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

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

USAGE
	${0##*/} [-h] [-v|-vv] [-u] DIRECTORY

	-h displays this message
	-v displays general progress updates
	-vv displays progress updates and verbose git output

	DIRECTORY should be where the repositories should go.

EXAMPLE
	${0##*/} /standardebooks.org/ebooks
EOF
	exit
}

# Terminate on CTRL-C
trap ctrl_c INT
ctrl_c() {
	printf "** Trapped CTRL-C\n"
	exit
}

verbosity=0
update_only="false"
while getopts ":hvu" option; do
	case "${option}" in
		h) usage ;;
		v) verbosity=$((verbosity + 1)) ;;
		u) update_only="true" ;;
		?) usage ;;
	esac
done
shift "$((OPTIND -1))"

if [ -z "$*" ]; then
	usage
fi

if ! [ -d "$*" ]; then
	>&2 printf "%s does not exist.\n" "$*"
	exit
fi

if ! cd "$*"; then
	>&2 printf "Couldn't cd into %s.\n" "$*"
	exit
fi

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

for item in ./*; do
	[ -e "${item}" ] || break
	if [ "${verbosity}" -gt 0 ]; then
		printf "Updating %s\n" "${item}"
	fi

	if [ "${verbosity}" -gt 1 ]; then
		git -C "${item}" fetch -v
	else
		git -C "${item}" fetch -q
	fi
done

if [ "${update_only}" = "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 "\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 [ "${verbosity}" -gt 0 ]; then
		printf "Cloning %s\n" "${repourl}"
	fi

	if [ "${verbosity}" -gt 1 ]; then
		git clone -v --bare "${repourl}"
	else
		git clone -q --bare "${repourl}"
	fi

	if ! [ -d "${repourl##*/}" ]; then
		>&2 printf "%s wasn't cloned." "${repourl}"
	fi
done