import React from 'react'
import {observer} from 'mobx-react-lite'
import {
  Animated,
  TouchableOpacity,
  TouchableWithoutFeedback,
  StyleSheet,
  View,
} from 'react-native'
import {AppBskyEmbedImages} from '@atproto/api'
import {AtUri} from '../../../third-party/uri'
import {
  FontAwesomeIcon,
  FontAwesomeIconStyle,
  Props,
} from '@fortawesome/react-native-fontawesome'
import {NotificationsViewItemModel} from '../../../state/models/notifications-view'
import {PostThreadViewModel} from '../../../state/models/post-thread-view'
import {s, colors} from '../../lib/styles'
import {ago, pluralize} from '../../../lib/strings'
import {HeartIconSolid} from '../../lib/icons'
import {Text} from '../util/text/Text'
import {UserAvatar} from '../util/UserAvatar'
import {ImageHorzList} from '../util/images/ImageHorzList'
import {ErrorMessage} from '../util/error/ErrorMessage'
import {Post} from '../post/Post'
import {Link} from '../util/Link'
import {usePalette} from '../../lib/hooks/usePalette'
import {useAnimatedValue} from '../../lib/hooks/useAnimatedValue'

const MAX_AUTHORS = 5

const EXPANDED_AUTHOR_EL_HEIGHT = 35

interface Author {
  href: string
  handle: string
  displayName?: string
  avatar?: string
}

export const FeedItem = observer(function FeedItem({
  item,
}: {
  item: NotificationsViewItemModel
}) {
  const pal = usePalette('default')
  const [isAuthorsExpanded, setAuthorsExpanded] = React.useState<boolean>(false)
  const itemHref = React.useMemo(() => {
    if (item.isUpvote || item.isRepost) {
      const urip = new AtUri(item.subjectUri)
      return `/profile/${urip.host}/post/${urip.rkey}`
    } else if (item.isFollow || item.isAssertion) {
      return `/profile/${item.author.handle}`
    } else if (item.isReply) {
      const urip = new AtUri(item.uri)
      return `/profile/${urip.host}/post/${urip.rkey}`
    }
    return ''
  }, [item])
  const itemTitle = React.useMemo(() => {
    if (item.isUpvote || item.isRepost) {
      return 'Post'
    } else if (item.isFollow || item.isAssertion) {
      return item.author.handle
    } else if (item.isReply) {
      return 'Post'
    }
  }, [item])

  const onToggleAuthorsExpanded = () => {
    setAuthorsExpanded(!isAuthorsExpanded)
  }

  if (item.additionalPost?.notFound) {
    // don't render anything if the target post was deleted or unfindable
    return <View />
  }

  if (item.isReply || item.isMention) {
    return (
      <Link href={itemHref} title={itemTitle} noFeedback>
        <Post
          uri={item.uri}
          initView={item.additionalPost}
          style={
            item.isRead
              ? undefined
              : [
                  styles.outerUnread,
                  {backgroundColor: pal.colors.unreadNotifBg},
                ]
          }
        />
      </Link>
    )
  }

  let action = ''
  let icon: Props['icon'] | 'HeartIconSolid'
  let iconStyle: Props['style'] = []
  if (item.isUpvote) {
    action = 'liked your post'
    icon = 'HeartIconSolid'
    iconStyle = [
      s.red3 as FontAwesomeIconStyle,
      {position: 'relative', top: -4},
    ]
  } else if (item.isRepost) {
    action = 'reposted your post'
    icon = 'retweet'
    iconStyle = [s.green3 as FontAwesomeIconStyle]
  } else if (item.isReply) {
    action = 'replied to your post'
    icon = ['far', 'comment']
  } else if (item.isFollow) {
    action = 'followed you'
    icon = 'user-plus'
    iconStyle = [s.blue3 as FontAwesomeIconStyle]
  } else {
    return <></>
  }

  let authors: Author[] = [
    {
      href: `/profile/${item.author.handle}`,
      handle: item.author.handle,
      displayName: item.author.displayName,
      avatar: item.author.avatar,
    },
  ]
  if (item.additional?.length) {
    authors = authors.concat(
      item.additional.map(item2 => ({
        href: `/profile/${item2.author.handle}`,
        handle: item2.author.handle,
        displayName: item2.author.displayName,
        avatar: item2.author.avatar,
      })),
    )
  }

  return (
    <Link
      style={[
        styles.outer,
        pal.view,
        pal.border,
        item.isRead
          ? undefined
          : [styles.outerUnread, {backgroundColor: pal.colors.unreadNotifBg}],
      ]}
      href={itemHref}
      title={itemTitle}
      noFeedback>
      <View style={styles.layout}>
        <View style={styles.layoutIcon}>
          {icon === 'HeartIconSolid' ? (
            <HeartIconSolid size={28} style={[styles.icon, ...iconStyle]} />
          ) : (
            <FontAwesomeIcon
              icon={icon}
              size={24}
              style={[styles.icon, ...iconStyle]}
            />
          )}
        </View>
        <View style={styles.layoutContent}>
          <TouchableWithoutFeedback
            onPress={authors.length > 1 ? onToggleAuthorsExpanded : () => {}}>
            <View>
              <CondensedAuthorsList
                visible={!isAuthorsExpanded}
                authors={authors}
                onToggleAuthorsExpanded={onToggleAuthorsExpanded}
              />
              <ExpandedAuthorsList
                visible={isAuthorsExpanded}
                authors={authors}
              />
              <View style={styles.meta}>
                <Link
                  key={authors[0].href}
                  style={styles.metaItem}
                  href={authors[0].href}
                  title={`@${authors[0].handle}`}>
                  <Text style={[pal.text, s.bold]}>
                    {authors[0].displayName || authors[0].handle}
                  </Text>
                </Link>
                {authors.length > 1 ? (
                  <>
                    <Text style={[styles.metaItem, pal.text]}>and</Text>
                    <Text style={[styles.metaItem, pal.text, s.bold]}>
                      {authors.length - 1}{' '}
                      {pluralize(authors.length - 1, 'other')}
                    </Text>
                  </>
                ) : undefined}
                <Text style={[styles.metaItem, pal.text]}>{action}</Text>
                <Text style={[styles.metaItem, pal.textLight]}>
                  {ago(item.indexedAt)}
                </Text>
              </View>
            </View>
          </TouchableWithoutFeedback>
          {item.isUpvote || item.isRepost ? (
            <AdditionalPostText additionalPost={item.additionalPost} />
          ) : (
            <></>
          )}
        </View>
      </View>
    </Link>
  )
})

function CondensedAuthorsList({
  visible,
  authors,
  onToggleAuthorsExpanded,
}: {
  visible: boolean
  authors: Author[]
  onToggleAuthorsExpanded: () => void
}) {
  const pal = usePalette('default')
  if (!visible) {
    return (
      <View style={styles.avis}>
        <TouchableOpacity
          style={styles.expandedAuthorsCloseBtn}
          onPress={onToggleAuthorsExpanded}>
          <FontAwesomeIcon
            icon="angle-up"
            size={18}
            style={[styles.expandedAuthorsCloseBtnIcon, pal.text]}
          />
          <Text type="sm-medium" style={pal.text}>
            Hide
          </Text>
        </TouchableOpacity>
      </View>
    )
  }
  if (authors.length === 1) {
    return (
      <View style={styles.avis}>
        <Link
          style={s.mr5}
          href={authors[0].href}
          title={`@${authors[0].handle}`}>
          <UserAvatar
            size={35}
            displayName={authors[0].displayName}
            handle={authors[0].handle}
            avatar={authors[0].avatar}
          />
        </Link>
      </View>
    )
  }
  return (
    <View style={styles.avis}>
      {authors.slice(0, MAX_AUTHORS).map(author => (
        <View key={author.href} style={s.mr5}>
          <UserAvatar
            size={35}
            displayName={author.displayName}
            handle={author.handle}
            avatar={author.avatar}
          />
        </View>
      ))}
      {authors.length > MAX_AUTHORS ? (
        <Text style={[styles.aviExtraCount, pal.textLight]}>
          +{authors.length - MAX_AUTHORS}
        </Text>
      ) : undefined}
      <FontAwesomeIcon
        icon="angle-down"
        size={18}
        style={[styles.expandedAuthorsCloseBtnIcon, pal.textLight]}
      />
    </View>
  )
}

function ExpandedAuthorsList({
  visible,
  authors,
}: {
  visible: boolean
  authors: Author[]
}) {
  const pal = usePalette('default')
  const heightInterp = useAnimatedValue(visible ? 1 : 0)
  const targetHeight =
    authors.length * (EXPANDED_AUTHOR_EL_HEIGHT + 10) /*10=margin*/
  const heightStyle = {
    height: Animated.multiply(heightInterp, targetHeight),
  }
  React.useEffect(() => {
    Animated.timing(heightInterp, {
      toValue: visible ? 1 : 0,
      duration: 200,
      useNativeDriver: false,
    }).start()
  }, [heightInterp, visible])
  return (
    <Animated.View
      style={[
        heightStyle,
        styles.overflowHidden,
        visible ? s.mb10 : undefined,
      ]}>
      {authors.map(author => (
        <Link
          key={author.href}
          href={author.href}
          title={author.displayName || author.handle}
          style={styles.expandedAuthor}>
          <View style={styles.expandedAuthorAvi}>
            <UserAvatar
              size={35}
              displayName={author.displayName}
              handle={author.handle}
              avatar={author.avatar}
            />
          </View>
          <View style={s.flex1}>
            <Text type="lg-bold" numberOfLines={1} style={pal.text}>
              {author.displayName || author.handle}
              &nbsp;
              <Text style={[pal.textLight]}>{author.handle}</Text>
            </Text>
          </View>
        </Link>
      ))}
    </Animated.View>
  )
}

function AdditionalPostText({
  additionalPost,
}: {
  additionalPost?: PostThreadViewModel
}) {
  const pal = usePalette('default')
  if (!additionalPost || !additionalPost.thread?.postRecord) {
    return <View />
  }
  if (additionalPost.error) {
    return <ErrorMessage message={additionalPost.error} />
  }
  const text = additionalPost.thread?.postRecord.text
  const images = (
    additionalPost.thread.post.embed as AppBskyEmbedImages.Presented
  )?.images
  return (
    <>
      {text?.length > 0 && <Text style={pal.textLight}>{text}</Text>}
      {images && images?.length > 0 && (
        <ImageHorzList
          uris={images?.map(img => img.thumb)}
          style={styles.additionalPostImages}
        />
      )}
    </>
  )
}

const styles = StyleSheet.create({
  overflowHidden: {
    overflow: 'hidden',
  },

  outer: {
    padding: 10,
    paddingRight: 15,
    borderTopWidth: 1,
  },
  outerUnread: {
    borderColor: colors.blue1,
  },
  layout: {
    flexDirection: 'row',
  },
  layoutIcon: {
    width: 70,
    alignItems: 'flex-end',
    paddingTop: 2,
  },
  icon: {
    marginRight: 10,
    marginTop: 4,
  },
  avis: {
    flexDirection: 'row',
    alignItems: 'center',
  },
  aviExtraCount: {
    fontWeight: 'bold',
    paddingLeft: 6,
  },
  layoutContent: {
    flex: 1,
  },
  meta: {
    flexDirection: 'row',
    flexWrap: 'wrap',
    paddingTop: 6,
    paddingBottom: 2,
  },
  metaItem: {
    paddingRight: 3,
  },
  postText: {
    paddingBottom: 5,
    color: colors.black,
  },
  additionalPostImages: {
    marginTop: 5,
    marginLeft: 2,
    opacity: 0.8,
  },

  addedContainer: {
    paddingTop: 4,
    paddingLeft: 36,
  },

  expandedAuthorsCloseBtn: {
    flexDirection: 'row',
    alignItems: 'center',
    paddingTop: 10,
    paddingBottom: 6,
  },
  expandedAuthorsCloseBtnIcon: {
    marginLeft: 4,
    marginRight: 4,
  },
  expandedAuthor: {
    flexDirection: 'row',
    alignItems: 'center',
    marginTop: 10,
    height: EXPANDED_AUTHOR_EL_HEIGHT,
  },
  expandedAuthorAvi: {
    marginRight: 5,
  },
})