#!/bin/sh
# vim: set ts=2 sw=2 et:

set -e
set -u

# Generate SSH keypair on control machine (in temporary directory)
TEMP_DIR=$(mktemp -d)
MIGRATION_SSH_KEY="$TEMP_DIR/dokku-sync-migration_ed25519"
SSH_KEY="/path/to/control/key"
ssh-keygen -t ed25519 -f "$SSH_KEY" -N ""

usage() {
  echo "Usage: $0 --src USER@HOSTNAME --dest USER@HOSTNAME --privkey PATH_TO_PRIVATE_KEY"
  echo
  echo "Options:"
  echo "  --src      Source SSH address in the format USER@HOSTNAME"
  echo "  --dest     Destination SSH address in the format USER@HOSTNAME"
  echo "  --privkey  Path to the private SSH key"
  echo "  -h, --help Show this help message"
}

dest_run() {
        ssh -i "$SSH_KEY" "$SOURCE_SSH_ADDR" "$*"
}

source_run() {
        ssh -i "$SSH_KEY" "$SOURCE_SSH_ADDR" "$*"
}

## ENTRYPOINT

# Loop and parse command line arguments
while [ "$#" -gt 0 ]; do
  case "$1" in
    --src)
      SRC_SSH_ADDR="$2"
      shift 2
      ;;
    --dest)
      DEST_SSH_ADDR="$2"
      shift 2
      ;;
    --privkey)
      SSH_KEY="$2"
      shift 2
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "Unknown option: $1"
      usage
      exit 1
      ;;
  esac
done

# Split values for SRC and DEST
DEST_HOST=$(echo "$DEST_SSH_ADDR" | cut -d'@' -f2)
DEST_USER=$(echo "$DEST_SSH_ADDR" | cut -d'@' -f1)
SOURCE_HOST=$(echo "$SRC_SSH_ADDR" | cut -d'@' -f2)
SOURCE_USER=$(echo "$SRC_SSH_ADDR" | cut -d'@' -f1)

# Stop all remote services
source_run "dokku ps:stop --all"

source_run "dokku mariadb:list |tail -n+2 |xargs -iSERVICE -- dokku mariadb:stop SERVICE"
source_run "dokku postgres:list |tail -n+2 |xargs -iSERVICE -- dokku postgres:stop SERVICE"
source_run "dokku redis:list |tail -n+2 |xargs -iSERVICE -- dokku redis:stop SERVICE"
source_run "dokku mongo:list |tail -n+2 |xargs -iSERVICE -- dokku mongo:stop SERVICE"

source_run "systemctl stop docker"
source_run "systemctl stop docker.socket"


# Stop all local services
dest_run "dokku ps:stop --all"
dest_run "systemctl stop docker"
dest_run "systemctl stop docker.socket"

# Prepare directories
dest_run "mkdir -p /home/dokku/"
dest_run "mkdir -p /home/data/"
dest_run "mkdir -p /var/lib/dokku/"

# Copy all data
rsync -avz --delete "$SOURCE_SSH_ADDR:/home/dokku/" "$DEST_SSH_ADDR:/home/dokku/"
rsync -avz --delete "$SOURCE_SSH_ADDR:/var/lib/dokku/" "$DEST_SSH_ADDR:/var/lib/dokku/"
rsync -avz --delete "$SOURCE_SSH_ADDR:/home/data/" "$DEST_SSH_ADDR:/home/data/"
rsync -avz --delete "$SOURCE_SSH_ADDR:/home/git/" "$DEST_SSH_ADDR:/home/git/"

# FIXME: check if rsync succeeded

# Start all local services
dest_run "dokku apps:list"

# Patch URLs from imported domains
dest_run "find /home/dokku/ -name VHOST -or -name URLS -print0 | xargs -0 -iFILE -- sed -i \"s/$SOURCE_HOST/$DEST_HOST/g\" FILE"

echo "SUCCESS"