#!/bin/sh
# Read-only node health; patch only the named Factorio Deployment.
set -eu
node=$(kubectl get node arschrock --ignore-not-found -o json)
deployment=$(kubectl -n factorio get deployment factorio -o json)
current=$(printf '%s' "$deployment" | jq -c '.spec.template.spec.affinity.nodeAffinity.requiredDuringSchedulingIgnoredDuringExecution.nodeSelectorTerms[0].matchExpressions[0].values')
if [ -z "$node" ]; then
  mode=odroids
else
  mode=$(printf '%s' "$node" | jq -r '
    if .metadata.labels["factorio.brunner.ninja/unavailable"] == "true" or .spec.unschedulable == true then "odroids"
    else ([.status.conditions[] | select(.type == "Ready")][0]) as $ready |
      if $ready == null then "hold"
      elif (now - ($ready.lastTransitionTime | sub("\\.[0-9]+Z$"; "Z") | fromdateiso8601)) < 300 then "hold"
      elif $ready.status == "True" then "primary" else "odroids" end
    end')
fi
case "$mode" in
  primary) desired='["arschrock"]' ;;
  odroids) desired='["odroid-h3-00","odroid-h3-01","odroid-h3-02","odroid-h3-03","odroid-h3-04","odroid-h3-05"]' ;;
  hold) echo 'Node health transition less than five minutes ago; holding placement'; exit 0 ;;
  *) exit 1 ;;
esac
if [ "$current" = "$desired" ]; then
  echo "Placement unchanged: $mode"
  exit 0
fi
# Optimistic concurrency: never overwrite a concurrent deployment or maintenance action.
patch=$(printf '%s' "$deployment" | jq -c --argjson nodes "$desired" '[
 {op:"test",path:"/metadata/resourceVersion",value:.metadata.resourceVersion},
 {op:"replace",path:"/spec/template/spec/affinity/nodeAffinity/requiredDuringSchedulingIgnoredDuringExecution/nodeSelectorTerms/0/matchExpressions/0/values",value:$nodes}
]')
kubectl -n factorio patch deployment factorio --type=json -p "$patch"
echo "Placement changed to $mode"