#!/bin/bash
# Share data to a running Shrlok instance.

socket_path="/run/shrlok/shr.sock"

usage() {
    echo "Usage: $0 [-s SOCKET_PATH] [-o key1=value1,key2=value2,…] TYPE FILE"
    echo "  -s  override shrlok socket path (default: $socket_path)"
    echo "  -o  comma separated "k=v" pairs to add to the shrlok header"
}

header_args=
while getopts "hs:o:" OPTION; do
    case $OPTION in
        h) usage; exit 0 ;;
        s) socket_path="$OPTARG" ;;
        o) readarray -d "," -t header_args <<< "$OPTARG" ;;
        *) usage; exit 1 ;;
    esac
done
shift $(( OPTIND - 1 ))
[ $# != 2 ] && usage && exit 1

share_type="$1"
input_file="$2"

if [ ! -S "$socket_path" ]; then
    echo "$socket_path is not a valid Unix socket. Is shrlok running?"
    exit 1
fi

header_args_str=""
if [[ -n "$header_args" ]]; then
    for item in "${header_args[@]}"; do
        readarray -d "=" -t kv <<< "$item"
        key="${kv[0]}"
        val="$(echo "${kv[1]}" | xargs)"  # strip trailing LFs
        header_args_str+=",\"$key\":\"$val\""
    done
fi

# The first thing sent through the socket is the total packet length, as ASCII
# digits for the convenience of scripts. Build the header before hand to get its
# size, then get the file length and push everything to the socket with socat.
header="{\"type\":\"$share_type\"$header_args_str}"
header_length="${#header}"
file_length="$(wc -c "$input_file" | cut -d' ' -f1)"
full_length="$(( $header_length + 1 + $file_length ))"

cat <(printf "${full_length}\x00${header}\x00") "$input_file" \
    | socat - UNIX-CONNECT:"$socket_path" ; echo