//
// Copyright 2019 AT&T Intellectual Property
// Copyright 2019 Nokia
//
// 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 managers

import (
	"e2mgr/e2managererrors"
	"e2mgr/e2pdus"
	"e2mgr/logger"
	"e2mgr/models"
	"e2mgr/rNibWriter"
	"e2mgr/rmrCgo"
	"e2mgr/services"
	"gerrit.o-ran-sc.org/r/ric-plt/nodeb-rnib.git/entities"
)

type RanSetupManager struct {
	logger             *logger.Logger
	rnibWriterProvider func() rNibWriter.RNibWriter
	rmrService         *services.RmrService
}

func NewRanSetupManager(logger *logger.Logger, rmrService *services.RmrService, rnibWriterProvider func() rNibWriter.RNibWriter) *RanSetupManager {
	return &RanSetupManager{
		logger:             logger,
		rnibWriterProvider: rnibWriterProvider,
		rmrService        : rmrService,
	}
}


// Update retries and connection status (connecting)
func (m *RanSetupManager) updateConnectionStatusConnecting(nodebInfo *entities.NodebInfo) error {
	// Update retries and connection status (connecting)
	nodebInfo.ConnectionStatus = entities.ConnectionStatus_CONNECTING
	nodebInfo.ConnectionAttempts++
	err:= m.rnibWriterProvider().UpdateNodebInfo(nodebInfo)
	if err != nil {
		m.logger.Errorf("#ran_setup_manager.updateConnectionStatusConnecting - failed to update RAN's connection status to CONNECTING: %s", err)
	} else {
		m.logger.Infof("#ran_setup_manager.updateConnectionStatusConnecting - successfully updated RAN's connection status to CONNECTING: %s", err)
	}
	return err
}

// Decrement retries and connection status (disconnected)
func (m *RanSetupManager) updateConnectionStatusDisconnected(nodebInfo *entities.NodebInfo) error {
	// Update retries and connection status (connecting)
	nodebInfo.ConnectionStatus = entities.ConnectionStatus_DISCONNECTED
	nodebInfo.ConnectionAttempts--
	err := m.rnibWriterProvider().UpdateNodebInfo(nodebInfo)
	if err != nil {
		m.logger.Errorf("#ran_setup_manager.updateConnectionStatusDisconnected - failed to update RAN's connection status to DISCONNECTED : %s", err)
	} else {
		m.logger.Errorf("#ran_setup_manager.updateConnectionStatusDisconnected - successfully updated RAN's connection status to DISCONNECTED : %s", err)
	}
	return err
}

func (m *RanSetupManager) prepareSetupRequest(nodebInfo *entities.NodebInfo) (int, *models.E2RequestMessage, error) {
	// Build the endc/x2 setup request
	switch nodebInfo.E2ApplicationProtocol {
	case entities.E2ApplicationProtocol_X2_SETUP_REQUEST:
		rmrMsgType := rmrCgo.RIC_X2_SETUP_REQ
		request := models.NewE2RequestMessage(nodebInfo.RanName /*tid*/, nodebInfo.Ip, uint16(nodebInfo.Port), nodebInfo.RanName, e2pdus.PackedX2setupRequest)
		return rmrMsgType, request, nil
	case entities.E2ApplicationProtocol_ENDC_X2_SETUP_REQUEST:
		rmrMsgType := rmrCgo.RIC_ENDC_X2_SETUP_REQ
		request:= models.NewE2RequestMessage(nodebInfo.RanName /*tid*/, nodebInfo.Ip, uint16(nodebInfo.Port), nodebInfo.RanName, e2pdus.PackedEndcX2setupRequest)
		return rmrMsgType, request, nil
	}

	m.logger.Errorf("#ran_setup_manager.ExecuteSetup - unsupported nodebInfo.E2ApplicationProtocol %d ", nodebInfo.E2ApplicationProtocol)
	return 0, nil, e2managererrors.NewInternalError()
}

// ExecuteSetup updates the connection status and number of attempts in the nodebInfo and send an endc/x2 setup request to establish a connection with the RAN
func (m *RanSetupManager) ExecuteSetup(nodebInfo *entities.NodebInfo) error {

	// Update retries and connection status (connecting)
	if err := m.updateConnectionStatusConnecting(nodebInfo); err != nil {
		return e2managererrors.NewRnibDbError()
	}

	// Build the endc/x2 setup request
	rmrMsgType,request, err := m.prepareSetupRequest(nodebInfo)
	if err != nil {
		return err
	}
	
	// Send the endc/x2 setup request
	response := &models.NotificationResponse{MgsType: rmrMsgType, RanName: nodebInfo.RanName, Payload: request.GetMessageAsBytes(m.logger)}
	if err := m.rmrService.SendRmrMessage(response); err != nil {
		m.logger.Errorf("#ran_setup_manager.ExecuteSetup - failed to send setup request to RMR: %s", err)

		// Decrement retries and connection status (disconnected)
		if err := m.updateConnectionStatusDisconnected(nodebInfo); err != nil {
			return e2managererrors.NewRnibDbError()
		}

		return e2managererrors.NewRmrError()
	}
	return nil
}