#!/bin/bash -e

if ! command -v buildah > /dev/null; then
    echo install buildah 1.19.3 or later
    exit 1
fi

bv=$(buildah --version)
# translate to array of version components
bv="${bv#buildah version }"
bv="${bv% (*}"
bv=(${bv//./ })

maj=${bv[0]}
min=${bv[1]}
patch=${bv[2]}

ok=$(( maj > 1 || ( maj == 1 && min > 19 ) || ( maj == 1 && min == 19 && patch >= 3 ) ))

if (( ! ok )); then 
    echo install buildah 1.19.3 or later
    exit 1
fi

if ! command -v reg > /dev/null; then
    echo install the reg command for registry inspection
    exit 1
fi

if reg digest $(<tools/toolchain/image) > /dev/null; then
    echo "Toolchain image $(<tools/toolchain/image) exists; select a new name"
    exit 1
fi

# docker arch has a diffrent spelling than uname arch
declare -A docker_arch=(
    [x86_64]=amd64
    [aarch64]=arm64
    [s390x]=s390x
)

usage() {
    cat <<EOF

Options:
  --clang-build-mode <mode> specify one of following build modes:
                            SKIP: skip building optimized clang
                            INSTALL: build and install an optimized clang compiler binary, and save it as a tarball.
                            INSTALL_FROM: install optimized clang from a tarball.
  --clang-archive <file>   specify optimized clang tarball path
  --help                   this help snippet
EOF
}

CLANG_BUILD="SKIP"
while [[ $# -gt 0 ]]; do
    case "$1" in
        "--clang-build-mode")
            if [[ -z "$2" ]]; then
                usage
                exit 1
            fi
            CLANG_BUILD="$2"
            shift 2
            ;;
        "--clang-archive")
            if [[ -z "$2" ]]; then
                usage
                exit 1
            fi
            CLANG_ARCHIVE="$(realpath -m --relative-to=. "$2")"
            shift 2
            ;;
        "--help")
            usage
            exit 0
            ;;
        *)
            usage
            exit 1
            ;;
    esac
done

case "${CLANG_BUILD}" in
    "SKIP" | "INSTALL" | "INSTALL_FROM")
        ;;
    *)
        echo "Invalid mode specified on CLANG_BUILD: ${CLANG_BUILD}"
        exit 1
        ;;
esac

# clang archive file need to be under scylla directory, since we only share
# scylla directory with the container
if [[ "${CLANG_ARCHIVE}" = "../"* ]]; then
    echo "clang archive file need to be under scylla directory"
    exit 1
fi

# set default archive path if not specified
if [[ -z "${CLANG_ARCHIVE}" ]]; then
    CURDIR="$(dirname "$0")"
    LLVM_CLANG_TAG="$(sed -n -e 's/^LLVM_CLANG_TAG=\(.*\)/\1/p' "${CURDIR}"/optimized_clang.sh)"
    IMAGE_ID="$(sed -e 's#docker.io/scylladb/scylla-toolchain:##' "${CURDIR}"/image)"
    CLANG_ARCHIVE="clang_build/optimized_clang_${LLVM_CLANG_TAG}_${IMAGE_ID}.$(arch).tar.gz"
fi

if [[ "${CLANG_BUILD}" = "INSTALL_FROM" ]] && [[ ! -f "${CLANG_ARCHIVE}" ]]; then
    echo "${CLANG_ARCHIVE}" does not exist.
    echo "Please specify vaild file with --clang-archive"
    exit 1
fi

buildah bud --platform="linux/${docker_arch[$(arch)]}" --jobs 0 --squash --no-cache --pull -f tools/toolchain/Dockerfile --manifest "$(<tools/toolchain/image)" -v "$(realpath ./):/mnt:Z" --build-arg CLANG_BUILD="${CLANG_BUILD}" --build-arg CLANG_ARCHIVE="${CLANG_ARCHIVE}"

echo "Done building $(<tools/toolchain/image). You can now test it, and push with"
echo ""
echo "    podman manifest push --all $(<tools/toolchain/image) docker://$(<tools/toolchain/image)"
if [[ "${CLANG_BUILD}" = "INSTALL" ]]; then
    echo ""
    echo "Optimized clang archive saved at:"
    echo "    ${CLANG_ARCHIVE}"
    echo "You can rebuild frozen toolchain without rebuilding optimized clang by:"
    echo "    ./tools/toolchain/prepare --clang-build-mode INSTALL_FROM --clang-archive ${CLANG_ARCHIVE}"
fi