// Copyright 2018 The Harbor Authors. All rights reserved.

package pool

import (
	"fmt"
	"time"

	"github.com/gocraft/work"
	"github.com/vmware/harbor/src/jobservice/env"
	"github.com/vmware/harbor/src/jobservice/errs"
	"github.com/vmware/harbor/src/jobservice/job"
	"github.com/vmware/harbor/src/jobservice/logger"
	"github.com/vmware/harbor/src/jobservice/opm"
)

//RedisJob is a job wrapper to wrap the job.Interface to the style which can be recognized by the redis pool.
type RedisJob struct {
	job          interface{}         //the real job implementation
	context      *env.Context        //context
	statsManager opm.JobStatsManager //job stats manager
}

//NewRedisJob is constructor of RedisJob
func NewRedisJob(j interface{}, ctx *env.Context, statsManager opm.JobStatsManager) *RedisJob {
	return &RedisJob{
		job:          j,
		context:      ctx,
		statsManager: statsManager,
	}
}

//Run the job
func (rj *RedisJob) Run(j *work.Job) error {
	var (
		cancelled          = false
		buildContextFailed = false
		runningJob         job.Interface
		err                error
		execContext        env.JobContext
	)

	execContext, err = rj.buildContext(j)
	if err != nil {
		buildContextFailed = true
		goto FAILED //no need to retry
	}

	//Wrap job
	runningJob = Wrap(rj.job)

	defer func() {
		//Close open io stream first
		if closer, ok := execContext.GetLogger().(logger.Closer); ok {
			closer.Close()
		}

		if err == nil {
			return //nothing need to do
		}

		if buildContextFailed || rj.shouldDisableRetry(runningJob, j, cancelled) {
			j.Fails = 10000000000 //Make it big enough to avoid retrying
			now := time.Now().Unix()
			go func() {
				timer := time.NewTimer(2 * time.Second) //make sure the failed job is already put into the dead queue
				defer timer.Stop()

				<-timer.C

				rj.statsManager.DieAt(j.ID, now)
			}()
		}
	}()

	defer func() {
		if r := recover(); r != nil {
			err = fmt.Errorf("Runtime error: %s", r)
		}
	}()

	//Start to run
	rj.jobRunning(j.ID)
	//Inject data
	err = runningJob.Run(execContext, j.Args)

	//update the proper status
	if err == nil {
		rj.jobSucceed(j.ID)
		return nil
	}

	if errs.IsJobStoppedError(err) {
		rj.jobStopped(j.ID)
		return nil // no need to put it into the dead queue for resume
	}

	if errs.IsJobCancelledError(err) {
		rj.jobCancelled(j.ID)
		cancelled = true
		return err //need to resume
	}

FAILED:
	rj.jobFailed(j.ID)
	return err
}

func (rj *RedisJob) jobRunning(jobID string) {
	rj.statsManager.SetJobStatus(jobID, job.JobStatusRunning)
}

func (rj *RedisJob) jobFailed(jobID string) {
	rj.statsManager.SetJobStatus(jobID, job.JobStatusError)
}

func (rj *RedisJob) jobStopped(jobID string) {
	rj.statsManager.SetJobStatus(jobID, job.JobStatusStopped)
}

func (rj *RedisJob) jobCancelled(jobID string) {
	rj.statsManager.SetJobStatus(jobID, job.JobStatusCancelled)
}

func (rj *RedisJob) jobSucceed(jobID string) {
	rj.statsManager.SetJobStatus(jobID, job.JobStatusSuccess)
}

func (rj *RedisJob) buildContext(j *work.Job) (env.JobContext, error) {
	//Build job execution context
	jData := env.JobData{
		ID:        j.ID,
		Name:      j.Name,
		Args:      j.Args,
		ExtraData: make(map[string]interface{}),
	}

	checkOPCmdFuncFactory := func(jobID string) job.CheckOPCmdFunc {
		return func() (string, bool) {
			cmd, err := rj.statsManager.CtlCommand(jobID)
			if err != nil {
				return "", false
			}
			return cmd, true
		}
	}

	jData.ExtraData["opCommandFunc"] = checkOPCmdFuncFactory(j.ID)

	checkInFuncFactory := func(jobID string) job.CheckInFunc {
		return func(message string) {
			rj.statsManager.CheckIn(jobID, message)
		}
	}

	jData.ExtraData["checkInFunc"] = checkInFuncFactory(j.ID)

	return rj.context.JobContext.Build(jData)
}

func (rj *RedisJob) shouldDisableRetry(j job.Interface, wj *work.Job, cancelled bool) bool {
	maxFails := j.MaxFails()
	if maxFails == 0 {
		maxFails = 4 //Consistent with backend worker pool
	}
	fails := wj.Fails
	fails++ //as the fail is not returned to backend pool yet

	if cancelled && fails < int64(maxFails) {
		return true
	}

	if !cancelled && fails < int64(maxFails) && !j.ShouldRetry() {
		return true
	}

	return false
}