import { homedir } from 'node:os';
import { isAbsolute, join, resolve } from 'node:path';

/**
 * The single canonical home for all VideoClaw projects: `~/videoclaw`.
 * Every project lives at `<CANONICAL_WORKSPACE_ROOT>/projects/<slug>/`. This is
 * the default workspace root for project creation, every project-reading
 * command, and Mission Control discovery — replacing the old per-invocation
 * `process.cwd()` default that scattered projects wherever `vclaw` happened to
 * run.
 */
export const CANONICAL_WORKSPACE_ROOT = join(homedir(), 'videoclaw');

/** Expand a leading `~/`, then make the path absolute. */
function expandWorkspacePath(p: string): string {
  if (p.startsWith('~/')) return join(homedir(), p.slice(2));
  return isAbsolute(p) ? p : resolve(p);
}

/**
 * Resolve the workspace root from the environment alone (no CLI flags).
 * Precedence: `VCLAW_WORKSPACE` → `VIDEOCLAW_WORKSPACE` → the canonical home.
 *
 * Used as the default by library/test callers (workspace.ts, projects.ts) that
 * do not receive a `--root` flag; the arg-aware `resolveWorkspaceRoot` in
 * cli/args.ts layers explicit-flag precedence on top of this. A blank/whitespace
 * env value is ignored (falls through to the home), so an empty
 * `VCLAW_WORKSPACE=` never resolves projects to the filesystem root.
 */
export function resolveWorkspaceRootFromEnv(env: NodeJS.ProcessEnv = process.env): string {
  const raw = env.VCLAW_WORKSPACE ?? env.VIDEOCLAW_WORKSPACE;
  if (raw && raw.trim()) return expandWorkspacePath(raw.trim());
  return CANONICAL_WORKSPACE_ROOT;
}