package server

import (
	"fmt"
	"time"

	"github.com/fatedier/frp/assets"
	"github.com/fatedier/frp/models/config"
	"github.com/fatedier/frp/models/msg"
	"github.com/fatedier/frp/utils/log"
	"github.com/fatedier/frp/utils/net"
	"github.com/fatedier/frp/utils/util"
	"github.com/fatedier/frp/utils/version"
	"github.com/fatedier/frp/utils/vhost"
)

// Server service.
type Service struct {
	// Accept connections from client.
	listener net.Listener

	// For http proxies, route requests to different clients by hostname and other infomation.
	VhostHttpMuxer *vhost.HttpMuxer

	// For https proxies, route requests to different clients by hostname and other infomation.
	VhostHttpsMuxer *vhost.HttpsMuxer

	// Manage all controllers.
	ctlManager *ControlManager

	// Manage all proxies.
	pxyManager *ProxyManager
}

func NewService() (svr *Service, err error) {
	svr = &Service{
		ctlManager: NewControlManager(),
		pxyManager: NewProxyManager(),
	}

	// Init assets.
	err = assets.Load(config.ServerCommonCfg.AssetsDir)
	if err != nil {
		err = fmt.Errorf("Load assets error: %v", err)
		return
	}

	// Listen for accepting connections from client.
	svr.listener, err = net.ListenTcp(config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.BindPort)
	if err != nil {
		err = fmt.Errorf("Create server listener error, %v", err)
		return
	}

	// Create http vhost muxer.
	if config.ServerCommonCfg.VhostHttpPort != 0 {
		var l net.Listener
		l, err = net.ListenTcp(config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.VhostHttpPort)
		if err != nil {
			err = fmt.Errorf("Create vhost http listener error, %v", err)
			return
		}
		svr.VhostHttpMuxer, err = vhost.NewHttpMuxer(l, 30*time.Second)
		if err != nil {
			err = fmt.Errorf("Create vhost httpMuxer error, %v", err)
			return
		}
	}

	// Create https vhost muxer.
	if config.ServerCommonCfg.VhostHttpsPort != 0 {
		var l net.Listener
		l, err = net.ListenTcp(config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.VhostHttpsPort)
		if err != nil {
			err = fmt.Errorf("Create vhost https listener error, %v", err)
			return
		}
		svr.VhostHttpsMuxer, err = vhost.NewHttpsMuxer(l, 30*time.Second)
		if err != nil {
			err = fmt.Errorf("Create vhost httpsMuxer error, %v", err)
			return
		}
	}

	// Create dashboard web server.
	if config.ServerCommonCfg.DashboardPort != 0 {
		err = RunDashboardServer(config.ServerCommonCfg.BindAddr, config.ServerCommonCfg.DashboardPort)
		if err != nil {
			err = fmt.Errorf("Create dashboard web server error, %v", err)
			return
		}
	}
	return
}

func (svr *Service) Run() {
	// Listen for incoming connections from client.
	for {
		c, err := svr.listener.Accept()
		if err != nil {
			log.Warn("Listener for incoming connections from client closed")
			return
		}

		// Start a new goroutine for dealing connections.
		go func(frpConn net.Conn) {
			var rawMsg msg.Message
			if rawMsg, err = msg.ReadMsg(frpConn); err != nil {
				log.Warn("Failed to read message: %v", err)
				frpConn.Close()
				return
			}

			switch m := rawMsg.(type) {
			case *msg.Login:
				err = svr.RegisterControl(frpConn, m)
				// If login failed, send error message there.
				// Otherwise send success message in control's work goroutine.
				if err != nil {
					frpConn.Warn("%v", err)
					msg.WriteMsg(frpConn, &msg.LoginResp{
						Version: version.Full(),
						Error:   err.Error(),
					})
					frpConn.Close()
				}
			case *msg.NewWorkConn:
				svr.RegisterWorkConn(frpConn, m)
			default:
				log.Warn("Error message type for the new connection [%s]", frpConn.RemoteAddr().String())
				frpConn.Close()
			}
		}(c)
	}
}

func (svr *Service) RegisterControl(ctlConn net.Conn, loginMsg *msg.Login) (err error) {
	ctlConn.Info("client login info: ip [%s] version [%s] hostname [%s] os [%s] arch [%s]",
		ctlConn.RemoteAddr().String(), loginMsg.Version, loginMsg.Hostname, loginMsg.Os, loginMsg.Arch)

	// Check client version.
	if ok, msg := version.Compat(loginMsg.Version); !ok {
		err = fmt.Errorf("%s", msg)
		return
	}

	// Check auth.
	nowTime := time.Now().Unix()
	if config.ServerCommonCfg.AuthTimeout != 0 && nowTime-loginMsg.Timestamp > config.ServerCommonCfg.AuthTimeout {
		err = fmt.Errorf("authorization timeout")
		return
	}
	if util.GetAuthKey(config.ServerCommonCfg.PrivilegeToken, loginMsg.Timestamp) != loginMsg.PrivilegeKey {
		err = fmt.Errorf("authorization failed")
		return
	}

	// If client's RunId is empty, it's a new client, we just create a new controller.
	// Otherwise, we check if there is one controller has the same run id. If so, we release previous controller and start new one.
	if loginMsg.RunId == "" {
		loginMsg.RunId, err = util.RandId()
		if err != nil {
			return
		}
	}

	ctl := NewControl(svr, ctlConn, loginMsg)

	if oldCtl := svr.ctlManager.Add(loginMsg.RunId, ctl); oldCtl != nil {
		oldCtl.allShutdown.WaitDown()
	}

	ctlConn.AddLogPrefix(loginMsg.RunId)
	ctl.Start()
	return
}

// RegisterWorkConn register a new work connection to control and proxies need it.
func (svr *Service) RegisterWorkConn(workConn net.Conn, newMsg *msg.NewWorkConn) {
	ctl, exist := svr.ctlManager.GetById(newMsg.RunId)
	if !exist {
		workConn.Warn("No client control found for run id [%s]", newMsg.RunId)
		return
	}
	ctl.RegisterWorkConn(workConn)
	return
}

func (svr *Service) RegisterProxy(name string, pxy Proxy) error {
	err := svr.pxyManager.Add(name, pxy)
	return err
}

func (svr *Service) DelProxy(name string) {
	svr.pxyManager.Del(name)
}