git-publish-generated-branch

#!/usr/bin/env bash

set -e

VERSION="0"

USAGE="\
usage:

git-publish-generated-branch <BUILD_DIR> --branch-prefix <PREFIX="x-build/">
git-publish-generated-branch <BUILD_DIR> --branch <FULL_NAME_OF_NEW_BRANCH="{prefix}{source-branch}">

required:
    [--dir] BUILD_DIR


optional:
    -p, --branch-prefix                    = "x-build/"
    -b, --branch                           = "{prefix}{source-branch}"

        --extra-commit-body                = ""
        --remote                           = origin

    -V, --version
    -h, --help


git-publish-generated-branch v${VERSION}
"

while (( $# > 0 )); do
	case $1 in
		-d|--dir)
		 	shift
			BUILD_DIR="$1"
			shift
			;;

		-p|--branch-prefix)
		 	shift
			BUILD_BRANCH_PREFIX="$1"
			shift
			;;
		
		-b|--branch)
			shift
			BUILD_BRANCH="$1"
			shift
			;;

		--extra-commit-body)
			shift
			EXTRA_COMMIT_BODY="$1"
			shift
			;;

		# -v|--verbose)
		# 	shift
		# 	VERBOSE_FLAG="-v"
		# 	;;

		-V|--version)
			shift
			printf "git-publish-generated-branch v${VERSION}"
			exit 0
			;;

		-h|--help)
			shift
			printf "$USAGE"
			exit 0
			;;

		*)
			if [ -z "$BUILD_DIR" ]; then
				BUILD_DIR="$1"
				shift
			else
				printf "\nunknown option "$1".\n\n"
				exit 1
			fi
		;;
	esac
done

[ -z "$BUILD_DIR" ] && {
	printf "$USAGE"
	exit 1
}

SOURCE_BRANCH="$(git branch --show-current)"
SOURCE_BRANCH_COMMIT="$(git rev-parse "$SOURCE_BRANCH")"

# both set
[ -n "$BUILD_BRANCH" ] && [ -n "$BUILD_BRANCH_PREFIX" ] && {
	>&2 printf "\nWARNING: both --branch-prefix and --branch were specified; ignoring --branch-prefix.\n\n"
	unset BUILD_BRANCH_PREFIX
}
# only prefix set
[ -z "$BUILD_BRANCH" ] && [ -n "$BUILD_BRANCH_PREFIX" ] && {
	BUILD_BRANCH="${BUILD_BRANCH_PREFIX}${SOURCE_BRANCH}"
	unset BUILD_BRANCH_PREFIX
}
# neither set
[ -z "$BUILD_BRANCH" ] && [ -z "$BUILD_BRANCH_PREFIX" ] && {
	BUILD_BRANCH_PREFIX="x-build/"
	BUILD_BRANCH="${BUILD_BRANCH_PREFIX}${SOURCE_BRANCH}"
	unset BUILD_BRANCH_PREFIX
	printf "\nneither --branch-prefix nor --branch specified. defaulting to ${BUILD_BRANCH}.\n\n"
}

[ -z "$EXTRA_COMMIT_BODY" ] && EXTRA_COMMIT_BODY=""

TMP_BUILD_DIR="$(mktemp -d)"
mv -v "$BUILD_DIR" "$TMP_BUILD_DIR"
# ~~TODO~~ handle case where user tracks their BUILD_DIR in git (in the non-derived branch).
# edit: wait, in that case they don't need this tool lol

repo_has_uncommitted_changes() {
	local HAS=0
	local DOES_NOT_HAVE=1
	[ -n "$(git status -s)" ] && return $HAS || return $DOES_NOT_HAVE
}

FOUND_UNTRACKED_CHANGES_OUTSIDE_BUILD=0
repo_has_uncommitted_changes && {
	FOUND_UNTRACKED_CHANGES_OUTSIDE_BUILD=1

	git status

	printf "\nWARNING: untracked changes found. resetting them.\n\n"
	git checkout -- .
	git add .
	git reset --hard HEAD
}

# https://stackoverflow.com/a/31914717/9285308
if git rev-parse --quiet --verify "origin/$BUILD_BRANCH"; then
	echo "remote branch __does__ exist"
	git checkout "$BUILD_BRANCH"
	git pull --rebase
else
	echo "remote branch __does NOT__ exist"
	git checkout --orphan "$BUILD_BRANCH"
fi

git clean -xdf
git rm -rf .

mv -v -f "$TMP_BUILD_DIR/$BUILD_DIR"/* .

git add .

NO_CHANGES_IN_BUILD=0
ALLOW_EMPTY_FLAG=()
COMMIT_TITLE_PREFIX=""
repo_has_uncommitted_changes || {
	printf "\nWARNING: 0 changes detected. will create an empty commit.\n\n"
	NO_CHANGES_IN_BUILD=1
	ALLOW_EMPTY_FLAG=("--allow-empty")
	COMMIT_TITLE_PREFIX="(NO CHANGES) "
}

cat <<EOF | git commit ${ALLOW_EMPTY_FLAG[@]} -F-
${COMMIT_TITLE_PREFIX}build $SOURCE_BRANCH_COMMIT from $SOURCE_BRANCH

---
NETWORK_OVERRIDES_BOT_VERSION: 0
FOUND_UNTRACKED_CHANGES_OUTSIDE_BUILD: $FOUND_UNTRACKED_CHANGES_OUTSIDE_BUILD
NO_CHANGES_IN_BUILD: $NO_CHANGES_IN_BUILD
---

$EXTRA_COMMIT_BODY
EOF

git -c push.autoSetupRemote=true push --force