/*
Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
Copyright (C) ITsysCOM GmbH

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>
*/

package engine

import (
	"errors"
	"fmt"
	"strings"
	"sync"
	"time"

	"github.com/cgrates/cgrates/config"
	"github.com/cgrates/cgrates/utils"
	"github.com/cgrates/rpcclient"
)

func NewRPCPool(dispatchStrategy string, keyPath, certPath, caPath string, connAttempts, reconnects int,
	connectTimeout, replyTimeout time.Duration, rpcConnCfgs []*config.RemoteHost,
	internalConnChan chan rpcclient.RpcClientConnection, ttl time.Duration, lazyConnect bool) (*rpcclient.RpcClientPool, error) {
	var rpcClient *rpcclient.RpcClient
	var err error
	rpcPool := rpcclient.NewRpcClientPool(dispatchStrategy, replyTimeout)
	atLestOneConnected := false // If one connected we don't longer return errors
	for _, rpcConnCfg := range rpcConnCfgs {
		if rpcConnCfg.Address == utils.MetaInternal {
			var internalConn rpcclient.RpcClientConnection
			select {
			case internalConn = <-internalConnChan:
				internalConnChan <- internalConn
			case <-time.After(ttl):
				return nil, errors.New("TTL triggered")
			}
			rpcClient, err = rpcclient.NewRpcClient("", "", rpcConnCfg.TLS, keyPath, certPath, caPath, connAttempts,
				reconnects, connectTimeout, replyTimeout, rpcclient.INTERNAL_RPC, internalConn, lazyConnect)
		} else if utils.IsSliceMember([]string{utils.MetaJSONrpc, utils.MetaGOBrpc, ""}, rpcConnCfg.Transport) {
			codec := utils.GOB
			if rpcConnCfg.Transport != "" {
				codec = rpcConnCfg.Transport[1:] // Transport contains always * before codec understood by rpcclient
			}
			rpcClient, err = rpcclient.NewRpcClient("tcp", rpcConnCfg.Address, rpcConnCfg.TLS, keyPath, certPath, caPath,
				connAttempts, reconnects, connectTimeout, replyTimeout, codec, nil, lazyConnect)
		} else {
			return nil, fmt.Errorf("Unsupported transport: <%s>", rpcConnCfg.Transport)
		}
		if err == nil {
			atLestOneConnected = true
		}
		rpcPool.AddClient(rpcClient)
	}
	if atLestOneConnected {
		err = nil
	}
	return rpcPool, err
}

var IntRPC *InternalRPC

func init() {
	IntRPC = &InternalRPC{subsystems: make(map[string]rpcclient.RpcClientConnection)}
}

type InternalRPC struct {
	sync.Mutex
	subsystems map[string]rpcclient.RpcClientConnection
}

func (irpc *InternalRPC) AddConnection(name string, conn rpcclient.RpcClientConnection) {
	if conn == nil {
		return
	}
	irpc.Lock()
	irpc.subsystems[name] = conn
	irpc.Unlock()
}

func (irpc *InternalRPC) Call(method string, args interface{}, reply interface{}) error {
	methodSplit := strings.Split(method, ".")
	if len(methodSplit) != 2 {
		return rpcclient.ErrUnsupporteServiceMethod
	}
	irpc.Lock()
	defer irpc.Unlock()
	conn, has := irpc.subsystems[methodSplit[0]]
	if !has {
		return rpcclient.ErrUnsupporteServiceMethod
	}
	return conn.Call(method, args, reply)
}

func (irpc *InternalRPC) GetConnChan() (connChan chan rpcclient.RpcClientConnection) {
	connChan = make(chan rpcclient.RpcClientConnection, 1)
	connChan <- irpc
	return
}