#!/usr/bin/env bash

original_image=
hosts=
image_prefix=
prog=rbd-replay
delay=0

while test -n "$1"; do
  case "$1" in
    --original-image)
        original_image="$2"
        shift
        ;;
    --original-image=*)
        original_image="${1#--original-image=}"
        ;;
    --image-prefix)
        image_prefix="$2"
        shift
        ;;
    --image-prefix=*)
        image_prefix="${1#--image-prefix=}"
        ;;
    --exec)
        prog="$2"
        shift
        ;;
    --exec=*)
        prog="${1#--exec=}"
        ;;
    --delay)
        delay="$2"
        shift
        ;;
    --delay=*)
        delay="${1#--delay=}"
        ;;
    --help|-h)
        echo "Usage: $0 [options] --original-image=<name> <host1> [<host2> [...]] -- <rbd-replay-args>"
        echo "Options:"
        echo "  --original-image=name  Name (and snap) of the image that was originally traced"
        echo "  --image-prefix=prefix  Prefix of the image names to replay against"
        echo "  --exec=program         Path to the rbd-replay executable"
        echo "  --delay=seconds        Wait <seconds> between starting each replay"
        exit 0
        ;;
    --)
        # remaining args are passed directly to rbd-replay
        shift
        break
        ;;
    -*)
        echo "Unrecognized argument: $1" >&2
        echo "(If you want to pass an argument directly to rbd-replay, use it after '--'.)" >&2
        exit 1
        ;;
    *)
        hosts="$hosts $1"
        ;;
  esac
  shift
done

if test -z "$original_image"; then
   echo "Specify the original image name with --original-image." >&2
   exit 1
fi

if test -z "$hosts"; then
   echo "No hosts specified." >&2
   exit 1
fi

if test -z "$image_prefix"; then
   image_prefix="$original_image"
fi

index=0
for host in $hosts; do
    echo ssh $host "'$prog'" --map-image "'${original_image}=${image_prefix}-${index}'" "$@"
    ssh $host "'$prog'" --map-image "'${original_image}=${image_prefix}-${index}'" "$@" &
    index=$((index + 1))
    if [ $delay -gt 0 ]; then
       sleep $delay
    fi
done
wait