Generalize cache get with expire param

2022-09-14 17:12:48 +08:00
parent 7e327abbae
commit afb73b70ff
10 changed files with 132 additions and 112 deletions
--- a/datasources/mtr/bus/busstops.go
+++ b/datasources/mtr/bus/busstops.go
@@ -0,0 +1,98 @@
+package bus
+
+import (
+    "encoding/csv"
+    "fmt"
+    "io"
+    "net/http"
+    "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 CSV_BUSSTOPS 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) {
+
+    QUERY_FUNC := func() ( io.ReadCloser, error ) {
+        resp, err := http.Get( "https://opendata.mtr.com.hk/data/mtr_bus_stops.csv" )
+        if err != nil {
+            return nil, err
+        }
+        return resp.Body, nil
+    }
+
+    buff, err := utils.CacheStream( CSV_BUSSTOPS, QUERY_FUNC, 7 * 24 * 3600 )
+    if err != nil {
+        return nil, err
+    }
+
+    return readBusStopData( buff )
+}