golifehk/businfo/mtr/busstops.go
2022-09-13 21:44:06 +08:00

142 lines
3.2 KiB
Go

package mtr
import (
"encoding/csv"
"fmt"
"io"
"net/http"
"os"
"path/filepath"
"strconv"
"strings"
"github.com/tgckpg/golifehk/utils"
)
type BusStop struct {
RouteId string
Direction string
StationSeq string
StationId string
Latitude float64
Longtitude float64
Name_zhant string
Name_en string
}
var mBusStops *map[string]BusStop
var DEF_CSV string = filepath.Join( utils.WORKDIR, "mtr_bus_stops.csv" )
func readBusStopData( r io.Reader ) ( *map[string]BusStop, error ) {
reader := csv.NewReader( r )
entries, err := reader.ReadAll()
if err != nil {
return nil, err
}
busStops := map[string]BusStop{}
var headers []string
for i, line := range entries {
if i == 0 {
headers = line
line[0] = strings.TrimLeft( line[0], utils.BOM )
continue
}
var entry BusStop
for j, value := range line {
switch headers[j] {
case "ROUTE_ID":
entry.RouteId = value
case "DIRECTION":
entry.Direction = value
case "STATION_SEQNO":
entry.StationSeq = value
case "STATION_ID":
entry.StationId = value
case "STATION_LATITUDE":
v, _ := strconv.ParseFloat( value, 64 )
entry.Latitude = v
case "STATION_LONGITUDE":
v, _ := strconv.ParseFloat( value, 64 )
entry.Longtitude = v
case "STATION_NAME_CHI":
entry.Name_zhant = value
case "STATION_NAME_ENG":
entry.Name_en = value
default:
return nil, fmt.Errorf( "Unknown header \"%s\"", headers[j] )
}
}
if _, t := busStops[ entry.StationId ]; t {
return nil, fmt.Errorf( "Duplicated entry %+v", entry )
}
busStops[ entry.StationId ] = entry
}
return &busStops, nil
}
func getBusStops() (*map[string]BusStop, error) {
if mBusStops != nil {
return mBusStops, nil
}
mBusStops, err := pullLocal()
if mBusStops != nil {
return mBusStops, err
}
mBusStops, err = pullRemote()
if mBusStops != nil {
return mBusStops, err
}
return nil, err
}
func pullRemote() (*map[string]BusStop, error) {
err := os.MkdirAll( filepath.Dir( DEF_CSV ), 0750 )
if err != nil {
return nil, err
}
resp, err := http.Get( "https://opendata.mtr.com.hk/data/mtr_bus_stops.csv" )
if err != nil {
return nil, err
}
defer resp.Body.Close()
f, err := os.OpenFile( DEF_CSV, os.O_CREATE | os.O_RDWR, 0644 )
if err != nil {
return nil, err
}
defer f.Close()
_, err = io.Copy( f, resp.Body )
if err != nil {
return nil, err
}
f.Seek( 0, 0 )
return readBusStopData( f )
}
func pullLocal() (*map[string]BusStop, error) {
f, err := os.Open( DEF_CSV )
if err != nil {
return nil, err
}
defer f.Close()
return readBusStopData( f )
}