@@ -5,10 +5,12 @@ "context"
 	"fmt"
 	"io"
 	"net/http"
+	"os"
 	"strings"
 	"time"
 
 	"alin.ovh/searchix/internal/config"
+	"alin.ovh/searchix/internal/file"
 
 	"alin.ovh/x/log"
 	"github.com/Southclaws/fault"
@@ -32,22 +34,49 @@ func (r *brotliReadCloser) Close() error {
 	return fault.Wrap(r.src.Close(), fmsg.With("failed to call close on underlying reader"))
 }
 
-func FetchFileIfNeeded(
+type Options struct {
+	Logger *log.Logger
+	Root   *file.Root
+}
+
+type Fetcher struct {
+	logger *log.Logger
+	root   *file.Root
+}
+
+func NewFetcher(options *Options) *Fetcher {
+	return &Fetcher{
+		logger: options.Logger,
+		root:   options.Root,
+	}
+}
+
+func (h *Fetcher) FetchFileIfNeeded(
 	ctx context.Context,
-	log *log.Logger,
-	mtime time.Time,
+	filename string,
 	url string,
-) (io.ReadCloser, time.Time, error) {
-	var newMtime time.Time
+) (io.ReadCloser, error) {
+	stat, err := h.root.StatIfExists(filename)
+	if err != nil {
+		return nil, fault.Wrap(
+			err,
+			fmsg.Withf("failed to stat file %s", filename),
+		)
+	}
 	var ifModifiedSince string
-	if !mtime.IsZero() {
-		ifModifiedSince = strings.Replace(mtime.UTC().Format(time.RFC1123), "UTC", "GMT", 1)
+	if stat != nil && stat.Size() > 0 && !stat.ModTime().IsZero() {
+		ifModifiedSince = strings.Replace(
+			stat.ModTime().UTC().Format(time.RFC1123),
+			"UTC",
+			"GMT",
+			1,
+		)
 	}
 
-	req, baseErr := http.NewRequestWithContext(ctx, "GET", url, http.NoBody)
-	if baseErr != nil {
-		return nil, newMtime, fault.Wrap(
-			baseErr,
+	req, err := http.NewRequestWithContext(ctx, "GET", url, http.NoBody)
+	if err != nil {
+		return nil, fault.Wrap(
+			err,
 			fmsg.Withf("could not create HTTP request for %s", url),
 		)
 	}
@@ -57,26 +86,24 @@
 	if ifModifiedSince != "" {
 		req.Header.Set("If-Modified-Since", ifModifiedSince)
 	}
-	res, baseErr := http.DefaultClient.Do(req)
-	if baseErr != nil {
-		return nil, newMtime, fault.Wrap(
-			baseErr,
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fault.Wrap(
+			err,
 			fmsg.Withf("could not make HTTP request to %s", url),
 		)
 	}
 
 	var body io.ReadCloser
-	var err error
+	var newMtime time.Time
+	encoding := res.Header.Get("Content-Encoding")
 	switch res.StatusCode {
 	case http.StatusNotModified:
-		newMtime = mtime
-
-		return nil, newMtime, nil
 	case http.StatusOK:
 		var baseErr error
 		newMtime, baseErr = time.Parse(time.RFC1123, res.Header.Get("Last-Modified"))
 		if baseErr != nil {
-			log.Warn(
+			h.logger.Warn(
 				"could not parse Last-Modified header from response",
 				"value",
 				res.Header.Get("Last-Modified"),
@@ -84,18 +111,51 @@ )
 			newMtime = time.Now()
 		}
 
-		switch ce := res.Header.Get("Content-Encoding"); ce {
+		switch encoding {
 		case "br":
-			log.Debug("using brotli encoding")
 			body = newBrotliReader(res.Body)
 		case "", "identity", "gzip":
 			body = res.Body
 		default:
-			err = fault.Newf("cannot handle a body with content-encoding %s", ce)
+			return nil, fault.Newf("cannot handle a body with content-encoding %s", encoding)
+		}
+
+		writer, err := h.root.OpenFile(filename, os.O_CREATE|os.O_RDWR|os.O_TRUNC, 0o644)
+		if err != nil {
+			return nil, fault.Wrap(err, fmsg.Withf("failed to open file %s", filename))
+		}
+
+		_, err = io.Copy(writer, body)
+		if err != nil {
+			return nil, fault.Wrap(
+				err,
+				fmsg.Withf("failed to copy response body to file %s", filename),
+			)
+		}
+
+		err = writer.Sync()
+		if err != nil {
+			return nil, fault.Wrap(err, fmsg.Withf("failed to sync file %s", filename))
+		}
+
+		err = writer.Close()
+		if err != nil {
+			return nil, fault.Wrap(err, fmsg.Withf("failed to close file %s", filename))
+		}
+
+		err = h.root.Chtimes(filename, time.Time{}, newMtime)
+		if err != nil {
+			return nil, fault.Wrap(err, fmsg.Withf("failed to update file times %s", filename))
 		}
+
 	default:
-		err = fault.Newf("got response code %d, don't know what to do", res.StatusCode)
+		return nil, fault.Newf("got response code %d, don't know what to do", res.StatusCode)
+	}
+
+	reader, err := h.root.Open(filename)
+	if err != nil {
+		return nil, fault.Wrap(err, fmsg.Withf("failed to open file %s", filename))
 	}
 
-	return NewReadCloser(body), newMtime, err
+	return reader, nil
 }