#!/bin/sh

PROGRAM=setup-apkrepos
PREFIX=

. $PREFIX/lib/libalpine.sh


get_hostname_from_url() {
	local n=${1#*://}
	echo ${n%%/*}
}

prompt_setup_method() {
	echo "r) Add random from the above list"
	echo "f) Detect and add fastest mirror from above list"
	echo "e) Edit /etc/apk/repositores with text editor"
	echo ""
	echo -n "Enter mirror number (1-$mirror_count) or URL to add (or r/f/e/done) [$1]: "
}

add_random_mirror() {
	local i=0
	local random_mirror_index=$(( $RANDOM % $mirror_count ))
	
	echo -n "Picking random mirror... "
	for mirror in $MIRRORS; do
		if [ $i -eq $random_mirror_index ]; then
			break
		fi
		i=$(( $i + 1 ))
	done
	add_mirror $mirror
}

add_fastest_mirror() {
	local tmp_mirror_nslookup
	local tmp_mirror_time
	local tmp_mirror_time_failed
	local tmp_mirror_rtt
	local mirror_lowest_rtt
	local mirror_lowest_rtt_mirror

	echo -n "Finding fastest mirror... "
	mirror_lowest_rtt=-1
	for mirror in $MIRRORS; do
		tmp_mirror_time="`(time wget -qO - $mirror) 2>&1 || echo "E_MIRROR_FAILED"`"
		tmp_mirror_time_failed=`echo $tmp_mirror_time | grep "E_MIRROR_FAILED"`
		if [ ${#tmp_mirror_time_failed} -eq 0 ]; then
			tmp_mirror_rtt=`echo "$tmp_mirror_time" | grep -E "^real" | sed -r "s/^real[ 	]+[0-9]+m[ 	]+([0-9]+)\.([0-9]+)s$/\1\2/"`
			if [ $mirror_lowest_rtt -eq -1 ]; then
				mirror_lowest_rtt=$tmp_mirror_rtt
				mirror_lowest_rtt_mirror=$mirror
			else
				if [ $tmp_mirror_rtt -lt $mirror_lowest_rtt ]; then
					mirror_lowest_rtt=$tmp_mirror_rtt
					mirror_lowest_rtt_mirror=$mirror
				fi
			fi
		fi
	done
	mirror=$mirror_lowest_rtt_mirror
	add_mirror "$mirror"
}

# show mirrors and store how many in global mirror_count
show_mirror_list() {
	local mirror i=0
	mirror_count=0
	[ -z "$MIRRORS" ] && return
	echo ""
	echo "Available mirrors:"
	for mirror in $MIRRORS; do
		i=$(($i + 1))
		echo "$i) $(get_hostname_from_url $mirror)"
	done
	echo ""
	mirror_count=$i
}

add_from_list() {
	local mirror_index=$1
	if [ $mirror_index -lt 1 ] || [ $mirror_index -gt $mirror_count ]; then
		return 1
	fi
	set $MIRRORS
	eval "mirror=\$$mirror_index"
	add_mirror "$mirror"
}

get_alpine_release() {
	local version=$(cat /etc/alpine-release 2>/dev/null)
	case "$version" in
		*_git*) release="edge";;
		[0-9]*.[0-9]*.[0-9]*)
			# release in x.y.z format, cut last digit
			release=v${version%.[0-9]*};;
		*)	# fallback to edge
			release="edge";;
	esac
}

add_mirror() {
	local mirror="$1"
	echo "$mirror/$release/main" >> $APKREPOS_PATH
	echo "#$mirror/$release/testing" >> $APKREPOS_PATH
	echo "" >> $APKREPOS_PATH
	echo "Added mirror $(get_hostname_from_url $mirror)"
}

add_from_url() {
	echo "$1" >> $APKREPOS_PATH
	echo "" >> $APKREPOS_PATH
}

edit_repositories() {
	local md5=$(md5sum $APKREPOS_PATH)
	${EDITOR:-vi} "$APKREPOS_PATH"
	# return true if file changed
	test "$(md5sum $APKREPOS_PATH)" != "$md5"
}

# main
# install alpine-mirrors if its not already there
to_uninstall=
if ! apk info -q -e alpine-mirrors; then
	apk add -q alpine-mirrors
	to_uninstall=alpine-mirrors
fi

MIRRORS_PATH=/usr/share/alpine-mirrors/MIRRORS.txt
if [ -z "$MIRRORS" ] && [ -r "$MIRRORS_PATH" ]; then
	MIRRORS=`cat $MIRRORS_PATH`
fi

RELEASES_PATH=/usr/share/alpine-mirrors/RELEASES.txt
if [ -z "$RELEASES" ] && [ -r "$RELEASES_PATH" ]; then
	RELEASES=`cat $RELEASES_PATH`
fi

APKREPOS_PATH=/etc/apk/repositories
if [ -r "$APKREPOS_PATH" ]; then
	APKREPOS=`cat "$APKREPOS_PATH"`
fi

get_alpine_release
default_answer=f
changed=
while true; do
	show_mirror_list
	prompt_setup_method $default_answer

	default_read answer $default_answer
	case "$answer" in
		"done") break;;
		[0-9]*) add_from_list $answer && changed=1;;
		/*|http://*|ftp://*|https://*) add_from_url "$answer" && changed=1;;
		r) add_random_mirror && changed=1;;
		f) add_fastest_mirror && changed=1;;
		e) edit_repositories && changed=1 && break;;
	esac
	if [ -n "$changed" ]; then
		default_answer="done"
	fi
done

if [ -n "$changed" ]; then
	echo -n "Updating repository indexes... "
	apk update -q && echo "done."
fi

# clean up
if [ -n "$to_uninstall" ]; then
	apk del -q alpine-mirrors
fi