src/git_helper.ts

// Copyright 2026 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// The module 'vscode' contains the VS Code extensibility API
// Import the module and reference it with the alias vscode in your code below
import * as vscode from 'vscode';

const OSSCS_BASE = 'https://cs.opensource.google/fuchsia/fuchsia/+/main:';

// The object received when the extension is called from context-menu / right click
type ContextMenuCommandArg = {
  path: string,
};

/**
 * Initialize the openInCodeSearch command.
 */
export function setUpGitHelper(ctx: vscode.ExtensionContext) {
  ctx.subscriptions.push(vscode.commands.registerCommand('fuchsia.openInCodeSearch', async (arg) => {
    await openAtMain(arg);
  }));
}

/**
 * Returns the root Fuchsia directory.
 */
function getRoot(): vscode.Uri | undefined {
  if (vscode.workspace.workspaceFolders !== undefined) {
    // Try to find a top-level directory named "fuchsia"
    for (let dir of vscode.workspace.workspaceFolders) {
      if (dir.name === 'fuchsia') {
        return dir.uri;
      }
    }
  }

  return undefined;
}

/**
 * Returns the path segment within the Fuchsia tree for the given context menu argument.
 */
function getPathSegment(arg: ContextMenuCommandArg) {
  let root = getRoot()?.fsPath;

  let fullPath =
    arg?.path || // Try to use the passed in path, if available
    vscode.window.activeTextEditor?.document.fileName || // Fallback to the active editor's path
    root || // Fallback to the root of the workspace
    '';

  return fullPath.slice(root?.length);
}

/**
 * Returns the current line number, if applicable.
 */
function getLineSegment(): string | null {
  const activeEditor = vscode.window.activeTextEditor;
  if (activeEditor) {
    let line = (activeEditor.selection.active.line + 1);
    return line.toString();
  }
  return null;
}

/**
 * Returns the URL for the given path and line number.
 */
function makeUrl(path: string, line: string | null): vscode.Uri {
  let url = OSSCS_BASE + path;
  if (line !== null) {
    url += ';l=' + line;
  }

  return vscode.Uri.parse(url);
}

/**
 * Opens the current file, at the current line, on branch main in osscs.
 */
async function openAtMain(arg: ContextMenuCommandArg) {
  let cutPath = getPathSegment(arg);
  let line = getLineSegment();
  await vscode.commands.executeCommand('vscode.open', makeUrl(cutPath, line));
}