// We tart it up with airframe and schedule data, trim out stale entries, and trim to fit box
func getAirspaceForDisplay(c context.Context, bbox geo.LatlongBox) (airspace.Airspace, error) {
a := airspace.NewAirspace()
if err := a.JustAircraftFromMemcache(c); err != nil {
return a, err
}
airframes := ref.NewAirframeCache(c)
schedules := ref.NewScheduleCache(c)
for k, aircraft := range a.Aircraft {
age := time.Since(a.Aircraft[k].Msg.GeneratedTimestampUTC)
if age > kMaxStaleDuration {
delete(a.Aircraft, k)
continue
}
if !bbox.SW.IsNil() && !bbox.Contains(aircraft.Msg.Position) {
delete(a.Aircraft, k)
continue
}
if af := airframes.Get(string(k)); af != nil {
// Update entry in map to include the airframe data we just found
aircraft.Airframe = *af
a.Aircraft[k] = aircraft
}
if schedules != nil && time.Since(schedules.LastUpdated) < kMaxStaleScheduleDuration {
if fs := schedules.Get(string(k)); fs != nil {
aircraft.Schedule = fs.Identity.Schedule
a.Aircraft[k] = aircraft
}
}
}
return a, nil
}
// For clients, fetching from a pi/frontend via JSON
func Fetch(client *http.Client, host string, bbox geo.LatlongBox) (*Airspace, error) {
as := Airspace{}
if host == "" {
host = "fdb.serfr1.org"
}
url := fmt.Sprintf("http://%s/?json=1&%s", host, bbox.ToCGIArgs("box"))
if resp, err := client.Get(url); err != nil {
return nil, err
} else if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("Bad status: %v", resp.Status)
} else if err := json.NewDecoder(resp.Body).Decode(&as); err != nil {
return nil, err
}
return &as, nil
}
func (t Track) TimesInBox(b geo.LatlongBox) (s, e time.Time) {
inside := false
for _, tp := range t {
if tp.AltitudeFeet == 0 || tp.SpeedKnots == 0 {
continue
}
if !inside && b.Contains(tp.Latlong) {
s = tp.TimestampUTC
inside = true
} else if inside {
e = tp.TimestampUTC // keep overwriting e until we're outside (or we've landed)
if !b.Contains(tp.Latlong) {
break
}
}
}
return
}
// WARNING: If we find something, we will annotate the track in-place
func (track Track) LevelFlightAcrossBox(maxAbsDelta float64, box geo.LatlongBox, name string) *LevelFlightEvent {
iStart, iEnd := 0, 0
for i, tp := range track {
if iStart == 0 {
if box.Contains(tp.Latlong) {
iStart = i
}
} else {
if !box.Contains(tp.Latlong) {
iEnd = i - 1
break
}
}
}
if iStart == 0 || iEnd == 0 || iStart == iEnd {
return nil
}
ev := LevelFlightEvent{
Start: track[iStart],
End: track[iEnd],
I: iStart,
J: iEnd,
}
if math.Abs(ev.End.AltitudeFeet-ev.Start.AltitudeFeet) > maxAbsDelta {
return nil
}
for i := iStart; i <= iEnd; i++ {
track[i].X_Annotation = fmt.Sprintf("\n** LEVEL FLIGHT across %s", name)
track[i].X_MapIcon = "red"
}
return &ev
}
