'use client'

import { useState, useEffect } from 'react'
import { useTranslations, useLocale } from 'next-intl'
import { useAuth } from '@/hooks/use-auth'
import { ProtectedRoute } from '@/components/auth/protected-route'
import { useRouter } from 'next/navigation'
import {
  Container,
  Paper,
  Box,
  Typography,
  Card,
  CardContent,
  CardActions,
  Button,
  Chip,
  Divider,
  IconButton,
  Alert,
  CircularProgress,
  Tab,
  Tabs,
  List,
  ListItem,
  ListItemIcon,
  ListItemText,
} from '@mui/material'
import {
  Bookmark,
  BookmarkBorder,
  MenuBook,
  Article,
  Delete,
  Launch,
  AccessTime,
  Note
} from '@mui/icons-material'

interface BookmarkItem {
  id: string
  type: 'chapter' | 'verse'
  title: string
  subtitle: string
  note?: string
  createdAt: string
  color?: string
  text?: string
  navigation: {
    bookId: string
    chapterNum: number
    verseNum?: number
    versionId: string
  }
  verse?: {
    id: string
  }
}

interface BookmarkStats {
  total: number
  chapters: number
  verses: number
}

export default function BookmarksPage() {
  const { user } = useAuth()
  const t = useTranslations('bookmarks')
  const locale = useLocale()
  const router = useRouter()

  const [bookmarks, setBookmarks] = useState<BookmarkItem[]>([])
  const [stats, setStats] = useState<BookmarkStats>({ total: 0, chapters: 0, verses: 0 })
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState('')
  const [activeTab, setActiveTab] = useState(0)
  const [deletingIds, setDeletingIds] = useState<Set<string>>(new Set())

  // Fetch bookmarks
  useEffect(() => {
    if (user) {
      fetchBookmarks()
    }
  }, [user])

  const fetchBookmarks = async () => {
    try {
      setLoading(true)
      setError('')

      const token = localStorage.getItem('authToken')
      if (!token) {
        setError(t('authRequired'))
        return
      }

      const response = await fetch(`/api/bookmarks/all?locale=${locale}`, {
        headers: {
          'Authorization': `Bearer ${token}`
        }
      })

      if (response.ok) {
        const data = await response.json()
        setBookmarks(data.bookmarks || [])
        setStats(data.stats || { total: 0, chapters: 0, verses: 0 })
      } else {
        const data = await response.json()
        setError(data.error || t('loadError'))
      }
    } catch (error) {
      console.error('Error fetching bookmarks:', error)
      setError(t('loadError'))
    } finally {
      setLoading(false)
    }
  }

  const handleNavigateToBookmark = (bookmark: BookmarkItem) => {
    const params = new URLSearchParams({
      book: bookmark.navigation.bookId,
      chapter: bookmark.navigation.chapterNum.toString(),
      version: bookmark.navigation.versionId
    })

    if (bookmark.navigation.verseNum) {
      params.set('verse', bookmark.navigation.verseNum.toString())
    }

    router.push(`/${locale}/bible?${params.toString()}`)
  }

  const handleDeleteBookmark = async (bookmark: BookmarkItem) => {
    if (!user) return

    setDeletingIds(prev => new Set(prev).add(bookmark.id))
    const token = localStorage.getItem('authToken')

    if (!token) {
      setDeletingIds(prev => {
        const newSet = new Set(prev)
        newSet.delete(bookmark.id)
        return newSet
      })
      return
    }

    try {
      const endpoint = bookmark.type === 'chapter'
        ? `/api/bookmarks/chapter?bookId=${bookmark.navigation.bookId}&chapterNum=${bookmark.navigation.chapterNum}&locale=${locale}`
        : `/api/bookmarks/verse?verseId=${bookmark.verse!.id}&locale=${locale}`

      const response = await fetch(endpoint, {
        method: 'DELETE',
        headers: {
          'Authorization': `Bearer ${token}`
        }
      })

      if (response.ok) {
        // Remove from local state
        setBookmarks(prev => prev.filter(b => b.id !== bookmark.id))
        setStats(prev => ({
          total: prev.total - 1,
          chapters: bookmark.type === 'chapter' ? prev.chapters - 1 : prev.chapters,
          verses: bookmark.type === 'verse' ? prev.verses - 1 : prev.verses
        }))
      }
    } catch (error) {
      console.error('Error deleting bookmark:', error)
    } finally {
      setDeletingIds(prev => {
        const newSet = new Set(prev)
        newSet.delete(bookmark.id)
        return newSet
      })
    }
  }

  const formatDate = (dateString: string) => {
    const date = new Date(dateString)
    return date.toLocaleDateString(locale, {
      year: 'numeric',
      month: 'short',
      day: 'numeric'
    })
  }

  const filteredBookmarks = () => {
    switch (activeTab) {
      case 1: return bookmarks.filter(b => b.type === 'chapter')
      case 2: return bookmarks.filter(b => b.type === 'verse')
      default: return bookmarks
    }
  }

  if (loading) {
    return (
      <ProtectedRoute>
        <Container maxWidth="lg" sx={{ py: 4 }}>
          <Box sx={{ display: 'flex', justifyContent: 'center', alignItems: 'center', minHeight: 400 }}>
            <CircularProgress size={48} />
          </Box>
        </Container>
      </ProtectedRoute>
    )
  }

  return (
    <ProtectedRoute>
      <Container maxWidth="lg" sx={{ py: 4 }}>
        <Paper elevation={3} sx={{ p: 4 }}>
          {/* Header */}
          <Box textAlign="center" mb={4}>
            <Typography variant="h3" component="h1" gutterBottom>
              <Bookmark sx={{ fontSize: 40, mr: 2, verticalAlign: 'middle' }} />
              {t('title')}
            </Typography>
            <Typography variant="body1" color="text.secondary">
              {t('subtitle')}
            </Typography>
          </Box>

          {/* Stats */}
          <Box sx={{ display: 'flex', gap: 3, flexWrap: 'wrap', mb: 4 }}>
            <Box sx={{ flex: { xs: '1 1 100%', sm: '1 1 calc(33.33% - 16px)' } }}>
              <Card variant="outlined">
                <CardContent sx={{ textAlign: 'center' }}>
                  <Typography variant="h4" color="primary">
                    {stats.total}
                  </Typography>
                  <Typography variant="body2" color="text.secondary">
                    {t('totalBookmarks')}
                  </Typography>
                </CardContent>
              </Card>
            </Box>
            <Box sx={{ flex: { xs: '1 1 100%', sm: '1 1 calc(33.33% - 16px)' } }}>
              <Card variant="outlined">
                <CardContent sx={{ textAlign: 'center' }}>
                  <Typography variant="h4" color="success.main">
                    {stats.chapters}
                  </Typography>
                  <Typography variant="body2" color="text.secondary">
                    {t('chapterBookmarks')}
                  </Typography>
                </CardContent>
              </Card>
            </Box>
            <Box sx={{ flex: { xs: '1 1 100%', sm: '1 1 calc(33.33% - 16px)' } }}>
              <Card variant="outlined">
                <CardContent sx={{ textAlign: 'center' }}>
                  <Typography variant="h4" color="warning.main">
                    {stats.verses}
                  </Typography>
                  <Typography variant="body2" color="text.secondary">
                    {t('verseBookmarks')}
                  </Typography>
                </CardContent>
              </Card>
            </Box>
          </Box>

          <Divider sx={{ mb: 3 }} />

          {error && (
            <Alert severity="error" sx={{ mb: 3 }}>
              {error}
            </Alert>
          )}

          {/* Filter Tabs */}
          <Box sx={{ borderBottom: 1, borderColor: 'divider', mb: 3 }}>
            <Tabs value={activeTab} onChange={(_, newValue) => setActiveTab(newValue)}>
              <Tab
                label={`${t('allBookmarks')} (${stats.total})`}
                icon={<Bookmark />}
                iconPosition="start"
              />
              <Tab
                label={`${t('chapters')} (${stats.chapters})`}
                icon={<MenuBook />}
                iconPosition="start"
              />
              <Tab
                label={`${t('verses')} (${stats.verses})`}
                icon={<Article />}
                iconPosition="start"
              />
            </Tabs>
          </Box>

          {/* Bookmarks List */}
          {filteredBookmarks().length === 0 ? (
            <Box textAlign="center" py={6}>
              <BookmarkBorder sx={{ fontSize: 64, color: 'text.secondary', mb: 2 }} />
              <Typography variant="h6" color="text.secondary" gutterBottom>
                {t('noBookmarks')}
              </Typography>
              <Typography variant="body2" color="text.secondary" sx={{ mb: 3 }}>
                {t('noBookmarksDescription')}
              </Typography>
              <Button
                variant="contained"
                onClick={() => router.push(`/${locale}/bible`)}
                startIcon={<MenuBook />}
              >
                {t('startReading')}
              </Button>
            </Box>
          ) : (
            <Box sx={{ display: 'flex', flexDirection: 'column', gap: 3 }}>
              {filteredBookmarks().map((bookmark) => (
                <Box key={bookmark.id}>
                  <Card variant="outlined" sx={{ transition: 'all 0.2s', '&:hover': { elevation: 2 } }}>
                    <CardContent>
                      <Box display="flex" justifyContent="space-between" alignItems="flex-start">
                        <Box flex={1}>
                          <Box display="flex" alignItems="center" gap={1} mb={1}>
                            {bookmark.type === 'chapter' ? (
                              <MenuBook color="primary" fontSize="small" />
                            ) : (
                              <Article color="warning" fontSize="small" />
                            )}
                            <Typography variant="h6" component="h3">
                              {bookmark.title}
                            </Typography>
                            <Chip
                              label={bookmark.type === 'chapter' ? t('chapter') : t('verse')}
                              size="small"
                              color={bookmark.type === 'chapter' ? 'primary' : 'warning'}
                              variant="outlined"
                            />
                          </Box>

                          <Typography variant="body2" color="text.secondary" gutterBottom>
                            {bookmark.subtitle}
                          </Typography>

                          {bookmark.text && (
                            <Typography variant="body1" sx={{
                              my: 1,
                              p: 1,
                              bgcolor: 'grey.50',
                              borderRadius: 1,
                              fontStyle: 'italic'
                            }}>
                              "{bookmark.text}"
                            </Typography>
                          )}

                          {bookmark.note && (
                            <Box display="flex" alignItems="center" gap={1} mt={1}>
                              <Note fontSize="small" color="action" />
                              <Typography variant="body2" color="text.secondary">
                                {bookmark.note}
                              </Typography>
                            </Box>
                          )}

                          <Box display="flex" alignItems="center" gap={1} mt={1}>
                            <AccessTime fontSize="small" color="action" />
                            <Typography variant="caption" color="text.secondary">
                              {formatDate(bookmark.createdAt)}
                            </Typography>
                          </Box>
                        </Box>

                        <Box display="flex" flexDirection="column" gap={1}>
                          <Button
                            variant="contained"
                            size="small"
                            startIcon={<Launch />}
                            onClick={() => handleNavigateToBookmark(bookmark)}
                          >
                            {t('goTo')}
                          </Button>
                          <IconButton
                            size="small"
                            color="error"
                            onClick={() => handleDeleteBookmark(bookmark)}
                            disabled={deletingIds.has(bookmark.id)}
                          >
                            {deletingIds.has(bookmark.id) ? (
                              <CircularProgress size={20} />
                            ) : (
                              <Delete />
                            )}
                          </IconButton>
                        </Box>
                      </Box>
                    </CardContent>
                  </Card>
                </Box>
              ))}
            </Box>
          )}
        </Paper>
      </Container>
    </ProtectedRoute>
  )
}
