#!/bin/bash

set -e
cd "$(dirname "$0")"

# This script is meant to be executed on the management machine.
# it reaches out to an SSH endpoint and provisions that machine
# to use LXD.

DATA_PLANE_MACVLAN_INTERFACE=
DISK_TO_USE=

# override the cluster name.
CLUSTER_NAME="${1:-}"
if [ -z "$CLUSTER_NAME" ]; then
    echo "ERROR: The cluster name was not provided. Syntax is: 'ss-cluster CLUSTER_NAME SSH_HOST_FQDN'"
    echo "  for example: 'ss-cluster dev clusterhost01.domain.tld"
    exit 1
fi

#shellcheck disable=SC1091
source ../defaults.sh

export CLUSTER_PATH="$CLUSTERS_DIR/$CLUSTER_NAME"
CLUSTER_DEFINITION="$CLUSTER_PATH/cluster_definition"
export CLUSTER_DEFINITION="$CLUSTER_DEFINITION"

mkdir -p "$CLUSTER_PATH"
if [ ! -f "$CLUSTER_DEFINITION" ]; then
    # stub out a cluster_definition.
    cat >"$CLUSTER_DEFINITION" <<EOL
#!/bin/bash

# see https://www.sovereign-stack.org/cluster-definition for more info!

export LXD_CLUSTER_PASSWORD="$(gpg --gen-random --armor 1 14)"
export BITCOIN_CHAIN="regtest"
export PROJECT_PREFIX="dev"
#export REGISTRY_URL=http://registry.domain.tld:5000

EOL

    chmod 0744 "$CLUSTER_DEFINITION"
    echo "We stubbed out a '$CLUSTER_DEFINITION' file for you."
    echo "Use this file to customize your cluster deployment;"
    echo "Check out 'https://www.sovereign-stack.org/cluster-definition' for more information."
    exit 1
fi

source "$CLUSTER_DEFINITION"

if ! lxc remote list | grep -q "$CLUSTER_NAME"; then
    FQDN="${2:-}"

    if [ -z "$FQDN" ]; then
        echo "ERROR: You MUST provide the FQDN of the cluster host."
        exit
    fi

    shift

    if [ -z "$FQDN" ]; then
        echo "ERROR: The Fully Qualified Domain Name of the new cluster member was not set."
        exit 1
    fi

    # let's check to ensure we have SSH access to the specified host.
    if ! wait-for-it -t 5 "$FQDN:22"; then
        echo "ERROR: We can't get an SSH connection to '$FQDN:22'. Ensure you have the host set up correctly."
        exit 1
    fi

    # grab any modifications from the command line.
    for i in "$@"; do
        case $i in
            --data-plane-interface=*)
                DATA_PLANE_MACVLAN_INTERFACE="${i#*=}"
                shift
            ;;
            --disk=*)
                DISK_TO_USE="${i#*=}"
                shift
            ;;
            *)

            ;;
        esac
    done

    # first let's copy our ssh pubkey to the remote server so we don't have to login constantly.
    ssh-copy-id -i "$HOME/.ssh/id_rsa.pub" "ubuntu@$FQDN"

    if [ -z "$DATA_PLANE_MACVLAN_INTERFACE" ]; then
        echo "INFO: It looks like you didn't provide input on the command line for the data plane macvlan interface."
        echo "      We need to know which interface that is! Enter it here now."
        echo ""

        ssh "ubuntu@$FQDN" ip link

        echo "Please enter the network interface that's dedicated to the Sovereign Stack data plane: "
        read -r DATA_PLANE_MACVLAN_INTERFACE

    fi

    if [ -z "$DISK_TO_USE" ]; then
        echo "INFO: It looks like the DISK_TO_USE has not been set. Enter it now."
        echo ""

        ssh "ubuntu@$FQDN" lsblk --paths

        echo "Please enter the disk or partition that Sovereign Stack will use to store data (default: loop):  "
        read -r DISK_TO_USE
    fi

else
    echo "ERROR: the cluster already exists! You need to go delete your lxd remote if you want to re-create your cluster."
    echo "       It's may also be helpful to reset/rename your cluster path."
    exit 1
fi

# if the disk is loop-based, then we assume the / path exists.
if [ "$DISK_TO_USE" != loop ]; then
    # ensure we actually have that disk/partition on the system.
    if ! ssh "ubuntu@$FQDN" lsblk --paths | grep -q "$DISK_TO_USE"; then
        echo "ERROR: We could not findthe disk you specified. Please run this command again and supply a different disk."
        echo "NOTE: You can always specify on the command line by adding the '--disk=/dev/sdd', for example."
        exit 1
    fi
fi

# The MGMT Plane IP is the IP address that the LXD API binds to, which happens
# to be the same as whichever SSH connection you're coming in on.
MGMT_PLANE_IP="$(ssh ubuntu@"$FQDN" env | grep SSH_CONNECTION | cut -d " " -f 3)"
IP_OF_MGMT_MACHINE="$(ssh ubuntu@"$FQDN" env | grep SSH_CLIENT | cut -d " " -f 1 )"
IP_OF_MGMT_MACHINE="${IP_OF_MGMT_MACHINE#*=}"
IP_OF_MGMT_MACHINE="$(echo "$IP_OF_MGMT_MACHINE" | cut -d: -f1)"

# error out if the cluster password is unset.
if [ -z "$LXD_CLUSTER_PASSWORD" ]; then
    echo "ERROR: LXD_CLUSTER_PASSWORD must be set in your cluster_definition."
    exit 1
fi

if ! command -v lxc >/dev/null 2>&1; then
    if lxc profile list --format csv | grep -q "$BASE_IMAGE_VM_NAME"; then
        lxc profile delete "$BASE_IMAGE_VM_NAME"
        sleep 1
    fi

    if lxc network list --format csv | grep -q lxdbr0; then
        lxc network delete lxdbr0
        sleep 1
    fi

fi

# install dependencies.
ssh "ubuntu@$FQDN" sudo apt-get update && sudo apt-get upgrade -y && sudo apt install htop dnsutils nano -y
if ! ssh "ubuntu@$FQDN" snap list | grep -q lxd; then
    ssh "ubuntu@$FQDN" sudo snap install lxd --channel=5.10/stable
    sleep 10
fi

# if the DATA_PLANE_MACVLAN_INTERFACE is not specified, then we 'll
# just attach VMs to the network interface used for for the default route.
if [ -z "$DATA_PLANE_MACVLAN_INTERFACE" ]; then
    DATA_PLANE_MACVLAN_INTERFACE="$(ssh -t ubuntu@"$FQDN" ip route | grep default | cut -d " " -f 5)"
fi

export DATA_PLANE_MACVLAN_INTERFACE="$DATA_PLANE_MACVLAN_INTERFACE"

echo "DATA_PLANE_MACVLAN_INTERFACE: $DATA_PLANE_MACVLAN_INTERFACE"
# run lxd init on the remote server.
cat <<EOF | ssh ubuntu@"$FQDN" lxd init --preseed
config:
  core.https_address: ${MGMT_PLANE_IP}:8443
  core.trust_password: ${LXD_CLUSTER_PASSWORD}
  core.dns_address: ${MGMT_PLANE_IP}
  images.auto_update_interval: 15
  
networks:
- name: lxdbr0
  description: "ss-config,${DATA_PLANE_MACVLAN_INTERFACE:-error}"
  type: bridge
  config:
    ipv4.nat: true
    ipv4.dhcp: true
    ipv6.address: none
    dns.mode: managed
profiles:
- config: {}
  description: "default profile for sovereign-stack instances."
  devices:
    root:
      path: /
      pool: ss-base
      type: disk
  name: default
cluster:
  server_name: ${CLUSTER_NAME}
  enabled: true
  member_config: []
  cluster_address: ""
  cluster_certificate: ""
  server_address: ""
  cluster_password: ""
  cluster_certificate_path: ""
  cluster_token: ""
EOF

# ensure the lxd service is available over the network, then add a lxc remote, then switch the active remote to it.
if wait-for-it -t 20 "$FQDN:8443"; then
    # now create a remote on your local LXC client and switch to it.
    # the software will now target the new cluster.
    lxc remote add "$CLUSTER_NAME" "$FQDN" --password="$LXD_CLUSTER_PASSWORD" --protocol=lxd --auth-type=tls --accept-certificate
    lxc remote switch "$CLUSTER_NAME"

    echo "INFO: You have create a new cluster named '$CLUSTER_NAME'. Great! We switched your lxd remote to it."
else
    echo "ERROR: Could not detect the LXD endpoint. Something went wrong."
    exit 1
fi

# create the default storage pool if necessary
if ! lxc storage list --format csv | grep -q ss-base; then

    if [ "$DISK_TO_USE" != loop ]; then
        # we omit putting a size here so, so LXD will consume the entire disk if '/dev/sdb' or partition if '/dev/sdb1'.
        # TODO do some sanity/resource checking on DISK_TO_USE. Impelment full-disk encryption?
        lxc storage create ss-base zfs source="$DISK_TO_USE"

    else
        # if a disk is the default 'loop', then we create a zfs storage pool 
        # on top of the existing filesystem using a loop device, per LXD docs
        lxc storage create ss-base zfs
    fi
fi