Reorganise repo

nrod/download.go

@@ -0,0 +1,74 @@
+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
+}