#!/usr/bin/env bash
# Explicit storage paths also work when a rootless Podman agent runs as UID 0
# inside its user namespace. Changing HOME alone then selects the system store.
moshiro_setup_buildah() {
  local store_home="${1:?Buildah cache directory is required}"
  local config="$store_home/.config/containers/moshiro-storage.conf"
  local key runroot
  key="$(printf '%s' "$store_home" | sha256sum | cut -c1-16)"
  runroot="${XDG_RUNTIME_DIR:-/tmp}/moshiro-buildah-$(id -u)/$key"
  mkdir -p "$store_home/.local/share/containers/storage" "$(dirname "$config")" "$runroot"
  (
    umask 077
    printf '[storage]\ndriver = "%s"\ngraphroot = "%s"\nrunroot = "%s"\n' \
      "${STORAGE_DRIVER:-overlay}" "$store_home/.local/share/containers/storage" "$runroot" > "$config"
  )
  chmod 700 "$runroot"
  export CONTAINERS_STORAGE_CONF="$config"
  # The outer Podman container provides the user namespace and capabilities;
  # RUN does not need a second OCI runtime or nested cgroup management.
  export BUILDAH_ISOLATION="${BUILDAH_ISOLATION:-chroot}"
  buildah info >/dev/null
  echo "Buildah store: $store_home/.local/share/containers/storage ($BUILDAH_ISOLATION)"
}