import {useCallback} from 'react'
import {type AppBskyFeedDefs} from '@atproto/api'
import {type Client} from '@atproto/lex'
import {AtUri, type AtUriString, type HandleString} from '@atproto/syntax'
import {deleteLike, deletePost, deleteRepost, like, repost} from '@bsky/sdk'
import {
  type QueryClient,
  useMutation,
  useQuery,
  useQueryClient,
} from '@tanstack/react-query'

import {useToggleMutationQueue} from '#/lib/hooks/useToggleMutationQueue'
import {updatePostShadow} from '#/state/cache/post-shadow'
import {type Shadow} from '#/state/cache/types'
import {useDisableViaRepostNotification} from '#/state/preferences/disable-via-repost-notification'
import {useAppviewClient, usePdsClient, useSession} from '#/state/session'
import * as userActionHistory from '#/state/userActionHistory'
import {useAnalytics} from '#/analytics'
import {type Metrics, toClout} from '#/analytics/metrics'
import {maybeCelebrateSixSevenLike} from '#/features/sixSeven'
import {app, com} from '#/lexicons'
import {useIsThreadMuted, useSetThreadMute} from '../cache/thread-mutes'
import {findProfileQueryData} from './profile'

const RQKEY_ROOT = 'post'
export const RQKEY = (postUri: string) => [RQKEY_ROOT, postUri]

export function usePostQuery(uri: string | undefined) {
  const client = useAppviewClient()
  return useQuery<app.bsky.feed.defs.PostView>({
    queryKey: RQKEY(uri || ''),
    queryFn: async () => {
      if (!uri) throw new Error('[unreachable] No URI provided')

      const post = await fetchPost(client, uri)
      if (post) {
        return post
      }

      throw new Error('No data')
    },
    enabled: !!uri,
  })
}

/**
 * Read one post by AT-URI, resolving a handle authority first when the URI
 * carries one.
 *
 * The appview response is asserted to the generated view at this single
 * boundary rather than at every consumer.
 */
async function fetchPost(
  client: Client,
  uri: string,
): Promise<app.bsky.feed.defs.PostView | undefined> {
  const urip = new AtUri(uri)

  if (!urip.host.startsWith('did:')) {
    const data = await client.call(com.atproto.identity.resolveHandle, {
      handle: urip.host as HandleString,
    })
    urip.host = data.did
  }

  const data = await client.call(app.bsky.feed.getPosts, {
    uris: [urip.toString()],
  })
  return data.posts[0]
}

export function precachePost(
  queryClient: QueryClient,
  uri: string,
  post: app.bsky.feed.defs.PostView,
) {
  queryClient.setQueryData(RQKEY(uri), post)
}

export function* findAllPostsInQueryData(
  queryClient: QueryClient,
  uri: string,
): Generator<AppBskyFeedDefs.PostView, void> {
  const post = queryClient.getQueryData<AppBskyFeedDefs.PostView>(RQKEY(uri))
  if (post) {
    yield post
  }
}

export function useGetPost() {
  const queryClient = useQueryClient()
  const client = useAppviewClient()
  return useCallback(
    async ({uri}: {uri: string}) => {
      return queryClient.fetchQuery({
        queryKey: RQKEY(uri || ''),
        async queryFn() {
          const post = await fetchPost(client, uri)
          if (post) {
            return post
          }

          throw new Error('useGetPost: post not found')
        },
      })
    },
    [queryClient, client],
  )
}

export function useGetPosts() {
  const queryClient = useQueryClient()
  const client = useAppviewClient()
  return useCallback(
    async ({uris}: {uris: string[]}) => {
      return queryClient.fetchQuery({
        queryKey: RQKEY(uris.join(',') || ''),
        async queryFn() {
          const data = await client.call(app.bsky.feed.getPosts, {
            uris: uris as AtUriString[],
          })
          // See the note on `fetchPost` about the view shapes.
          return data.posts
        },
      })
    },
    [queryClient, client],
  )
}

export function usePostLikeMutationQueue(
  post: Shadow<app.bsky.feed.defs.PostView>,
  viaRepost: {uri: string; cid: string} | undefined,
  feedDescriptor: string | undefined,
  logContext: Metrics['post:like']['logContext'],
) {
  const queryClient = useQueryClient()
  const postUri = post.uri
  const postCid = post.cid
  const initialLikeUri = post.viewer?.like
  const likeMutation = usePostLikeMutation(feedDescriptor, logContext, post)
  const disableViaRepostNotification = useDisableViaRepostNotification()
  const unlikeMutation = usePostUnlikeMutation(feedDescriptor, logContext, post)

  const queueToggle = useToggleMutationQueue({
    initialState: initialLikeUri,
    runMutation: async (prevLikeUri, shouldLike) => {
      if (shouldLike) {
        const {uri: likeUri} = await likeMutation.mutateAsync({
          uri: postUri,
          cid: postCid,
          via: disableViaRepostNotification ? undefined : viaRepost,
        })
        userActionHistory.like([postUri])
        return likeUri
      } else {
        if (prevLikeUri) {
          await unlikeMutation.mutateAsync({
            postUri: postUri,
            likeUri: prevLikeUri,
          })
          userActionHistory.unlike([postUri])
        }
        return undefined
      }
    },
    onSuccess(finalLikeUri) {
      // finalize
      updatePostShadow(queryClient, postUri, {
        likeUri: finalLikeUri,
      })
    },
  })

  const queueLike = useCallback(() => {
    maybeCelebrateSixSevenLike({
      wasLiked: Boolean(post.viewer?.like),
      likeCount: post.likeCount,
    })

    // optimistically update
    updatePostShadow(queryClient, postUri, {
      likeUri: 'pending',
    })
    return queueToggle(true)
  }, [post.likeCount, post.viewer?.like, queryClient, postUri, queueToggle])

  const queueUnlike = useCallback(() => {
    // optimistically update
    updatePostShadow(queryClient, postUri, {
      likeUri: undefined,
    })
    return queueToggle(false)
  }, [queryClient, postUri, queueToggle])

  return [queueLike, queueUnlike] as const
}

function usePostLikeMutation(
  feedDescriptor: string | undefined,
  logContext: Metrics['post:like']['logContext'],
  post: Shadow<app.bsky.feed.defs.PostView>,
) {
  const {currentAccount} = useSession()
  const queryClient = useQueryClient()
  const postAuthor = post.author
  const pdsClient = usePdsClient()
  const ax = useAnalytics()
  return useMutation<
    {uri: AtUriString}, // responds with the uri of the like
    Error,
    {uri: string; cid: string; via?: {uri: string; cid: string}} // the post's uri and cid, and the repost uri/cid if present
  >({
    mutationFn: ({uri, cid, via}) => {
      let ownProfile: app.bsky.actor.defs.ProfileViewDetailed | undefined
      if (currentAccount) {
        ownProfile = findProfileQueryData(queryClient, currentAccount.did)
      }
      ax.metric('post:like', {
        uri,
        authorDid: postAuthor.did,
        logContext,
        doesPosterFollowLiker: postAuthor.viewer
          ? Boolean(postAuthor.viewer.followedBy)
          : undefined,
        doesLikerFollowPoster: postAuthor.viewer
          ? Boolean(postAuthor.viewer.following)
          : undefined,
        likerClout: toClout(ownProfile?.followersCount),
        postClout:
          post.likeCount != null &&
          post.repostCount != null &&
          post.replyCount != null
            ? toClout(post.likeCount + post.repostCount + post.replyCount)
            : undefined,
        feedDescriptor: feedDescriptor,
      })
      return pdsClient.call(like, {
        uri: uri as AtUriString,
        cid: cid,
        via: via ? {uri: via.uri as AtUriString, cid: via.cid} : undefined,
      })
    },
  })
}

function usePostUnlikeMutation(
  feedDescriptor: string | undefined,
  logContext: Metrics['post:unlike']['logContext'],
  post: Shadow<app.bsky.feed.defs.PostView>,
) {
  const pdsClient = usePdsClient()
  const ax = useAnalytics()
  return useMutation<void, Error, {postUri: string; likeUri: string}>({
    mutationFn: ({postUri, likeUri}) => {
      ax.metric('post:unlike', {
        uri: postUri,
        authorDid: post.author.did,
        logContext,
        feedDescriptor,
      })
      return pdsClient.call(deleteLike, likeUri as AtUriString)
    },
  })
}

export function usePostRepostMutationQueue(
  post: Shadow<app.bsky.feed.defs.PostView>,
  viaRepost: {uri: string; cid: string} | undefined,
  feedDescriptor: string | undefined,
  logContext: Metrics['post:repost']['logContext'],
) {
  const queryClient = useQueryClient()
  const postUri = post.uri
  const postCid = post.cid
  const initialRepostUri = post.viewer?.repost
  const disableViaRepostNotification = useDisableViaRepostNotification()
  const repostMutation = usePostRepostMutation(feedDescriptor, logContext, post)
  const unrepostMutation = usePostUnrepostMutation(
    feedDescriptor,
    logContext,
    post,
  )

  const queueToggle = useToggleMutationQueue({
    initialState: initialRepostUri,
    runMutation: async (prevRepostUri, shouldRepost) => {
      if (shouldRepost) {
        const {uri: repostUri} = await repostMutation.mutateAsync({
          uri: postUri,
          cid: postCid,
          via: disableViaRepostNotification ? undefined : viaRepost,
        })
        return repostUri
      } else {
        if (prevRepostUri) {
          await unrepostMutation.mutateAsync({
            postUri: postUri,
            repostUri: prevRepostUri,
          })
        }
        return undefined
      }
    },
    onSuccess(finalRepostUri) {
      // finalize
      updatePostShadow(queryClient, postUri, {
        repostUri: finalRepostUri,
      })
    },
  })

  const queueRepost = useCallback(() => {
    // optimistically update
    updatePostShadow(queryClient, postUri, {
      repostUri: 'pending',
    })
    return queueToggle(true)
  }, [queryClient, postUri, queueToggle])

  const queueUnrepost = useCallback(() => {
    // optimistically update
    updatePostShadow(queryClient, postUri, {
      repostUri: undefined,
    })
    return queueToggle(false)
  }, [queryClient, postUri, queueToggle])

  return [queueRepost, queueUnrepost] as const
}

function usePostRepostMutation(
  feedDescriptor: string | undefined,
  logContext: Metrics['post:repost']['logContext'],
  post: Shadow<app.bsky.feed.defs.PostView>,
) {
  const pdsClient = usePdsClient()
  const ax = useAnalytics()
  return useMutation<
    {uri: AtUriString}, // responds with the uri of the repost
    Error,
    {uri: string; cid: string; via?: {uri: string; cid: string}} // the post's uri and cid, and the repost uri/cid if present
  >({
    mutationFn: ({uri, cid, via}) => {
      ax.metric('post:repost', {
        uri,
        authorDid: post.author.did,
        logContext,
        feedDescriptor,
      })
      return pdsClient.call(repost, {
        uri: uri as AtUriString,
        cid: cid,
        via: via ? {uri: via.uri as AtUriString, cid: via.cid} : undefined,
      })
    },
  })
}

function usePostUnrepostMutation(
  feedDescriptor: string | undefined,
  logContext: Metrics['post:unrepost']['logContext'],
  post: Shadow<app.bsky.feed.defs.PostView>,
) {
  const pdsClient = usePdsClient()
  const ax = useAnalytics()
  return useMutation<void, Error, {postUri: string; repostUri: string}>({
    mutationFn: ({postUri, repostUri}) => {
      ax.metric('post:unrepost', {
        uri: postUri,
        authorDid: post.author.did,
        logContext,
        feedDescriptor,
      })
      return pdsClient.call(deleteRepost, repostUri as AtUriString)
    },
  })
}

export function usePostDeleteMutation() {
  const queryClient = useQueryClient()
  const pdsClient = usePdsClient()
  return useMutation<void, Error, {uri: string}>({
    mutationFn: async ({uri}) => {
      await pdsClient.call(deletePost, uri as AtUriString)
    },
    onSuccess(_, variables) {
      updatePostShadow(queryClient, variables.uri, {isDeleted: true})
    },
  })
}

export function useThreadMuteMutationQueue(
  post: Shadow<app.bsky.feed.defs.PostView>,
  rootUri: string,
) {
  const threadMuteMutation = useThreadMuteMutation()
  const threadUnmuteMutation = useThreadUnmuteMutation()
  const isThreadMuted = useIsThreadMuted(rootUri, post.viewer?.threadMuted)
  const setThreadMute = useSetThreadMute()

  const queueToggle = useToggleMutationQueue<boolean>({
    initialState: isThreadMuted,
    runMutation: async (_prev, shouldMute) => {
      if (shouldMute) {
        await threadMuteMutation.mutateAsync({
          uri: rootUri,
        })
        return true
      } else {
        await threadUnmuteMutation.mutateAsync({
          uri: rootUri,
        })
        return false
      }
    },
    onSuccess(finalIsMuted) {
      // finalize
      setThreadMute(rootUri, finalIsMuted)
    },
  })

  const queueMuteThread = useCallback(() => {
    // optimistically update
    setThreadMute(rootUri, true)
    return queueToggle(true)
  }, [setThreadMute, rootUri, queueToggle])

  const queueUnmuteThread = useCallback(() => {
    // optimistically update
    setThreadMute(rootUri, false)
    return queueToggle(false)
  }, [rootUri, setThreadMute, queueToggle])

  return [isThreadMuted, queueMuteThread, queueUnmuteThread] as const
}

function useThreadMuteMutation() {
  const appviewClient = useAppviewClient()
  return useMutation<
    {},
    Error,
    {uri: string} // the root post's uri
  >({
    mutationFn: async ({uri}) => {
      await appviewClient.call(app.bsky.graph.muteThread, {
        root: uri as AtUriString,
      })
      return {}
    },
  })
}

function useThreadUnmuteMutation() {
  const appviewClient = useAppviewClient()
  return useMutation<{}, Error, {uri: string}>({
    mutationFn: async ({uri}) => {
      await appviewClient.call(app.bsky.graph.unmuteThread, {
        root: uri as AtUriString,
      })
      return {}
    },
  })
}