// Copyright 2019 Yang ZhongXi
// 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 core

import (
	"errors"
	"net"
	"time"

	"golang.org/x/crypto/ssh"
)

// SSHClient SSH客户端
type SSHClient struct {
	client   *ssh.Client
	isOpened bool
}

// Open 打开连接
func (c *SSHClient) Open(address string, username string, password string) error {
	if c.isOpened {
		return errors.New("已打开")
	}
	config := &ssh.ClientConfig{
		User: username,
		Auth: []ssh.AuthMethod{ssh.Password(password)},
		HostKeyCallback: func(hostname string, remote net.Addr, key ssh.PublicKey) error {
			return nil
		}, Timeout: time.Second,
	}
	var err error
	c.client, err = ssh.Dial("tcp", address, config)
	return err
}

// Close 关闭
func (c *SSHClient) Close() {
	if !c.isOpened {
		return
	}
	if c.client != nil {
		c.client.Close()
	}
}

// Execute 执行指令
func (c *SSHClient) Execute(cmds []string) ([]string, error) {
	if !c.isOpened {
		return nil, errors.New("连接未打开")
	}
	session, err := c.client.NewSession()
	if err != nil {
		return nil, err
	}
	defer session.Close()

	var results []string
	for _, cmd := range cmds {
		res, err := session.CombinedOutput(cmd)
		if err != nil {
			results = append(results, "执行失败")
			continue
		} else {
			results = append(results, string(res))
		}
	}
	return results, nil
}