packages/coding-agent/src/core/tools/pi/utils/paths.ts

// Adapted from Pi c20cb09772bf4e2590a316cb54514cef76df4293.
// Copyright (c) 2025 Mario Zechner. MIT license: licenses/third-party-notices.txt.
import { homedir } from "node:os";
import { isAbsolute, join, resolve as nodeResolvePath } from "node:path";
import { fileURLToPath } from "node:url";

const UNICODE_SPACES = /[\u00A0\u2000-\u200A\u202F\u205F\u3000]/g;

export interface PathInputOptions {
  /** Trim leading/trailing whitespace before normalization. */
  trim?: boolean;
  /** Expand leading `~` to a home directory. Defaults to true. */
  expandTilde?: boolean;
  /** Home directory used for `~` expansion. Defaults to `os.homedir()`. */
  homeDir?: string;
  /** Strip a leading `@`, used for CLI @file paths. */
  stripAtPrefix?: boolean;
  /** Normalize unicode space variants to regular spaces. */
  normalizeUnicodeSpaces?: boolean;
}

/** Convert Git Bash, MSYS, Cygwin, and WSL drive paths to a form native Windows APIs accept. */
export function normalizeWindowsShellPath(filePath: string): string {
  if (!filePath.startsWith("/") || filePath.startsWith("//") || filePath.includes("\\")) return filePath;
  const match = filePath.match(/^\/(?:mnt\/|cygdrive\/)?([a-z])(?:\/(.*))?$/i);
  if (!match) return filePath;
  const suffix = match[2]?.replaceAll("/", "\\");
  return `${match[1].toUpperCase()}:\\${suffix ?? ""}`;
}

export function normalizePath(input: string, options: PathInputOptions = {}): string {
  let normalized = options.trim ? input.trim() : input;
  if (options.normalizeUnicodeSpaces) {
    normalized = normalized.replace(UNICODE_SPACES, " ");
  }
  if (options.stripAtPrefix && normalized.startsWith("@")) {
    normalized = normalized.slice(1);
  }
  if (process.platform === "win32") {
    normalized = normalizeWindowsShellPath(normalized);
  }

  if (options.expandTilde ?? true) {
    const home = options.homeDir ?? homedir();
    if (normalized === "~") return home;
    if (normalized.startsWith("~/") || (process.platform === "win32" && normalized.startsWith("~\\"))) {
      return join(home, normalized.slice(2));
    }
  }

  if (/^file:\/\//.test(normalized)) {
    return fileURLToPath(normalized);
  }

  return normalized;
}

export function resolvePath(
  input: string,
  baseDir: string = process.cwd(),
  options: PathInputOptions = {},
): string {
  const normalized = normalizePath(input, options);
  const normalizedBaseDir = normalizePath(baseDir);
  return isAbsolute(normalized)
    ? nodeResolvePath(normalized)
    : nodeResolvePath(normalizedBaseDir, normalized);
}