timetable-mgr/nrod/download.go

75 lines
2.0 KiB
Go

package nrod
import (
"compress/gzip"
"fmt"
"io"
"net/http"
"time"
"git.fjla.uk/owlboard/timetable-mgr/helpers"
"git.fjla.uk/owlboard/timetable-mgr/log"
"go.uber.org/zap"
)
// Downloads NROD Data over HTTP from the given URL, extracted data is returned
func NrodDownload(url string, cfg *helpers.Configuration) (*[]byte, error) {
log.Msg.Debug("Fetching NROD data", zap.String("Request URL", url))
client := http.Client{
Timeout: time.Second * 10,
}
req, err := http.NewRequest("GET", url, nil)
if err != nil {
log.Msg.Error("Error creating HTTP Request", zap.String("Request URL", url), zap.Error(err))
return nil, err
}
req.Header.Add("Authorization", "Basic "+helpers.BasicAuth(cfg.NrodUser, cfg.NrodPass))
resp, err := client.Do(req)
if err != nil {
log.Msg.Error("Error carrying out HTTP Request", zap.String("Request URL", url), zap.Error(err))
return nil, err
}
if resp.StatusCode != http.StatusOK {
err := fmt.Errorf("unexpected status code: %d", resp.StatusCode)
log.Msg.Error("Non-Successful status code from http response", zap.String("Request URL", url), zap.Error(err))
return nil, err
}
// Yes, I know `readedData` is not proper English. But readData reads more like a verb action.
readedData, err := nrodExtract(resp)
if err != nil {
log.Msg.Error("Unable to read response data")
return nil, err
}
return readedData, nil
}
// Extracts GZIP Data from an HTTP Response and returns the decompresses data as a byte array
func nrodExtract(resp *http.Response) (*[]byte, error) {
log.Msg.Debug("Extracting HTTP Response Data")
gzReader, err := gzip.NewReader(resp.Body)
if err != nil {
log.Msg.Warn("Unable to create GZIP Reader, data probably not GZIPPED")
data, err := io.ReadAll(resp.Body)
if err != nil {
log.Msg.Error("Unable to read response body")
return nil, err
}
return &data, nil
}
defer gzReader.Close()
log.Msg.Debug("GZIP Reader Opened")
extractedData, err := io.ReadAll(gzReader)
if err != nil {
log.Msg.Error("Failed to read GZIPped data", zap.Error(err))
}
return &extractedData, nil
}