/*
    Copyright (c) 2016 VMware, Inc. All Rights Reserved.
    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 job

import (
	"time"

	"github.com/vmware/harbor/dao"
	"github.com/vmware/harbor/models"
	"github.com/vmware/harbor/utils/log"
)

// StateHandler handles transition, it associates with each state, will be called when
// SM enters and exits a state during a transition.
type StateHandler interface {
	// Enter returns the next state, if it returns empty string the SM will hold the current state or
	// or decide the next state.
	Enter() (string, error)
	//Exit should be idempotent
	Exit() error
}

// DummyHandler is the default implementation of StateHander interface, which has empty Enter and Exit methods.
type DummyHandler struct {
	JobID int64
}

// Enter ...
func (dh DummyHandler) Enter() (string, error) {
	return "", nil
}

// Exit ...
func (dh DummyHandler) Exit() error {
	return nil
}

// StatusUpdater implements the StateHandler interface which updates the status of a job in DB when the job enters
// a status.
type StatusUpdater struct {
	DummyHandler
	State string
}

// Enter updates the status of a job and returns "_continue" status to tell state machine to move on.
// If the status is a final status it returns empty string and the state machine will be stopped.
func (su StatusUpdater) Enter() (string, error) {
	err := dao.UpdateRepJobStatus(su.JobID, su.State)
	if err != nil {
		log.Warningf("Failed to update state of job: %d, state: %s, error: %v", su.JobID, su.State, err)
	}
	var next = models.JobContinue
	if su.State == models.JobStopped || su.State == models.JobError || su.State == models.JobFinished {
		next = ""
	}
	return next, err
}

// ImgPuller was for testing
type ImgPuller struct {
	DummyHandler
	img    string
	logger *log.Logger
}

// Enter ...
func (ip ImgPuller) Enter() (string, error) {
	ip.logger.Infof("I'm pretending to pull img:%s, then sleep 30s", ip.img)
	time.Sleep(30 * time.Second)
	ip.logger.Infof("wake up from sleep....")
	return "push-img", nil
}

// ImgPusher is a statehandler for testing
type ImgPusher struct {
	DummyHandler
	targetURL string
	logger    *log.Logger
}

// Enter ...
func (ip ImgPusher) Enter() (string, error) {
	ip.logger.Infof("I'm pretending to push img to:%s, then sleep 30s", ip.targetURL)
	time.Sleep(30 * time.Second)
	ip.logger.Infof("wake up from sleep....")
	return models.JobContinue, nil
}