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 { useGetTasksQuery, useDeleteTaskMutation } 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 type { ChallengeTask } from '../../types/challenge'
import { toaster } from '../../components/ui/toaster'

export const TasksListPage: React.FC = () => {
  const navigate = useNavigate()
  const { t } = useTranslation()
  const { data: tasks, isLoading, error, refetch } = useGetTasksQuery()
  const [deleteTask] = useDeleteTaskMutation()

  const [searchQuery, setSearchQuery] = useState('')

  const handleDeleteTask = async (task: ChallengeTask) => {
    const confirmed = window.confirm(
      t('challenge.admin.tasks.delete.confirm.message', { title: task.title })
    )

    if (!confirmed) return

    try {
      await deleteTask(task.id).unwrap()
      toaster.create({
        title: t('challenge.admin.common.success'),
        description: t('challenge.admin.tasks.deleted'),
        type: 'success',
      })
    } catch (_err) {
      toaster.create({
        title: t('challenge.admin.common.error'),
        description: t('challenge.admin.tasks.delete.error'),
        type: 'error',
      })
    }
  }

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

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

  const filteredTasks = tasks.filter((task) =>
    task.title.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.tasks.list.title')}</Heading>
        <Button colorPalette="teal" onClick={() => navigate(URLs.taskNew)}>
          {t('challenge.admin.tasks.list.create.button')}
        </Button>
      </Flex>

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

      {filteredTasks.length === 0 && tasks.length === 0 ? (
        <EmptyState
          title={t('challenge.admin.tasks.list.empty.title')}
          description={t('challenge.admin.tasks.list.empty.description')}
          actionLabel={t('challenge.admin.tasks.list.empty.action')}
          onAction={() => navigate(URLs.taskNew)}
        />
      ) : filteredTasks.length === 0 ? (
        <EmptyState
          title={t('challenge.admin.common.not.found')}
          description={t('challenge.admin.tasks.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.tasks.list.table.title')}</Table.ColumnHeader>
                <Table.ColumnHeader>{t('challenge.admin.tasks.list.table.creator')}</Table.ColumnHeader>
                <Table.ColumnHeader>{t('challenge.admin.tasks.list.table.created')}</Table.ColumnHeader>
                <Table.ColumnHeader>{t('challenge.admin.tasks.list.table.hidden.instructions')}</Table.ColumnHeader>
                <Table.ColumnHeader textAlign="right">{t('challenge.admin.tasks.list.table.actions')}</Table.ColumnHeader>
              </Table.Row>
            </Table.Header>
            <Table.Body>
              {filteredTasks.map((task) => (
                <Table.Row key={task.id}>
                  <Table.Cell fontWeight="medium">{task.title}</Table.Cell>
                  <Table.Cell>
                    <Text fontSize="sm" color="gray.600">
                      {task.creator?.preferred_username || 'N/A'}
                    </Text>
                  </Table.Cell>
                  <Table.Cell>
                    <Text fontSize="sm" color="gray.600">
                      {formatDate(task.createdAt)}
                    </Text>
                  </Table.Cell>
                  <Table.Cell>
                    {task.hiddenInstructions ? (
                      <Badge colorPalette="purple" variant="subtle">
                        {t('challenge.admin.tasks.list.badge.has.instructions')}
                      </Badge>
                    ) : (
                      <Text fontSize="sm" color="gray.400">
                        —
                      </Text>
                    )}
                  </Table.Cell>
                  <Table.Cell textAlign="right">
                    <HStack gap={2} justify="flex-end">
                      <Button
                        size="sm"
                        variant="ghost"
                        onClick={() => navigate(URLs.taskEdit(task.id))}
                      >
                        {t('challenge.admin.tasks.list.button.edit')}
                      </Button>
                      <Button
                        size="sm"
                        variant="ghost"
                        colorPalette="red"
                        onClick={() => handleDeleteTask(task)}
                      >
                        {t('challenge.admin.tasks.list.button.delete')}
                      </Button>
                    </HStack>
                  </Table.Cell>
                </Table.Row>
              ))}
            </Table.Body>
          </Table.Root>
        </Box>
      )}
    </Box>
  )
}