package kubernetes

import (
	"fmt"

	executionv1alpha1 "git.ddupan.top/panxiao81/ayatori/api/execution/v1alpha1"
	batchv1 "k8s.io/api/batch/v1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime/schema"
)

const (
	ControllerName = "execution.ayatori.ddupan.top/kubernetes"
	ReferenceType  = "Job"
	JobUIDLabel    = "execution.ayatori.ddupan.top/job-uid"
)

var ayatoriJobGVK = schema.GroupVersionKind{
	Group:   executionv1alpha1.GroupVersion.Group,
	Version: executionv1alpha1.GroupVersion.Version,
	Kind:    "Job",
}

// BuildJob translates the stable execution API into the Kubernetes adapter's
// backend object. It intentionally does not accept or expose a PodSpec.
func BuildJob(
	job *executionv1alpha1.Job,
	parameters *executionv1alpha1.KubernetesExecutionParameters,
	resources executionv1alpha1.ExecutionResourceRequirements,
) *batchv1.Job {
	backoffLimit := int32(0)
	controller := true
	blockOwnerDeletion := true

	//nolint:modernize // ObjectMeta is promoted through embedded TypeMeta; embedlit produces invalid Go here.
	return &batchv1.Job{
		ObjectMeta: metav1.ObjectMeta{
			Name:      job.Name,
			Namespace: job.Namespace,
			Labels: map[string]string{
				JobUIDLabel: string(job.UID),
			},
			OwnerReferences: []metav1.OwnerReference{{
				APIVersion:         ayatoriJobGVK.GroupVersion().String(),
				Kind:               ayatoriJobGVK.Kind,
				Name:               job.Name,
				UID:                job.UID,
				Controller:         &controller,
				BlockOwnerDeletion: &blockOwnerDeletion,
			}},
		},
		Spec: batchv1.JobSpec{
			BackoffLimit: &backoffLimit,
			Template: corev1.PodTemplateSpec{
				ObjectMeta: metav1.ObjectMeta{Labels: map[string]string{JobUIDLabel: string(job.UID)}},
				Spec: corev1.PodSpec{
					RestartPolicy:      corev1.RestartPolicyNever,
					ServiceAccountName: parameters.Spec.ServiceAccountName,
					RuntimeClassName:   optionalString(parameters.Spec.RuntimeClassName),
					NodeSelector:       parameters.Spec.Scheduling.NodeSelector,
					Tolerations:        parameters.Spec.Scheduling.Tolerations,
					SecurityContext:    parameters.Spec.PodSecurityContext,
					ImagePullSecrets:   job.Spec.Task.ImagePullSecrets,
					Containers: []corev1.Container{{
						Name:            "task",
						Image:           job.Spec.Task.Image,
						ImagePullPolicy: parameters.Spec.ImagePullPolicy,
						Command:         job.Spec.Task.Command,
						Args:            job.Spec.Task.Args,
						WorkingDir:      job.Spec.Task.WorkingDir,
						Env:             environment(job.Spec.Task.Env),
						Resources:       resourceRequirements(resources),
					}},
				},
			},
		},
	}
}

func ValidateOwnership(owner *executionv1alpha1.Job, backend *batchv1.Job) error {
	if backend.Labels[JobUIDLabel] != string(owner.UID) {
		return fmt.Errorf("backend Job %s/%s is not owned by Ayatori Job UID %s", backend.Namespace, backend.Name, owner.UID)
	}
	return nil
}

func environment(values []executionv1alpha1.EnvVar) []corev1.EnvVar {
	result := make([]corev1.EnvVar, 0, len(values))
	for _, value := range values {
		env := corev1.EnvVar{Name: value.Name}
		if value.Value != nil {
			env.Value = *value.Value
		}
		if value.ValueFrom != nil {
			env.ValueFrom = &corev1.EnvVarSource{
				SecretKeyRef:    value.ValueFrom.SecretKeyRef,
				ConfigMapKeyRef: value.ValueFrom.ConfigMapKeyRef,
			}
		}
		result = append(result, env)
	}
	return result
}

func resourceRequirements(resources executionv1alpha1.ExecutionResourceRequirements) corev1.ResourceRequirements {
	return corev1.ResourceRequirements{
		Requests: resourceList(resources.Requests),
		Limits:   resourceList(resources.Limits),
	}
}

func resourceList(values executionv1alpha1.ResourceValues) corev1.ResourceList {
	result := corev1.ResourceList{}
	if values.CPU != nil {
		result[corev1.ResourceCPU] = values.CPU.DeepCopy()
	}
	if values.Memory != nil {
		result[corev1.ResourceMemory] = values.Memory.DeepCopy()
	}
	if len(result) == 0 {
		return nil
	}
	return result
}

func optionalString(value string) *string {
	if value == "" {
		return nil
	}
	return &value
}