package cassandra

import (
	"context"
	"fmt"
	"net"
	"strconv"
	"time"

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

// CassandraConnector Cassandra连接器实现
type CassandraConnector struct {
	host string
	port string
}

// CassandraProxyDialer 实现gocql.Dialer接口，支持代理连接
type CassandraProxyDialer struct {
	timeout time.Duration
}

// DialContext 实现代理拨号
func (d *CassandraProxyDialer) DialContext(ctx context.Context, network, addr string) (net.Conn, error) {
	host, port, err := net.SplitHostPort(addr)
	if err != nil {
		return nil, err
	}
	return common.WrapperTcpWithContext(ctx, network, fmt.Sprintf("%s:%s", host, port))
}

// NewCassandraConnector 创建Cassandra连接器
func NewCassandraConnector() *CassandraConnector {
	return &CassandraConnector{}
}

// Connect 连接到Cassandra服务
func (c *CassandraConnector) Connect(ctx context.Context, info *common.HostInfo) (interface{}, error) {
	c.host = info.Host
	c.port = info.Ports
	
	// 创建Cassandra集群配置
	cluster := gocql.NewCluster(c.host)
	
	// 解析端口
	port, err := strconv.Atoi(c.port)
	if err != nil {
		return nil, fmt.Errorf("无效的端口号: %s", c.port)
	}
	cluster.Port = port
	
	// 设置连接参数
	timeout := time.Duration(common.Timeout) * time.Second
	cluster.Timeout = timeout
	cluster.ConnectTimeout = timeout
	cluster.ProtoVersion = 4
	cluster.Consistency = gocql.One
	
	// 如果配置了代理，设置自定义Dialer
	if common.Socks5Proxy != "" {
		cluster.Dialer = &CassandraProxyDialer{
			timeout: timeout,
		}
	}
	
	// 设置重试策略
	cluster.RetryPolicy = &gocql.SimpleRetryPolicy{NumRetries: 3}
	
	return cluster, nil
}

// Authenticate 认证
func (c *CassandraConnector) Authenticate(ctx context.Context, conn interface{}, cred *base.Credential) error {
	cluster, ok := conn.(*gocql.ClusterConfig)
	if !ok {
		return fmt.Errorf("无效的连接类型")
	}
	
	// 创建集群配置副本
	authCluster := *cluster
	
	// 设置认证信息
	if cred.Username != "" || cred.Password != "" {
		authCluster.Authenticator = gocql.PasswordAuthenticator{
			Username: cred.Username,
			Password: cred.Password,
		}
	}
	
	// 创建会话通道以支持Context超时
	sessionChan := make(chan struct {
		session *gocql.Session
		err     error
	}, 1)
	
	// 在goroutine中创建会话，以便可以通过Context取消
	go func() {
		session, err := authCluster.CreateSession()
		select {
		case <-ctx.Done():
			if session != nil {
				session.Close()
			}
		case sessionChan <- struct {
			session *gocql.Session
			err     error
		}{session, err}:
		}
	}()
	
	// 等待会话创建或Context取消
	var session *gocql.Session
	var err error
	select {
	case result := <-sessionChan:
		session, err = result.session, result.err
		if err != nil {
			return fmt.Errorf("Cassandra认证失败: %v", err)
		}
	case <-ctx.Done():
		return fmt.Errorf("Cassandra连接超时: %v", ctx.Err())
	}
	
	defer session.Close()
	
	// 尝试执行查询验证连接
	resultChan := make(chan struct {
		success bool
		err     error
	}, 1)
	
	go func() {
		var err error
		
		// 尝试两种查询，确保至少一种成功
		err = session.Query("SELECT peer FROM system.peers").WithContext(ctx).Scan(nil)
		if err != nil {
			err = session.Query("SELECT now() FROM system.local").WithContext(ctx).Scan(nil)
		}
		
		select {
		case <-ctx.Done():
		case resultChan <- struct {
			success bool
			err     error
		}{err == nil, err}:
		}
	}()
	
	// 等待查询结果或Context取消
	select {
	case result := <-resultChan:
		if !result.success && result.err != nil {
			return fmt.Errorf("Cassandra查询验证失败: %v", result.err)
		}
		return nil
	case <-ctx.Done():
		return fmt.Errorf("Cassandra查询超时: %v", ctx.Err())
	}
}

// Close 关闭连接
func (c *CassandraConnector) Close(conn interface{}) error {
	// Cassandra集群配置无需显式关闭
	return nil
}