/*
Copyright 2021 The Karmada 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 helper

import (
	"encoding/json"
	"fmt"
	"strings"

	batchv1 "k8s.io/api/batch/v1"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/klog/v2"

	workv1alpha2 "github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
)

// ParsingJobStatus generates new status of given 'AggregatedStatusItem'.
//
//nolint:gocyclo
func ParsingJobStatus(obj *batchv1.Job, status []workv1alpha2.AggregatedStatusItem) (*batchv1.JobStatus, error) {
	var jobFailed []string
	var startTime, completionTime *metav1.Time
	successfulJobs, completionJobs := 0, 0
	newStatus := &batchv1.JobStatus{}
	for _, item := range status {
		if item.Status == nil {
			continue
		}
		temp := &batchv1.JobStatus{}
		if err := json.Unmarshal(item.Status.Raw, temp); err != nil {
			klog.Errorf("Failed to unmarshal status of job(%s/%s): %v", obj.Namespace, obj.Name, err)
			return nil, err
		}
		klog.V(3).Infof("Grab job(%s/%s) status from cluster(%s), active: %d, succeeded %d, failed: %d",
			obj.Namespace, obj.Name, item.ClusterName, temp.Active, temp.Succeeded, temp.Failed)

		newStatus.Active += temp.Active
		newStatus.Succeeded += temp.Succeeded
		newStatus.Failed += temp.Failed

		isFinished, finishedStatus := GetJobFinishedStatus(temp)
		if isFinished && finishedStatus == batchv1.JobComplete {
			successfulJobs++
		} else if isFinished && finishedStatus == batchv1.JobFailed {
			jobFailed = append(jobFailed, item.ClusterName)
		}

		// StartTime
		if startTime == nil || temp.StartTime.Before(startTime) {
			startTime = temp.StartTime
		}
		// CompletionTime
		if temp.CompletionTime != nil {
			completionJobs++
			if completionTime == nil || completionTime.Before(temp.CompletionTime) {
				completionTime = temp.CompletionTime
			}
		}
	}

	if len(jobFailed) != 0 {
		newStatus.Conditions = append(newStatus.Conditions, batchv1.JobCondition{
			Type:               batchv1.JobFailed,
			Status:             corev1.ConditionTrue,
			LastProbeTime:      metav1.Now(),
			LastTransitionTime: metav1.Now(),
			Reason:             "JobFailed",
			Message:            fmt.Sprintf("Job executed failed in member clusters %s", strings.Join(jobFailed, ",")),
		})
	}

	// aggregated status can be empty when the binding is just created
	// in which case we should not set the job status to complete
	if successfulJobs == len(status) && successfulJobs > 0 {
		newStatus.Conditions = append(newStatus.Conditions, batchv1.JobCondition{
			Type:               batchv1.JobComplete,
			Status:             corev1.ConditionTrue,
			LastProbeTime:      metav1.Now(),
			LastTransitionTime: metav1.Now(),
			Reason:             "Completed",
			Message:            "Job completed",
		})
	}

	if startTime != nil {
		newStatus.StartTime = startTime.DeepCopy()
	}
	if completionTime != nil && completionJobs == len(status) {
		newStatus.CompletionTime = completionTime.DeepCopy()
	}

	return newStatus, nil
}

// GetJobFinishedStatus checks whether the given Job has finished execution.
// It does not discriminate between successful and failed terminations.
func GetJobFinishedStatus(jobStatus *batchv1.JobStatus) (bool, batchv1.JobConditionType) {
	for _, c := range jobStatus.Conditions {
		if (c.Type == batchv1.JobComplete || c.Type == batchv1.JobFailed) && c.Status == corev1.ConditionTrue {
			return true, c.Type
		}
	}
	return false, ""
}