package worker

import (
	"context"
	"math/rand"
	"time"

	pbs "github.com/hashicorp/boundary/internal/gen/controller/servers/services"
	"github.com/hashicorp/boundary/internal/servers"
	"github.com/hashicorp/boundary/internal/types/resource"
	"google.golang.org/grpc/resolver"
)

// In the future we could make this configurable
const (
	statusInterval = 2 * time.Second
)

type LastStatusInformation struct {
	*pbs.StatusResponse
	StatusTime time.Time
}

func (w *Worker) startStatusTicking(cancelCtx context.Context) {
	go func() {
		r := rand.New(rand.NewSource(time.Now().UnixNano()))
		// This function exists to desynchronize calls to controllers from
		// workers so we aren't always getting status updates at the exact same
		// intervals, to ease the load on the DB.
		getRandomInterval := func() time.Duration {
			// 0 to 0.5 adjustment to the base
			f := r.Float64() / 2
			// Half a chance to be faster, not slower
			if r.Float32() > 0.5 {
				f = -1 * f
			}
			return statusInterval + time.Duration(f*float64(time.Second))
		}

		timer := time.NewTimer(0)
		for {
			select {
			case <-cancelCtx.Done():
				w.logger.Info("status ticking shutting down")
				return

			case <-timer.C:
				var activeJobs []*pbs.JobStatus
				w.cancellationMap.Range(func(key, value interface{}) bool {
					activeJobs = append(activeJobs, &pbs.JobStatus{
						Job:    &pbs.Job{JobId: key.(string)},
						Status: pbs.JobStatus_STATUS_ACTIVE,
					})
					return true
				})
				client := w.controllerConn.Load().(pbs.ServerCoordinationServiceClient)
				result, err := client.Status(cancelCtx, &pbs.StatusRequest{
					Jobs: activeJobs,
					Worker: &servers.Server{
						PrivateId:   w.conf.RawConfig.Worker.Name,
						Name:        w.conf.RawConfig.Worker.Name,
						Type:        resource.Worker.String(),
						Description: w.conf.RawConfig.Worker.Description,
						Address:     w.listeningAddress,
					},
				})
				if err != nil {
					w.logger.Error("error making status request to controller", "error", err)
				} else {
					w.logger.Trace("successfully sent status to controller")
					addrs := make([]resolver.Address, 0, len(result.Controllers))
					strAddrs := make([]string, 0, len(result.Controllers))
					for _, v := range result.Controllers {
						addrs = append(addrs, resolver.Address{Addr: v.Address})
						strAddrs = append(strAddrs, v.Address)
					}
					w.Resolver().UpdateState(resolver.State{Addresses: addrs})
					w.logger.Trace("found controllers", "addresses", strAddrs)
					w.lastStatusSuccess.Store(&LastStatusInformation{StatusResponse: result, StatusTime: time.Now()})

					for _, id := range result.GetJobsRequests() {
						if cancel, ok := w.cancellationMap.LoadAndDelete(id); ok {
							cancel.(context.CancelFunc)()
							w.logger.Info("canceled job", "job_id", id)
						} else {
							w.logger.Warn("asked to cancel job but could not find a cancellation function for it", "job_id", id)
						}
					}
				}
				timer.Reset(getRandomInterval())
			}
		}
	}()
}

func (w *Worker) LastStatusSuccess() *LastStatusInformation {
	return w.lastStatusSuccess.Load().(*LastStatusInformation)
}