import { Event, TreeDataProvider, TreeItem, TreeItemCollapsibleState } from 'vscode';
import { PijulChannel, Repository } from '../pijul';

import { Event, TreeDataProvider, TreeItem, TreeItemCollapsibleState, Uri } from 'vscode';
import { PijulChange, PijulChannel, Repository } from '../pijul';

export class ChannelsViewProvider implements TreeDataProvider<PijulChannel> {

export class ChannelsViewProvider implements TreeDataProvider<PijulChannel | PijulChange> {

  getTreeItem (element: PijulChannel): TreeItem | Thenable<TreeItem> {
    return {
      id: element.name,
      label: element.name,
      description: element.isCurrent ? 'Current' : undefined,
      collapsibleState: TreeItemCollapsibleState.None,
      // Different context menu options for current and inactive channels
      contextValue: 'pijulChannel' + (element.isCurrent ? 'Current' : '')
    };

  getTreeItem (element: PijulChannel | PijulChange): TreeItem | Thenable<TreeItem> {
    if (element instanceof PijulChannel) {
      return {
        id: element.name,
        label: element.name,
        description: element.isCurrent ? 'Current' : undefined,
        collapsibleState: element.isCurrent ? TreeItemCollapsibleState.None : TreeItemCollapsibleState.Collapsed,
        // Different context menu options for current and inactive channels
        contextValue: 'pijulChannel' + (element.isCurrent ? 'Current' : '')
      };
    } else {
      return {
        label: element.message,
        description: `${element.author.name}, ${element.date.toISOString()}`,
        collapsibleState: TreeItemCollapsibleState.None,
        contextValue: 'pijulChange',
        tooltip: `${element.hash}\nRecorded by ${element.author.fullName ?? element.author.name} at ${element.date.toISOString()}\n\n\t${element.message}\n`,
        command: {
          command: 'vscode.open',
          title: 'Open Change TOML',
          arguments: [Uri.parse('pijul-change:' + element.hash)]
        }
      };
    }

  async getChildren (element?: PijulChannel): Promise<PijulChannel[] | null | undefined> {

  async getChildren (element?: PijulChannel | PijulChange): Promise<Array<PijulChannel | PijulChange> | null | undefined> {

      // TODO: Show the changes in this channel as children
      return null;

      if (element instanceof PijulChannel) {
        return await this.repository.getLog(element.name);
      } else {
        return null;
      }

   * A dictionary for holding a cache of change hashes to avoid recalculating them each time

   * A dictionary for holding a cache of change hashes to avoid recalculating them each time.
   * Persists between refreshes.

  // TODO: Create a number of sets which hold the state of the channels in memory.
  // Instead of each log, remote, or channel listing operation interacting with the CLI,
  // the state of the repository will be loaded each refresh and then accessed through the cache.

   * @param channel optional name of a channel to get the log for

  async getLog (): Promise<PijulChange[]> {

  async getLog (channel?: string): Promise<PijulChange[]> {

    const additionalArgs: string[] = [];
    if (channel) {
      additionalArgs.push('--channel', channel);
    }

    const result = await this._pijul.exec(this.repositoryRoot, ['log']);

    const result = await this._pijul.exec(this.repositoryRoot, ['log', ...additionalArgs]);