Files
golifehk/datasources/mtr/bus/busschedule.go

147 lines
3.0 KiB
Go

package bus
import (
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"path/filepath"
"time"
"github.com/tgckpg/golifehk/utils"
)
type Location struct {
latitude float32
longitude float32
}
type Bus struct {
ETA int `json:"arrivalTimeInSecond,string"`
ETAText string `json:"arrivalTimeText"`
BusId string `json:"busId"`
BusLocation Location `json:"busLocation"`
ETD string `json:"departureTimeInSecond"`
ETDText string `json:"departureTimeText"`
Delayed string `json:"isDelayed"`
Scheduled string `json:"isScheduled"`
LineRef string `json:"lineRef"`
}
type BusStopBuses struct {
Buses []Bus `json:"bus"`
BusStopId string `json:"busStopId"`
Suspended string `json:"isSuspended"`
}
type ScheduleStatusTime struct {
time.Time
}
type BusSchedule struct {
RefreshTime int `json:"appRefreshTimeInSecond,string"`
BusStops []BusStopBuses `json:"busStop"`
StatusTime ScheduleStatusTime `json:"routeStatusTime"`
RemarksTitle string `json:"routeStatusRemarkTitle"`
// 0 = OK
// 100 = Rate limit ( Unconfirmed. Not in spec )
Status int `json:"status,string"`
}
func (t *ScheduleStatusTime) UnmarshalJSON(b []byte) (err error) {
date, err := time.Parse(`"2006\/01\/02 15:04"`, string(b))
if err != nil {
return err
}
t.Time = date
return
}
func getSchedule(lang string, routeName string) (*BusSchedule, error) {
CACHE_PATH := filepath.Join(
utils.WORKDIR,
"mtr_bsch"+"-"+lang+"-"+routeName+".json",
)
postLang := "en"
if lang == "zh-Hant" {
postLang = "zh"
}
QUERY_FUNC := func() (io.ReadCloser, error) {
// Query Remote
values := map[string]string{"language": postLang, "routeName": routeName}
jsonValue, _ := json.Marshal(values)
resp, err := http.Post(
"https://rt.data.gov.hk/v1/transport/mtr/bus/getSchedule",
"application/json",
bytes.NewBuffer(jsonValue),
)
if err != nil {
return nil, err
}
return resp.Body, nil
}
cs, err := utils.CacheStreamEx(CACHE_PATH, QUERY_FUNC)
if err != nil {
return nil, err
}
oldSch := BusSchedule{
Status: -1,
}
if cs.Local != nil {
err = json.Unmarshal(cs.Local.Bytes(), &oldSch)
if err != nil {
return nil, err
}
}
newSch := BusSchedule{
Status: -1,
}
for i := 0; i < 3; i++ {
if cs.Remote != nil {
err = json.Unmarshal(cs.Remote.Bytes(), &newSch)
if err != nil {
return nil, err
}
}
if newSch.Status == 0 {
cs.Commit()
return &newSch, nil
}
if oldSch.Status == 0 {
if cs.NotExpired(60) || oldSch.StatusTime.Time == newSch.StatusTime.Time {
log.Printf("Using cache: %s", CACHE_PATH)
return &oldSch, nil
}
}
// First time + try again i times
err = cs.Reload()
log.Printf("Reloading (%d): %s", i, CACHE_PATH)
if err != nil {
err = fmt.Errorf("Error retrieving data: %s", err)
return nil, err
}
}
if newSch.Status != 0 {
err = fmt.Errorf("%s (%d)", newSch.RemarksTitle, newSch.Status)
}
return &newSch, err
}