/*
==================================================================================
  Copyright (c) 2019 AT&T Intellectual Property.
  Copyright (c) 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.

   This source code is part of the near-RT RIC (RAN Intelligent Controller)
   platform project (RICP).

==================================================================================
*/
/*
  Mnemonic:	nngpipe.go
  Abstract: mangos (NNG) Pipeline SBI implementation
  Date:		12 March 2019
*/

package sbi

/*
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <rmr/rmr.h>
#include <rmr/RIC_message_types.h>


#cgo CFLAGS: -I../
#cgo LDFLAGS: -lrmr_nng -lnng
*/
import "C"

import (
	"bytes"
	"crypto/md5"
	"errors"
	"gerrit.o-ran-sc.org/r/ric-plt/xapp-frame/pkg/xapp"
	"nanomsg.org/go/mangos/v2"
	"nanomsg.org/go/mangos/v2/protocol/push"
	_ "nanomsg.org/go/mangos/v2/transport/all"
	"routing-manager/pkg/rtmgr"
	"strconv"
	"time"
	"fmt"
)

type NngPush struct {
	Sbi
	NewSocket CreateNewNngSocketHandler
	rcChan    chan *xapp.RMRParams
}

type RMRParams struct {
        *xapp.RMRParams
}


func (params *RMRParams) String() string {
        var b bytes.Buffer
        sum := md5.Sum(params.Payload)
        fmt.Fprintf(&b, "params(Src=%s Mtype=%d SubId=%d Xid=%s Meid=%s Paylens=%d/%d Payhash=%x)", params.Src, params.Mtype, params.SubId, params.Xid, params.Meid.RanName, params.PayloadLen, len(params.Payload), sum)
        return b.String()
}

func NewNngPush() *NngPush {
	instance := new(NngPush)
	instance.NewSocket = createNewPushSocket
	return instance
}

func createNewPushSocket() (NngSocket, error) {
	xapp.Logger.Debug("Invoked: createNewPushSocket()")
	socket, err := push.NewSocket()
	if err != nil {
		return nil, errors.New("can't create new push socket due to:" + err.Error())
	}
	socket.SetPipeEventHook(pipeEventHandler)
	return socket, nil
}

func pipeEventHandler(event mangos.PipeEvent, pipe mangos.Pipe) {
	xapp.Logger.Debug("Invoked: pipeEventHandler()")
	xapp.Logger.Debug("Received pipe event for " + pipe.Address() + " address")
	for _, ep := range rtmgr.Eps {
		uri := DefaultNngPipelineSocketPrefix + ep.Ip + ":" + strconv.Itoa(DefaultNngPipelineSocketNumber)
		if uri == pipe.Address() {
			switch event {
			case 1:
				ep.IsReady = true
				xapp.Logger.Debug("Endpoint " + uri + " successfully attached")
			default:
				ep.IsReady = false
				xapp.Logger.Debug("Endpoint " + uri + " has been detached")
			}
		}
	}
}

func (c *NngPush) Initialize(ip string) error {
	return nil
}

func (c *NngPush) Terminate() error {
	return nil
}

func (c *NngPush) AddEndpoint(ep *rtmgr.Endpoint) error {

	xapp.Logger.Debug("Invoked sbi.AddEndpoint")
	xapp.Logger.Debug("args: %v", *ep)
	endpoint := ep.Ip + ":" + strconv.Itoa(DefaultNngPipelineSocketNumber)
	ep.Whid = int(xapp.Rmr.Openwh(endpoint))
	if ep.Whid < 0   {
		return errors.New("can't open warmhole connection for endpoint:" + ep.Uuid + " due to invalid Wormhole ID: " + string(ep.Whid))
	}else {
		xapp.Logger.Debug("Wormhole ID is %v and EP is %v",ep.Whid,endpoint)
	}

	return nil
}

func (c *NngPush) DeleteEndpoint(ep *rtmgr.Endpoint) error {
	xapp.Logger.Debug("Invoked sbi. DeleteEndpoint")
	xapp.Logger.Debug("args: %v", *ep)

	xapp.Rmr.Closewh(ep.Whid)
	return nil
}

func (c *NngPush) UpdateEndpoints(rcs *rtmgr.RicComponents) {
	c.updateEndpoints(rcs, c)
}

/*
NOTE: Asynchronous dial starts a goroutine which keep maintains the connection to the given endpoint
*/
func (c *NngPush) dial(ep *rtmgr.Endpoint) error {
	xapp.Logger.Debug("Dialing to endpoint: " + ep.Uuid)
	uri := DefaultNngPipelineSocketPrefix + ep.Ip + ":" + strconv.Itoa(DefaultNngPipelineSocketNumber)
	options := make(map[string]interface{})
	options[mangos.OptionDialAsynch] = true
	if err := ep.Socket.(NngSocket).DialOptions(uri, options); err != nil {
		return errors.New("can't dial on push socket to " + uri + " due to: " + err.Error())
	}
	return nil
}

func (c *NngPush) DistributeAll(policies *[]string) error {
	xapp.Logger.Debug("Invoked: sbi.DistributeAll")
	xapp.Logger.Debug("args: %v", *policies)

	for _, ep := range rtmgr.Eps {
		go c.send(ep, policies)
	}

	return nil
}

func (c *NngPush) send(ep *rtmgr.Endpoint, policies *[]string) {
	xapp.Logger.Debug("Push policy to endpoint: " + ep.Uuid)

	for _, pe := range *policies {
		params := &RMRParams{&xapp.RMRParams{}}
		params.Mtype = 20
		params.PayloadLen = len([]byte(pe))
		params.Payload =[]byte(pe)
		params.Mbuf = nil
		params.Whid = ep.Whid
		time.Sleep(1 * time.Millisecond)
		xapp.Rmr.SendMsg(params.RMRParams)
	}
	xapp.Logger.Info("NNG PUSH to endpoint " + ep.Uuid + ": OK (# of Entries:" + strconv.Itoa(len(*policies)) + ")")
}

func (c *NngPush) CreateEndpoint(payload string) (*rtmgr.Endpoint){
	return c.createEndpoint(payload, c)
}

func (c *NngPush) DistributeToEp(policies *[]string, ep *rtmgr.Endpoint) error {
	xapp.Logger.Debug("Invoked: sbi.DistributeToEp")
	xapp.Logger.Debug("args: %v", *policies)

	go c.send(ep, policies)

	return nil
}