#!/usr/bin/env bash
# gstack-paths — output portable state-root paths for skill bash blocks
# Usage: eval "$(gstack-paths)"  → sets GSTACK_STATE_ROOT, PLAN_ROOT, TMP_ROOT
# Or:    gstack-paths            → prints GSTACK_STATE_ROOT=... etc.
#        gstack-paths --explain  → which variable selected the state root, and why
#
# Resolves three roots with explicit fallback chains so skills work the same
# whether installed as a Claude Code plugin (CLAUDE_PLUGIN_DATA / CLAUDE_PLANS_DIR
# set), a global ~/.claude/skills/gstack/ install, or a local checkout under
# CI / container env where HOME may be unset.
#
# Chains:
#   GSTACK_STATE_ROOT: GSTACK_STATE_ROOT -> GSTACK_HOME -> GSTACK_STATE_DIR
#                      -> CLAUDE_PLUGIN_DATA (only when CLAUDE_PLUGIN_ROOT=*gstack*)
#                      -> $HOME/.gstack -> .gstack
#                      (one rule, owned by bin/gstack-state-root.sh; set GSTACK_HOME
#                      to relocate state; GSTACK_STATE_ROOT is this script's output,
#                      also honored as input; GSTACK_STATE_DIR is a legacy alias)
#   PLAN_ROOT:         GSTACK_PLAN_DIR -> CLAUDE_PLANS_DIR -> $HOME/.claude/plans -> .claude/plans
#   TMP_ROOT:          TMPDIR -> TMP -> .gstack/tmp (and mkdir -p, best-effort)
# Docs: https://github.com/garrytan/gstack/blob/main/docs/state-root.md
#
# Callers guard the eval, because eval "$(f)" succeeds even when f fails:
#   eval "$(gstack-paths)"; : "${GSTACK_STATE_ROOT:?gstack-paths failed; reinstall with ./setup or /gstack-upgrade}"
#
# Output: values are emitted shell-quoted (printf %q) so `eval` round-trips them
# byte-for-byte. This matters on Windows, where $TMP is a backslash path like
# C:\Users\me\AppData\Local\Temp — with a bare `echo`, eval consumes the
# backslashes as escapes and the caller gets C:UsersmeAppDataLocalTemp. A value
# containing a space (C:\Program Files\Temp) is worse: eval word-splits it and
# the variable ends up empty. Quoting here is the only fix that works, because
# the corruption happens during eval, before the caller has anything to quote.
# Callers should still quote expansions ("$GSTACK_STATE_ROOT") for the same
# reason any path variable needs quoting.
set -u

_GSTACK_DOC="https://github.com/garrytan/gstack/blob/main/docs/state-root.md"
_GSTACK_TWIN="$(cd "$(dirname "${BASH_SOURCE[0]}")" 2>/dev/null && pwd)/gstack-state-root.sh"

# Fail stop: never print a payload that would set an empty GSTACK_STATE_ROOT.
_gstack_paths_fail() {
  echo "gstack-paths: cannot resolve the gstack state root: $1" >&2
  echo "fix: reinstall gstack with ./setup (in the gstack checkout) or /gstack-upgrade. Docs: $_GSTACK_DOC" >&2
  exit 1
}
if [ ! -f "$_GSTACK_TWIN" ] || ! . "$_GSTACK_TWIN" 2>/dev/null || ! command -v gstack_state_root_select >/dev/null 2>&1; then
  _gstack_paths_fail "missing or broken $_GSTACK_TWIN"
fi

# State root: where gstack writes projects/, sessions/, analytics/.
gstack_state_root_select
_state_root="$_gstack_sr_root"
[ -n "$_state_root" ] || _gstack_paths_fail "the resolver in $_GSTACK_TWIN returned an empty root"

if [ "${1:-}" = "--explain" ]; then
  echo "state root: $_state_root (selected by $_gstack_sr_var)"
  echo "chain (first non-empty wins):"
  _gstack_sel_seen=0
  for _v in GSTACK_STATE_ROOT GSTACK_HOME GSTACK_STATE_DIR CLAUDE_PLUGIN_DATA; do
    eval "_val=\${$_v:-}"
    if [ -z "$_val" ]; then
      printf '  %-20s unset\n' "$_v"
    elif [ "$_v" = "$_gstack_sr_var" ]; then
      printf '  %-20s %s  selected\n' "$_v" "$_val"
    elif [ "$_v" = CLAUDE_PLUGIN_DATA ] && [ "$_gstack_sr_var" = default ]; then
      printf '  %-20s %s  ignored (CLAUDE_PLUGIN_ROOT does not contain "gstack")\n' "$_v" "$_val"
    else
      printf '  %-20s %s  ignored\n' "$_v" "$_val"
    fi
  done
  _gstack_user_home
  if [ -n "$_gstack_home_val" ]; then
    _gstack_default="$_gstack_home_val/.gstack"
  else
    _gstack_default=".gstack"
  fi
  if [ "$_gstack_sr_var" = default ]; then
    printf '  %-20s %s  selected\n' "default" "$_gstack_default"
  else
    printf '  %-20s %s  ignored\n' "default" "$_gstack_default"
    _gstack_has_state=no
    for _e in "$_gstack_default"/* "$_gstack_default"/.[!.]*; do
      [ -e "$_e" ] && { _gstack_has_state=yes; break; }
    done
    echo "default root $_gstack_default also holds gstack state: $_gstack_has_state"
  fi
  echo "merged privacy keys (most restrictive value across roots wins):"
  for _k in telemetry memorable_recall codex_reviews update_check; do
    gstack_config_select "$_k"
    if [ -n "$_gstack_cfg_value" ]; then
      printf '  %-17s %s (from %s/config.yaml)\n' "$_k:" "$_gstack_cfg_value" "$_gstack_cfg_root"
    else
      printf '  %-17s not set (default applies)\n' "$_k:"
    fi
  done
  echo "docs: $_GSTACK_DOC"
  exit 0
fi

# Plan root: where /context-save and /codex consult write plan files.
if [ -n "${GSTACK_PLAN_DIR:-}" ]; then
  _plan_root="$GSTACK_PLAN_DIR"
elif [ -n "${CLAUDE_PLANS_DIR:-}" ]; then
  _plan_root="$CLAUDE_PLANS_DIR"
elif [ -n "${HOME:-}" ]; then
  _plan_root="$HOME/.claude/plans"
else
  _plan_root=".claude/plans"
fi

# Tmp root: where ephemeral files (codex stderr captures, etc.) live.
# Honor TMPDIR / TMP for Windows + container compat; fall back to a
# project-local .gstack/tmp so we never write to a system /tmp that may
# be read-only or shared.
if [ -n "${TMPDIR:-}" ]; then
  _tmp_root="$TMPDIR"
elif [ -n "${TMP:-}" ]; then
  _tmp_root="$TMP"
else
  _tmp_root=".gstack/tmp"
fi
# macOS exports TMPDIR with a trailing slash; mktemp templates built as
# "$TMP_ROOT/name-XXXXXX" would then carry "//", and any consumer comparing
# paths gets a spurious mismatch. Strip it (never strips a bare "/"). #2091
case "$_tmp_root" in
  */) [ "$_tmp_root" != "/" ] && _tmp_root="${_tmp_root%/}" ;;
esac

# Strip any trailing slash so consumers can safely concatenate "$TMP_ROOT/name"
# without producing a double slash. On macOS $TMPDIR ends in `/` by default
# (e.g. /var/folders/.../T/), which would otherwise yield paths like
# `…/T//codex-err-…`. Normalizing at the source means every consumer benefits,
# not just /codex.
_tmp_root="${_tmp_root%/}"
# A value of "/" collapses to "" above; restore it so TMP_ROOT is never empty.
[ -z "$_tmp_root" ] && _tmp_root="/"

# Best-effort mkdir; if it fails (read-only fs, permission denied), the caller
# will discover that on their own write attempt. Don't fail the eval here.
mkdir -p "$_tmp_root" 2>/dev/null || true

printf 'GSTACK_STATE_ROOT=%q\n' "$_state_root"
printf 'PLAN_ROOT=%q\n' "$_plan_root"
printf 'TMP_ROOT=%q\n' "$_tmp_root"