# This is NOT run under do_with_retries.
function download_git_kernel_bundle() {
	# See https://mirrors.edge.kernel.org/pub/scm/.bundles/pub/scm/linux/kernel/git/

	# rpardini: I'm a bit undecided about using the stable bundle (5gb) or the Linus bundle (3gb)
	# the stable seems much better at the end of the day.
	declare bundle_type="${bundle_type:-"stable"}" linux_clone_bundle_url=""
	case "${bundle_type}" in
		stable)
			display_alert "Using Kernel bundle" "${bundle_type}" "debug"
			linux_clone_bundle_url="https://mirrors.edge.kernel.org/pub/scm/.bundles/pub/scm/linux/kernel/git/stable/linux/clone.bundle"
			;;
		linus)
			display_alert "Using Kernel bundle" "${bundle_type}" "debug"
			linux_clone_bundle_url="https://mirrors.edge.kernel.org/pub/scm/.bundles/pub/scm/linux/kernel/git/torvalds/linux/clone.bundle"
			;;
	esac

	declare git_bundles_dir="${SRC}/cache/git-bundles/kernel"
	run_host_command_logged mkdir -pv "${git_bundles_dir}"

	# defines outer scope value
	linux_kernel_clone_bundle_file="${git_bundles_dir}/linux-${bundle_type}.bundle"
	declare linux_kernel_clone_bundle_file_tmp="${linux_kernel_clone_bundle_file}.tmp"

	# if the file already exists, do nothing
	if [[ -f "${linux_kernel_clone_bundle_file}" ]]; then
		display_alert "Kernel bundle already exists" "${bundle_type}" "cachehit"
		return 0
	fi

	# download into the tmp_file until it works, then rename to final; use axel.
	do_with_retries 5 kernel_download_bundle_with_axel

	# move into place, only if everything worked, retried or not.
	run_host_command_logged mv -v "${linux_kernel_clone_bundle_file_tmp}" "${linux_kernel_clone_bundle_file}"

	return 0
}

function download_git_kernel_gitball_via_oras() {
	declare git_bundles_dir="${SRC}/cache/git-bundles/kernel"
	declare git_kernel_ball_fn="linux-complete.git.tar"

	run_host_command_logged mkdir -p "${git_bundles_dir}"

	# defines outer scope value
	linux_kernel_clone_tar_file="${git_bundles_dir}/${git_kernel_ball_fn}"

	# if the file already exists, do nothing
	if [[ -f "${linux_kernel_clone_tar_file}" ]]; then
		display_alert "Kernel git-tarball already exists" "${git_kernel_ball_fn}" "cachehit"
		return 0
	fi

	#do_with_retries 5 xxx ?
	oras_pull_artifact_file "ghcr.io/rpardini/armbian-git-shallow/kernel-git:latest" "${git_bundles_dir}" "${git_kernel_ball_fn}"

	# sanity check
	if [[ ! -f "${linux_kernel_clone_tar_file}" ]]; then
		exit_with_error "Kernel git-tarball download failed ${linux_kernel_clone_tar_file}"
	fi

	return 0

}

function kernel_cleanup_bundle_artifacts() {
	declare git_bundles_dir="${SRC}/cache/git-bundles/kernel"

	if [[ -d "${git_bundles_dir}" ]]; then
		display_alert "Cleaning up Kernel git bundle artifacts" "no longer needed" "cachehit"
		run_host_command_logged rm -rf "${git_bundles_dir}"
	fi

	return 0
}

function kernel_download_bundle_with_axel() {
	display_alert "Downloading Kernel bundle" "${bundle_type}; this might take a long time" "info"
	declare -a verbose_params=()
	if_user_on_terminal_and_not_logging_add verbose_params "--verbose" "--alternate"
	if_user_not_on_terminal_or_is_logging_add verbose_params "--quiet"
	run_host_command_logged axel "${verbose_params[@]}" "--output=${linux_kernel_clone_bundle_file_tmp}" \
		"${linux_clone_bundle_url}"
}

function kernel_prepare_bare_repo_from_oras_gitball() {
	kernel_git_bare_tree="${SRC}/cache/git-bare/kernel" # sets the outer scope variable
	declare kernel_git_bare_tree_done_marker="${kernel_git_bare_tree}/.git/armbian-bare-tree-done"

	if [[ ! -d "${kernel_git_bare_tree}" || ! -f "${kernel_git_bare_tree_done_marker}" ]]; then
		display_alert "Preparing bare kernel git tree" "this might take a long time" "info"

		if [[ -d "${kernel_git_bare_tree}" ]]; then
			display_alert "Removing old kernel bare tree" "${kernel_git_bare_tree}" "info"
			run_host_command_logged rm -rf "${kernel_git_bare_tree}"
		fi

		# now, make sure we've the bundle downloaded correctly...
		# this defines linux_kernel_clone_bundle_file
		declare linux_kernel_clone_tar_file
		download_git_kernel_gitball_via_oras # sets linux_kernel_clone_tar_file or dies

		# Just extract the tar_file into the "${kernel_git_bare_tree}" directory, no further work needed.
		run_host_command_logged mkdir -p "${kernel_git_bare_tree}"
		# @TODO chance of a pv thingy here?
		run_host_command_logged tar -xf "${linux_kernel_clone_tar_file}" -C "${kernel_git_bare_tree}"

		# sanity check
		if [[ ! -d "${kernel_git_bare_tree}/.git" ]]; then
			exit_with_error "Kernel bare tree is missing .git directory ${kernel_git_bare_tree}"
		fi

		# write the marker file
		touch "${kernel_git_bare_tree_done_marker}"
	else
		display_alert "Kernel bare tree already exists" "${kernel_git_bare_tree}" "cachehit"
	fi

	git_ensure_safe_directory "${kernel_git_bare_tree}"

	return 0
}

function kernel_prepare_bare_repo_from_bundle() {
	kernel_git_bare_tree="${SRC}/cache/git-bare/kernel" # sets the outer scope variable
	declare kernel_git_bare_tree_done_marker="${kernel_git_bare_tree}/.git/armbian-bare-tree-done"

	if [[ ! -d "${kernel_git_bare_tree}" || ! -f "${kernel_git_bare_tree_done_marker}" ]]; then
		if [[ -d "${kernel_git_bare_tree}" ]]; then
			display_alert "Removing old kernel bare tree" "${kernel_git_bare_tree}" "info"
			rm -rf "${kernel_git_bare_tree}"
		fi

		# now, make sure we've the bundle downloaded correctly...
		# this defines linux_kernel_clone_bundle_file
		declare linux_kernel_clone_bundle_file
		download_git_kernel_bundle

		# fetch it, completely, into the bare tree; use clone, not fetch.
		display_alert "Cloning from bundle into bare tree" "this might take a very long time" "info"
		declare -a verbose_params=() && if_user_on_terminal_and_not_logging_add verbose_params "--verbose" "--progress"
		run_host_command_logged git clone "${verbose_params[@]}" --tags --no-checkout \
			"${linux_kernel_clone_bundle_file}" "${kernel_git_bare_tree}"

		# write the marker file
		touch "${kernel_git_bare_tree_done_marker}"
	fi

	return 0
}

function kernel_prepare_git_pre_fetch() {
	local remote_name="kernel-stable-${KERNEL_MAJOR_MINOR}"
	local remote_url="${MAINLINE_KERNEL_SOURCE}"
	local remote_tags_to_fetch="v${KERNEL_MAJOR_MINOR}*"

	# shellcheck disable=SC2154 # do_add_origin is defined in fetch_from_repo, and this is hook for it, so it's in context.
	if [[ "${do_add_origin}" == "yes" ]]; then
		# @TODO: let's not add remotes anymore please? it's unwieldy and unnecessary
		display_alert "Fetching mainline stable tags" "${remote_name} tags: ${remote_tags_to_fetch}" "git"
		regular_git remote add "${remote_name}" "${remote_url}" # Add the remote to the warmup source

		# Fetch the tags. This allows working -rcX versions of still-unreleased minor versions.
		improved_git_fetch "${remote_name}" "'refs/tags/${remote_tags_to_fetch}:refs/tags/${remote_tags_to_fetch}'" || true # Fetch the remote branch tags
		display_alert "After mainline stable tags, working copy size" "$(du -h -s | awk '{print $1}')" "git"                # Show size after bundle pull
	fi
}

function kernel_prepare_git() {
	[[ -z $KERNELSOURCE ]] && return 0 # do nothing if no kernel source... but again, why were we called then?

	display_alert "Downloading sources" "kernel" "git"

	GIT_FIXED_WORKDIR="${LINUXSOURCEDIR}" \
		GIT_PRE_FETCH_HOOK=kernel_prepare_git_pre_fetch_tags \
		GIT_BARE_REPO_FOR_WORKTREE="${kernel_git_bare_tree}" \
		GIT_BARE_REPO_INITIAL_BRANCH="master" \
		fetch_from_repo "$KERNELSOURCE" "kernel:${KERNEL_MAJOR_MINOR}" "$KERNELBRANCH" "yes"
		# second parameter, "dir", is ignored, since we've passed GIT_FIXED_WORKDIR
}