import React, { useState } from 'react'
import { useNavigate } from 'react-router-dom'
import { useTranslation } from 'react-i18next'
import {
  Box,
  Heading,
  Button,
  Table,
  Flex,
  Input,
  HStack,
  Text,
  Badge,
} from '@chakra-ui/react'
import { useGetChainsQuery, useDeleteChainMutation, useUpdateChainMutation } from '../../__data__/api/api'
import { URLs } from '../../__data__/urls'
import { LoadingSpinner } from '../../components/LoadingSpinner'
import { ErrorAlert } from '../../components/ErrorAlert'
import { EmptyState } from '../../components/EmptyState'
import { DuplicateChainDialog } from '../../components/DuplicateChainDialog'
import { ClearSubmissionsDialog } from '../../components/ClearSubmissionsDialog'
import type { ChallengeChain } from '../../types/challenge'
import { toaster } from '../../components/ui/toaster'

export const ChainsListPage: React.FC = () => {
  const navigate = useNavigate()
  const { t } = useTranslation()
  const { data: chains, isLoading, error, refetch } = useGetChainsQuery()
  const [deleteChain] = useDeleteChainMutation()

  const [searchQuery, setSearchQuery] = useState('')
  const [chainToDuplicate, setChainToDuplicate] = useState<ChallengeChain | null>(null)
  const [chainToClearSubmissions, setChainToClearSubmissions] = useState<ChallengeChain | null>(null)
  const [updatingChainId, setUpdatingChainId] = useState<string | null>(null)
  const [updateChain] = useUpdateChainMutation()

  const handleDeleteChain = async (chain: ChallengeChain) => {
    const confirmed = window.confirm(
      t('challenge.admin.chains.delete.confirm.message', { name: chain.name })
    )

    if (!confirmed) return

    try {
      await deleteChain(chain.id).unwrap()
      toaster.create({
        title: t('challenge.admin.common.success'),
        description: t('challenge.admin.chains.deleted'),
        type: 'success',
      })
    } catch (err) {
      toaster.create({
        title: t('challenge.admin.common.error'),
        description: t('challenge.admin.chains.delete.error'),
        type: 'error',
      })
    }
  }

  const handleToggleActive = async (chain: ChallengeChain, nextValue: boolean) => {
    setUpdatingChainId(chain.id)

    try {
      await updateChain({
        id: chain.id,
        data: { isActive: nextValue },
      }).unwrap()
      toaster.create({
        title: t('challenge.admin.common.success'),
        description: t('challenge.admin.chains.updated'),
        type: 'success',
      })
    } catch {
      toaster.create({
        title: t('challenge.admin.common.error'),
        description: t('challenge.admin.chains.save.error'),
        type: 'error',
      })
    } finally {
      setUpdatingChainId(null)
    }
  }

  if (isLoading) {
    return <LoadingSpinner message={t('challenge.admin.chains.list.loading')} />
  }

  if (error || !chains) {
    return <ErrorAlert message={t('challenge.admin.chains.list.load.error')} onRetry={refetch} />
  }

  const filteredChains = chains.filter((chain) =>
    chain.name.toLowerCase().includes(searchQuery.toLowerCase())
  )

  const formatDate = (dateStr: string) => {
    return new Date(dateStr).toLocaleDateString('ru-RU', {
      year: 'numeric',
      month: 'short',
      day: 'numeric',
    })
  }

  return (
    <Box>
      <Flex justify="space-between" align="center" mb={6}>
        <Heading>{t('challenge.admin.chains.list.title')}</Heading>
        <Button colorPalette="teal" onClick={() => navigate(URLs.chainNew)}>
          {t('challenge.admin.chains.list.create.button')}
        </Button>
      </Flex>

      {chains.length > 0 && (
        <Box mb={4}>
          <Input
            placeholder={t('challenge.admin.chains.list.search.placeholder')}
            value={searchQuery}
            onChange={(e) => setSearchQuery(e.target.value)}
            maxW="400px"
          />
        </Box>
      )}

      {filteredChains.length === 0 && chains.length === 0 ? (
        <EmptyState
          title={t('challenge.admin.chains.list.empty.title')}
          description={t('challenge.admin.chains.list.empty.description')}
          actionLabel={t('challenge.admin.chains.list.empty.action')}
          onAction={() => navigate(URLs.chainNew)}
        />
      ) : filteredChains.length === 0 ? (
        <EmptyState
          title={t('challenge.admin.common.not.found')}
          description={t('challenge.admin.chains.list.search.empty', { query: searchQuery })}
        />
      ) : (
        <Box bg="white" borderRadius="lg" boxShadow="sm" borderWidth="1px" borderColor="gray.200" overflowX="auto">
          <Table.Root size="sm">
            <Table.Header>
              <Table.Row>
                <Table.ColumnHeader>{t('challenge.admin.chains.list.table.name')}</Table.ColumnHeader>
                <Table.ColumnHeader>{t('challenge.admin.chains.list.table.tasks.count')}</Table.ColumnHeader>
                <Table.ColumnHeader>{t('challenge.admin.chains.list.table.created')}</Table.ColumnHeader>
                <Table.ColumnHeader>{t('challenge.admin.chains.list.table.status')}</Table.ColumnHeader>
                <Table.ColumnHeader textAlign="right">{t('challenge.admin.chains.list.table.actions')}</Table.ColumnHeader>
              </Table.Row>
            </Table.Header>
            <Table.Body>
              {filteredChains.map((chain) => (
                <Table.Row key={chain.id}>
                  <Table.Cell fontWeight="medium">{chain.name}</Table.Cell>
                  <Table.Cell>
                    <Badge colorPalette="teal" variant="subtle">
                      {chain.tasks.length} {t('challenge.admin.chains.list.badge.tasks')}
                    </Badge>
                  </Table.Cell>
                  <Table.Cell>
                    <Text fontSize="sm" color="gray.600">
                      {formatDate(chain.createdAt)}
                    </Text>
                  </Table.Cell>
                  <Table.Cell>
                    <HStack gap={3} justify="flex-start">
                      <Badge colorPalette={chain.isActive ? 'green' : 'gray'} variant="subtle">
                        {chain.isActive
                          ? t('challenge.admin.chains.list.status.active')
                          : t('challenge.admin.chains.list.status.inactive')}
                      </Badge>
                      <Button
                        size="xs"
                        variant="outline"
                        onClick={() => handleToggleActive(chain, !chain.isActive)}
                        disabled={updatingChainId === chain.id}
                      >
                        {chain.isActive
                          ? t('challenge.admin.chains.list.status.inactive')
                          : t('challenge.admin.chains.list.status.active')}
                      </Button>
                    </HStack>
                  </Table.Cell>
                  <Table.Cell textAlign="right">
                    <HStack gap={2} justify="flex-end">
                      <Button
                        size="sm"
                        variant="ghost"
                        onClick={() => navigate(URLs.chainEdit(chain.id))}
                      >
                        {t('challenge.admin.chains.list.button.edit')}
                      </Button>
                      <Button
                        size="sm"
                        variant="ghost"
                        onClick={() => setChainToDuplicate(chain)}
                      >
                        {t('challenge.admin.chains.duplicate.button')}
                      </Button>
                      <Button
                        size="sm"
                        variant="ghost"
                        colorPalette="red"
                        onClick={() => setChainToClearSubmissions(chain)}
                      >
                        {t('challenge.admin.chains.clear.submissions.button')}
                      </Button>
                      <Button
                        size="sm"
                        variant="ghost"
                        colorPalette="red"
                        onClick={() => handleDeleteChain(chain)}
                      >
                        {t('challenge.admin.chains.list.button.delete')}
                      </Button>
                    </HStack>
                  </Table.Cell>
                </Table.Row>
              ))}
            </Table.Body>
          </Table.Root>
        </Box>
      )}

      <DuplicateChainDialog
        isOpen={!!chainToDuplicate}
        onClose={() => setChainToDuplicate(null)}
        chain={chainToDuplicate}
      />

      <ClearSubmissionsDialog
        isOpen={!!chainToClearSubmissions}
        onClose={() => setChainToClearSubmissions(null)}
        chain={chainToClearSubmissions}
      />
    </Box>
  )
}