package zsshrpc_server

import (
	"fmt"
	"golang.org/x/crypto/ssh"
	"net"
	"strings"
)

type ZSshRpcServer struct {
	sshcfg           *ssh.ServerConfig
	stopchan         chan int
	logger           SvrLogFunc
	ioBlockSize      int
	OperationHandelr ZSshRpcOperationHandler
}

func NewZSshRpcServer(conf *ZSshRpcServerCfg) *ZSshRpcServer {
	o := &ZSshRpcServer{}
	o.sshcfg = &ssh.ServerConfig{
		ServerVersion:               "SSH-2.0-zSshRpcTest-1.0",
		NoClientAuth:                conf.NoClientAuth,
		MaxAuthTries:                conf.MaxAuthTries,
		PasswordCallback:            conf.PasswordCallback,
		PublicKeyCallback:           conf.PublicKeyCallback,
		KeyboardInteractiveCallback: conf.KeyboardInteractiveCallback,
		AuthLogCallback:             conf.AuthLogCallback,
	}
	ciphers := []string{
		"aes128-ctr", "aes192-ctr", "aes256-ctr", "aes128-gcm@openssh.com", "arcfour256", "arcfour128",
	}
	if conf.Support_AES128_CBC {
		ciphers = append(ciphers, "aes128-cbc")
	}
	o.sshcfg.Ciphers = ciphers
	o.sshcfg.AddHostKey(conf.HostKey)
	o.logger = conf.ServerLogger
	o.OperationHandelr = conf.OperationHandler
	o.ioBlockSize = conf.IOBlockSize
	return o
}

func (this *ZSshRpcServer) Stop() {
	this.stopchan <- 1
}

func (this *ZSshRpcServer) StartWithListener(listener net.Listener) error {
	this.stopchan = make(chan int)
	go func() {
		<-this.stopchan
		listener.Close()
	}()
	go func() {
		for {
			nconn, err := listener.Accept()
			if err == nil {
				this.logger(SvrLogLevel_INFO, fmt.Sprintf("Client '%v' Come In.", nconn.RemoteAddr()), nil)
				go HandleNewSession(nconn, this.sshcfg, this.logger, this.OperationHandelr, this.ioBlockSize)
			} else {
				if strings.Contains(err.Error(), "use of closed network connection") {
					this.logger(SvrLogLevel_INFO, "Server Terminated By User.", err)
				} else {
					this.logger(SvrLogLevel_ERROR, fmt.Sprintf("Failed Handle Connection From Client '%v'", nconn.RemoteAddr()), err)
				}
			}
		}
	}()
	return nil
}

func (this *ZSshRpcServer) ListenTCP(network string, addr *net.TCPAddr) error {
	lis, err := net.ListenTCP(network, addr)
	if err != nil {
		return err
	}
	this.StartWithListener(lis)
	return nil
}