            <Label>
              {t('Amount')} ({currencyLabel})
            </Label>
            <Input
              type='number'
              step={tokensOnly ? 1 : 0.000001}
              min={mode === 'override' ? undefined : 0}
              placeholder={placeholder}
              value={amount}
              onChange={(e) => setAmount(e.target.value)}
              onKeyDown={(e) => {
                if (e.key === 'Enter') handleConfirm()
              }}
            />
          </div>
        </div>
        <DialogFooter>
          <Button variant='outline' onClick={handleCancel}>
            {t('Cancel')}
          </Button>
          <Button onClick={handleConfirm} disabled={loading}>
            {loading ? t('Processing...') : t('Confirm')}
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  )
}
