package imap

import (
	"context"
	"crypto/tls"
	"fmt"
	"net"
	"regexp"
	"strings"
	"time"

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

// IMAPPlugin IMAP插件实现
type IMAPPlugin struct {
	*base.ServicePlugin
	exploiter *IMAPExploiter
}

// NewIMAPPlugin 创建IMAP插件
func NewIMAPPlugin() *IMAPPlugin {
	// 插件元数据
	metadata := &base.PluginMetadata{
		Name:        "imap",
		Version:     "2.0.0",
		Author:      "fscan-team",
		Description: "IMAP邮件服务扫描和利用插件",
		Category:    "service",
		Ports:       []int{143, 993}, // IMAP和IMAPS端口
		Protocols:   []string{"tcp"},
		Tags:        []string{"imap", "mail", "bruteforce"},
	}
	
	// 创建连接器和服务插件
	connector := NewIMAPConnector()
	servicePlugin := base.NewServicePlugin(metadata, connector)
	
	// 创建IMAP插件
	plugin := &IMAPPlugin{
		ServicePlugin: servicePlugin,
		exploiter:     NewIMAPExploiter(),
	}
	
	// 设置能力
	plugin.SetCapabilities([]base.Capability{
		base.CapWeakPassword,
		base.CapDataExtraction,
	})
	
	
	return plugin
}

// Scan 重写扫描方法以支持服务识别
func (p *IMAPPlugin) 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)
	}
	
	// 执行基础的密码扫描
	result, err := p.ServicePlugin.Scan(ctx, info)
	if err != nil || !result.Success {
		return result, err
	}
	
	// 记录成功的弱密码发现
	target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
	cred := result.Credentials[0]
	common.LogSuccess(i18n.GetText("imap_weak_pwd_success", target, cred.Username, cred.Password))
	
	return result, nil
}

// 已移除未使用的 generateCredentials 方法

// Exploit 使用exploiter执行利用
func (p *IMAPPlugin) 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 *IMAPPlugin) GetExploitMethods() []base.ExploitMethod {
	return p.exploiter.GetExploitMethods()
}

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

// performServiceIdentification 执行IMAP服务识别（-nobr模式）
func (p *IMAPPlugin) performServiceIdentification(ctx context.Context, info *common.HostInfo) (*base.ScanResult, error) {
	target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
	
	// 根据端口选择连接类型
	var conn net.Conn
	var err error
	
	if info.Ports == "993" {
		// IMAPS端口，使用TLS连接
		tlsConfig := &tls.Config{
			InsecureSkipVerify: true,
		}
		conn, err = common.WrapperTlsWithContext(ctx, "tcp", target, tlsConfig)
	} else {
		// IMAP端口，使用普通连接
		conn, err = common.WrapperTcpWithContext(ctx, "tcp", target)
	}
	
	if err != nil {
		return &base.ScanResult{
			Success: false,
			Error:   err,
		}, nil
	}
	defer conn.Close()
	
	// 读取IMAP Banner
	imapInfo, isIMAP := p.identifyIMAPService(conn)
	if isIMAP {
		// 记录服务识别成功
		service := "IMAP"
		if info.Ports == "993" {
			service = "IMAPS"
		}
		common.LogSuccess(i18n.GetText("imap_service_identified", target, imapInfo))
		
		return &base.ScanResult{
			Success: true,
			Service: service,
			Banner:  imapInfo,
			Extra: map[string]interface{}{
				"service": service,
				"port":    info.Ports,
				"info":    imapInfo,
			},
		}, nil
	}
	
	// 如果无法识别为IMAP，返回失败
	return &base.ScanResult{
		Success: false,
		Error:   fmt.Errorf("无法识别为IMAP服务"),
	}, nil
}

// identifyIMAPService 通过Banner识别IMAP服务
func (p *IMAPPlugin) identifyIMAPService(conn net.Conn) (string, bool) {
	// 设置读取超时
	conn.SetReadDeadline(time.Now().Add(time.Duration(common.Timeout) * time.Second))
	
	// IMAP服务器在连接后会发送欢迎消息
	banner := make([]byte, 512)
	n, err := conn.Read(banner)
	if err != nil || n < 4 {
		return "", false
	}
	
	bannerStr := strings.TrimSpace(string(banner[:n]))
	
	// 检查IMAP协议标识
	if strings.Contains(bannerStr, "* OK") && (strings.Contains(strings.ToLower(bannerStr), "imap") || 
		strings.Contains(strings.ToLower(bannerStr), "dovecot") || 
		strings.Contains(strings.ToLower(bannerStr), "courier") ||
		strings.Contains(strings.ToLower(bannerStr), "cyrus")) {
		
		// 提取服务器信息
		if matched := regexp.MustCompile(`\* OK (.+?) ready`).FindStringSubmatch(bannerStr); len(matched) >= 2 {
			return fmt.Sprintf("IMAP服务: %s", matched[1]), true
		}
		
		if matched := regexp.MustCompile(`\* OK (.+?)$`).FindStringSubmatch(bannerStr); len(matched) >= 2 {
			return fmt.Sprintf("IMAP服务: %s", matched[1]), true
		}
		
		return fmt.Sprintf("IMAP服务: %s", bannerStr), true
	}
	
	return "", false
}

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

// RegisterIMAPPlugin 注册IMAP插件
func RegisterIMAPPlugin() {
	factory := base.NewSimplePluginFactory(
		&base.PluginMetadata{
			Name:        "imap",
			Version:     "2.0.0",
			Author:      "fscan-team",
			Description: "IMAP邮件服务扫描和利用插件",
			Category:    "service",
			Ports:       []int{143, 993}, // IMAP和IMAPS端口
			Protocols:   []string{"tcp"},
			Tags:        []string{"imap", "mail", "bruteforce"},
		},
		func() base.Plugin {
			return NewIMAPPlugin()
		},
	)
	
	base.GlobalPluginRegistry.Register("imap", factory)
}

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