#!/usr/bin/env bash
# Resolve a Python interpreter that can import the MuseHub app.
#
# Sourced by every scripts/verify/verify_*.sh wrapper. Sets PY to an interpreter
# whose environment satisfies `import musehub.main`, or exits non-zero.
#
# Fails closed on purpose: an L1 checkpoint that silently passes because no
# interpreter was available is worse than one that refuses to run. The three
# MuseHub verify checks exist precisely because "the suite was green" was
# accepted as proof that the app worked, so "the check did not run" must never
# be reported as success.
#
# Resolution order:
#   1. $MUSEHUB_VERIFY_PYTHON — explicit override (CI, containers)
#   2. .venv/bin/python       — local developer environment
#   3. python3 on PATH        — only if it can already import musehub
#
# Docker is deliberately not attempted: docker-compose.override.yml bind-mounts
# ../contracts, which is empty on at least one developer machine, so a container
# fallback would fail with a misleading error instead of a clear setup message.

set -euo pipefail

_verify_can_import() {
  "$1" -c 'import musehub.main' >/dev/null 2>&1
}

PY=""

if [[ -n "${MUSEHUB_VERIFY_PYTHON:-}" ]]; then
  if [[ ! -x "${MUSEHUB_VERIFY_PYTHON}" ]]; then
    echo "FAIL: MUSEHUB_VERIFY_PYTHON=${MUSEHUB_VERIFY_PYTHON} is not executable" >&2
    exit 3
  fi
  PY="${MUSEHUB_VERIFY_PYTHON}"
elif [[ -x ".venv/bin/python" ]]; then
  PY=".venv/bin/python"
elif command -v python3 >/dev/null 2>&1 && _verify_can_import "python3"; then
  PY="python3"
else
  cat >&2 <<'SETUP'
FAIL: no Python interpreter can import the MuseHub app.

The L1 verify checks refuse to report success when they cannot run.

Set up a local environment (pyproject requires Python >= 3.14, and the [dev]
extra cannot install because muse_contracts is published on no index):

    python3.14 -m venv .venv
    .venv/bin/python -m pip install -e .
    .venv/bin/python -m pip install -e ../muse
    .venv/bin/python -m pip install pytest httpx

Or point the checks at an existing interpreter:

    MUSEHUB_VERIFY_PYTHON=/path/to/python ok verify-step <step>
SETUP
  exit 3
fi

export PY