| 1 | package main
|
| 2 |
|
| 3 | import (
|
| 4 | "encoding/csv"
|
| 5 | "fmt"
|
| 6 | "io"
|
| 7 | "math"
|
| 8 | "os"
|
| 9 | "strconv"
|
| 10 | "strings"
|
| 11 | )
|
| 12 |
|
| 13 | const d2r = (math.Pi / 180.0)
|
| 14 |
|
| 15 | // Haversine calculates linear distance between two pairs
|
| 16 | func Haversine(start, dest [2]float64) float64 {
|
| 17 | dlong := (dest[1] - start[1]) * d2r
|
| 18 | dlat := (dest[0] - start[0]) * d2r
|
| 19 | a := math.Pow(math.Sin(dlat/2.0), 2) + math.Cos(start[0]*d2r)*math.Cos(dest[0]*d2r)*math.Pow(math.Sin(dlong/2.0), 2)
|
| 20 | c := 2 * math.Atan2(math.Sqrt(a), math.Sqrt(1-a))
|
| 21 | distance := 6367 * c
|
| 22 | return distance
|
| 23 | }
|
| 24 |
|
| 25 | func GetDistance(start, dest Airport) float64 {
|
| 26 | return Haversine([2]float64{start.Latitude, start.Longitude}, [2]float64{dest.Latitude, dest.Longitude})
|
| 27 | }
|
| 28 |
|
| 29 | func NearBy(threshold float64, start Airport, airports AirportMap) []Airport {
|
| 30 | nearby := []Airport{}
|
| 31 | for _, dest := range airports {
|
| 32 | if GetDistance(start, dest) <= threshold {
|
| 33 | if dest.Code != start.Code {
|
| 34 | nearby = append(nearby, dest)
|
| 35 | }
|
| 36 | }
|
| 37 | }
|
| 38 | return nearby
|
| 39 | }
|
| 40 |
|
| 41 | func FindRoutes(threshold float64, airports map[string]Airport, departure, arrival Airport) ([]Airport, []Airport) {
|
| 42 | return NearBy(threshold, departure, airports), NearBy(threshold, arrival, airports)
|
| 43 | }
|
| 44 |
|
| 45 | // icao_code,iata_code,name,city,country,lat_deg,lat_min,lat_sec,lat_dir,lon_deg,lon_min,lon_sec,lon_dir,altitude,lat_decimal,lon_decimal
|
| 46 | // AYGA:GKA:GOROKA:GOROKA:PAPUA NEW GUINEA:006:004:054:S:145:023:030:E:01610:-6.082:145.392
|
| 47 | func parseAirport(row []string) *Airport {
|
| 48 | if len(row) != 16 {
|
| 49 | return nil
|
| 50 | }
|
| 51 | if row[1] == "N/A" {
|
| 52 | return nil
|
| 53 | }
|
| 54 | latitude, _ := strconv.ParseFloat(row[14], 64)
|
| 55 | longitude, _ := strconv.ParseFloat(row[15], 64)
|
| 56 | if latitude == 0 || longitude == 0 {
|
| 57 | return nil
|
| 58 | }
|
| 59 | airport := &Airport{
|
| 60 | Code: row[1],
|
| 61 | Name: row[2],
|
| 62 | City: row[3],
|
| 63 | Country: row[4],
|
| 64 | Latitude: latitude,
|
| 65 | Longitude: longitude,
|
| 66 | }
|
| 67 | return airport
|
| 68 | }
|
| 69 |
|
| 70 | //2B,410,AER,2965,KZN,2990,,0,CR2
|
| 71 | func parseRoute(airports AirportMap, row []string) *Route {
|
| 72 | if len(row) != 9 {
|
| 73 | return nil
|
| 74 | }
|
| 75 | start, end := row[2], row[4]
|
| 76 | if airports.HasCode(start) && airports.HasCode(end) {
|
| 77 | if start != end {
|
| 78 | return &Route{
|
| 79 | to: airports.Airport(end),
|
| 80 | from: airports.Airport(start),
|
| 81 | }
|
| 82 | } else {
|
| 83 | return nil
|
| 84 | }
|
| 85 | } else {
|
| 86 | return nil
|
| 87 | }
|
| 88 | }
|
| 89 |
|
| 90 | func Airports() AirportMap {
|
| 91 | airports := map[string]Airport{}
|
| 92 | reader := csv.NewReader(strings.NewReader(airportData))
|
| 93 | reader.Comma = ':'
|
| 94 | for {
|
| 95 | row, err := reader.Read()
|
| 96 | if err == io.EOF {
|
| 97 | return airports
|
| 98 | }
|
| 99 | airport := parseAirport(row)
|
| 100 | if airport != nil {
|
| 101 | airports[airport.Code] = *airport
|
| 102 | }
|
| 103 | }
|
| 104 | }
|
| 105 |
|
| 106 | func Routes(airports AirportMap) []Route {
|
| 107 | var routes []Route
|
| 108 | reader := csv.NewReader(strings.NewReader(routeData))
|
| 109 | reader.Comma = ','
|
| 110 | for {
|
| 111 | row, err := reader.Read()
|
| 112 | if err == io.EOF {
|
| 113 | return routes
|
| 114 | }
|
| 115 | route := parseRoute(airports, row)
|
| 116 | if route != nil {
|
| 117 | routes = append(routes, *route)
|
| 118 | }
|
| 119 | }
|
| 120 | }
|
| 121 |
|
| 122 | func maybe(err error) {
|
| 123 | if err != nil {
|
| 124 | fmt.Printf("Error: %s\n", err)
|
| 125 | os.Exit(1)
|
| 126 | }
|
| 127 | }
|