#!/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.
#
# 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_HOME -> CLAUDE_PLUGIN_DATA -> $HOME/.gstack -> .gstack
#   PLAN_ROOT:         GSTACK_PLAN_DIR -> CLAUDE_PLANS_DIR -> $HOME/.claude/plans -> .claude/plans
#   TMP_ROOT:          TMPDIR -> TMP -> .gstack/tmp (and mkdir -p, best-effort)
#
# Security: output values are not sanitized — callers may receive paths with
# shell-special characters if env vars contain them. Skills should always quote
# expansions ("$GSTACK_STATE_ROOT", not $GSTACK_STATE_ROOT).
set -u

# State root: where gstack writes projects/, sessions/, analytics/.
if [ -n "${GSTACK_HOME:-}" ]; then
  _state_root="$GSTACK_HOME"
elif [ -n "${CLAUDE_PLUGIN_DATA:-}" ]; then
  _state_root="$CLAUDE_PLUGIN_DATA"
elif [ -n "${HOME:-}" ]; then
  _state_root="$HOME/.gstack"
else
  _state_root=".gstack"
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

# 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

echo "GSTACK_STATE_ROOT=$_state_root"
echo "PLAN_ROOT=$_plan_root"
echo "TMP_ROOT=$_tmp_root"