import {
  createContext,
  FC,
  useCallback,
  useContext,
  useEffect,
  useMemo,
  useState,
} from 'react'
import { useProjectContext } from '@/shared/context/project-context'
import {
  CommentId,
  ThreadId,
} from '../../../../../types/review-panel/review-panel'
import { ReviewPanelCommentThread } from '../../../../../types/review-panel/comment-thread'
import { useConnectionContext } from '@/features/ide-react/context/connection-context'
import useSocketListener from '@/features/ide-react/hooks/use-socket-listener'
import { ReviewPanelCommentThreadMessageApi } from '../../../../../types/review-panel/api'
import { UserId } from '../../../../../types/user'
import { deleteJSON, getJSON, postJSON } from '@/infrastructure/fetch-json'
import RangesTracker from '@overleaf/ranges-tracker'
import { CommentOperation } from '../../../../../types/change'
import useScopeValue from '@/shared/hooks/use-scope-value'
import { DocumentContainer } from '@/features/ide-react/editor/document-container'

export type Threads = Record<ThreadId, ReviewPanelCommentThread>

export const ThreadsContext = createContext<Threads | undefined>(undefined)

type ThreadsActions = {
  addComment: (pos: number, text: string, content: string) => Promise<void>
  resolveThread: (threadId: ThreadId) => Promise<void>
  reopenThread: (threadId: ThreadId) => Promise<void>
  deleteThread: (threadId: ThreadId) => Promise<void>
  addMessage: (threadId: ThreadId, content: string) => Promise<void>
  editMessage: (
    threadId: ThreadId,
    commentId: CommentId,
    content: string
  ) => Promise<void>
  deleteMessage: (threadId: ThreadId, commentId: CommentId) => Promise<void>
}

const ThreadsActionsContext = createContext<ThreadsActions | undefined>(
  undefined
)

export const ThreadsProvider: FC = ({ children }) => {
  const { _id: projectId } = useProjectContext()

  const [currentDoc] = useScopeValue<DocumentContainer | null>(
    'editor.sharejs_doc'
  )

  // const [error, setError] = useState<Error>()
  const [data, setData] = useState<Threads>()

  // load the initial threads data
  useEffect(() => {
    const abortController = new AbortController()

    getJSON(`/project/${projectId}/threads`, {
      signal: abortController.signal,
    }).then(data => {
      setData(data)
    })
    // .catch(error => {
    //   setError(error)
    // })
  }, [projectId])

  const { socket } = useConnectionContext()

  useSocketListener(
    socket,
    'new-comment',
    useCallback(
      (threadId: ThreadId, comment: ReviewPanelCommentThreadMessageApi) => {
        setData(value => {
          if (value) {
            const { submitting, ...thread } = value[threadId] ?? {
              messages: [],
            }

            return {
              ...value,
              [threadId]: {
                ...thread,
                messages: [
                  ...thread.messages,
                  {
                    ...comment,
                    user: comment.user, // TODO
                    timestamp: new Date(comment.timestamp),
                  },
                ],
              },
            }
          }
        })
      },
      []
    )
  )

  useSocketListener(
    socket,
    'edit-message',
    useCallback((threadId: ThreadId, commentId: CommentId, content: string) => {
      setData(value => {
        if (value) {
          const thread = value[threadId] ?? { messages: [] }

          return {
            ...value,
            [threadId]: {
              ...thread,
              messages: thread.messages.map(message =>
                message.id === commentId ? { ...message, content } : message
              ),
            },
          }
        }
      })
    }, [])
  )

  useSocketListener(
    socket,
    'delete-message',
    useCallback((threadId: ThreadId, commentId: CommentId) => {
      setData(value => {
        if (value) {
          const thread = value[threadId] ?? { messages: [] }

          return {
            ...value,
            [threadId]: {
              ...thread,
              messages: thread.messages.filter(
                message => message.id !== commentId
              ),
            },
          }
        }
      })
    }, [])
  )

  useSocketListener(
    socket,
    'resolve-thread',
    useCallback(
      (
        threadId: ThreadId,
        user: { email: string; first_name: string; id: UserId }
      ) => {
        setData(value => {
          if (value) {
            const thread = value[threadId] ?? { messages: [] }

            return {
              ...value,
              [threadId]: {
                ...thread,
                resolved: true,
                resolved_by_user: user, // TODO
                resolved_at: new Date().toISOString(),
              },
            }
          }
        })
      },
      []
    )
  )

  useSocketListener(
    socket,
    'reopen-thread',
    useCallback((threadId: ThreadId) => {
      setData(value => {
        if (value) {
          const thread = value[threadId] ?? { messages: [] }

          return {
            ...value,
            [threadId]: {
              ...thread,
              resolved: undefined,
              resolved_by_user: undefined,
              resolved_at: undefined,
            },
          }
        }
      })
    }, [])
  )

  useSocketListener(
    socket,
    'delete-thread',
    useCallback((threadId: ThreadId) => {
      setData(value => {
        if (value) {
          const _value = { ...value }
          delete _value[threadId]
          return _value
        }
      })
    }, [])
  )

  const actions = useMemo(
    () => ({
      async addComment(pos: number, text: string, content: string) {
        const threadId = RangesTracker.generateId() as ThreadId

        await postJSON(`/project/${projectId}/thread/${threadId}/messages`, {
          body: { content },
        })

        const op: CommentOperation = {
          c: text,
          p: pos,
          t: threadId,
        }

        currentDoc?.submitOp(op)
      },
      async resolveThread(threadId: string) {
        await postJSON(
          `/project/${projectId}/doc/${currentDoc?.doc_id}/thread/${threadId}/resolve`
        )
      },
      async reopenThread(threadId: string) {
        await postJSON(
          `/project/${projectId}/doc/${currentDoc?.doc_id}/thread/${threadId}/reopen`
        )
      },
      async deleteThread(threadId: string) {
        await deleteJSON(
          `/project/${projectId}/doc/${currentDoc?.doc_id}/thread/${threadId}`
        )
        currentDoc?.ranges?.removeCommentId(threadId)
      },
      async addMessage(threadId: ThreadId, content: string) {
        await postJSON(`/project/${projectId}/thread/${threadId}/messages`, {
          body: { content },
        })
        // TODO: error_submitting_comment
      },
      async editMessage(
        threadId: ThreadId,
        commentId: CommentId,
        content: string
      ) {
        await postJSON(
          `/project/${projectId}/thread/${threadId}/messages/${commentId}/edit`,
          { body: { content } }
        )
      },
      async deleteMessage(threadId: ThreadId, commentId: CommentId) {
        await deleteJSON(
          `/project/${projectId}/thread/${threadId}/messages/${commentId}`
        )
      },
    }),
    [currentDoc, projectId]
  )

  return (
    <ThreadsActionsContext.Provider value={actions}>
      <ThreadsContext.Provider value={data}>{children}</ThreadsContext.Provider>
    </ThreadsActionsContext.Provider>
  )
}

export const useThreadsContext = () => {
  return useContext(ThreadsContext)
}

export const useThreadsActionsContext = () => {
  const context = useContext(ThreadsActionsContext)
  if (!context) {
    throw new Error(
      'useThreadsActionsContext is only available inside ThreadsProvider'
    )
  }
  return context
}