#!/usr/bin/env bash
# Run a command inside the DarkRoom Android build container.
#
#   ./docker/android/build.sh cargo ndk -t arm64-v8a build --release
#   ./docker/android/build.sh cargo check --target aarch64-linux-android
#   ./docker/android/build.sh                    # interactive shell
#
# Builds the image on first use. Rebuild after editing the Dockerfile with:
#   ./docker/android/build.sh --rebuild
set -euo pipefail

IMAGE="darkroom-android:latest"
HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO="$(cd "${HERE}/../.." && pwd)"

# Prefer podman (rootless by default); fall back to docker.
if command -v podman >/dev/null 2>&1; then
    ENGINE=podman
elif command -v docker >/dev/null 2>&1; then
    ENGINE=docker
else
    echo "error: neither podman nor docker found" >&2
    exit 1
fi

if [[ "${1:-}" == "--rebuild" ]]; then
    shift
    "${ENGINE}" build -t "${IMAGE}" "${HERE}"
elif ! "${ENGINE}" image exists "${IMAGE}" 2>/dev/null && \
     ! "${ENGINE}" image inspect "${IMAGE}" >/dev/null 2>&1; then
    echo "==> building ${IMAGE} (first run; several minutes)"
    "${ENGINE}" build -t "${IMAGE}" "${HERE}"
fi

# Persist the cargo registry and target dir across runs, or every build
# re-downloads the crate index.
CACHE="${XDG_CACHE_HOME:-${HOME}/.cache}/darkroom-android"
mkdir -p "${CACHE}/registry" "${CACHE}/target"

ARGS=(
    --rm
    -v "${REPO}:/work:z"
    -v "${CACHE}/registry:/opt/cargo/registry:z"
    -v "${CACHE}/target:/work/target-android:z"
    -e CARGO_TARGET_DIR=/work/target-android
    -w /work
)

# Rootless podman already maps the host user; docker needs it stated.
if [[ "${ENGINE}" == "docker" ]]; then
    ARGS+=(--user "$(id -u):$(id -g)")
fi

if [[ $# -eq 0 ]]; then
    ARGS+=(-it)
    set -- /bin/bash
fi

exec "${ENGINE}" run "${ARGS[@]}" "${IMAGE}" "$@"