#!/usr/bin/env bash

# Create a local k3d cluster with only agents that join a remote K3s server.
# This uses k3s args: --server and --token applied to all agent nodes.

set -euo pipefail

: "${K3D_CLUSTER_NAME:=knoe-remote-agents}"
: "${K3D_AGENTS:=2}"
: "${K3D_IMAGE:=}"  # e.g. rancher/k3s:v1.30.6-k3s1
: "${K3D_REGISTRY_CONFIG:=}"  # optional path to registries.yaml

# Remote server details
: "${K3S_REMOTE_SERVER_HOST:=raspberry.prole.org}"
: "${K3S_REMOTE_SERVER_PORT:=6443}"
: "${K3S_REMOTE_TOKEN:=}"  # required

if [[ -z "${K3S_REMOTE_TOKEN}" ]]; then
  echo "[error] K3S_REMOTE_TOKEN is required. Obtain it using k3s/get_remote_k3s_node_token.sh" >&2
  exit 1
fi

SERVER_URL="https://${K3S_REMOTE_SERVER_HOST}:${K3S_REMOTE_SERVER_PORT}"

K3D_ARGS=(cluster create "${K3D_CLUSTER_NAME}" \
  --servers 0 \
  --agents "${K3D_AGENTS}" \
  --k3s-arg "--server=${SERVER_URL}@agent:*" \
  --k3s-arg "--token=${K3S_REMOTE_TOKEN}@agent:*"
)

if [[ -n "${K3D_IMAGE}" ]]; then
  K3D_ARGS+=(--image "${K3D_IMAGE}")
fi

if [[ -n "${K3D_REGISTRY_CONFIG}" ]]; then
  if [[ ! -f "${K3D_REGISTRY_CONFIG}" ]]; then
    echo "[error] Registry config not found: ${K3D_REGISTRY_CONFIG}" >&2
    exit 1
  fi
  K3D_ARGS+=(--registry-config "${K3D_REGISTRY_CONFIG}")
fi

echo "[info] Creating k3d agents-only cluster '${K3D_CLUSTER_NAME}' joining ${SERVER_URL}"
set -x
k3d "${K3D_ARGS[@]}"
set +x

echo "[ok] k3d cluster '${K3D_CLUSTER_NAME}' created with ${K3D_AGENTS} agent(s) joining ${SERVER_URL}"