// Copyright (c) Jupyter Development Team.
// Distributed under the terms of the Modified BSD License.

import {
  ClientSession, IClientSession
} from '@jupyterlab/apputils';

import {
  IEditorMimeTypeService
} from '@jupyterlab/codeeditor';

import {
  PathExt, Time, uuid
} from '@jupyterlab/coreutils';

import {
  RenderMimeRegistry
} from '@jupyterlab/rendermime';

import {
  ServiceManager
} from '@jupyterlab/services';

import {
  Token
} from '@phosphor/coreutils';

import {
  Message
} from '@phosphor/messaging';

import {
  Panel
} from '@phosphor/widgets';

import {
  CodeConsole
} from './widget';


/**
 * The class name added to console panels.
 */
const PANEL_CLASS = 'jp-ConsolePanel';

const CONSOLE_ICON_CLASS = 'jp-CodeConsoleIcon';


/**
 * A panel which contains a console and the ability to add other children.
 */
export
class ConsolePanel extends Panel {
  /**
   * Construct a console panel.
   */
  constructor(options: ConsolePanel.IOptions) {
    super();
    this.addClass(PANEL_CLASS);
    let {
      rendermime, mimeTypeService, path, basePath, name, manager, modelFactory
    } = options;
    let contentFactory = this.contentFactory = (
      options.contentFactory || ConsolePanel.defaultContentFactory
    );
    let count = Private.count++;
    if (!path) {
      path = `${basePath || ''}/console-${count}-${uuid()}`;
    }

    let session = this._session = new ClientSession({
      manager: manager.sessions,
      path,
      name: name || `Console ${count}`,
      type: 'console',
      kernelPreference: options.kernelPreference
    });

    let resolver = new RenderMimeRegistry.UrlResolver({
      session,
      contents: manager.contents
    });
    rendermime = rendermime.clone({ resolver });

    this.console = contentFactory.createConsole({
      rendermime, session, mimeTypeService, contentFactory, modelFactory
    });
    this.addWidget(this.console);

    session.ready.then(() => {
      this._connected = new Date();
      this._updateTitle();
    });

    this.console.executed.connect(this._onExecuted, this);
    session.kernelChanged.connect(this._updateTitle, this);
    session.propertyChanged.connect(this._updateTitle, this);

    this.title.icon = CONSOLE_ICON_CLASS;
    this.title.closable = true;
    this.id = `console-${count}`;
  }

  /**
   * The content factory used by the console panel.
   */
  readonly contentFactory: ConsolePanel.IContentFactory;

  /**
   * The console widget used by the panel.
   */
  readonly console: CodeConsole;

  /**
   * The session used by the panel.
   */
  get session(): IClientSession {
    return this._session;
  }

  /**
   * Dispose of the resources held by the widget.
   */
  dispose(): void {
    this.console.dispose();
    super.dispose();
  }

  /**
   * Handle `'after-attach'` messages.
   */
  protected onAfterAttach(msg: Message): void {
    this._session.initialize();
    let prompt = this.console.promptCell;
    if (prompt) {
      prompt.editor.focus();
    }
  }

  /**
   * Handle `'activate-request'` messages.
   */
  protected onActivateRequest(msg: Message): void {
    let prompt = this.console.promptCell;
    if (prompt) {
      prompt.editor.focus();
    }
  }

  /**
   * Handle `'close-request'` messages.
   */
  protected onCloseRequest(msg: Message): void {
    super.onCloseRequest(msg);
    this.dispose();
  }

  /**
   * Handle a console execution.
   */
  private _onExecuted(sender: CodeConsole, args: Date) {
    this._executed = args;
    this._updateTitle();
  }

  /**
   * Update the console panel title.
   */
  private _updateTitle(): void {
    Private.updateTitle(this, this._connected, this._executed);
  }

  private _executed: Date | null = null;
  private _connected: Date | null = null;
  private _session: ClientSession;
}


/**
 * A namespace for ConsolePanel statics.
 */
export
namespace ConsolePanel {
  /**
   * The initialization options for a console panel.
   */
  export
  interface IOptions {
    /**
     * The rendermime instance used by the panel.
     */
    rendermime: RenderMimeRegistry;

    /**
     * The content factory for the panel.
     */
    contentFactory: IContentFactory;

    /**
     * The service manager used by the panel.
     */
    manager: ServiceManager.IManager;

    /**
     * The path of an existing console.
     */
    path?: string;

    /**
     * The base path for a new console.
     */
    basePath?: string;

    /**
     * The name of the console.
     */
    name?: string;

    /**
     * A kernel preference.
     */
    kernelPreference?: IClientSession.IKernelPreference;

    /**
     * The model factory for the console widget.
     */
    modelFactory?: CodeConsole.IModelFactory;

    /**
     * The service used to look up mime types.
     */
    mimeTypeService: IEditorMimeTypeService;
  }

  /**
   * The console panel renderer.
   */
  export
  interface IContentFactory extends CodeConsole.IContentFactory {
    /**
     * Create a new console panel.
     */
    createConsole(options: CodeConsole.IOptions): CodeConsole;
  }

  /**
   * Default implementation of `IContentFactory`.
   */
  export
  class ContentFactory extends CodeConsole.ContentFactory implements IContentFactory {
    /**
     * Create a new console panel.
     */
    createConsole(options: CodeConsole.IOptions): CodeConsole {
      return new CodeConsole(options);
    }
  }

  /**
   * A namespace for the console panel content factory.
   */
  export
  namespace ContentFactory {
    /**
     * Options for the code console content factory.
     */
    export
    interface IOptions extends CodeConsole.ContentFactory.IOptions { }
  }

  /**
   * A default code console content factory.
   */
  export
  const defaultContentFactory: IContentFactory = new ContentFactory();

  /* tslint:disable */
  /**
   * The console renderer token.
   */
  export
  const IContentFactory = new Token<IContentFactory>('@jupyterlab/console:IContentFactory');
  /* tslint:enable */
}


/**
 * A namespace for private data.
 */
namespace Private {
  /**
   * The counter for new consoles.
   */
  export
  let count = 1;

  /**
   * Update the title of a console panel.
   */
  export
  function updateTitle(panel: ConsolePanel, connected: Date | null, executed: Date | null) {
    let session = panel.console.session;
    let caption = (
      `Name: ${session.name}\n` +
      `Directory: ${PathExt.dirname(session.path)}\n` +
      `Kernel: ${session.kernelDisplayName}`
    );
    if (connected) {
      caption += `\nConnected: ${Time.format(connected.toISOString())}`;
    }
    if (executed) {
      caption += `\nLast Execution: ${Time.format(executed.toISOString())}`;
    }
    panel.title.label = session.name;
    panel.title.caption = caption;
  }
}