/* --------------------------------------------------------------------------------------------
 * Copyright (c) Microsoft Corporation. All rights reserved.
 * Licensed under the MIT License. See License.txt in the project root for license information.
 * ------------------------------------------------------------------------------------------ */
import * as path from 'path'
import {
  workspace as Workspace,
  window as Window,
  ExtensionContext,
  TextDocument,
  OutputChannel,
  WorkspaceFolder,
  Uri,
} from 'vscode'
import {
  LanguageClient,
  LanguageClientOptions,
  TransportKind,
} from 'vscode-languageclient'
import { registerConfigErrorHandler } from './lib/registerConfigErrorHandler'
import { LANGUAGES } from './lib/languages'

let defaultClient: LanguageClient
let clients: Map<string, LanguageClient> = new Map()

let _sortedWorkspaceFolders: string[] | undefined
function sortedWorkspaceFolders(): string[] {
  if (_sortedWorkspaceFolders === void 0) {
    _sortedWorkspaceFolders = Workspace.workspaceFolders
      ? Workspace.workspaceFolders
          .map((folder) => {
            let result = folder.uri.toString()
            if (result.charAt(result.length - 1) !== '/') {
              result = result + '/'
            }
            return result
          })
          .sort((a, b) => {
            return a.length - b.length
          })
      : []
  }
  return _sortedWorkspaceFolders
}
Workspace.onDidChangeWorkspaceFolders(
  () => (_sortedWorkspaceFolders = undefined)
)

function getOuterMostWorkspaceFolder(folder: WorkspaceFolder): WorkspaceFolder {
  let sorted = sortedWorkspaceFolders()
  for (let element of sorted) {
    let uri = folder.uri.toString()
    if (uri.charAt(uri.length - 1) !== '/') {
      uri = uri + '/'
    }
    if (uri.startsWith(element)) {
      return Workspace.getWorkspaceFolder(Uri.parse(element))!
    }
  }
  return folder
}

export function activate(context: ExtensionContext) {
  let module = context.asAbsolutePath(
    path.join('dist', 'server', 'index.js')
  )
  let outputChannel: OutputChannel = Window.createOutputChannel(
    'lsp-multi-server-example'
  )

  function didOpenTextDocument(document: TextDocument): void {
    // We are only interested in language mode text
    if (
      LANGUAGES.indexOf(document.languageId) === -1 ||
      (document.uri.scheme !== 'file' && document.uri.scheme !== 'untitled')
    ) {
      return
    }

    let uri = document.uri
    // Untitled files go to a default client.
    if (uri.scheme === 'untitled' && !defaultClient) {
      let debugOptions = { execArgv: ['--nolazy', '--inspect=6010'] }
      let serverOptions = {
        run: { module, transport: TransportKind.ipc },
        debug: { module, transport: TransportKind.ipc, options: debugOptions },
      }
      let clientOptions: LanguageClientOptions = {
        documentSelector: LANGUAGES.map((language) => ({
          scheme: 'untitled',
          language,
        })),
        diagnosticCollectionName: 'lsp-multi-server-example',
        outputChannel: outputChannel,
      }
      defaultClient = new LanguageClient(
        'lsp-multi-server-example',
        'LSP Multi Server Example',
        serverOptions,
        clientOptions
      )
      defaultClient.start()
      return
    }
    let folder = Workspace.getWorkspaceFolder(uri)
    // Files outside a folder can't be handled. This might depend on the language.
    // Single file languages like JSON might handle files outside the workspace folders.
    if (!folder) {
      return
    }
    // If we have nested workspace folders we only start a server on the outer most workspace folder.
    folder = getOuterMostWorkspaceFolder(folder)

    if (!clients.has(folder.uri.toString())) {
      let debugOptions = {
        execArgv: ['--nolazy', `--inspect=${6011 + clients.size}`],
      }
      let serverOptions = {
        run: { module, transport: TransportKind.ipc },
        debug: { module, transport: TransportKind.ipc, options: debugOptions },
      }
      let clientOptions: LanguageClientOptions = {
        documentSelector: LANGUAGES.map((language) => ({
          scheme: 'file',
          language,
          pattern: `${folder.uri.fsPath}/**/*`,
        })),
        diagnosticCollectionName: 'lsp-multi-server-example',
        workspaceFolder: folder,
        outputChannel: outputChannel,
        middleware: {},
      }
      let client = new LanguageClient(
        'lsp-multi-server-example',
        'LSP Multi Server Example',
        serverOptions,
        clientOptions
      )

      client.onReady().then(() => {
        registerConfigErrorHandler(client)
      })

      client.start()
      clients.set(folder.uri.toString(), client)
    }
  }

  Workspace.onDidOpenTextDocument(didOpenTextDocument)
  Workspace.textDocuments.forEach(didOpenTextDocument)
  Workspace.onDidChangeWorkspaceFolders((event) => {
    for (let folder of event.removed) {
      let client = clients.get(folder.uri.toString())
      if (client) {
        clients.delete(folder.uri.toString())
        client.stop()
      }
    }
  })
}

export function deactivate(): Thenable<void> {
  let promises: Thenable<void>[] = []
  if (defaultClient) {
    promises.push(defaultClient.stop())
  }
  for (let client of clients.values()) {
    promises.push(client.stop())
  }
  return Promise.all(promises).then(() => undefined)
}