package client

import (
	"context"
	"fmt"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/azoic/wormhole-client/internal/config"
	"github.com/azoic/wormhole-client/internal/proxy"
	"github.com/azoic/wormhole-client/internal/routing"
	"github.com/azoic/wormhole-client/internal/system"
	"github.com/azoic/wormhole-client/pkg/dns"
	"github.com/azoic/wormhole-client/pkg/logger"
)

type Client struct {
	mode           string
	config         *config.Config
	socks5Proxy    *proxy.SOCKS5Proxy
	dnsProxy       *dns.DNSProxy
	systemProxyMgr *system.SystemProxyManager
	routeMatcher   *routing.RouteMatcher
	httpServer     *http.Server
	ctx            context.Context
	cancel         context.CancelFunc
}

func NewClient(mode string) *Client {
	ctx, cancel := context.WithCancel(context.Background())
	return &Client{
		mode:           mode,
		systemProxyMgr: system.NewSystemProxyManager(),
		ctx:            ctx,
		cancel:         cancel,
	}
}

func (c *Client) Start(configPath string) error {
	// 加载配置
	cfg, err := config.LoadConfig(configPath)
	if err != nil {
		return fmt.Errorf("failed to load config: %v", err)
	}

	if err := cfg.Validate(); err != nil {
		return fmt.Errorf("invalid config: %v", err)
	}

	c.config = cfg

	// 设置日志级别
	logger.SetLevel(cfg.LogLevel)

	logger.Info("🚀 Starting Wormhole SOCKS5 Client")
	logger.Info("📄 Config loaded from: %s", configPath)
	logger.Info("🔧 Mode: %s", c.mode)
	logger.Info("🎯 SOCKS5 Server: %s", cfg.GetServerAddr())

	// 创建SOCKS5代理客户端
	c.socks5Proxy = proxy.NewSOCKS5Proxy(
		cfg.GetServerAddr(),
		cfg.Server.Username,
		cfg.Server.Password,
		cfg.Timeout,
	)

	// 初始化路由匹配器（如果有路由配置）
	if c.mode == "global" && len(cfg.GlobalProxy.Routing.BypassDomains) > 0 || len(cfg.GlobalProxy.Routing.ForceDomains) > 0 {
		c.routeMatcher, err = routing.NewRouteMatcher(&cfg.GlobalProxy.Routing)
		if err != nil {
			logger.Warn("Failed to initialize route matcher: %v", err)
		} else {
			logger.Info("🛣️  Route matcher initialized")
		}
	}

	// 设置信号处理
	c.setupSignalHandler()

	switch c.mode {
	case "http":
		return c.startHTTPProxy()
	case "global":
		return c.startGlobalProxy()
	case "transparent":
		return c.startTransparentProxy()
	default:
		return fmt.Errorf("unsupported mode: %s", c.mode)
	}
}

func (c *Client) startHTTPProxy() error {
	logger.Info("🌐 Starting HTTP proxy mode...")
	logger.Info("💡 Setting up HTTP proxy on port %d", c.config.Proxy.LocalPort)

	c.httpServer = c.socks5Proxy.CreateHTTPProxy(c.config.Proxy.LocalPort)

	logger.Info("✅ HTTP proxy started on :%d", c.config.Proxy.LocalPort)
	logger.Info("💡 Configure your browser to use HTTP proxy: 127.0.0.1:%d", c.config.Proxy.LocalPort)
	logger.Info("📊 Statistics available at: http://127.0.0.1:%d/stats", c.config.Proxy.LocalPort)
	logger.Info("💚 Health check available at: http://127.0.0.1:%d/health", c.config.Proxy.LocalPort)

	return c.httpServer.ListenAndServe()
}

func (c *Client) startGlobalProxy() error {
	logger.Info("🌍 Starting global proxy mode...")
	logger.Info("💡 This will configure system-wide proxy settings")
	logger.Info("⚠️  Requires administrator privileges")

	// 启动HTTP代理服务器
	c.httpServer = c.socks5Proxy.CreateHTTPProxy(c.config.Proxy.LocalPort)

	errChan := make(chan error, 1)
	go func() {
		if err := c.httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			errChan <- fmt.Errorf("HTTP proxy server failed: %v", err)
		}
	}()

	// 等待服务器启动
	time.Sleep(500 * time.Millisecond)

	// 设置系统代理
	httpProxy := fmt.Sprintf("127.0.0.1:%d", c.config.Proxy.LocalPort)
	httpsProxy := httpProxy

	logger.Info("📡 Setting system proxy to %s", httpProxy)
	if err := c.systemProxyMgr.SetGlobalProxy(httpProxy, httpsProxy, ""); err != nil {
		logger.Error("Failed to set system proxy: %v", err)
		logger.Warn("💡 You may need to run with administrator privileges")
		logger.Info("📋 Manual setup instructions:")
		logger.Info("   - Set HTTP proxy to: %s", httpProxy)
		logger.Info("   - Set HTTPS proxy to: %s", httpsProxy)
	} else {
		logger.Info("✅ System proxy configured successfully")
	}

	// 启动DNS代理（如果启用）
	if c.config.GlobalProxy.DNSProxy {
		logger.Info("🔍 Starting DNS proxy on port %d", c.config.GlobalProxy.DNSPort)

		// 创建DNS代理（通过SOCKS5转发DNS查询）
		c.dnsProxy = dns.NewDNSProxy("8.8.8.8:53", c.config.GlobalProxy.DNSPort)
		if err := c.dnsProxy.Start(); err != nil {
			logger.Warn("Failed to start DNS proxy: %v", err)
		} else {
			logger.Info("✅ DNS proxy started")
			logger.Info("💡 Configure your system DNS to: 127.0.0.1:%d", c.config.GlobalProxy.DNSPort)
		}
	}

	// 显示路由配置信息
	if c.routeMatcher != nil {
		stats := c.routeMatcher.GetStats()
		logger.Info("🛣️  Routing configuration:")
		logger.Info("   - Bypass domains: %v", stats["bypass_domains_count"])
		logger.Info("   - Force domains: %v", stats["force_domains_count"])
		logger.Info("   - Bypass local: %v", stats["bypass_local"])
		logger.Info("   - Bypass private: %v", stats["bypass_private"])
	}

	logger.Info("🎉 Global proxy mode started successfully")
	logger.Info("📍 HTTP/HTTPS Proxy: %s", httpProxy)
	if c.dnsProxy != nil {
		logger.Info("📍 DNS Proxy: 127.0.0.1:%d", c.config.GlobalProxy.DNSPort)
	}
	logger.Info("📊 Statistics: http://%s/stats", httpProxy)
	logger.Info("💚 Health check: http://%s/health", httpProxy)
	logger.Info("🛑 Press Ctrl+C to stop")

	// 检查是否有错误
	select {
	case err := <-errChan:
		return err
	case <-c.ctx.Done():
		return nil
	}
}

func (c *Client) startTransparentProxy() error {
	logger.Info("🔍 Starting transparent proxy mode...")
	logger.Info("💡 This will intercept network traffic transparently")
	logger.Info("⚠️  Requires root privileges and iptables support")

	// TODO: 实现透明代理
	logger.Error("❌ Transparent proxy mode is not yet implemented")
	logger.Info("💡 Available alternatives:")
	logger.Info("   - Use global mode: ./bin/wormhole-client -mode global")
	logger.Info("   - Use HTTP mode: ./bin/wormhole-client -mode http")

	return fmt.Errorf("transparent proxy mode not implemented")
}

func (c *Client) setupSignalHandler() {
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, os.Interrupt, syscall.SIGTERM)

	go func() {
		<-sigChan
		logger.Info("🛑 Received shutdown signal...")
		c.shutdown()
	}()
}

func (c *Client) shutdown() {
	logger.Info("🔄 Shutting down gracefully...")

	// 停止HTTP服务器
	if c.httpServer != nil {
		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		defer cancel()

		if err := c.httpServer.Shutdown(ctx); err != nil {
			logger.Error("Failed to shutdown HTTP server gracefully: %v", err)
		} else {
			logger.Info("✅ HTTP server stopped")
		}
	}

	// 恢复系统代理设置
	if c.systemProxyMgr != nil && c.systemProxyMgr.IsEnabled() {
		logger.Info("🔄 Restoring system proxy settings...")
		if err := c.systemProxyMgr.RestoreProxy(); err != nil {
			logger.Error("Failed to restore system proxy: %v", err)
		}
	}

	// 停止DNS代理
	if c.dnsProxy != nil {
		logger.Info("🔄 Stopping DNS proxy...")
		if err := c.dnsProxy.Stop(); err != nil {
			logger.Error("Failed to stop DNS proxy: %v", err)
		} else {
			logger.Info("✅ DNS proxy stopped")
		}
	}

	// 显示统计信息
	if c.socks5Proxy != nil {
		stats := c.socks5Proxy.GetStats()
		logger.Info("📊 Final statistics:")
		logger.Info("   - Total connections: %d", stats.TotalConnections)
		logger.Info("   - Successful requests: %d", stats.SuccessfulRequests)
		logger.Info("   - Failed requests: %d", stats.FailedRequests)
		logger.Info("   - Success rate: %.2f%%", stats.GetSuccessRate())
		logger.Info("   - Total bytes: %d", stats.GetTotalBytes())
		logger.Info("   - Uptime: %v", stats.Uptime)
	}

	logger.Info("✅ Cleanup completed")

	// 取消上下文
	c.cancel()

	// 给一点时间让goroutines优雅退出
	time.Sleep(100 * time.Millisecond)
	os.Exit(0)
}

// GetStats 获取客户端统计信息
func (c *Client) GetStats() map[string]interface{} {
	stats := make(map[string]interface{})

	if c.socks5Proxy != nil {
		proxyStats := c.socks5Proxy.GetStats()
		stats["proxy"] = proxyStats
	}

	if c.systemProxyMgr != nil {
		stats["system_proxy_enabled"] = c.systemProxyMgr.IsEnabled()
		if currentProxy, err := c.systemProxyMgr.GetCurrentProxy(); err == nil {
			stats["current_system_proxy"] = currentProxy
		}
	}

	if c.routeMatcher != nil {
		stats["routing"] = c.routeMatcher.GetStats()
	}

	stats["mode"] = c.mode
	stats["config_file"] = c.config

	return stats
}