#!/usr/bin/env bash
# gstack-codex-probe: shared helper for /codex and /autoplan skills.
# Sourced from template bash blocks; never execute directly.
#
# Functions (all prefixed with _gstack_codex_ for namespace hygiene):
#   _gstack_codex_auth_probe      — multi-signal auth check (env + file)
#   _gstack_codex_select_model    — resolve + print the runtime model (#2914)
#   _gstack_codex_sandbox_mode    — read-only, or full access only for GSTACK_CODEX_NO_SANDBOX=1
#   _gstack_codex_sandbox_preflight — free `codex sandbox` check before paid calls (Linux)
#   _gstack_codex_model_probe     — round-trip probe of the selected model (#2477)
#   _gstack_codex_version_check   — warn on known-bad Codex CLI versions
#   _gstack_codex_timeout_wrapper — gtimeout -> timeout -> bash-native watchdog
#   _gstack_codex_log_event       — telemetry emission to ~/.gstack/analytics/
#
# Hygiene rules (enforced by test/codex-hardening.test.ts):
#   - Never change -e / -u / traps / IFS / PATH in the caller shell.
#   - All internal vars prefix with _GSTACK_CODEX_.
#   - All functions prefix with _gstack_codex_.
#   - No command execution at source time (only function defs).

# --- Auth probe -------------------------------------------------------------

_gstack_codex_auth_probe() {
  # Multi-signal: env vars OR auth file OR a custom provider's env_key. Avoids
  # false negatives for env-auth users (CI, platform engineers, self-hosted
  # OpenAI-compatible providers) that a file-only check would reject.
  local _codex_home="${CODEX_HOME:-$HOME/.codex}"
  # Use `-n` which returns true only for non-empty non-whitespace. Bash's [ -n ]
  # alone allows whitespace; pair with a whitespace strip for robustness.
  local _k1 _k2
  _k1=$(printf '%s' "${CODEX_API_KEY:-}" | tr -d '[:space:]')
  _k2=$(printf '%s' "${OPENAI_API_KEY:-}" | tr -d '[:space:]')
  if [ -n "$_k1" ] || [ -n "$_k2" ] || [ -f "$_codex_home/auth.json" ]; then
    echo "AUTH_OK"
    return 0
  fi
  # Custom OpenAI-compatible providers (#2192): a [model_providers.<id>]
  # table names its credential variable in env_key. Only keys inside those
  # tables count, comments are ignored, and the name must be a plain shell
  # identifier before it is dereferenced.
  local _env_key _resolved _missing=""
  if [ -f "$_codex_home/config.toml" ]; then
    while IFS= read -r _env_key; do
      case "$_env_key" in ''|[0-9]*|*[!A-Za-z0-9_]*) continue ;; esac
      _resolved=$(printf '%s' "${!_env_key:-}" | tr -d '[:space:]')
      if [ -n "$_resolved" ]; then
        echo "AUTH_OK"
        return 0
      fi
      _missing="${_missing:+$_missing, }$_env_key"
    done < <(awk '/^[[:space:]]*#/ { next }
      /^[[:space:]]*\[/ { in_provider = ($0 ~ /^[[:space:]]*\[model_providers\.[^]]+\][[:space:]]*(#.*)?$/); next }
      in_provider && /^[[:space:]]*env_key[[:space:]]*=/ { v = $0; sub(/^[^=]*=[[:space:]]*/, "", v); sub(/[[:space:]]*#.*$/, "", v); gsub(/["\047[:space:]]/, "", v); print v }' "$_codex_home/config.toml" 2>/dev/null)
  fi
  echo "AUTH_FAILED"
  [ -n "$_missing" ] && echo "HINT: $_codex_home/config.toml names a custom provider key ($_missing), but it is not set in this shell. Export it, or run codex login." >&2
  return 1
}

# --- Runtime model selection (#2914) ---------------------------------------

_gstack_codex_select_model() {
  # One selection record per invocation kind, shared by the probe and the
  # dispatch flag in the same block: explicit request ($2), GSTACK_CODEX_MODEL,
  # Codex config.toml (review_model first for native review), gstack default.
  # The TOML is read by the TypeScript resolver; bash never parses it.
  local _kind="${1:-exec}" _explicit="${2:-}" _line _rc
  case "$_kind" in exec|review) ;; *) echo "ERROR: _gstack_codex_select_model takes exec or review" >&2; return 2 ;; esac
  if ! command -v bun >/dev/null 2>&1; then
    echo "CODEX_MODEL: unresolved — bun is not on PATH, so gstack cannot read the Codex model choice. Reinstall gstack with ./setup; no Codex call was made." >&2
    return 1
  fi
  if [ -n "$_explicit" ]; then
    _line=$(bun run "${BASH_SOURCE[0]%/*}/../scripts/resolve-codex-generation-model.ts" --runtime "$_kind" --explicit "$_explicit")
  else
    _line=$(bun run "${BASH_SOURCE[0]%/*}/../scripts/resolve-codex-generation-model.ts" --runtime "$_kind")
  fi
  _rc=$?
  _GSTACK_CODEX_SEL="${_line%%$'\t'*}"
  _GSTACK_CODEX_SEL_SRC="${_line#*$'\t'}"
  case "$_GSTACK_CODEX_SEL" in ''|*[!A-Za-z0-9._:/-]*) _rc=1 ;; esac
  if [ "$_rc" -ne 0 ] || [ "${#_GSTACK_CODEX_SEL}" -gt 100 ]; then
    _GSTACK_CODEX_SEL=""
    _GSTACK_CODEX_SEL_SRC=""
    echo "CODEX_MODEL: invalid — Codex outside review unavailable; missing coverage. No Codex call was made. Fix the model choice above; gstack never substitutes its default for it." >&2
    return 1
  fi
  _GSTACK_CODEX_SEL_KIND="$_kind"
  echo "CODEX_MODEL: $_GSTACK_CODEX_SEL ($_kind; source: $_GSTACK_CODEX_SEL_SRC)" >&2
  _gstack_codex_sandbox_mode
}

# --- Sandbox (B1) -----------------------------------------------------------

_gstack_codex_sandbox_mode() {
  # Every gstack Codex command passes -s / sandbox_mode from this variable, so
  # one place decides it. Codex has no read-only mode without its sandbox, so
  # the escape hatch is full access: honored only for exactly 1, only from the
  # shell environment (never a dotenv file or config), and announced each use.
  if [ "${GSTACK_CODEX_NO_SANDBOX:-}" = "1" ]; then
    _GSTACK_CODEX_SANDBOX="danger-full-access"
    echo "WARNING: GSTACK_CODEX_NO_SANDBOX=1: Codex runs this review without a sandbox and can read and write anything your user can. Use it only inside a container you trust." >&2
  else
    _GSTACK_CODEX_SANDBOX="read-only"
  fi
}

_gstack_codex_sandbox_preflight() {
  # Free check before the first paid call: `codex sandbox` starts the same
  # bubblewrap sandbox with no model. Only a recognized sandbox failure blocks
  # (exit 3, printed as missing coverage); success, a timeout, or an older CLI
  # without the subcommand defers to the post-run classifier. Linux only, and
  # skipped when the user turned the sandbox off. Fixtures:
  # test/fixtures/codex-sandbox/.
  [ "${GSTACK_CODEX_NO_SANDBOX:-}" = "1" ] && return 0
  [ "$(uname -s 2>/dev/null)" = "Linux" ] || return 0
  local _out _code _line
  _out=$(_gstack_codex_timeout_wrapper 10 codex sandbox -c 'sandbox_mode="read-only"' true </dev/null 2>&1)
  _code=$?
  { [ "$_code" -eq 0 ] || [ "$_code" -eq 124 ]; } && return 0
  _line=$(printf '%s\n' "$_out" | grep -m1 -iE '^[[:space:]]*bwrap: |bubblewrap is unavailable|landlock.{0,60}(fail|error|not supported|unsupported)|seccomp.{0,60}(fail|error)|user namespaces?.{0,80}(not (allowed|permitted|supported)|denied|disabled)' | sed 's/^[[:space:]]*//' | cut -c1-240)
  [ -n "$_line" ] || return 0
  echo "CODEX_SANDBOX: unavailable"
  echo "Codex outside review unavailable: Codex's sandbox could not start here ($_line). No review ran; this is missing coverage, not a pass. Fix: enable unprivileged user namespaces for this container, or set GSTACK_CODEX_NO_SANDBOX=1." >&2
  _gstack_codex_log_event "codex_sandbox_unavailable" 2>/dev/null || true
  return 3
}

# --- Model round-trip probe (#2477) ------------------------------------------

_gstack_codex_model_probe() {
  # Auth-exists is a weaker signal than the auth probe implies: a ChatGPT
  # account can be valid while the model gstack will request is unavailable.
  # A short real round trip with the selected model catches model rejection
  # and entitlement changes in one shot (#2477). The model comes from
  # _gstack_codex_select_model ($1 = exec|review, default exec), the same
  # record the dispatch flag uses, so the probe never checks a different model.
  #
  # Contract:
  #   MODEL_OK (exit 0)              — round trip succeeded; cached 1h.
  #   MODEL_UNUSABLE (exit 1)        — deterministic model rejection (400, or a
  #     404 from a retired model or a wrong custom-provider base_url) or an
  #     invalid model choice; hints name the cause. The 400 is cached 15 min: re-probing every
  #     preflight charged the affected user a 30s round trip + real tokens per
  #     review section, forever. Changing the model or config.toml changes the
  #     cache signature and re-probes immediately; the short TTL covers
  #     server-side entitlement recovery the signature can't see.
  #   MODEL_UNUSABLE_INSTALL (exit 2) — the CLI cannot execute at all (spawn
  #     ENOENT, non-executable binary, missing vendor payload). Deterministic,
  #     so fail-open is wrong: retrying never helps. Never cached — a reinstall
  #     fixes it and must be picked up on the very next probe (#2742).
  #   MODEL_PROBE_INCONCLUSIVE (exit 0) — timeout/transient; the review still
  #     runs so a slow network never wedges codex mode, but readiness is
  #     unverified (_GSTACK_CODEX_PROBE_STATE=inconclusive, CODEX_MODE:
  #     unverified) and the review's own classification decides. Never cached.
  #
  # Only call this AFTER _gstack_codex_auth_probe passes — probing without
  # auth just measures the auth failure again.
  local _kind="${1:-exec}"
  if [ -z "${_GSTACK_CODEX_SEL:-}" ] || [ "${_GSTACK_CODEX_SEL_KIND:-}" != "$_kind" ]; then
    if ! _gstack_codex_select_model "$_kind"; then
      echo "MODEL_UNUSABLE"
      echo "HINT: the requested Codex model is not a valid model id; fix it as described above."
      return 1
    fi
  fi
  local _model="$_GSTACK_CODEX_SEL"
  local _codex_home="${CODEX_HOME:-$HOME/.codex}"
  # State root from the shared twin (sourced in a subshell, so the caller's
  # shell is untouched). A missing twin only disables the cache.
  local _gstack_home _cache=""
  _gstack_home="$(. "${BASH_SOURCE[0]%/*}/gstack-state-root.sh" 2>/dev/null && gstack_state_root)" || _gstack_home=""
  [ -n "$_gstack_home" ] && _cache="$_gstack_home/.codex-model-probe"
  # Cache signature (#2787): everything that can change the round trip's
  # outcome without the hour passing — the model, the Codex home and its
  # config.toml mtime, the auth mode (which env var or auth.json, plus its
  # mtime; never a credential value), and the resolved codex binary and its
  # mtime (an upgrade or PATH swap re-probes). Folded through cksum so paths
  # with spaces stay one field of the cache line.
  # GNU-first stat order + numeric validation (the #2195 pattern): on GNU
  # stat, `-f` means FILESYSTEM mode, so the BSD-first form emitted a
  # multi-line filesystem block on Linux — the signature then never matched
  # its own cache line and the cache missed on every read. BSD stat rejects
  # `-c` cleanly, so GNU-first degrades correctly on macOS.
  local _cfg_m _auth_m _auth_mode="" _bin _bin_m _sig
  _cfg_m=$(stat -c %Y "$_codex_home/config.toml" 2>/dev/null || stat -f %m "$_codex_home/config.toml" 2>/dev/null || echo 0)
  _auth_m=$(stat -c %Y "$_codex_home/auth.json" 2>/dev/null || stat -f %m "$_codex_home/auth.json" 2>/dev/null || echo 0)
  case "$_cfg_m" in ''|*[!0-9]*) _cfg_m=0 ;; esac
  case "$_auth_m" in ''|*[!0-9]*) _auth_m=0 ;; esac
  [ -n "$(printf '%s' "${CODEX_API_KEY:-}" | tr -d '[:space:]')" ] && _auth_mode="${_auth_mode}env-codex,"
  [ -n "$(printf '%s' "${OPENAI_API_KEY:-}" | tr -d '[:space:]')" ] && _auth_mode="${_auth_mode}env-openai,"
  [ -f "$_codex_home/auth.json" ] && _auth_mode="${_auth_mode}file,"
  _bin=$(command -v codex 2>/dev/null || echo none)
  _bin=$(readlink -f "$_bin" 2>/dev/null || printf '%s' "$_bin")
  _bin_m=$(stat -c %Y "$_bin" 2>/dev/null || stat -f %m "$_bin" 2>/dev/null || echo 0)
  case "$_bin_m" in ''|*[!0-9]*) _bin_m=0 ;; esac
  _sig=$(printf '%s\n' "$_model" "$_codex_home" "$_cfg_m" "$_auth_mode" "$_auth_m" "$_bin" "$_bin_m" | cksum | tr -d ' ')
  local _now
  _now=$(date +%s 2>/dev/null || echo 0)
  if [ -n "$_cache" ] && [ -f "$_cache" ]; then
    local _c_line _c_status _c_ts _c_sig
    _c_line=$(head -1 "$_cache" 2>/dev/null)
    _c_status=$(printf '%s' "$_c_line" | cut -d' ' -f1)
    _c_ts=$(printf '%s' "$_c_line" | cut -d' ' -f2)
    _c_sig=$(printf '%s' "$_c_line" | cut -d' ' -f3)
    case "$_c_ts" in ''|*[!0-9]*) _c_ts=0 ;; esac
    if [ "$_c_status" = "MODEL_OK" ] && [ "$_c_sig" = "$_sig" ] && [ $((_now - _c_ts)) -lt 3600 ]; then
      echo "MODEL_OK (cached)"
      return 0
    fi
    if [ "$_c_status" = "MODEL_UNUSABLE" ] && [ "$_c_sig" = "$_sig" ] && [ $((_now - _c_ts)) -lt 900 ]; then
      echo "MODEL_UNUSABLE (cached)"
      echo "HINT: gstack requested model '$_model' (source: $_GSTACK_CODEX_SEL_SRC)."
      echo "HINT: choose a model your account can use: set GSTACK_CODEX_MODEL=<supported-model>, set model in $_codex_home/config.toml, or name one for this request."
      return 1
    fi
  fi
  local _out _code
  _out=$(_gstack_codex_timeout_wrapper 30 codex exec --skip-git-repo-check -s read-only -c "model=\"$_model\"" -c 'skills.include_instructions=false' "reply OK" </dev/null 2>&1)
  _code=$?
  if [ "$_code" -eq 0 ]; then
    [ -n "$_cache" ] && { mkdir -p "$_gstack_home" 2>/dev/null; printf 'MODEL_OK %s %s\n' "$_now" "$_sig" > "$_cache" 2>/dev/null; }
    echo "MODEL_OK"
    return 0
  fi
  # A model rejection is deterministic: a 400 ("is not supported", "requires a
  # newer version of Codex") or a 404. A retired model answers 404 "does not
  # exist or you do not have access to it", and a custom provider with a wrong
  # base_url answers a bare 404; neither is network luck, so neither may fall
  # through to the inconclusive branch below and report ready (#2843).
  if printf '%s' "$_out" | grep -qiE 'model.{0,40}is not supported|"status":[[:space:]]*40[04]|requires a newer version of codex|does not exist or you do not have access|model.{0,40}does not exist|404 not found|status:?[[:space:]]*404'; then
    [ -n "$_cache" ] && { mkdir -p "$_gstack_home" 2>/dev/null; printf 'MODEL_UNUSABLE %s %s\n' "$_now" "$_sig" > "$_cache" 2>/dev/null; }
    echo "MODEL_UNUSABLE"
    printf '%s\n' "$_out" | grep -iE "model|404" | head -3
    echo "HINT: gstack requested model '$_model' (source: $_GSTACK_CODEX_SEL_SRC)."
    if printf '%s' "$_out" | grep -qiE 'requires a newer version of codex|upgrade to the latest (app|version|cli)'; then
      echo "HINT: the server refused it because this Codex CLI is too old; no model choice fixes that. Upgrade the CLI (\`codex doctor\` prints the command; usually npm install -g @openai/codex)."
      _gstack_codex_log_event "codex_cli_outdated" 2>/dev/null || true
    elif printf '%s' "$_out" | grep -qiE 'does not exist|404'; then
      echo "HINT: Codex answered 404: either the model is retired or not visible to this account, or a custom provider's base_url in $_codex_home/config.toml is wrong."
      echo "HINT: choose a current model (GSTACK_CODEX_MODEL=<supported-model> or model in config.toml), or fix that provider's base_url."
      _gstack_codex_log_event "codex_model_retired" 2>/dev/null || true
    else
      echo "HINT: choose a model your account can use: set GSTACK_CODEX_MODEL=<supported-model>, set model in $_codex_home/config.toml, or name one for this request."
      _gstack_codex_log_event "codex_model_unusable" 2>/dev/null || true
    fi
    return 1
  fi
  # A CLI that cannot execute is deterministic, not transient: the fail-open
  # below exists for network luck, and swallowing this here is what let a
  # missing vendor binary report CODEX_MODE: ready while every Codex pass was
  # silently skipped (#2742). 126 = found but not executable, 127 = not found.
  # String signatures only count on a FAILED, NON-TIMEOUT spawn: a successful
  # response that mentions "permission denied" must not classify as broken,
  # and neither may a timed-out (124) probe whose partial output quotes such
  # strings — 124 keeps its fail-open contract below.
  _BROKEN_SIG='ENOENT|ENOEXEC|EACCES|no such file or directory|cannot execute binary file|not executable|permission denied'
  if [ "$_code" -eq 126 ] || [ "$_code" -eq 127 ] || { [ "$_code" -ne 0 ] && [ "$_code" -ne 124 ] && printf '%s' "$_out" | grep -qiE "$_BROKEN_SIG"; }; then
    echo "MODEL_UNUSABLE_INSTALL"
    printf '%s\n' "$_out" | grep -iE "$_BROKEN_SIG" | head -3
    echo "HINT: the Codex CLI is on PATH but cannot run — its binary or vendor payload is missing."
    echo "HINT: reinstall with: npm install -g @openai/codex"
    _gstack_codex_log_event "codex_broken_install" 2>/dev/null || true
    return 2
  fi
  # Timeout (124) or transient failure: fail-open with a warning. The probe
  # exists to catch the deterministic model 400, not to gate on network luck.
  # Callers report CODEX_MODE: unverified, never ready; the exit stays 0 so
  # skills rendered before this marker keep running the review.
  _GSTACK_CODEX_PROBE_STATE="inconclusive"
  echo "MODEL_PROBE_INCONCLUSIVE (exit $_code) — CODEX_MODE: unverified; proceeding, and the review's own result is still checked. If invocations fail with a model 400, see the codex skill's Error Handling entry."
  return 0
}

# --- Version check ----------------------------------------------------------

_gstack_codex_version_check() {
  # Warn on known-bad Codex CLI versions. Anchored regex prevents false
  # positives like 0.120.10 or 0.120.20 from matching. 0.120.2-beta still
  # matches the bad release and gets warned (it IS buggy).
  # Update this list when a new Codex CLI version regresses.
  local _ver _vcode
  # Capture the code from codex, not from `head` — a pipeline reports the LAST
  # command's status, which is why a CLI that only ever printed a spawn error
  # still read as healthy here (#2742). Keep stderr: it carries the diagnosis.
  _ver=$(codex --version 2>&1)
  _vcode=$?
  _ver=$(printf '%s' "$_ver" | head -1)
  # Only a NON-ZERO exit is evidence of a broken CLI. Empty-but-successful
  # output stays silent by design (a CLI may legitimately print nothing), which
  # the "empty output → OK" case in this file's suite pins.
  if [ "$_vcode" -ne 0 ]; then
    echo "WARN: \`codex --version\` failed (exit $_vcode) — the CLI is on PATH but may not be runnable."
    [ -n "$_ver" ] && echo "WARN: it said: $_ver"
    echo "WARN: if Codex passes are being skipped, reinstall with: npm install -g @openai/codex"
    _gstack_codex_log_event "codex_version_unreadable" 2>/dev/null || true
    return 0
  fi
  [ -z "$_ver" ] && return 0
  if echo "$_ver" | grep -Eq '(^|[^0-9.])0\.120\.(0|1|2)([^0-9.]|$)'; then
    echo "WARN: Codex CLI $_ver has known stdin deadlock bugs. Run: npm install -g @openai/codex@latest"
    _gstack_codex_log_event "codex_version_warning"
  fi
}

# --- Timeout wrapper --------------------------------------------------------

_gstack_codex_timeout_wrapper() {
  # Resolve wrapper binary: prefer gtimeout (Homebrew coreutils on macOS),
  # fall back to timeout (Linux), else a bash-native watchdog. Arguments:
  # $1 is the duration in seconds; rest is the command to run.
  # A child that ignores TERM is KILLed after a grace period
  # (_GSTACK_CODEX_KILL_AFTER seconds, default 10), so the deadline always
  # ends the provider before the caller's outer tool gate (#2776). Either
  # way a deadline reports timeout(1)'s exit 124; output already written stays.
  local _duration="$1"
  shift
  local _grace="${_GSTACK_CODEX_KILL_AFTER:-10}"
  local _to _rc _start
  _to=$(command -v gtimeout 2>/dev/null || command -v timeout 2>/dev/null || echo "")
  if [ -n "$_to" ]; then
    _start=$(date +%s 2>/dev/null || echo 0)
    "$_to" -k "$_grace" "$_duration" "$@"
    _rc=$?
    # 137 = timeout(1)'s KILL escalation; it is still the deadline firing.
    if [ "$_rc" -eq 137 ] && [ $(( $(date +%s 2>/dev/null || echo 0) - _start )) -ge "${_duration%%.*}" ]; then
      _rc=124
    fi
    return "$_rc"
  else
    # Stock macOS ships neither coreutils gtimeout nor timeout(1); running
    # unwrapped let a hung `codex exec` block the probe — and the calling
    # workflow — indefinitely. Emulate: background the command, TERM it at
    # the deadline, KILL it after the grace period if it is still alive, and
    # mirror timeout(1)'s exit-124 contract. The watchdog's stdout is
    # detached so an early finish never blocks a caller's $(...) capture on
    # the orphaned sleep.
    # Without job control a background command's stdin is /dev/null; keep the
    # caller's stdin so prompts fed with `codex exec -` arrive (#1674).
    "$@" <&0 &
    local _cmd_pid=$!
    (
      sleep "$_duration" && trap '' TERM && kill -TERM "$_cmd_pid" 2>/dev/null || exit 0  # best-effort: the command already exited, nothing to stop
      _GSTACK_CODEX_WAITED=0
      while [ "$_GSTACK_CODEX_WAITED" -lt "$_grace" ] && kill -0 "$_cmd_pid" 2>/dev/null; do
        sleep 1
        _GSTACK_CODEX_WAITED=$((_GSTACK_CODEX_WAITED + 1))
      done
      pkill -KILL -P "$_cmd_pid" 2>/dev/null
      kill -KILL "$_cmd_pid" 2>/dev/null
      exit 124
    ) >/dev/null 2>&1 &
    local _watch_pid=$!
    wait "$_cmd_pid"
    _rc=$?
    kill "$_watch_pid" 2>/dev/null
    wait "$_watch_pid" 2>/dev/null
    if [ "$?" -eq 124 ]; then
      _rc=124
    fi
    return "$_rc"
  fi
}

# --- Telemetry event --------------------------------------------------------

_gstack_codex_log_event() {
  # Emit a telemetry event to ~/.gstack/analytics/skill-usage.jsonl.
  # Gated on $_TEL != "off" (caller sets this from gstack-config).
  # Event types: codex_timeout, codex_auth_failed, codex_cli_missing,
  #              codex_version_warning, codex_model_unusable, codex_sandbox_unavailable,
#              codex_model_retired, codex_cli_outdated.
  # Payload schema: {skill, event, duration_s, ts}. NEVER includes prompt
  # content, env var values, or auth tokens.
  local _event="$1"
  local _duration="${2:-0}"
  [ "${_TEL:-off}" = "off" ] && return 0
  local _root
  _root="$(. "${BASH_SOURCE[0]%/*}/gstack-state-root.sh" 2>/dev/null && gstack_state_root)" || return 0
  [ -n "$_root" ] || return 0
  mkdir -p "$_root/analytics" 2>/dev/null || return 0
  local _ts
  _ts=$(date -u +%Y-%m-%dT%H:%M:%SZ 2>/dev/null || echo unknown)
  printf '{"skill":"codex","event":"%s","duration_s":"%s","ts":"%s"}\n' \
    "$_event" "$_duration" "$_ts" \
    >> "$_root/analytics/skill-usage.jsonl" 2>/dev/null || true
}

# --- Learnings log on hang --------------------------------------------------

_gstack_codex_log_hang() {
  # Invoked when a codex invocation times out (exit 124). Records an
  # operational learning so future /investigate sessions surface the pattern.
  # Best-effort: errors swallowed.
  local _mode="${1:-unknown}"
  local _prompt_size="${2:-0}"
  local _log_bin="$HOME/.claude/skills/gstack/bin/gstack-learnings-log"
  [ -x "$_log_bin" ] || return 0
  local _key="codex-hang-$(date +%s 2>/dev/null || echo unknown)"
  "$_log_bin" "$(printf '{"skill":"codex","type":"operational","key":"%s","insight":"Codex hit its timeout wrapper during [%s] invocation. Prompt size: %s. Consider splitting prompt or checking network.","confidence":8,"source":"observed","files":["codex/SKILL.md.tmpl","autoplan/SKILL.md.tmpl"]}' "$_key" "$_mode" "$_prompt_size")" \
    >/dev/null 2>&1 || true
}