/*
 * Copyright 2020-present Open Networking Foundation
 *
 * 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 adaptercoreonu provides the utility for onu devices, flows and statistics
package adaptercoreonu

import (
	"context"
	"encoding/hex"
	"fmt"
	"sync"
	"time"

	"github.com/opencord/omci-lib-go"
	me "github.com/opencord/omci-lib-go/generated"
	"github.com/opencord/voltha-lib-go/v5/pkg/log"
	"github.com/opencord/voltha-protos/v4/go/voltha"
)

//OnuImageStatus implements methods to get status info of onu images
type OnuImageStatus struct {
	pDevEntry              *OnuDeviceEntry
	deviceID               string
	requestedAttributes    me.AttributeValueMap
	mutexWaitingForResp    sync.RWMutex
	waitingForResp         bool
	respChannel            chan Message
	mutexPLastTxMeInstance sync.RWMutex
	pLastTxMeInstance      *me.ManagedEntity
}

const (
	cImgVersion     = "Version"
	cImgIsCommitted = "IsCommitted"
	cImgIsActive    = "IsActive"
	cImgIsValid     = "IsValid"
	cImgProductCode = "ProductCode"
	cImgImageHash   = "ImageHash"
)
const cResponse = "response: "

//NewOnuImageStatus creates a new instance of OnuImageStatus
func NewOnuImageStatus(pDevEntry *OnuDeviceEntry) *OnuImageStatus {
	return &OnuImageStatus{
		pDevEntry:           pDevEntry,
		deviceID:            pDevEntry.deviceID,
		requestedAttributes: make(me.AttributeValueMap),
		waitingForResp:      false,
		respChannel:         make(chan Message),
	}
}

func (oo *OnuImageStatus) getOnuImageStatus(ctx context.Context) (*voltha.OnuImages, error) {

	if !oo.pDevEntry.baseDeviceHandler.isReadyForOmciConfig() {
		logger.Errorw(ctx, "command rejected - improper device state", log.Fields{"device-id": oo.deviceID})
		return nil, fmt.Errorf("command-rejected-improper-device-state")
	}
	if oo.pDevEntry.PDevOmciCC == nil {
		logger.Errorw(ctx, "omciCC not ready to receive omci messages", log.Fields{"device-id": oo.deviceID})
		return nil, fmt.Errorf("omciCC-not-ready-to-receive-omci-messages")
	}
	var images voltha.OnuImages

	for i := firstSwImageMeID; i <= secondSwImageMeID; i++ {
		logger.Debugw(ctx, "getOnuImageStatus for image id", log.Fields{"image-id": i, "device-id": oo.deviceID})

		var image voltha.OnuImage

		// TODO: Since the summed length of the attributes exceeds the capacity of a single response,
		// it is distributed on several requests here. It should be discussed whether, in the course of a refactoring,
		// a global mechanism should be implemented that automates this distribution - which would entail quite some
		// changes on the respective receiver sides.

		oo.requestedAttributes = me.AttributeValueMap{cImgVersion: "", cImgIsCommitted: 0, cImgIsActive: 0, cImgIsValid: 0}
		if err := oo.requestOnuImageAttributes(ctx, uint16(i), &image); err != nil {
			logger.Errorw(ctx, err.Error(), log.Fields{"requestedAttributes": oo.requestedAttributes, "device-id": oo.deviceID})
			return nil, err
		}
		oo.requestedAttributes = me.AttributeValueMap{cImgProductCode: ""}
		if err := oo.requestOnuImageAttributes(ctx, uint16(i), &image); err != nil {
			logger.Errorw(ctx, err.Error(), log.Fields{"requestedAttributes": oo.requestedAttributes, "device-id": oo.deviceID})
			return nil, err
		}
		oo.requestedAttributes = me.AttributeValueMap{cImgImageHash: 0}
		if err := oo.requestOnuImageAttributes(ctx, uint16(i), &image); err != nil {
			logger.Errorw(ctx, err.Error(), log.Fields{"requestedAttributes": oo.requestedAttributes, "device-id": oo.deviceID})
			return nil, err
		}
		images.Items = append(images.Items, &image)
	}
	logger.Debugw(ctx, "images of the ONU", log.Fields{"images": images})
	oo.updateOnuSwImagePersistentData(ctx)
	return &images, nil
}

func (oo *OnuImageStatus) requestOnuImageAttributes(ctx context.Context, imageID uint16, image *voltha.OnuImage) error {
	oo.mutexPLastTxMeInstance.Lock()
	meInstance, err := oo.pDevEntry.PDevOmciCC.sendGetMe(log.WithSpanFromContext(context.TODO(), ctx), me.SoftwareImageClassID,
		imageID, oo.requestedAttributes, oo.pDevEntry.pOpenOnuAc.omciTimeout, true, oo.respChannel)
	if err != nil {
		oo.mutexPLastTxMeInstance.Unlock()
		logger.Errorw(ctx, "can't send omci request to get data for image id", log.Fields{"image-id": imageID, "device-id": oo.deviceID})
		return fmt.Errorf("can't-send-omci-request-to-get-data-for-image-id-%d", imageID)
	}
	oo.pLastTxMeInstance = meInstance
	oo.mutexPLastTxMeInstance.Unlock()

	if err = oo.waitForGetOnuImageStatus(ctx, image); err != nil {
		logger.Errorw(ctx, err.Error(), log.Fields{"device-id": oo.deviceID})
		return err
	}
	return nil
}

func (oo *OnuImageStatus) waitForGetOnuImageStatus(ctx context.Context, image *voltha.OnuImage) error {
	oo.setWaitingForResp(true)
	select {
	// maybe be also some outside cancel (but no context modeled for the moment ...)
	case <-ctx.Done():
		logger.Errorw(ctx, "waitForGetOnuImageStatus context done", log.Fields{"device-id": oo.deviceID})
		oo.setWaitingForResp(false)
		return fmt.Errorf("wait-for-image-status-context-done")
	case <-time.After(oo.pDevEntry.PDevOmciCC.GetMaxOmciTimeoutWithRetries() * time.Second):
		logger.Errorw(ctx, "waitForGetOnuImageStatus timeout", log.Fields{"device-id": oo.deviceID})
		oo.setWaitingForResp(false)
		return fmt.Errorf("wait-for-image-status-timeout")
	case message, ok := <-oo.respChannel:
		if !ok {
			logger.Errorw(ctx, "waitForGetOnuImageStatus response error", log.Fields{"device-id": oo.deviceID})
			oo.setWaitingForResp(false)
			return fmt.Errorf("wait-for-image-status-response-error")
		}
		switch message.Type {
		case OMCI:
			msg, _ := message.Data.(OmciMessage)
			oo.setWaitingForResp(false)
			return oo.processGetOnuImageStatusResp(ctx, msg, image)
		case TestMsg:
			msg, _ := message.Data.(TestMessage)
			if msg.TestMessageVal == AbortMessageProcessing {
				logger.Info(ctx, "waitForGetOnuImageStatus abort msg received", log.Fields{"device-id": oo.deviceID})
				oo.setWaitingForResp(false)
				return fmt.Errorf("wait-for-image-status-abort-msg-received")
			}
		default:
			logger.Errorw(ctx, "waitForGetOnuImageStatus wrong msg type received", log.Fields{"msgType": message.Type, "device-id": oo.deviceID})
			oo.setWaitingForResp(false)
			return fmt.Errorf("wait-for-image-status-response-error")
		}
	}
	logger.Errorw(ctx, "waitForGetOnuImageStatus processing error", log.Fields{"device-id": oo.deviceID})
	oo.setWaitingForResp(false)
	return fmt.Errorf("wait-for-image-status-processing-error")

}

func (oo *OnuImageStatus) processGetOnuImageStatusResp(ctx context.Context, msg OmciMessage, image *voltha.OnuImage) error {
	if msg.OmciMsg.MessageType != omci.GetResponseType {
		logger.Errorw(ctx, "processGetOnuImageStatusResp wrong response type received", log.Fields{"respType": msg.OmciMsg.MessageType, "device-id": oo.deviceID})
		return fmt.Errorf("process-image-status-response-error")
	}
	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeGetResponse)
	if msgLayer == nil {
		logger.Errorw(ctx, "processGetOnuImageStatusResp omci Msg layer not found", log.Fields{"device-id": oo.deviceID})
		return fmt.Errorf("process-image-status-response-error")
	}
	msgObj, msgOk := msgLayer.(*omci.GetResponse)
	if !msgOk {
		logger.Errorw(ctx, "processGetOnuImageStatusResp omci msgObj layer could not be found", log.Fields{"device-id": oo.deviceID})
		return fmt.Errorf("process-image-status-response-error")
	}
	oo.mutexPLastTxMeInstance.RLock()
	if oo.pLastTxMeInstance != nil {
		if msgObj.EntityClass == oo.pLastTxMeInstance.GetClassID() &&
			msgObj.EntityInstance == oo.pLastTxMeInstance.GetEntityID() {
			oo.mutexPLastTxMeInstance.RUnlock()
			if err := oo.processAttributesReceived(ctx, msgObj, image); err != nil {
				logger.Errorw(ctx, err.Error(), log.Fields{"device-id": oo.deviceID})
				return err
			}
			return nil
		}
		oo.mutexPLastTxMeInstance.RUnlock()
		logger.Errorw(ctx, "processGetOnuImageStatusResp wrong MeInstance received", log.Fields{"device-id": oo.deviceID})
		return fmt.Errorf("process-image-status-response-error")
	}
	oo.mutexPLastTxMeInstance.RUnlock()
	logger.Errorw(ctx, "processGetOnuImageStatusResp pLastTxMeInstance is nil", log.Fields{"device-id": oo.deviceID})
	return fmt.Errorf("process-image-status-response-error")
}

func (oo *OnuImageStatus) processAttributesReceived(ctx context.Context, msgObj *omci.GetResponse, image *voltha.OnuImage) error {
	meAttributes := msgObj.Attributes
	logger.Debugw(ctx, "processAttributesReceived", log.Fields{"attributes": meAttributes, "device-id": oo.deviceID})

	if _, ok := oo.requestedAttributes[cImgVersion]; ok {
		if msgObj.Result != me.Success {
			logger.Errorw(ctx, "processAttributesReceived retrieval of mandatory attributes failed",
				log.Fields{"device-id": oo.deviceID})
			return fmt.Errorf("process-image-status-response-error")
		}
		oo.pDevEntry.handleSwImageIndications(ctx, msgObj.EntityInstance, meAttributes)
	}
	for k := range oo.requestedAttributes {

		switch k {
		// mandatory attributes
		case cImgIsCommitted:
			if meAttributes[cImgIsCommitted].(uint8) == swIsCommitted {
				image.IsCommited = true
			} else {
				image.IsCommited = false
			}
		case cImgIsActive:
			if meAttributes[cImgIsActive].(uint8) == swIsActive {
				image.IsActive = true
			} else {
				image.IsActive = false
			}
		case cImgIsValid:
			if meAttributes[cImgIsValid].(uint8) == swIsValid {
				image.IsValid = true
			} else {
				image.IsValid = false
			}
		case cImgVersion:
			image.Version = TrimStringFromMeOctet(meAttributes[cImgVersion])

		// optional attributes
		case cImgProductCode:
			if msgObj.Result == me.Success {
				image.ProductCode = TrimStringFromMeOctet(meAttributes[cImgProductCode])
			} else {
				sResult := msgObj.Result.String()
				logger.Infow(ctx, "processAttributesReceived - ProductCode",
					log.Fields{"result": sResult, "unsupported attribute mask": msgObj.UnsupportedAttributeMask, "device-id": oo.deviceID})
				image.ProductCode = cResponse + sResult
			}
		case cImgImageHash:
			if msgObj.Result == me.Success {
				bytes, _ := me.InterfaceToOctets(meAttributes[cImgImageHash])
				image.Hash = hex.EncodeToString(bytes)
			} else {
				sResult := msgObj.Result.String()
				logger.Infow(ctx, "processAttributesReceived - ImageHash",
					log.Fields{"result": sResult, "unsupported attribute mask": msgObj.UnsupportedAttributeMask, "device-id": oo.deviceID})
				image.Hash = cResponse + sResult
			}
		}
	}
	return nil
}

func (oo *OnuImageStatus) updateOnuSwImagePersistentData(ctx context.Context) {

	activeImageVersion := oo.pDevEntry.getActiveImageVersion(ctx)
	oo.pDevEntry.mutexPersOnuConfig.Lock()
	if oo.pDevEntry.sOnuPersistentData.PersActiveSwVersion != activeImageVersion {
		logger.Infow(ctx, "Active SW version has been changed at ONU - update persistent data",
			log.Fields{"old version": oo.pDevEntry.sOnuPersistentData.PersActiveSwVersion,
				"new version": activeImageVersion, "device-id": oo.deviceID})
		oo.pDevEntry.sOnuPersistentData.PersActiveSwVersion = activeImageVersion
		oo.pDevEntry.mutexPersOnuConfig.Unlock()
		if err := oo.pDevEntry.baseDeviceHandler.storePersistentData(ctx); err != nil {
			logger.Warnw(ctx, "store persistent data error - continue for now as there will be additional write attempts",
				log.Fields{"device-id": oo.deviceID, "err": err})
		}
		return
	}
	oo.pDevEntry.mutexPersOnuConfig.Unlock()
}

func (oo *OnuImageStatus) setWaitingForResp(value bool) {
	oo.mutexWaitingForResp.Lock()
	oo.waitingForResp = value
	oo.mutexWaitingForResp.Unlock()
}

func (oo *OnuImageStatus) isWaitingForResp() bool {
	oo.mutexWaitingForResp.RLock()
	value := oo.waitingForResp
	oo.mutexWaitingForResp.RUnlock()
	return value
}

//CancelProcessing ensures that interrupted processing is canceled while waiting for a response
func (oo *OnuImageStatus) CancelProcessing(ctx context.Context) {
	if oo.isWaitingForResp() {
		abortMsg := Message{
			Type: TestMsg,
			Data: TestMessage{
				TestMessageVal: AbortMessageProcessing,
			},
		}
		oo.respChannel <- abortMsg
	}
}