bazel

#!/usr/bin/env bash
# Project-local Bazel wrapper.
# Reads the required version from .bazelversion, downloads that exact Bazel
# binary on first use (cached in ~/.cache/bazel-versions/), and exec's it.
# Usage: ./bazel <bazel-args...>  — identical to running 'bazel' directly.

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
BAZELVERSION_FILE="${SCRIPT_DIR}/.bazelversion"

# ── Read version ────────────────────────────────────────────────────────────
if [[ ! -f "${BAZELVERSION_FILE}" ]]; then
  echo "ERROR: .bazelversion not found at ${BAZELVERSION_FILE}" >&2
  exit 1
fi

VERSION="$(tr -d '[:space:]' < "${BAZELVERSION_FILE}")"
if [[ -z "${VERSION}" ]]; then
  echo "ERROR: .bazelversion is empty" >&2
  exit 1
fi

# ── Detect platform ──────────────────────────────────────────────────────────
OS="$(uname -s)"
ARCH="$(uname -m)"

case "${OS}" in
  Darwin) OS_LABEL="darwin" ;;
  Linux)  OS_LABEL="linux"  ;;
  *)      echo "ERROR: Unsupported OS: ${OS}" >&2; exit 1 ;;
esac

case "${ARCH}" in
  arm64|aarch64) ARCH_LABEL="arm64"  ;;
  x86_64)        ARCH_LABEL="x86_64" ;;
  *)             echo "ERROR: Unsupported arch: ${ARCH}" >&2; exit 1 ;;
esac

# ── Resolve cache path ───────────────────────────────────────────────────────
CACHE_DIR="${HOME}/.cache/bazel-versions"
BAZEL_BIN="${CACHE_DIR}/bazel-${VERSION}-${OS_LABEL}-${ARCH_LABEL}"
DOWNLOAD_URL="https://github.com/bazelbuild/bazel/releases/download/${VERSION}/bazel-${VERSION}-${OS_LABEL}-${ARCH_LABEL}"

# ── Download if not cached ───────────────────────────────────────────────────
if [[ ! -x "${BAZEL_BIN}" ]]; then
  echo "[bazel] Downloading Bazel ${VERSION} (${OS_LABEL}/${ARCH_LABEL})..." >&2
  mkdir -p "${CACHE_DIR}"
  TMP="$(mktemp "${CACHE_DIR}/.download-XXXXXX")"
  trap 'rm -f "${TMP}"' EXIT

  if command -v curl &>/dev/null; then
    curl -fSL --progress-bar -o "${TMP}" "${DOWNLOAD_URL}"
  elif command -v wget &>/dev/null; then
    wget -q --show-progress -O "${TMP}" "${DOWNLOAD_URL}"
  else
    echo "ERROR: curl or wget is required to download Bazel" >&2
    exit 1
  fi

  chmod +x "${TMP}"
  mv "${TMP}" "${BAZEL_BIN}"
  echo "[bazel] Cached → ${BAZEL_BIN}" >&2
fi

# ── Ensure host packages ─────────────────────────────────────────────────────
SETUP_SCRIPT="${SCRIPT_DIR}/setup.sh"
if [[ -x "${SETUP_SCRIPT}" ]]; then
  "${SETUP_SCRIPT}"
fi


# ── Run ──────────────────────────────────────────────────────────────────────
exec "${BAZEL_BIN}" "$@"