dagger/cmd/dgr

#!/bin/bash

set -e

if [ "$DEBUG" ]; then
	set -x
fi

function main() {
	cmd="$1"; shift
	case "$cmd" in
		info)
			cat <<-EOF
			repo: $(repo)
			branch: $(branch)
			env: $(current_env)
			EOF
		;;
		list)
			dashA="${1:-}"
			if [ "$dashA" = "-a" ]; then
				list_all_envs
			else
				list_all_envs | {
					while read path; do
						if store_stat "dagger/$(branch)" "$path" ; then
							echo "$path"
						fi
					done
				}
			fi
		;;
		*)
			dagger "$cmd" "$@"
		;;
	esac
}

function current_env() {
	if [ "$(ls -A | grep '^.*\.cue$')" ]; then
		git rev-parse --show-prefix
	fi
}

function repo() {
	git rev-parse --show-toplevel
}

function list_all_envs() {
	(
		cd $(repo)
		find . \
			-type f -name '*.cue' -exec dirname {} \; \
			-o \
			-type d -name 'cue.mod' -prune \
		| sed 's/^\.\///' | sort -u
	)
}

function branch() {
	git branch --show-current
}

function dagger() {
	local env="$(current_env)"
	if [ -z "$env" ]; then
		fatal "current directory is not a valid environment"
	fi

	tmpHome="$(mktemp -d)"
	tmpState="${tmpHome}/.dagger/store/my/deployment.json"
	mkdir -p "$(dirname $tmpState)"
	loadState "$env" > "$tmpState"
	HOME="$tmpHome" "$(which dagger)" -e "my" "$@"
	cat "$tmpState" | saveState "$env"
}

function cleanPath() {
	echo "$1" | sed -E 's/\/+/\//g'
}

function loadState() {
	local env="$1"
	local stateFile="$(cleanPath $env/state.json)"
	# echo >&2 "Loading state for $(branch)::$env"
	store_read "dagger/$(branch)" "$stateFile" |
		jq ".name=\"my\"" |
		jq ".plan.type=\"dir\"" |
		jq ".plan.dir.path=\"$(repo)/$env\"" |
		jq ".id=\"my\""
}

function saveState() {
	local env="$1"
	local stateFile="$(cleanPath $env/state.json)"
	# echo >&2 "Saving state for $(branch)::$env"
	newState="$(cat)"
	echo "$newState" | store_write "dagger/$(branch)" "$stateFile" "Write state for env $env"
}

function fatal() {
	echo >&2 "$@"
	exit 1
}

function store_read() {
	local \
		branch="$1" \
		path="$2"
	git cat-file -p "${branch}^{tree}:$path" 2>/dev/null || echo '{}'
}

function store_stat() {
	local \
		branch="$1" \
		path="$2"
	git cat-file -p "${branch}^{tree}:$path" >/dev/null 2>&1
}

function store_write() {
	local \
		branch="$1" \
		path="$2" \
		msg="${3:-write $path}"
		blob="$(git hash-object -w --stdin)" \
		idx="$(mktemp -d)/idx" \
		oldcommit="$(git show-ref "refs/$branch" -s || true)"
	# Load current state into index (will fail if state branch doesn't exist)
	GIT_INDEX_FILE="$idx" git read-tree "refs/$branch" 2>&1 || true
	GIT_INDEX_FILE="$idx" git \
		update-index \
		--add \
		--cacheinfo 100644 "$blob" "$path"
	# Create new tree object
	local newtree=$(GIT_INDEX_FILE="$idx" git write-tree)
	# Create new commit object
	if [ -z "$oldcommit" ]; then
		local newcommit="$(echo $msg | git commit-tree $newtree)"
	else
		local newcommit="$(echo $msg | git commit-tree $newtree -p $oldcommit)"
	fi
	git update-ref "refs/$branch" "$newcommit"
}

main "$@"