package health

import corev1 "k8s.io/api/core/v1"

// NodeHealth describes the health of a single node. It is richer than a Level
// (callers surface the individual signals), so Node returns the struct; map it
// to a Level at the call site if a coarse verdict is needed.
type NodeHealth struct {
	Ready         bool
	Unschedulable bool
	Pressures     []string // "MemoryPressure", "DiskPressure", "PIDPressure"
	Version       string   // kubelet version
	Reason        string   // condition message if NotReady
}

// Node evaluates a node's conditions and spec.
func Node(node *corev1.Node) NodeHealth {
	h := NodeHealth{
		Unschedulable: node.Spec.Unschedulable,
		Version:       node.Status.NodeInfo.KubeletVersion,
	}

	for _, cond := range node.Status.Conditions {
		switch cond.Type {
		case corev1.NodeReady:
			h.Ready = cond.Status == corev1.ConditionTrue
			if !h.Ready && cond.Message != "" {
				h.Reason = cond.Message
			}
		case corev1.NodeMemoryPressure:
			if cond.Status == corev1.ConditionTrue {
				h.Pressures = append(h.Pressures, "MemoryPressure")
			}
		case corev1.NodeDiskPressure:
			if cond.Status == corev1.ConditionTrue {
				h.Pressures = append(h.Pressures, "DiskPressure")
			}
		case corev1.NodePIDPressure:
			if cond.Status == corev1.ConditionTrue {
				h.Pressures = append(h.Pressures, "PIDPressure")
			}
		}
	}

	return h
}