#!/bin/bash
set -e
set -o pipefail

usage(){
	fmt <<EOF
DESCRIPTION
	Syncs books from standardebooks.org GitHub org to specified folder.

USAGE
	${0##*/} [-v,-vv,--verbosity=INTEGER] [-u,--update-only] DIRECTORY

	With -v or --verbosity=1, display general progress updates.
	With -vv or --verbosity=2, display general progress updates and verbose git output.
	With --update-only, only sync existing repositories, do not download new repositories.

	DIRECTORY should be where the repositories should go.

EXAMPLE
	${0##*/} /standardebooks.org/ebooks
EOF
	exit
}
die(){ printf "\033[0;7;31mError:\033[0m %s\n" "${1}" 1>&2; exit 1; }
if [ $#  -eq 1 ]; then if [ "$1" = "--help" ] || [ "$1" = "-h" ]; then usage; fi fi
# End boilerplate

# Terminate on CTRL-C
trap ctrl_c INT
ctrl_c() {
	exit
}

if [[ $# -lt 1 ]]; then
	usage
fi

verbosity=0
updateOnly="false"
target=""

for i in "$@"
do
	case $i in
		-h|--help)
			usage
		;;
		-v)
			verbosity=1
			shift
		;;
		-vv)
			verbosity=2
			shift
		;;
		--verbosity=*)
			verbosity=${i//[-a-zA-Z0-9]*=/}
			shift
		;;
		-u|--update-only)
			updateOnly="true"
			shift
		;;
		*)
			target="${i}"
			shift
	esac
done

if ! [ -d "${target}" ]; then
	die "${target} is not a directory."
fi

if ! cd "${target}"; then
	die "Couldn’t cd into ${target}"
fi

if [ "${verbosity}" -gt 0 ]; then
	printf "Updating local repositories ... \n"
fi

for item in ./*; do
	[ -e "${item}" ] || break

	if [ "${verbosity}" -eq 1 ]; then
		printf "Updating %s ... " "${item}"
		git -C "${item}" fetch -q
		printf "Done.\n"
	elif [ "${verbosity}" -gt 1 ]; then
		printf "Updating %s ... \n" "${item}"
		git -C "${item}" fetch -v
	fi
done

if [ "${updateOnly}" = "true" ]; then
	exit
fi

if [ "${verbosity}" -gt 0 ]; then
	printf "Cloning remote repositories ... \n"
	printf "Fetching repository urls ..."
fi

page=1
urls=""
pageurls="placeholder"
while [ -n "${pageurls}" ]; do
	pageurls=$(curl -s "https://api.github.com/orgs/standardebooks/repos?per_page=100&page=${page}" \
		| awk 'BEGIN { FS="\""; RS="," }; { if ($2 == "clone_url") {print $4} }')
	urls=$(printf "%s\n%s" "${urls}" "${pageurls}")
	page=$((page + 1))

	if [ "${verbosity}" -gt 0 ]; then
		printf "."
	fi
done

if [ "${verbosity}" -gt 0 ]; then
	printf " Done.\n"
fi

urls=$(printf "%s\n" "${urls}" | grep -v -e "/tools.git\$" -e "/web.git\$" -e "/manual.git\$" | awk 'NF')

printf "%s\n" "${urls}" | while IFS= read -r repourl; do
	[ -n "${repourl}" ] || continue
	[ -d "${repourl##*/}" ] && continue

	if [ "${verbosity}" -gt 1 ]; then
		printf "Cloning %s ... \n" "${repourl}"
		git clone -v --bare "${repourl}"
		if ! [ -d "${repourl##*/}" ]; then
			printf "Failed.\n"
		fi
	else
		if [ "${verbosity}" -gt 0 ]; then
			printf "Cloning %s ... " "${repourl}"
		fi
		git clone -q --bare "${repourl}"
		if [ "${verbosity}" -gt 0 ]; then
			if ! [ -d "${repourl##*/}" ]; then
				printf "Failed.\n"
			else
				printf "Done.\n"
			fi
		fi
	fi
done