#!/bin/bash
# requires: wget, lftp, jq, python3.5, lxml, pyquery 
# set -x
set -e 
set -u 
set -o pipefail

_here=`dirname $(realpath $0)`
GET_FILELIST="${_here}/helpers/docker-ce-filelist.py"

BASE_URL="${TUNASYNC_UPSTREAM_URL:-"https://download.docker.com/linux/static/"}"

REMOTE_FILELIST="${TUNASYNC_WORKING_DIR}/.filelist.remote"
LOCAL_FILELIST="${TUNASYNC_WORKING_DIR}/.filelist.local"
[[ -f $REMOTE_FILELIST ]] && rm $REMOTE_FILELIST
[[ -f $LOCAL_FILELIST ]] && rm $LOCAL_FILELIST

function cleanup () {
	echo "cleaning up"
	[[ -f $REMOTE_FILELIST ]] && rm $REMOTE_FILELIST
	[[ -f $LOCAL_FILELIST ]] && rm $LOCAL_FILELIST
}

trap cleanup EXIT

# download
while read remote_url; do
	dst_rel_file=${remote_url#$BASE_URL}
	dst_file="${TUNASYNC_WORKING_DIR}/${dst_rel_file}"
	dst_dir=`dirname ${dst_file}`

	echo "${dst_rel_file}" >> $REMOTE_FILELIST

	echo "downloading ${remote_url}"
	if [[ -f ${dst_file} ]]; then
		remote_filesize=`curl -sI ${remote_url} | grep -i '^content-length:' | awk '{print $2}' | tr -d '\n\r'`
		local_filesize=`stat -c "%s" ${dst_file}`
		if (( ${remote_filesize} != ${local_filesize} )); then
			rm ${dst_file}
		fi
	else
		mkdir -p $dst_dir
	fi
	
	(cd ${dst_dir} && wget -c -N -q ${remote_url} || rm ${dst_file})
done < <($GET_FILELIST $BASE_URL)

# remove old files
(cd ${TUNASYNC_WORKING_DIR}; find . -type f ) | sed 's+^\./++' > ${LOCAL_FILELIST}
comm <(sort $REMOTE_FILELIST) <(sort $LOCAL_FILELIST) -13 | while read file; do
	file="${TUNASYNC_WORKING_DIR}/$file"
	echo "deleting ${file}"
	[[ -f $file ]] && rm ${file}
done