import Automerge from 'automerge'
import { createServer } from 'http'
import fs from 'fs'
import isEqual from 'lodash/isEqual'
import { createEditor, Editor, Element, Node, Transforms } from 'slate'

import { createDoc, SyncDoc, toJS, toSlateOp, getTarget } from '../bridge/index'
import {
  AutomergeCollaboration,
  IAutomergeMetaData,
  getActiveConnections
} from '../backend/index'
import withIOCollaboration from './withIOCollaboration'
import {
  AutomergeEditor,
  AutomergeOptions,
  SocketIOPluginOptions,
  WithSocketIOEditor
} from './interfaces'

const connectionSlug = 'test'
const docId = `/${connectionSlug}`
const options: AutomergeOptions & SocketIOPluginOptions = {
  docId,
  onError: msg => console.log('Encountered test error', msg),
  url: `http://localhost:5000/${connectionSlug}`,
  connectOpts: {
    query: {
      name: 'test-user',
      slug: connectionSlug
    },
    forceNew: true
  }
}

const waitForCondition = (condition: () => boolean, ms = 10) =>
  new Promise<void>(resolve => {
    const handle = setInterval(() => {
      if (condition()) {
        clearInterval(handle)
        resolve()
      }
    }, ms)
  })

const server = createServer(function(req, res) {
  res.writeHead(200, { 'Content-Type': 'text/plain' })
  res.write('Hello World!')
  res.end()
})

const defaultSlateJson = [{ type: 'paragraph', children: [{ text: '' }] }]
let operationTraces: IAutomergeMetaData[] = []
const collabBackend = new AutomergeCollaboration({
  entry: server,
  defaultValue: defaultSlateJson,
  saveFrequency: 1000,
  async onAuthRequest(query: string) {
    return { _id: 'test-id', name: 'Eric' }
  },
  async onDocumentLoad(pathname: string) {
    return defaultSlateJson
  },
  onTrace(metaData: any, socket: any, computationFn: () => void) {
    operationTraces.push(metaData)
    computationFn()
  }
})

describe('automerge editor client tests', () => {
  beforeAll(done => {
    //pass a callback to tell jest it is async
    //start the server before any test
    server.listen(5000, () => done())
  })

  let collabEditors: (Editor & WithSocketIOEditor & AutomergeEditor)[] = []
  afterEach(done => {
    // Clear our operation traces after each test
    operationTraces = []

    // Destroy any created collab editors after each test
    collabEditors.forEach(editor => editor.destroy())
    collabEditors = []

    // Ensure that the collab document has been cleaned up on the backend
    waitForCondition(() => !collabBackend.backend.getDocument(docId)).then(done)
  })

  const createCollabEditor = async (
    editorOptions?: Partial<AutomergeOptions> & Partial<SocketIOPluginOptions>
  ) => {
    // Given a docId we an generate the collab url
    if (editorOptions?.docId) {
      editorOptions.url = `http://localhost:5000${editorOptions?.docId}`
    }

    const editor = withIOCollaboration(createEditor(), {
      ...options,
      ...editorOptions
    })

    const oldReceiveDocument = editor.receiveDocument
    const promise = new Promise<void>(resolve => {
      editor.receiveDocument = data => {
        oldReceiveDocument(data)
        resolve()
      }
    })
    editor.connect()

    collabEditors.push(editor)
    await promise
    return editor
  }

  it('should receiveDocument', async () => {
    const editor = await createCollabEditor()
    expect(editor.children.length).toEqual(1)
    editor.destroy()
  })

  it('should send client update to server', async () => {
    const editor = await createCollabEditor()

    editor.insertNode({ type: 'paragraph', children: [{ text: 'hi' }] })

    await waitForCondition(() => {
      const serverDoc = toJS(collabBackend.backend.getDocument(docId))
      return serverDoc.children.length === 2
    })
  })

  it('should sync updates across two clients', async () => {
    const editor1 = await createCollabEditor()
    const editor2 = await createCollabEditor()

    editor1.insertNode({ type: 'paragraph', children: [{ text: 'hi' }] })

    await waitForCondition(() => {
      const serverDoc = toJS(collabBackend.backend.getDocument(docId))
      return serverDoc.children.length === 2 && editor2.children.length === 2
    })
  })

  it('should sync offline changes on reconnect', async () => {
    const editor1 = await createCollabEditor()
    const editor2 = await createCollabEditor()

    editor1.insertNode({ type: 'paragraph', children: [{ text: 'hi' }] })

    await waitForCondition(() => {
      const serverDoc = toJS(collabBackend.backend.getDocument(docId))
      return serverDoc.children.length === 2 && editor2.children.length === 2
    })

    editor1.destroy()

    editor1.insertNode({ type: 'paragraph', children: [{ text: 'offline' }] })

    editor1.connect()

    await waitForCondition(() => {
      const serverDoc = toJS(collabBackend.backend.getDocument(docId))
      return serverDoc.children.length === 3 && editor2.children.length === 3
    })

    expect(Node.string(editor2.children[2])).toEqual('offline')
  })

  it('should work with concurrent edits', async () => {
    const editor1 = await createCollabEditor()
    const editor2 = await createCollabEditor()

    const numEdits = 10
    for (let i = 0; i < numEdits; i++) {
      editor1.insertNode({ type: 'paragraph', children: [{ text: '' }] })
      editor2.insertNode({ type: 'paragraph', children: [{ text: '' }] })
    }

    await waitForCondition(() => {
      return (
        editor1.children.length === numEdits * 2 + 1 &&
        editor2.children.length === numEdits * 2 + 1
      )
    })

    expect(isEqual(editor1.children, editor2.children)).toBeTruthy()
  })

  it('should work with concurrent insert text operations', async () => {
    const editor1 = await createCollabEditor()
    const editor2 = await createCollabEditor()

    Transforms.select(editor1, [0, 0])
    Transforms.select(editor2, [0, 0])

    const numEdits = 10
    for (let i = 0; i < numEdits; i++) {
      editor1.insertText('a')
      editor2.insertText('b')
    }

    await waitForCondition(() => {
      return (
        Node.string(editor1.children[0]).length === numEdits * 2 &&
        Node.string(editor2.children[0]).length === numEdits * 2
      )
    })

    expect(isEqual(editor1.children, editor2.children)).toBeTruthy()
  })

  it('should not throw deep nested tree error', () => {
    // Read from our test json file for the deep tree error
    // This allows us to easily reproduce real production errors
    // and create test cases that resolve those errors
    const rawData = fs.readFileSync(
      `${__dirname}/test-json/deep-tree.json`,
      'utf-8'
    )
    const parsedData = JSON.parse(rawData)
    const { current, operations } = parsedData
    const currentDoc = Automerge.load<SyncDoc>(current)

    // ensure no errors throw when removing a deep tree node
    // that has already been removed
    toSlateOp(operations, currentDoc)
  })

  it('should update children for a root level children operation', async () => {
    const editor = await createCollabEditor()

    const oldDoc = collabBackend.backend.documentSetMap[docId].getDoc(docId)
    const newDoc = Automerge.change(oldDoc, changed => {
      // @ts-ignore
      changed.children = [
        { type: 'paragraph', children: [{ text: 'new' }] },
        { type: 'paragraph', children: [{ text: 'nodes' }] }
      ]
    })
    collabBackend.backend.documentSetMap[docId].setDoc(docId, newDoc)

    await waitForCondition(() => editor.children.length === 2)

    expect(editor.children.length).toEqual(2)
    expect(Node.string(editor.children[0])).toEqual('new')
    expect(Node.string(editor.children[1])).toEqual('nodes')
  })

  it('set node for children with missing value should not throw error', () => {
    const operations: Automerge.Diff[] = [
      {
        action: 'set',
        type: 'map',
        obj: '00000000-0000-0000-0000-000000000000',
        key: 'children',
        path: [],
        value: '6c7bf8a5-d0e0-4b08-a4a2-32df65b807e5',
        link: true,
        conflicts: [
          {
            actor: '8c5d5ada-3db9-4189-9e04-2e7c101d057d',
            value: 'e198d171-a00a-4d5c-a597-c0ff35a7f639',
            link: true
          }
        ]
      }
    ]

    const slateOps = toSlateOp(operations, createDoc())
    expect(slateOps.length).toEqual(0)
  })

  it('should not throw index error', () => {
    const doc: Element = { children: [] }
    const target = getTarget(doc, [0, 0])

    expect(target).toEqual(null)
  })

  it('should reconnect with no opCount', async () => {
    const editor1 = await createCollabEditor({ resetOnReconnect: true })

    await waitForCondition(() => {
      return getActiveConnections(collabBackend.backend, docId) === 1
    })

    editor1.disconnect()

    await waitForCondition(
      () => getActiveConnections(collabBackend.backend, docId) === 0
    )

    editor1.connect()

    await waitForCondition(
      () => getActiveConnections(collabBackend.backend, docId) === 1
    )

    // Wait for a few seconds to allow the client and server to synchronize their
    // document states
    await new Promise(res => setTimeout(res, 3000))

    // Expect that reconnecting with resetOnReconnect option set to true
    // does not result in any operations being sent from the client to the server
    expect(
      operationTraces.some(
        trace => trace.opCount !== undefined && trace.opCount > 0
      )
    ).toBeFalsy
  })

  afterAll(() => {
    collabBackend.destroy()
    server.close()
  })
})