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package importer
import (
"context"
"fmt"
"log/slog"
"net/http"
"os"
"searchix/internal/file"
"strings"
"time"
"github.com/pkg/errors"
)
func fetchFileIfNeeded(ctx context.Context, path string, url string) (needed bool, err error) {
stat, err := file.StatIfExists(path)
if err != nil {
return false, errors.WithMessagef(err, "could not stat file %s", path)
}
var mtime string
if stat != nil {
mtime = strings.Replace(stat.ModTime().UTC().Format(time.RFC1123), "UTC", "GMT", 1)
}
req, err := http.NewRequestWithContext(ctx, "GET", url, http.NoBody)
if err != nil {
return false, errors.WithMessagef(err, "could not create HTTP request for %s", url)
}
if mtime != "" {
req.Header.Set("If-Modified-Since", mtime)
}
res, err := http.DefaultClient.Do(req)
if err != nil {
return false, errors.WithMessagef(err, "could not make HTTP request to %s", url)
}
defer res.Body.Close()
switch res.StatusCode {
case http.StatusNotModified:
needed = false
case http.StatusOK:
newMtime, err := time.Parse(time.RFC1123, res.Header.Get("Last-Modified"))
if err != nil {
slog.Warn("could not parse Last-Modified header from response", "value", res.Header.Get("Last-Modified"))
}
err = file.WriteToFile(path, res.Body)
if err != nil {
return false, errors.WithMessagef(err, "could not write response body to file %s", path)
}
err = os.Chtimes(path, time.Time{}, newMtime)
if err != nil {
slog.Warn("could not update mtime on file", "file", path)
}
needed = true
default:
return false, fmt.Errorf("got response code %d, don't know what to do", res.StatusCode)
}
return needed, nil
}
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