import { useState, useMemo } from 'react'
import { Pencil, Plus, Search, Trash2 } from 'lucide-react'
import { useTranslation } from 'react-i18next'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import { safeJsonParseWithValidation } from '../utils/json-parser'
import { isObjectRecord } from '../utils/json-validators'
import { RateLimitDialog, type RateLimitEntryData } from './rate-limit-dialog'

type RateLimitVisualEditorProps = {
  value: string
  onChange: (value: string) => void
}

type RateLimitEntry = RateLimitEntryData

export function RateLimitVisualEditor({
  value,
  onChange,
}: RateLimitVisualEditorProps) {
  const { t } = useTranslation()
  const [searchText, setSearchText] = useState('')
  const [dialogOpen, setDialogOpen] = useState(false)
  const [editData, setEditData] = useState<RateLimitEntry | null>(null)

  const rateLimits = useMemo(() => {
    if (!value || value.trim() === '') return []

    const parsed = safeJsonParseWithValidation<Record<string, unknown>>(value, {
      fallback: {},
      validator: isObjectRecord,
      validatorMessage: 'Rate limits must be a JSON object',
      context: 'rate limits',
    })

    return Object.entries(parsed)
      .map(([groupName, limits]) => {
        if (
          Array.isArray(limits) &&
          limits.length === 2 &&
          typeof limits[0] === 'number' &&
          typeof limits[1] === 'number'
        ) {
          return {
            groupName,
            maxRequests: limits[0],
            maxSuccess: limits[1],
          }
        }
        return null
      })
      .filter((item): item is RateLimitEntry => item !== null)
  }, [value])

  const filteredRateLimits = useMemo(() => {
    if (!searchText) return rateLimits
    const lowerSearch = searchText.toLowerCase()
    return rateLimits.filter((limit) =>
      limit.groupName.toLowerCase().includes(lowerSearch)
    )
  }, [rateLimits, searchText])

  const handleSave = (data: RateLimitEntryData) => {
    const parsed = safeJsonParseWithValidation<Record<string, unknown>>(value, {
      fallback: {},
      validator: isObjectRecord,
      silent: true,
    })

    if (editData && editData.groupName !== data.groupName) {
      delete parsed[editData.groupName]
    }

    parsed[data.groupName] = [data.maxRequests, data.maxSuccess]

    onChange(JSON.stringify(parsed, null, 2))
  }

  const handleDelete = (groupName: string) => {
    const parsed = safeJsonParseWithValidation<Record<string, unknown>>(value, {
      fallback: {},
      validator: isObjectRecord,
      silent: true,
    })

    delete parsed[groupName]

    onChange(JSON.stringify(parsed, null, 2))
  }

  const handleEdit = (limit: RateLimitEntry) => {
    setEditData(limit)
    setDialogOpen(true)
  }

  const handleAdd = () => {
    setEditData(null)
    setDialogOpen(true)
  }

  return (
    <div className='space-y-4'>
      <div className='flex items-center gap-4'>
        <div className='relative flex-1'>
          <Search className='text-muted-foreground absolute top-2.5 left-2.5 h-4 w-4' />
          <Input
            placeholder={t('Search group names...')}
            value={searchText}
            onChange={(e) => setSearchText(e.target.value)}
            className='pl-9'
          />
        </div>
        <Button onClick={handleAdd}>
          <Plus className='mr-2 h-4 w-4' />
          {t('Add group')}
        </Button>
      </div>

      {filteredRateLimits.length === 0 ? (
        <div className='text-muted-foreground rounded-lg border border-dashed p-8 text-center'>
          {searchText
            ? t('No groups match your search')
            : t(
                'No group-based rate limits configured. Click "Add group" to get started.'
              )}
        </div>
      ) : (
        <div className='rounded-md border'>
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead>{t('Group Name')}</TableHead>
                <TableHead className='text-right'>
                  {t('Max Requests (incl. failures)')}
                </TableHead>
                <TableHead className='text-right'>{t('Max Success')}</TableHead>
                <TableHead className='text-right'>{t('Actions')}</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {filteredRateLimits.map((limit) => (
                <TableRow key={limit.groupName}>
                  <TableCell className='font-medium'>
                    {limit.groupName}
                  </TableCell>
                  <TableCell className='text-right'>
                    <span className='font-mono'>
                      {limit.maxRequests === 0
                        ? t('Unlimited')
                        : limit.maxRequests.toLocaleString()}
                    </span>
                  </TableCell>
                  <TableCell className='text-right'>
                    <span className='font-mono'>
                      {limit.maxSuccess.toLocaleString()}
                    </span>
                  </TableCell>
                  <TableCell className='text-right'>
                    <div className='flex justify-end gap-2'>
                      <Button
                        variant='ghost'
                        size='sm'
                        onClick={() => handleEdit(limit)}
                      >
                        <Pencil className='h-4 w-4' />
                      </Button>
                      <Button
                        variant='ghost'
                        size='sm'
                        onClick={() => handleDelete(limit.groupName)}
                      >
                        <Trash2 className='h-4 w-4' />
                      </Button>
                    </div>
                  </TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        </div>
      )}

      <RateLimitDialog
        open={dialogOpen}
        onOpenChange={setDialogOpen}
        onSave={handleSave}
        editData={editData}
      />
    </div>
  )
}