/*
Copyright 2026 The Cozystack Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package model

import (
	"testing"

	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"

	gpuv1alpha1 "github.com/cozystack/cozystack/api/gpu/v1alpha1"
)

func readyNode(mutate func(*corev1.Node)) *corev1.Node {
	n := &corev1.Node{Status: corev1.NodeStatus{Conditions: []corev1.NodeCondition{{Type: corev1.NodeReady, Status: corev1.ConditionTrue}}}}
	n.Name = "gpu-node-3"
	if mutate != nil {
		mutate(n)
	}
	return n
}

func withTaint(key string, effect corev1.TaintEffect) func(*corev1.Node) {
	return func(n *corev1.Node) {
		n.Spec.Taints = append(n.Spec.Taints, corev1.Taint{Key: key, Effect: effect})
	}
}

const farTaint = "medik8s.io/fence-agents-remediation"

func TestCordoned(t *testing.T) {
	tests := []struct {
		name string
		node *corev1.Node
		want bool
	}{
		{"unschedulable", readyNode(func(n *corev1.Node) { n.Spec.Unschedulable = true }), true},
		{"schedulable", readyNode(nil), false},
		{"Fence Agents Remediation taint alone", readyNode(withTaint(farTaint, corev1.TaintEffectNoSchedule)), false},
		{"unschedulable taint without the field", readyNode(withTaint(corev1.TaintNodeUnschedulable, corev1.TaintEffectNoSchedule)), false},
	}
	for _, tc := range tests {
		if got := Cordoned(tc.node); got != tc.want {
			t.Errorf("%s: Cordoned = %v, want %v", tc.name, got, tc.want)
		}
	}
}

func TestReady(t *testing.T) {
	tests := []struct {
		name string
		node *corev1.Node
		want bool
	}{
		{"ready", readyNode(nil), true},
		{"not ready", readyNode(func(n *corev1.Node) { n.Status.Conditions[0].Status = corev1.ConditionFalse }), false},
		{"unknown", readyNode(func(n *corev1.Node) { n.Status.Conditions[0].Status = corev1.ConditionUnknown }), false},
		{"no condition", readyNode(func(n *corev1.Node) { n.Status.Conditions = nil }), false},
	}
	for _, tc := range tests {
		if got := Ready(tc.node); got != tc.want {
			t.Errorf("%s: Ready = %v, want %v", tc.name, got, tc.want)
		}
	}
}

func TestEligible(t *testing.T) {
	tolerateFAR := []corev1.Toleration{{Key: farTaint, Operator: corev1.TolerationOpExists}}
	tests := []struct {
		name        string
		node        *corev1.Node
		tolerations []corev1.Toleration
		want        bool
	}{
		{name: "ready, schedulable, untainted", node: readyNode(nil), want: true},
		{name: "cordoned", node: readyNode(func(n *corev1.Node) { n.Spec.Unschedulable = true }), want: false},
		{name: "not ready", node: readyNode(func(n *corev1.Node) { n.Status.Conditions[0].Status = corev1.ConditionFalse }), want: false},
		{name: "untolerated NoSchedule", node: readyNode(withTaint(farTaint, corev1.TaintEffectNoSchedule)), want: false},
		{name: "untolerated NoExecute", node: readyNode(withTaint("example.com/maintenance", corev1.TaintEffectNoExecute)), want: false},
		{name: "tolerated NoSchedule", node: readyNode(withTaint(farTaint, corev1.TaintEffectNoSchedule)), tolerations: tolerateFAR, want: true},
		{name: "PreferNoSchedule does not count", node: readyNode(withTaint("example.com/soft", corev1.TaintEffectPreferNoSchedule)), want: true},
		// These taints mirror cordon and readiness, which the field and the
		// condition already decide.
		{name: "node.kubernetes.io/unschedulable taint on a schedulable node", node: readyNode(withTaint(corev1.TaintNodeUnschedulable, corev1.TaintEffectNoSchedule)), want: true},
		{name: "node.kubernetes.io/not-ready taint on a ready node", node: readyNode(withTaint(corev1.TaintNodeNotReady, corev1.TaintEffectNoExecute)), want: true},
		{name: "node.kubernetes.io/unreachable taint on a ready node", node: readyNode(withTaint(corev1.TaintNodeUnreachable, corev1.TaintEffectNoExecute)), want: true},
		// Pressure and network taints have no field or condition here that
		// decides them, so they block like any other taint.
		{name: "untolerated disk-pressure", node: readyNode(withTaint(corev1.TaintNodeDiskPressure, corev1.TaintEffectNoSchedule)), want: false},
		{name: "untolerated network-unavailable", node: readyNode(withTaint(corev1.TaintNodeNetworkUnavailable, corev1.TaintEffectNoSchedule)), want: false},
		{
			name: "Gt toleration does not count",
			node: readyNode(func(n *corev1.Node) {
				n.Spec.Taints = []corev1.Taint{{Key: "example.com/gpu-gen", Value: "5", Effect: corev1.TaintEffectNoSchedule}}
			}),
			tolerations: []corev1.Toleration{{Key: "example.com/gpu-gen", Operator: corev1.TolerationOpGt, Value: "3", Effect: corev1.TaintEffectNoSchedule}},
			want:        false,
		},
		{name: "toleration of another effect", node: readyNode(withTaint(farTaint, corev1.TaintEffectNoExecute)), tolerations: []corev1.Toleration{{Key: farTaint, Operator: corev1.TolerationOpExists, Effect: corev1.TaintEffectNoSchedule}}, want: false},
	}
	for _, tc := range tests {
		if got := Eligible(tc.node, tc.tolerations); got != tc.want {
			t.Errorf("%s: Eligible = %v, want %v", tc.name, got, tc.want)
		}
	}
}

func TestServedUnits(t *testing.T) {
	alloc := func(n int32) *int32 { return &n }
	yes, no := true, false
	node := &corev1.Node{Status: corev1.NodeStatus{Allocatable: corev1.ResourceList{
		h100Name: resource.MustParse("8"), l40sName: resource.MustParse("3"),
	}}}
	tests := []struct {
		name    string
		devices []gpuv1alpha1.GPUNodeDevice
		rn      corev1.ResourceName
		want    int64
	}{
		{name: "an mdev parent serves its allocatable, not one unit", rn: l40sName,
			devices: []gpuv1alpha1.GPUNodeDevice{{ResourceName: string(l40sName), Allocatable: alloc(3), Healthy: &yes}}, want: 3},
		{name: "a parent with one bad slot still serves its other slots", rn: l40sName,
			devices: []gpuv1alpha1.GPUNodeDevice{{ResourceName: string(l40sName), Allocatable: alloc(2), Healthy: &no}}, want: 2},
		{name: "without allocatable a healthy function serves one", rn: h100Name,
			devices: []gpuv1alpha1.GPUNodeDevice{{ResourceName: string(h100Name), Healthy: &yes}, {ResourceName: string(h100Name), Healthy: &no}}, want: 1},
		{name: "kubelet's count caps the agent's", rn: l40sName,
			devices: []gpuv1alpha1.GPUNodeDevice{{ResourceName: string(l40sName), Allocatable: alloc(4)}, {ResourceName: string(l40sName), Allocatable: alloc(4)}}, want: 3},
		{name: "a name no function carries is judged by the node", rn: h100Name, want: 8},
	}
	for _, tt := range tests {
		if got := ServedUnits(node, tt.devices, tt.rn); got != tt.want {
			t.Errorf("%s: ServedUnits = %d, want %d", tt.name, got, tt.want)
		}
	}
}