golifehk/datasources/mtr/bus/busschedule.go

package bus

import (
    "bytes"
    "encoding/json"
    "io"
    "net/http"
    "path/filepath"

    "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 BusSchedule struct {
    RefreshTime int `json:"appRefreshTimeInSecond,string"`
    BusStops [] BusStopBuses `json:"busStop"`
}

func getSchedule( lang string, routeName string ) ( *BusSchedule, error ) {

    CACHE_PATH := filepath.Join(
        utils.WORKDIR,
        "mtr_bsch" + "-" + lang + "-" + routeName + ".json",
    )

    QUERY_FUNC := func() ( io.ReadCloser, error ) {
        // Query Remote
        values := map[string]string { "language": lang , "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
    }

    buff, err := utils.CacheStream( CACHE_PATH, QUERY_FUNC, 60 )
    if err != nil {
        return nil, err
    }

    schedules := BusSchedule{}
    err = json.Unmarshal( buff.Bytes(), &schedules )
    if err != nil {
        return nil, err
    }

    return &schedules, nil
}