claudebox/claudebox.sh

# Parse claudebox flags
SKIP_AUDIT=false
DRY_RUN=false
CHECK_MODE=false
SHELL_MODE=false
CLAUDE_ARGS=()

while (( $# > 0 )); do
  case "$1" in
    --yes|-y) SKIP_AUDIT=true ;;
    --dry-run) DRY_RUN=true ;;
    --check) CHECK_MODE=true ;;
    --shell) SHELL_MODE=true ;;
    --) shift; CLAUDE_ARGS+=("$@"); break ;;
    *) CLAUDE_ARGS+=("$1") ;;
  esac
  shift
done
export SKIP_AUDIT  # consumed by Plan 02 audit display

# --check: verify prerequisites and exit (D-10, UX-05)
if [[ "$CHECK_MODE" == true ]]; then
  pass=true
  green=$'\033[32m' red=$'\033[31m' yellow=$'\033[33m' reset=$'\033[0m'

  check_cmd() {
    if command -v "$1" &>/dev/null; then
      echo "${green}OK${reset}    $1" >&2
    else
      echo "${red}FAIL${reset}  $1 -- not found" >&2
      pass=false
    fi
  }

  echo "claudebox prerequisites:" >&2
  echo "" >&2
  check_cmd bwrap
  check_cmd claude
  check_cmd git
  check_cmd curl
  check_cmd nix

  if [[ -d "$HOME/.claudebox" ]]; then
    echo "${green}OK${reset}    ~/.claudebox exists" >&2
  else
    echo "${red}FAIL${reset}  ~/.claudebox -- not found (will be created on first run)" >&2
  fi

  if [[ -v ANTHROPIC_API_KEY ]]; then
    echo "${green}OK${reset}    ANTHROPIC_API_KEY is set" >&2
  else
    echo "${yellow}WARN${reset}  ANTHROPIC_API_KEY is not set" >&2
  fi

  echo "" >&2
  if [[ "$pass" == true ]]; then
    echo "${green}All checks passed.${reset}" >&2
    exit 0
  else
    echo "${red}Some checks failed.${reset}" >&2
    exit 1
  fi
fi

# SANDBOX_PATH is injected by flake.nix via makeBinPath (only runtimeInputs, no host PATH)
# Resolve binary paths from runtimeInputs
SANDBOX_BASH="$(command -v bash)"
CLAUDE_BIN="$(command -v claude)"

# Record CWD
CWD=$(pwd)

# Ensure ~/.claudebox exists
mkdir -p "$HOME/.claudebox"

# Generate minimal .gitconfig (D-05)
GIT_NAME=$(git config --global user.name 2>/dev/null || echo "Claude User")
GIT_EMAIL=$(git config --global user.email 2>/dev/null || echo "claude@localhost")

GITCONFIG_TMP=$(mktemp)
trap 'rm -f "$GITCONFIG_TMP"' EXIT

cat > "$GITCONFIG_TMP" <<GITEOF
[user]
    name = $GIT_NAME
    email = $GIT_EMAIL
[safe]
    directory = *
GITEOF

# Build environment --setenv args array (D-03, D-04, SAND-02, SAND-03)
# Sandbox-generated vars -- set directly, never from host
ENV_ARGS=(
  --setenv HOME "$HOME"
  --setenv USER "$USER"
  --setenv PATH "$SANDBOX_PATH"
  --setenv SHELL "$SANDBOX_BASH"
  --setenv TMPDIR /tmp
  --setenv XDG_RUNTIME_DIR /tmp
  --setenv NIX_SSL_CERT_FILE /etc/ssl/certs/ca-certificates.crt
  --setenv SSL_CERT_FILE /etc/ssl/certs/ca-certificates.crt
)

# Allowlisted host vars -- only pass if set on host
HOST_ALLOWLIST=(TERM EDITOR LANG LC_ALL ANTHROPIC_API_KEY)
for var in "${HOST_ALLOWLIST[@]}"; do
  if [[ -v "$var" ]]; then
    ENV_ARGS+=(--setenv "$var" "${!var}")
  fi
done

# CLAUDEBOX_EXTRA_ENV escape hatch (D-03, comma-separated)
if [[ -v CLAUDEBOX_EXTRA_ENV ]]; then
  IFS=',' read -ra EXTRAS <<< "$CLAUDEBOX_EXTRA_ENV"
  for var in "${EXTRAS[@]}"; do
    var="${var// /}"  # trim whitespace
    if [[ -n "$var" ]] && [[ -v "$var" ]]; then
      ENV_ARGS+=(--setenv "$var" "${!var}")
    fi
  done
fi

# Build sandbox command
if [[ "$SHELL_MODE" == true ]]; then
  SANDBOX_CMD=("$SANDBOX_BASH" "${CLAUDE_ARGS[@]}")
else
  SANDBOX_CMD=("$CLAUDE_BIN" --dangerously-skip-permissions "${CLAUDE_ARGS[@]}")
fi

# --dry-run: print the bwrap command without executing (D-09, UX-04)
if [[ "$DRY_RUN" == true ]]; then
  {
    echo "bwrap \\"
    echo "  --clearenv \\"
    dry_run_i=0
    while (( dry_run_i < ${#ENV_ARGS[@]} )); do
      printf '  %s %s %q \\\n' "${ENV_ARGS[$dry_run_i]}" "${ENV_ARGS[$((dry_run_i+1))]}" "${ENV_ARGS[$((dry_run_i+2))]}"
      (( dry_run_i += 3 ))
    done
    echo "  --tmpfs / \\"
    echo "  --proc /proc \\"
    echo "  --dev /dev \\"
    echo "  --tmpfs /tmp \\"
    echo "  --ro-bind /nix/store /nix/store \\"
    echo "  --bind /nix/var/nix /nix/var/nix \\"
    echo "  --ro-bind /etc/resolv.conf /etc/resolv.conf \\"
    echo "  --ro-bind /etc/ssl /etc/ssl \\"
    echo "  --ro-bind /etc/static /etc/static \\"
    echo "  --ro-bind /etc/passwd /etc/passwd \\"
    echo "  --ro-bind /etc/group /etc/group \\"
    echo "  --ro-bind /etc/hosts /etc/hosts \\"
    echo "  --ro-bind /etc/nsswitch.conf /etc/nsswitch.conf \\"
    echo "  --ro-bind /etc/nix /etc/nix \\"
    printf '  --symlink %q /usr/bin/env \\\n' "$(readlink -f "$(command -v env)")"
    echo "  --tmpfs $HOME \\"
    echo "  --bind $HOME/.claudebox $HOME/.claude \\"
    printf '  --ro-bind %q %s/.gitconfig \\\n' "$GITCONFIG_TMP" "$HOME"
    echo "  --bind $CWD $CWD \\"
    echo "  --chdir $CWD \\"
    printf '  -- %s\n' "${SANDBOX_CMD[*]}"
  } >&2
  exit 0
fi

# exec bwrap (SAND-04 through SAND-15, UX-06, D-01)
exec bwrap \
  --clearenv \
  "${ENV_ARGS[@]}" \
  --tmpfs / \
  --proc /proc \
  --dev /dev \
  --tmpfs /tmp \
  --ro-bind /nix/store /nix/store \
  --bind /nix/var/nix /nix/var/nix \
  --ro-bind /etc/resolv.conf /etc/resolv.conf \
  --ro-bind /etc/ssl /etc/ssl \
  --ro-bind /etc/static /etc/static \
  --ro-bind /etc/passwd /etc/passwd \
  --ro-bind /etc/group /etc/group \
  --ro-bind /etc/hosts /etc/hosts \
  --ro-bind /etc/nsswitch.conf /etc/nsswitch.conf \
  --ro-bind /etc/nix /etc/nix \
  --symlink "$(readlink -f "$(command -v env)")" /usr/bin/env \
  --tmpfs "$HOME" \
  --bind "$HOME/.claudebox" "$HOME/.claude" \
  --ro-bind "$GITCONFIG_TMP" "$HOME/.gitconfig" \
  --bind "$CWD" "$CWD" \
  --chdir "$CWD" \
  -- "${SANDBOX_CMD[@]}"