/**
 * Legacy Claude Code source detection.
 *
 * After #37/#38 the DSH runtime prefers `~/.dsh` for skills and roles. The
 * `~/.claude` locations stay as a migration fallback: a machine that has not
 * rerun `dsh/install.sh --skills --roles` keeps working, but the agent should
 * say so once instead of serving legacy paths silently.
 */

import { homedir } from 'node:os'
import { join, sep } from 'node:path'

const warned = new Set()

/** Whether `path` lives under `<home>/.claude` (the legacy source root). */
export function isLegacyClaudePath(path, home = homedir()) {
  if (typeof path !== 'string' || path === '') return false
  return path.startsWith(join(home, '.claude') + sep)
}

/**
 * Warn once per process and per kind+path: `agent/pre-step` runs on every
 * step, so an unconditional warning would flood the log.
 */
export function warnLegacyOnce(logger, kind, path, flag = kind) {
  const key = `${kind}|${path}`
  if (warned.has(key)) return
  warned.add(key)
  logger?.warn?.(
    '[dsh-harness] legacy Claude Code source in use for %s: %s; run dsh/install.sh --%s',
    kind,
    path,
    flag,
  )
}