DMAC/internal/pkg/server/tuimanager.go

package server

import (
    "fmt"
    "time"
    "sync"
    "net"
    "log"
    "context"
    "FRMS/internal/pkg/logging"
    "google.golang.org/grpc"
    pb "FRMS/internal/pkg/grpc"
)

// implement tui specific manager to be called for each client conn

type TUIManager struct {
    *Manager        // embedded manager for access to methods and client
    Ip string
    Port *port
    StatusMon *StatusMonitor      // use it for all devs coming in
    Err chan error
    *Timeout
    *pb.UnimplementedManagementServer
}

type Timeout struct {
    Alert chan bool
    LastSeen time.Time
    TO time.Duration
    sync.Mutex
}

type port struct {
    Chan chan int
    int
}

func NewTUIManager(ip string, c *Client, sys *SystemViewer, err chan error) GeneralManager {
    m := NewManager(err)
    t := &TUIManager{Err: err}
    t.Port = &port{Chan:make(chan int)}
    alert := make(chan bool)
    t.Timeout = &Timeout{Alert:alert,TO:time.Duration(2500*time.Millisecond)}   // short time outs are fine because we will just rejoin 
    t.Manager = m
    t.Ip = ip
    t.StatusMon = NewStatusMonitor("TUI",t.Id,sys)
    return t
}

func (t *TUIManager) Start(cl *Client) {
    //
    t.PingReset()
    t.Manager.Start(cl)
    logging.Debug(logging.DStart,"TMA %v starting", t.Id)
    go t.Timeoutd()
    go t.Register() // begin tui server to respond to tui client reqs
    //go t.Monitor(conn)
}

func (t *TUIManager) Exit() {
    t.Manager.Exit()
    logging.Debug(logging.DExit,"TMA %v exiting",t.Id)
}

func (t *Timeout) PingReset() {
    t.Lock()
    defer t.Unlock()
    t.LastSeen = time.Now()
}

func (t *TUIManager) Timeoutd() {
    for t.IsActive() {
        if sleep, elapsed := t.Elapsed(); elapsed {
            // timeout elapsed
           logging.Debug(logging.DClient,"TMA %V client not responding", t.Id)
            t.Exit()
        } else {
            time.Sleep(sleep)
        }
    }
}

func (t *Timeout) Elapsed() (time.Duration, bool) {
    t.Lock()
    defer t.Unlock()
    now := time.Now()
    if now.After(t.LastSeen.Add(t.TO)) {
        // timeout expired
        return 0 * time.Second, true
    } else {
        sleep := t.LastSeen.Add(t.TO).Sub(now)
        return sleep, false
    }
}

func (t *TUIManager) Register() {
    lis, err := net.Listen("tcp", fmt.Sprintf("%v:0",t.Ip))
    if err != nil {
        log.Fatal(err)
    }
    grpcServer := grpc.NewServer()
    pb.RegisterManagementServer(grpcServer,t)
    go grpcServer.Serve(lis)
    // send port now that server is up
    t.Port.int = lis.Addr().(*net.TCPAddr).Port
    go func(ch chan int,p int) {
        ch <-p
    }(t.Port.Chan, t.Port.int)
    logging.Debug(logging.DClient, "TMA %v ready for client conn", t.Id)
    // up and running
}

func (t *TUIManager) GetPort() int {
    port := <-t.Port.Chan
    return port
}

// tui client requests and logic will be down here

func (t *TUIManager) GetDevices(ctx context.Context, req *pb.GetDevicesRequest) (*pb.GetDevicesResponse, error) {
    go t.PingReset()
    devices := []*pb.Dev{}
    resp := &pb.GetDevicesResponse{ClientId:t.Id,Devices:devices}
    if req.GetReactorId() > 0 || req.GetRefresh() {
        resp.ReactorId = req.GetReactorId()
        t.StatusMon.UpdateListener(t.Id, req.GetReactorId())
    }
    devs := t.StatusMon.GetBuffer() // always empty buffer

    for _, v := range devs {
        resp.Devices = append(resp.Devices, &pb.Dev{Id:v.Id,Type:v.Type,Status:v.Status,Data:v.Data,Index:v.Index})
    }
    logging.Debug(logging.DClient,"TMA %v sending devices to client" ,t.Id)
    return resp, nil
}

func (t *TUIManager) DeleteReactors(ctx context.Context, req *pb.DeleteReactorRequest) (*pb.DeleteReactorResponse, error) {
    go t.PingReset()
    //
    return &pb.DeleteReactorResponse{}, nil
}

func (t *TUIManager) DeleteReactorDevice(ctx context.Context, req *pb.DeleteReactorDeviceRequest) (*pb.DeleteReactorDeviceResponse, error) {
    go t.PingReset()
    //
    return &pb.DeleteReactorDeviceResponse{}, nil
}