package base

import (
	"context"
	"fmt"
	"github.com/shadow1ng/fscan/common"
	"github.com/shadow1ng/fscan/common/i18n"
	"strings"
	"sync"
	"time"
)

// =============================================================================
// 通用扫描器基础实现
// =============================================================================

// BaseScanner 基础扫描器，提供通用的扫描逻辑
type BaseScanner struct {
	Name         string
	metadata     *PluginMetadata
	capabilities []Capability
}

// NewBaseScanner 创建基础扫描器
func NewBaseScanner(name string, metadata *PluginMetadata) *BaseScanner {
	return &BaseScanner{
		Name:     name,
		metadata: metadata,
	}
}

// GetName 获取扫描器名称
func (s *BaseScanner) GetName() string {
	return s.Name
}

// GetCapabilities 获取扫描器支持的能力
func (s *BaseScanner) GetCapabilities() []Capability {
	return s.capabilities
}

// SetCapabilities 设置扫描器能力
func (s *BaseScanner) SetCapabilities(caps []Capability) {
	s.capabilities = caps
}

// GetMetadata 获取插件元数据
func (s *BaseScanner) GetMetadata() *PluginMetadata {
	return s.metadata
}

// =============================================================================
// 通用并发扫描框架
// =============================================================================

// ConcurrentScanConfig 并发扫描配置
type ConcurrentScanConfig struct {
	MaxConcurrent int           // 最大并发数
	Timeout       time.Duration // 单次扫描超时
	MaxRetries    int           // 最大重试次数
	RetryDelay    time.Duration // 重试延迟
}

// CredentialScanner 凭据扫描器接口
type CredentialScanner interface {
	// ScanCredential 扫描单个凭据
	ScanCredential(ctx context.Context, info *common.HostInfo, cred *Credential) (*ScanResult, error)
}

// ConcurrentCredentialScan 并发凭据扫描通用实现
func ConcurrentCredentialScan(
	ctx context.Context,
	scanner CredentialScanner,
	info *common.HostInfo,
	credentials []*Credential,
	config *ConcurrentScanConfig,
) (*ScanResult, error) {
	
	if len(credentials) == 0 {
		return nil, fmt.Errorf("没有提供凭据")
	}

	// 设置默认配置
	if config == nil {
		config = &ConcurrentScanConfig{
			MaxConcurrent: 10,
			Timeout:       time.Duration(common.Timeout) * time.Second,
			MaxRetries:    common.MaxRetries,
			RetryDelay:    500 * time.Millisecond,
		}
	}

	// 限制并发数
	maxConcurrent := config.MaxConcurrent
	if maxConcurrent <= 0 {
		maxConcurrent = 10
	}
	if maxConcurrent > len(credentials) {
		maxConcurrent = len(credentials)
	}

	// 创建工作池
	var wg sync.WaitGroup
	resultChan := make(chan *ScanResult, 1)
	workChan := make(chan *Credential, maxConcurrent)
	scanCtx, scanCancel := context.WithCancel(ctx)
	defer scanCancel()

	// 启动工作协程
	for i := 0; i < maxConcurrent; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			for credential := range workChan {
				select {
				case <-scanCtx.Done():
					return
				default:
					// 开始监控连接
					target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
					monitor := common.GetConcurrencyMonitor()
					monitor.StartConnection("credential", target)
					
					result := scanCredentialWithRetry(scanCtx, scanner, info, credential, config)
					
					// 完成连接监控
					monitor.FinishConnection("credential", target)
					
					if result != nil && result.Success {
						select {
						case resultChan <- result:
							scanCancel() // 找到有效凭据，取消其他工作
						default:
						}
						return
					}
				}
			}
		}()
	}

	// 发送工作
	go func() {
		for _, cred := range credentials {
			select {
			case <-scanCtx.Done():
				break
			default:
				workChan <- cred
			}
		}
		close(workChan)
	}()

	// 等待结果或完成
	go func() {
		wg.Wait()
		close(resultChan)
	}()

	// 获取结果
	select {
	case result, ok := <-resultChan:
		if ok && result != nil && result.Success {
			return result, nil
		}
		return nil, fmt.Errorf(i18n.GetText("plugin_all_creds_failed"))
	case <-ctx.Done():
		scanCancel()
		return nil, ctx.Err()
	}
}

// scanCredentialWithRetry 带重试的单凭据扫描
func scanCredentialWithRetry(
	ctx context.Context,
	scanner CredentialScanner,
	info *common.HostInfo,
	cred *Credential,
	config *ConcurrentScanConfig,
) *ScanResult {
	
	for retry := 0; retry < config.MaxRetries; retry++ {
		select {
		case <-ctx.Done():
			return &ScanResult{
				Success: false,
				Error:   ctx.Err(),
			}
		default:
			if retry > 0 {
				time.Sleep(config.RetryDelay)
			}

			// 创建独立的超时上下文
			connCtx, cancel := context.WithTimeout(ctx, config.Timeout)
			result, err := scanner.ScanCredential(connCtx, info, cred)
			cancel()

			if result != nil && result.Success {
				return result
			}

			// 检查是否需要重试
			if err != nil && !shouldRetry(err) {
				break
			}
		}
	}

	return &ScanResult{
		Success: false,
		Error:   fmt.Errorf("重试次数耗尽"),
	}
}

// shouldRetry 判断是否应该重试
func shouldRetry(err error) bool {
	if err == nil {
		return false
	}

	errStr := strings.ToLower(err.Error())
	
	// 不需要重试的错误
	noRetryErrors := []string{
		"access denied",
		"authentication failed",
		"invalid credentials",
		"permission denied",
		"unauthorized",
	}

	for _, noRetry := range noRetryErrors {
		if strings.Contains(errStr, noRetry) {
			return false
		}
	}

	return true
}

// =============================================================================
// 凭据生成工具
// =============================================================================

// GenerateCredentials 生成用户名密码组合的凭据列表
func GenerateCredentials(usernames []string, passwords []string) []*Credential {
	var credentials []*Credential
	
	for _, username := range usernames {
		for _, password := range passwords {
			// 支持 {user} 占位符替换
			actualPassword := strings.ReplaceAll(password, "{user}", username)
			
			credentials = append(credentials, &Credential{
				Username: username,
				Password: actualPassword,
				Extra:    make(map[string]string),
			})
		}
	}
	
	return credentials
}

// GeneratePasswordOnlyCredentials 生成仅密码的凭据列表（如Redis）
func GeneratePasswordOnlyCredentials(passwords []string) []*Credential {
	var credentials []*Credential
	
	for _, password := range passwords {
		credentials = append(credentials, &Credential{
			Password: password,
			Extra:    make(map[string]string),
		})
	}
	
	return credentials
}

// =============================================================================
// 结果处理工具
// =============================================================================

// SaveScanResult 保存扫描结果到通用输出系统
func SaveScanResult(info *common.HostInfo, result *ScanResult, pluginName string) {
	if result == nil || !result.Success {
		return
	}

	target := fmt.Sprintf("%s:%d", info.Host, info.Ports)
	
	// 保存成功的凭据
	for _, cred := range result.Credentials {
		var message string
		if cred.Username != "" && cred.Password != "" {
			message = fmt.Sprintf("%s %s %s %s", pluginName, target, cred.Username, cred.Password)
		} else if cred.Password != "" {
			message = fmt.Sprintf("%s %s [密码] %s", pluginName, target, cred.Password)
		} else {
			message = fmt.Sprintf("%s %s 未授权访问", pluginName, target)
		}
		
		common.LogSuccess(message)
		
		// 保存到输出系统的详细实现...
		// 这里可以调用common.SaveResult等函数
	}
}