package reactor

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

// implements grpc handler and device data aggregater handler
type DeviceStatus struct {
    Addr int
    Status string
    Type string
    Data string
}

// get reactor/device status
func (c *Coordinator) DevStatus(ch chan *DeviceStatus, a int, dm DeviceManager) {
    d := &DeviceStatus{Addr:a}
    d.Type = dm.GetType()
    d.Status = dm.GetStatus()
    d.Data = dm.GetData()
    ch <-d
}

func (c *Coordinator) GetStatus() []*DeviceStatus {
    var wg sync.WaitGroup
    devs := []*DeviceStatus{}
    statusChan := make(chan *DeviceStatus)
    c.Devices.Lock()
    for a,dm := range c.Devices.Managers {
        wg.Add(1)
        go c.DevStatus(statusChan,a,dm)
    }
    c.Devices.Unlock()
    allDone := make(chan struct{})
    go func(){
        wg.Wait()
        allDone <-struct{}{}
    }() // once all the status are sent we send all done on the chan
    for {
        select{
        case s:= <-statusChan:
            //fmt.Printf("%v is %v, ",s.Type,s.Status)
            devs = append(devs,s)
            wg.Done()
        case <-allDone:
            fmt.Printf("Devices scaned\n")
            return devs
        }
    }
}

// grpc status update handler

func (c *Coordinator) Register() {
    ip := c.hwinfo.Ip

    if lis, err := net.Listen("tcp", fmt.Sprintf("%v:0",ip)); err != nil {
        log.Fatal(err)
    } else {
        c.hwinfo.Port = lis.Addr().(*net.TCPAddr).Port
        grpcServer := grpc.NewServer()
        pb.RegisterMonitoringServer(grpcServer,c)
        go grpcServer.Serve(lis)
    }
    log.Printf("Listening for pings on %v:%v\n",ip,c.hwinfo.Port)
}

func (c *Coordinator) GetReactorStatus(ctx context.Context, ping *pb.ReactorStatusRequest) (*pb.ReactorStatusResponse, error) {
    // status request handler
    devs := []*pb.Device{}
    resp := &pb.ReactorStatusResponse{Id:c.Id,Devices:devs}
    devStatus := c.GetStatus()
    for _,v := range devStatus {
        d := &pb.Device{Addr:int32(v.Addr),Type:v.Type,Status:v.Status,Data:v.Data}
        resp.Devices = append(resp.Devices,d)
    }
    return resp, nil
}