#!/bin/sh

PROGRAM=setup-apkrepos
PREFIX=

. $PREFIX/lib/libalpine.sh

if [ "$ROOT" != "/" ]; then
	apk_root_opt="--root $ROOT"
fi

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 "${ROOT}"etc/apk/repositores with text editor"
	echo ""
	echo -n "Enter mirror number (1-$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
}

time_cmd() {
	local start=$(cut -d ' ' -f1 /proc/uptime)
	$@ >&2
	awk -v start=$start -v end=$(cut -d ' ' -f1 /proc/uptime) \
		'BEGIN {print end - start; exit}'
}

find_fastest_mirror() {
	export http_proxy=
	local url=
	for url in $MIRRORS; do
		echo $(time_cmd apk update --quiet $apk_root_opt \
				--repository $url/edge/main \
				--repositories-file /dev/null) $url
	done | awk ' {
		if (!current) {
			current=$1
			url=$2
		} else {
			if ($1 < current) {
				current=$1
				url=$2
			}
		}
		printf("%6.2f %s\n", $1, $2) > "/dev/stderr"
	}
	END { print url }'
}

add_fastest_mirror() {
	echo "Finding fastest mirror... "
	local fastest=$(find_fastest_mirror)
	add_mirror "$fastest"
}

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

add_mirror() {
	local mirror="$1"
	mkdir -p "${APKREPOS_PATH%/*}"
	echo "${mirror%/}/${release}/main" >> $APKREPOS_PATH
	case "$release" in
	v[0-9]*)
		echo "#${mirror%/}/edge/main" >> $APKREPOS_PATH;;
	esac
	echo "#${mirror%/}/edge/testing" >> $APKREPOS_PATH
	echo "" >> $APKREPOS_PATH
	echo "Added mirror $(get_hostname_from_url $mirror)"
}

add_from_url() {
	mkdir -p "${APKREPOS_PATH%/*}"
	echo "$1" >> $APKREPOS_PATH
	echo "" >> $APKREPOS_PATH
}

edit_repositories() {
	local md5=$(md5sum $APKREPOS_PATH 2>/dev/null)
	mkdir -p "${APKREPOS_PATH%/*}"
	${EDITOR:-vi} "$APKREPOS_PATH"
	# return true if file changed
	test "$(md5sum $APKREPOS_PATH 2>/dev/null)" != "$md5"
}

usage() {
	cat <<__EOF__
usage: setup-apkrepos [-hr]

Setup apk repositories

options:
 -h  Show this help
 -r  Add a random mirror and do not prompt
__EOF__
	exit 1

}

while getopts "hr" opt; do
        case $opt in
                h) usage;;
                r) JUSTADDRANDOM=1;;
        esac
done


# main
# install alpine-mirrors if its not already there
to_uninstall=
if ! apk info --quiet --installed alpine-mirrors; then
	apk add --quiet --virtual .setup-apkrepos alpine-mirrors
	to_uninstall=.setup-apkrepos
fi

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

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



get_alpine_release
default_answer=f
changed=
while true; do
	if [ -n "$JUSTADDRANDOM" ]; then
		show_mirror_list > /dev/null
		add_random_mirror && changed=1 && break
	else
		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
			break
		fi
	fi
done

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

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