#!/bin/sh

# A script to recursively pull git repositories behind origin.

# Copyright (c) 2022 Stefan Huber
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

set -e
set -u

showHelp()
{
	echo "Recursively pull git repositories behind origin."
	echo ""
	echo "Usage:"
	echo "  git-pull-all [OPTIONS]"
	echo "  git-pull-all [OPTIONS] DIR"
	echo ""
	echo "OPTIONS:"
	echo "  -a, --ask       ask user for each repo before pull"
	echo "  -h, --help      show this message"
	echo "  -n, --dry-run   do not actually perform pull"
	echo ""
	echo ""
	echo "Examples:"
	echo ""
	echo "Recursively find git repositories and invoke pull if"
	echo "branch is behind origin:"
	echo ""
	echo "  git-pull-all"
	echo ""
	echo "Find git repositories in home directory and print"
	echo "whether they are up to date:"
	echo ""
	echo "  git-pull-all -n ~"

}

if ! options=$(getopt -u -o ahn -l ask,help,dry-run -- "$@"); then
	showHelp >&2
	exit 1
fi
set -- $options

optDryRun=0
optAsk=0

#Parse the arguments
while [ $# -gt 0 ]; do
	case "$1" in
		-h|--help) showHelp; exit 0 ;;
		-n|--dry-run) optDryRun=1 ;;
		-a|--ask) optAsk=1 ;;
		--) shift; break ;;
		-*) echo "Unrecognized option $1" >&2; showHelp >&2; exit 1 ;;
		*) break ;;
	esac
	shift
done

for REPODIR in $(find "$@" -name .git -type d 2> /dev/null); do

	REPO=$(dirname ${REPODIR})
	echo "Run ${REPO} …"

	if [ "${optAsk}" = 1 ]; then
		read -p "  Process [y/N]? " -n1  response
		echo ""

		[ "${response}" = "y" ] || continue
	fi

	git -C ${REPO} remote update

	if [ -z "$(git -C ${REPO} status -uno | grep 'Your branch is behind')" ] ; then
		echo "\e[1;32m Already up to date\e[0m"
	else
		if [ "${optDryRun}" = 1 ]; then
			echo -e "\e[1;31m Skipping due to dry-run\e[0m"
			continue
		fi
		git -C ${REPO} pull
	fi

done