package memcached

import (
	"context"
	"fmt"
	"net"
	"strings"
	"time"

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

// MemcachedPlugin Memcached插件实现
type MemcachedPlugin struct {
	*base.ServicePlugin
	exploiter *MemcachedExploiter
}

// NewMemcachedPlugin 创建Memcached插件
func NewMemcachedPlugin() *MemcachedPlugin {
	// 插件元数据
	metadata := &base.PluginMetadata{
		Name:        "memcached",
		Version:     "2.0.0",
		Author:      "fscan-team",
		Description: "Memcached分布式内存缓存系统扫描和利用插件",
		Category:    "service",
		Ports:       []int{11211}, // 默认Memcached端口
		Protocols:   []string{"tcp"},
		Tags:        []string{"memcached", "cache", "unauthorized"},
	}
	
	// 创建连接器和服务插件
	connector := NewMemcachedConnector()
	servicePlugin := base.NewServicePlugin(metadata, connector)
	
	// 创建Memcached插件
	plugin := &MemcachedPlugin{
		ServicePlugin: servicePlugin,
		exploiter:     NewMemcachedExploiter(),
	}
	
	// 设置能力
	plugin.SetCapabilities([]base.Capability{
		base.CapUnauthorized,
		base.CapDataExtraction,
	})
	
	return plugin
}

// Scan 重写扫描方法，检测未授权访问
func (p *MemcachedPlugin) 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)
	
	// Memcached通常无认证，直接检查未授权访问
	unauthCred := &base.Credential{Username: "", Password: ""}
	result, err := p.ScanCredential(ctx, info, unauthCred)
	if err == nil && result.Success {
		// 未授权访问成功
		common.LogSuccess(i18n.GetText("memcached_unauth_access", target))
		
		return &base.ScanResult{
			Success:     true,
			Service:     "Memcached",
			Credentials: []*base.Credential{unauthCred},
			Extra: map[string]interface{}{
				"service":      "Memcached",
				"port":         info.Ports,
				"unauthorized": true,
				"access_type":  "no_authentication",
			},
		}, nil
	}
	
	// 如果未授权访问失败，返回失败结果
	return &base.ScanResult{
		Success: false,
		Error:   fmt.Errorf("Memcached服务不可访问或需要认证"),
	}, nil
}

// 已移除未使用的 generateCredentials 方法

// Exploit 使用exploiter执行利用
func (p *MemcachedPlugin) Exploit(ctx context.Context, info *common.HostInfo, creds *base.Credential) (*base.ExploitResult, error) {
	return p.exploiter.Exploit(ctx, info, creds)
}

// GetExploitMethods 获取利用方法
func (p *MemcachedPlugin) GetExploitMethods() []base.ExploitMethod {
	return p.exploiter.GetExploitMethods()
}

// IsExploitSupported 检查利用支持
func (p *MemcachedPlugin) IsExploitSupported(method base.ExploitType) bool {
	return p.exploiter.IsExploitSupported(method)
}

// performServiceIdentification 执行Memcached服务识别（-nobr模式）
func (p *MemcachedPlugin) performServiceIdentification(ctx context.Context, info *common.HostInfo) (*base.ScanResult, error) {
	target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
	
	// 尝试连接Memcached服务获取基本信息
	memcachedInfo, isMemcached := p.identifyMemcachedService(ctx, info)
	if isMemcached {
		// 记录服务识别成功
		common.LogSuccess(i18n.GetText("memcached_service_identified", target, memcachedInfo))
		
		return &base.ScanResult{
			Success: true,
			Service: "Memcached",
			Banner:  memcachedInfo,
			Extra: map[string]interface{}{
				"service": "Memcached",
				"port":    info.Ports,
				"info":    memcachedInfo,
			},
		}, nil
	}
	
	// 如果无法识别为Memcached，返回失败
	return &base.ScanResult{
		Success: false,
		Error:   fmt.Errorf("无法识别为Memcached服务"),
	}, nil
}

// identifyMemcachedService 通过连接识别Memcached服务
func (p *MemcachedPlugin) identifyMemcachedService(ctx context.Context, info *common.HostInfo) (string, bool) {
	target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
	timeout := time.Duration(common.Timeout) * time.Second
	
	// 尝试建立TCP连接
	conn, err := net.DialTimeout("tcp", target, timeout)
	if err != nil {
		return "", false
	}
	defer conn.Close()
	
	// 设置操作超时
	conn.SetDeadline(time.Now().Add(timeout))
	
	// 发送version命令获取版本信息
	if _, err := conn.Write([]byte("version\n")); err != nil {
		return "", false
	}
	
	// 读取响应
	buffer := make([]byte, 512)
	n, err := conn.Read(buffer)
	if err != nil {
		return "", false
	}
	
	response := strings.TrimSpace(string(buffer[:n]))
	
	// 检查是否是Memcached版本响应
	if strings.HasPrefix(response, "VERSION") {
		// 提取版本信息
		parts := strings.Fields(response)
		if len(parts) >= 2 {
			return fmt.Sprintf("Memcached %s", parts[1]), true
		}
		return "Memcached服务", true
	}
	
	// 尝试stats命令进行二次确认
	if _, err := conn.Write([]byte("stats\n")); err != nil {
		return "", false
	}
	
	n, err = conn.Read(buffer)
	if err != nil {
		return "", false
	}
	
	response = string(buffer[:n])
	
	// 检查是否包含STAT关键字
	if strings.Contains(response, "STAT") {
		return "Memcached服务", true
	}
	
	return "", false
}

// =============================================================================
// 插件注册
// =============================================================================

// RegisterMemcachedPlugin 注册Memcached插件
func RegisterMemcachedPlugin() {
	factory := base.NewSimplePluginFactory(
		&base.PluginMetadata{
			Name:        "memcached",
			Version:     "2.0.0",
			Author:      "fscan-team",
			Description: "Memcached分布式内存缓存系统扫描和利用插件",
			Category:    "service",
			Ports:       []int{11211}, // 默认Memcached端口
			Protocols:   []string{"tcp"},
			Tags:        []string{"memcached", "cache", "unauthorized"},
		},
		func() base.Plugin {
			return NewMemcachedPlugin()
		},
	)
	
	base.GlobalPluginRegistry.Register("memcached", factory)
}

// 自动注册
func init() {
	RegisterMemcachedPlugin()
}