package matchmaker

import (
	_ "embed"
	"fmt"
	"git.wamblee.org/converge/pkg/comms"
	"git.wamblee.org/converge/pkg/models"
	"git.wamblee.org/converge/pkg/server/admin"
	iowrappers2 "git.wamblee.org/converge/pkg/support/ioutils"
	"io"
	"log"
	"time"
)

// Use a fixed host key for all agents. Using a dynamic host key would be madness.
// An alternative would be to configure the host key on the server side and send it
// to agents before establishing a session.
//
//go:embed hostkey.pem
var hostPrivateKey []byte

type MatchMaker struct {
	admin    admin.Admin
	notifier Notifier
}

func NewMatchMaker(notifier Notifier) *MatchMaker {
	converge := MatchMaker{
		admin:    *admin.NewAdmin(),
		notifier: notifier,
	}
	converge.logStatus()
	return &converge
}

func (converge *MatchMaker) Close() {
	converge.admin.Close()
}

type WaitForAgentFunc func()

func (converge *MatchMaker) Register(publicId models.RendezVousId, conn io.ReadWriteCloser) (waitForAgentFunc WaitForAgentFunc, err error) {

	serverInfo := comms.ServerInfo{}

	agentInfo, err := comms.ServerInitialization(conn, serverInfo)
	if err != nil {
		return nil, err
	}

	agent, err := converge.admin.AddAgent(hostPrivateKey, publicId, agentInfo, conn)
	converge.logStatus()
	if err != nil {
		return nil, err
	}
	publicId = agent.Info.PublicId
	cleanupFunc := func() {
		_ = converge.admin.RemoveAgent(publicId)
		converge.logStatus()
	}
	defer func() {
		if err != nil {
			cleanupFunc()
		}
	}()

	go func() {
		comms.ListenForAgentEvents(agent.CommChannel.SideChannel,
			func(info comms.EnvironmentInfo) {
				agent.Info.EnvironmentInfo = info
				converge.logStatus()
			},
			func(session comms.SessionInfo) {
				log.Println("Recceived sessioninfo ", session)
				converge.admin.SetSessionType(models.ClientId(session.ClientId), models.SessionType(session.SessionType))
			},
			func(expiry comms.ExpiryTimeUpdate) {
				agent.Info.SetExpiryTime(expiry.ExpiryTime)
				converge.logStatus()
			},
			func(heartbeat comms.HeartBeat) {
				// Empty
			})
	}()

	return WaitForAgentFunc(func() {
		defer cleanupFunc()
		log.Printf("agentConnection registered: '%s'\n", publicId)
		for !agent.CommChannel.Session.IsClosed() {
			time.Sleep(250 * time.Millisecond)
		}
		log.Printf("Agent disconnected")
	}), nil
}

type SynchronizeStreamsFunc func()

func (converge *MatchMaker) Connect(wsProxyMode bool,
	publicId models.RendezVousId, conn iowrappers2.ReadWriteAddrCloser) (clientId models.ClientId, synchronizer SynchronizeStreamsFunc, err error) {

	defer func() {
		if err != nil {
			conn.Close()
		}
	}()
	log.Printf("Using wsproxy protocol %v", wsProxyMode)
	channel := comms.NewGOBChannel(conn)
	if wsProxyMode {
		err := comms.SendWithTimeout(
			channel,
			comms.ProtocolVersion{
				Version: comms.PROTOCOL_VERSION,
			})
		if err != nil {
			log.Printf("Error sending protocol version to client %v", err)
			return "", nil, err
		}
	}

	client, err := converge.admin.AddClient(publicId, conn)
	cleanUpFunc := func() {
		if client != nil {
			converge.admin.RemoveClient(client.Info.ClientId)
		}
		converge.logStatus()
	}
	defer func() {
		if err != nil {
			cleanUpFunc()
		}
	}()
	if err != nil {
		if wsProxyMode {
			_ = comms.SendWithTimeout(channel,
				comms.ClientConnectionInfo{
					Ok:      false,
					Message: err.Error(),
				})
		}
		return "", nil, err
	}
	log.Printf("Connecting client and agent: '%s'\n", publicId)
	if wsProxyMode {
		err = comms.SendWithTimeout(channel,
			comms.ClientConnectionInfo{
				Ok:      true,
				Message: "Connecting to agent",
			})
		if err != nil {
			return "", nil, fmt.Errorf("Error sending connection info to client: %v", err)
		}
		clientEnvironment, err := comms.ReceiveWithTimeout[comms.EnvironmentInfo](channel)
		if err != nil {
			return "", nil, fmt.Errorf("Error receiving environment info from client: %v", err)
		}
		client.Info.EnvironmentInfo = clientEnvironment
	}
	converge.logStatus()

	return client.Info.ClientId, SynchronizeStreamsFunc(func() {
		defer conn.Close()
		defer cleanUpFunc()
		client.Synchronize()
	}), nil
}

func (converge *MatchMaker) logStatus() {
	notification := converge.admin.CreateNotifification()
	logStatusImpl(notification, converge.notifier)
}

// logging without having the lock on the administration.
func logStatusImpl(admin *models.State, notifier Notifier) {
	format := "%-20s %-20s %-20s %-10s %-15s %-20s"

	lines := make([]string, 0, 100)

	lines = append(lines, fmt.Sprintf(format, "AGENT", "ACTIVE_SINCE", "EXPIRY_TIME",
		"USER", "HOST", "OS"))
	for _, agent := range admin.Agents {
		lines = append(lines, fmt.Sprintf(format, agent.PublicId,
			agent.StartTime.Format(time.DateTime),
			agent.GetExpiryTime().Format(time.DateTime),
			agent.EnvironmentInfo.Username,
			agent.EnvironmentInfo.Hostname,
			agent.EnvironmentInfo.OS))
	}
	lines = append(lines, "")
	format = "%-10s %-20s %-20s %-20s %-20s"
	lines = append(lines, fmt.Sprintf(format, "CLIENT", "AGENT", "ACTIVE_SINCE", "REMOTE_ADDRESS", "SESSION_TYPE"))
	for _, client := range admin.Clients {
		lines = append(lines, fmt.Sprintf(format,
			client.ClientId,
			client.PublicId,
			client.StartTime.Format(time.DateTime),
			client.RemoteAddr,
			client.SessionType))
	}
	lines = append(lines, "")
	for _, line := range lines {
		log.Println(line)
	}

	notifier.Publish(admin)
}