skyview/internal/parser/sbs1.go

package parser

import (
	"strconv"
	"strings"
	"time"
)

type TrackPoint struct {
	Timestamp time.Time `json:"timestamp"`
	Latitude  float64   `json:"lat"`
	Longitude float64   `json:"lon"`
	Altitude  int       `json:"altitude"`
	Speed     int       `json:"speed"`
	Track     int       `json:"track"`
}

type Aircraft struct {
	Hex          string       `json:"hex"`
	Flight       string       `json:"flight,omitempty"`
	Altitude     int          `json:"alt_baro,omitempty"`
	GroundSpeed  int          `json:"gs,omitempty"`
	Track        int          `json:"track,omitempty"`
	Latitude     float64      `json:"lat,omitempty"`
	Longitude    float64      `json:"lon,omitempty"`
	VertRate     int          `json:"vert_rate,omitempty"`
	Squawk       string       `json:"squawk,omitempty"`
	Emergency    bool         `json:"emergency,omitempty"`
	OnGround     bool         `json:"on_ground,omitempty"`
	LastSeen     time.Time    `json:"last_seen"`
	Messages     int          `json:"messages"`
	TrackHistory []TrackPoint `json:"track_history,omitempty"`
	RSSI         float64      `json:"rssi,omitempty"`
	Country      string       `json:"country,omitempty"`
	Registration string       `json:"registration,omitempty"`
}

type AircraftData struct {
	Now      int64               `json:"now"`
	Messages int                 `json:"messages"`
	Aircraft map[string]Aircraft `json:"aircraft"`
}

func ParseSBS1Line(line string) (*Aircraft, error) {
	parts := strings.Split(strings.TrimSpace(line), ",")
	if len(parts) < 22 {
		return nil, nil
	}

	// messageType := parts[1]
	// Accept all message types to get complete data
	// MSG types: 1=ES_IDENT_AND_CATEGORY, 2=ES_SURFACE_POS, 3=ES_AIRBORNE_POS
	// 4=ES_AIRBORNE_VEL, 5=SURVEILLANCE_ALT, 6=SURVEILLANCE_ID, 7=AIR_TO_AIR, 8=ALL_CALL_REPLY

	aircraft := &Aircraft{
		Hex:      strings.TrimSpace(parts[4]),
		LastSeen: time.Now(),
		Messages: 1,
	}

	// Different message types contain different fields
	// Always try to extract what's available
	if parts[10] != "" {
		aircraft.Flight = strings.TrimSpace(parts[10])
	}

	if parts[11] != "" {
		if alt, err := strconv.Atoi(parts[11]); err == nil {
			aircraft.Altitude = alt
		}
	}

	if parts[12] != "" {
		if gs, err := strconv.Atoi(parts[12]); err == nil {
			aircraft.GroundSpeed = gs
		}
	}

	if parts[13] != "" {
		if track, err := strconv.ParseFloat(parts[13], 64); err == nil {
			aircraft.Track = int(track)
		}
	}

	if parts[14] != "" && parts[15] != "" {
		if lat, err := strconv.ParseFloat(parts[14], 64); err == nil {
			aircraft.Latitude = lat
		}
		if lon, err := strconv.ParseFloat(parts[15], 64); err == nil {
			aircraft.Longitude = lon
		}
	}

	if parts[16] != "" {
		if vr, err := strconv.Atoi(parts[16]); err == nil {
			aircraft.VertRate = vr
		}
	}

	if parts[17] != "" {
		aircraft.Squawk = strings.TrimSpace(parts[17])
	}

	if parts[21] != "" {
		aircraft.OnGround = parts[21] == "1"
	}

	aircraft.Country = getCountryFromICAO(aircraft.Hex)
	aircraft.Registration = getRegistrationFromICAO(aircraft.Hex)

	return aircraft, nil
}

func getCountryFromICAO(icao string) string {
	if len(icao) < 6 {
		return "Unknown"
	}

	prefix := icao[:1]

	switch prefix {
	case "4":
		return getCountryFrom4xxxx(icao)
	case "A":
		return "United States"
	case "C":
		return "Canada"
	case "D":
		return "Germany"
	case "F":
		return "France"
	case "G":
		return "United Kingdom"
	case "I":
		return "Italy"
	case "J":
		return "Japan"
	case "P":
		return getPCountry(icao)
	case "S":
		return getSCountry(icao)
	case "O":
		return getOCountry(icao)
	default:
		return "Unknown"
	}
}

func getCountryFrom4xxxx(icao string) string {
	if len(icao) >= 2 {
		switch icao[:2] {
		case "40":
			return "United Kingdom"
		case "44":
			return "Austria"
		case "45":
			return "Denmark"
		case "46":
			return "Germany"
		case "47":
			return "Germany"
		case "48":
			return "Netherlands"
		case "49":
			return "Netherlands"
		}
	}
	return "Europe"
}

func getPCountry(icao string) string {
	if len(icao) >= 2 {
		switch icao[:2] {
		case "PH":
			return "Netherlands"
		case "PJ":
			return "Netherlands Antilles"
		}
	}
	return "Unknown"
}

func getSCountry(icao string) string {
	if len(icao) >= 2 {
		switch icao[:2] {
		case "SE":
			return "Sweden"
		case "SX":
			return "Greece"
		}
	}
	return "Unknown"
}

func getOCountry(icao string) string {
	if len(icao) >= 2 {
		switch icao[:2] {
		case "OO":
			return "Belgium"
		case "OH":
			return "Finland"
		}
	}
	return "Unknown"
}

func getRegistrationFromICAO(icao string) string {
	// This is a simplified conversion - real registration lookup would need a database
	country := getCountryFromICAO(icao)
	switch country {
	case "Germany":
		return "D-" + icao[2:]
	case "United Kingdom":
		return "G-" + icao[2:]
	case "France":
		return "F-" + icao[2:]
	case "Netherlands":
		return "PH-" + icao[2:]
	case "Sweden":
		return "SE-" + icao[2:]
	default:
		return icao
	}
}