package main

import (
	"fmt"
	"net"

	"github.com/magiconair/properties"
	"golang.org/x/crypto/ssh"
)

func main() {

	// 解析 server.properties
	conf := properties.MustLoadFile("server.properties", properties.UTF8)
	var SSH_SERVER struct {
		Host   string
		Port   string
		User   string
		Pass   string
		config *ssh.ServerConfig
	}

	SSH_SERVER.Host = conf.MustGetString("server-ip")
	SSH_SERVER.Port = conf.MustGetString("server-port")
	SSH_SERVER.User = conf.MustGetString("term-user")
	SSH_SERVER.Pass = conf.MustGetString("term-pass")

	// 创建 ssh 密码认证
	SSH_SERVER.config = &ssh.ServerConfig{
		PasswordCallback: func(conn ssh.ConnMetadata, password []byte) (*ssh.Permissions, error) {
			if conn.User() == SSH_SERVER.User && string(password) == SSH_SERVER.Pass {
				return nil, nil
			}

			return nil, ssh.ErrNoAuth
		},
	}

	// 创建 ssh 服务器密钥
	privateKeySigner, err := ssh.ParsePrivateKey(privatePEM)
	if err != nil {
		panic(fmt.Errorf("不能解析私钥: %v", err))
	}

	SSH_SERVER.config.AddHostKey(privateKeySigner)

	// 在指定端口开启服务
	address := net.JoinHostPort(SSH_SERVER.Host, SSH_SERVER.Port)

	listener, err := net.Listen("tcp", address)
	if err != nil {
		panic(fmt.Errorf("不能在 %s 上创建服务: %v", address, err))
	}

	fmt.Println("Server Address:", address)

	// 连接到系统 shell
	for {
		conn, err := listener.Accept()
		if err != nil {
			fmt.Println("Can not accept connection:", err)
		}

		go shell(conn, SSH_SERVER.config)
	}

}