package telnet

import (
	"context"
	"fmt"
	"strings"

	"github.com/shadow1ng/fscan/common"
	"github.com/shadow1ng/fscan/common/i18n"
	"github.com/shadow1ng/fscan/plugins/base"
)

// TelnetPlugin Telnet服务插件
type TelnetPlugin struct {
	*base.ServicePlugin
	exploiter *TelnetExploiter
}

// NewTelnetPlugin 创建Telnet插件
func NewTelnetPlugin() *TelnetPlugin {
	// 插件元数据
	metadata := &base.PluginMetadata{
		Name:        "telnet",
		Version:     "2.0.0",
		Author:      "fscan-team",
		Description: "Telnet远程终端协议服务检测和弱口令扫描",
		Category:    "service",
		Ports:       []int{23}, // Telnet默认端口
		Protocols:   []string{"tcp"},
		Tags:        []string{"telnet", "remote-access", "weak-password", "unauthorized-access"},
	}
	
	// 创建连接器和服务插件
	connector := NewTelnetConnector()
	servicePlugin := base.NewServicePlugin(metadata, connector)
	
	// 创建Telnet插件
	plugin := &TelnetPlugin{
		ServicePlugin: servicePlugin,
		exploiter:     NewTelnetExploiter(),
	}
	
	// 设置能力
	plugin.SetCapabilities([]base.Capability{
		base.CapWeakPassword,
		base.CapUnauthorized,
	})
	
	return plugin
}

// init 自动注册Telnet插件
func init() {
	// 创建插件工厂
	metadata := &base.PluginMetadata{
		Name:        "telnet",
		Version:     "2.0.0",
		Author:      "fscan-team", 
		Description: "Telnet远程终端协议服务检测和弱口令扫描",
		Category:    "service",
		Ports:       []int{23},
		Protocols:   []string{"tcp"},
		Tags:        []string{"telnet", "remote-access", "weak-password", "unauthorized-access"},
	}
	
	factory := base.NewSimplePluginFactory(metadata, func() base.Plugin {
		return NewTelnetPlugin()
	})
	
	base.GlobalPluginRegistry.Register("telnet", factory)
}

// Scan 重写扫描方法，进行Telnet服务扫描
func (p *TelnetPlugin) Scan(ctx context.Context, info *common.HostInfo) (*base.ScanResult, error) {
	// 如果禁用了暴力破解，只进行服务识别
	if common.DisableBrute {
		return p.performServiceIdentification(ctx, info)
	}
	
	target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
	
	// 生成凭据进行暴力破解
	credentials := p.generateCredentials()
	if len(credentials) == 0 {
		return &base.ScanResult{
			Success: false,
			Error:   fmt.Errorf("no credentials available"),
		}, nil
	}
	
	// 遍历凭据进行测试
	for _, cred := range credentials {
		result, err := p.ScanCredential(ctx, info, cred)
		if err == nil && result.Success {
			// 检查是否无需认证
			if result.Extra != nil && result.Extra["type"] == "unauthorized-access" {
				common.LogSuccess(i18n.GetText("telnet_unauthorized_access", target))
			} else {
				// 认证成功
				common.LogSuccess(i18n.GetText("telnet_weak_password_success", target, cred.Username, cred.Password))
			}
			
			return &base.ScanResult{
				Success:     true,
				Service:     "Telnet",
				Credentials: []*base.Credential{cred},
				Banner:      result.Banner,
				Extra: map[string]interface{}{
					"service":  "Telnet",
					"port":     info.Ports,
					"username": cred.Username,
					"password": cred.Password,
					"type":     "weak-password",
				},
			}, nil
		}
	}
	
	// 没有找到有效凭据
	return &base.ScanResult{
		Success: false,
		Service: "Telnet",
		Error:   fmt.Errorf("authentication failed for all credentials"),
	}, nil
}

// performServiceIdentification 执行服务识别
func (p *TelnetPlugin) performServiceIdentification(ctx context.Context, info *common.HostInfo) (*base.ScanResult, error) {
	// 尝试连接到服务进行基本识别
	conn, err := p.GetServiceConnector().Connect(ctx, info)
	if err != nil {
		return &base.ScanResult{
			Success: false,
			Error:   err,
		}, nil
	}
	defer p.GetServiceConnector().Close(conn)

	// 服务识别成功
	return &base.ScanResult{
		Success: true,
		Service: "Telnet",
		Banner:  "Telnet service detected",
		Extra: map[string]interface{}{
			"service": "Telnet",
			"port":    info.Ports,
			"type":    "service-identification",
		},
	}, nil
}

// generateCredentials 生成Telnet认证凭据
func (p *TelnetPlugin) generateCredentials() []*base.Credential {
	var credentials []*base.Credential

	// 获取用户名字典
	usernames := common.Userdict["telnet"]
	if len(usernames) == 0 {
		// 使用默认用户名
		usernames = []string{"admin", "root", "user", "test", "guest"}
	}

	// 获取密码字典
	passwords := common.Passwords
	if len(passwords) == 0 {
		// 使用默认密码
		passwords = []string{"", "admin", "root", "123456", "password", "test", "guest"}
	}

	// 生成凭据组合
	for _, username := range usernames {
		for _, password := range passwords {
			// 处理密码中的用户名占位符
			actualPassword := strings.Replace(password, "{user}", username, -1)
			
			credentials = append(credentials, &base.Credential{
				Username: username,
				Password: actualPassword,
			})
		}
	}

	return credentials
}