fix the installer world download

setup/internal/installer/assets.go

@@ -15,7 +15,7 @@ import (
 // use this so you can replace the assets
 const limboAssetsEnv = "SKYBLOCK_WORLD_ASSETS"
 
-func DownloadLimboAssets(ctx context.Context, installDir string) error {
+func DownloadLimboAssets(ctx context.Context, installDir string, events chan<- Event) error {
 	configDir := filepath.Join(installDir, "configuration")
 	if LimboAssetsPresent(configDir) {
 		return nil
@@ -25,13 +25,14 @@ func DownloadLimboAssets(ctx context.Context, installDir string) error {
 		return importLocalLimboAssets(localPath, configDir)
 	}
 
-	reqCtx, cancel := context.WithTimeout(ctx, 5*time.Minute)
+	reqCtx, cancel := context.WithTimeout(ctx, 3*time.Minute)
 	defer cancel()
 
 	req, err := http.NewRequestWithContext(reqCtx, http.MethodGet, LimboAssetsURL, nil)
 	if err != nil {
 		return err
 	}
+	req.Header.Set("User-Agent", "skyblock-installer/"+Version)
 	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return err
@@ -41,6 +42,12 @@ func DownloadLimboAssets(ctx context.Context, installDir string) error {
 	if resp.StatusCode < 200 || resp.StatusCode > 299 {
 		return fmt.Errorf("download returned %s", resp.Status)
 	}
+	emitAssetProgress(events, "Downloading world assets from %s", LimboAssetsURL)
+	if resp.ContentLength > 0 {
+		emitAssetProgress(events, "Remote asset size: %s", formatBytes(resp.ContentLength))
+	} else {
+		emitAssetProgress(events, "Remote asset size is unknown; showing downloaded bytes")
+	}
 
 	tmp, err := os.CreateTemp("", "skyblock-limbo-assets-*.zip")
 	if err != nil {
@@ -49,15 +56,22 @@ func DownloadLimboAssets(ctx context.Context, installDir string) error {
 	tmpPath := tmp.Name()
 	defer os.Remove(tmpPath)
 
-	if _, err := io.Copy(tmp, resp.Body); err != nil {
+	if err := copyWithProgress(reqCtx, cancel, tmp, resp.Body, resp.ContentLength, events); err != nil {
 		_ = tmp.Close()
 		return err
 	}
 	if err := tmp.Close(); err != nil {
 		return err
 	}
 
-	return extractZip(tmpPath, configDir)
+	emitAssetProgress(events, "Extracting world assets")
+	if err := extractZip(tmpPath, configDir); err != nil {
+		return err
+	}
+	if !LimboAssetsPresent(configDir) {
+		return fmt.Errorf("downloaded zip did not contain limbo.schem and world/")
+	}
+	return nil
 }
 
 func LimboAssetsPresent(configDir string) bool {
@@ -80,9 +94,132 @@ func importLocalLimboAssets(path, configDir string) error {
 		return err
 	}
 	if info.IsDir() {
-		return CopyDir(path, configDir)
+		if err := CopyDir(path, configDir); err != nil {
+			return err
+		}
+	} else if err := extractZip(path, configDir); err != nil {
+		return err
+	}
+	if !LimboAssetsPresent(configDir) {
+		return fmt.Errorf("local assets did not contain limbo.schem and world/")
+	}
+	return nil
+}
+
+func copyWithProgress(ctx context.Context, cancel context.CancelFunc, dst io.Writer, src io.Reader, total int64, events chan<- Event) error {
+	buf := make([]byte, 256*1024)
+	var downloaded int64
+	lastEmit := time.Now().Add(-time.Minute)
+	progress := make(chan struct{}, 1)
+	done := make(chan struct{})
+	defer close(done)
+
+	go func() {
+		timer := time.NewTimer(30 * time.Second)
+		defer timer.Stop()
+		for {
+			select {
+			case <-timer.C:
+				cancel()
+				return
+			case <-progress:
+				if !timer.Stop() {
+					select {
+					case <-timer.C:
+					default:
+					}
+				}
+				timer.Reset(30 * time.Second)
+			case <-done:
+				return
+			}
+		}
+	}()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return fmt.Errorf("download stalled or timed out after %s: %w", formatBytes(downloaded), ctx.Err())
+		default:
+		}
+
+		n, readErr := src.Read(buf)
+		if n > 0 {
+			written, writeErr := dst.Write(buf[:n])
+			if writeErr != nil {
+				return writeErr
+			}
+			if written != n {
+				return io.ErrShortWrite
+			}
+			downloaded += int64(n)
+			select {
+			case progress <- struct{}{}:
+			default:
+			}
+			if shouldEmitProgress(downloaded, total, lastEmit) {
+				emitDownloadProgress(events, downloaded, total)
+				lastEmit = time.Now()
+			}
+		}
+		if readErr == io.EOF {
+			if downloaded == 0 {
+				return fmt.Errorf("download returned no data")
+			}
+			emitDownloadProgress(events, downloaded, total)
+			return nil
+		}
+		if readErr != nil {
+			return readErr
+		}
+	}
+}
+
+func shouldEmitProgress(downloaded, total int64, lastEmit time.Time) bool {
+	if time.Since(lastEmit) >= 2*time.Second {
+		return true
+	}
+	if total > 0 {
+		percent := downloaded * 100 / total
+		lastPercent := (downloaded - 256*1024) * 100 / total
+		return percent != lastPercent
+	}
+	return downloaded%(1024*1024) < 256*1024
+}
+
+func emitDownloadProgress(events chan<- Event, downloaded, total int64) {
+	if total > 0 {
+		percent := int(downloaded * 100 / total)
+		emitAssetProgress(events, "World assets %s %s/%s %d%%", progressBar(percent), formatBytes(downloaded), formatBytes(total), percent)
+		return
+	}
+	emitAssetProgress(events, "World assets downloaded %s", formatBytes(downloaded))
+}
+
+func progressBar(percent int) string {
+	const width = 20
+	if percent < 0 {
+		percent = 0
+	}
+	if percent > 100 {
+		percent = 100
+	}
+	filled := percent * width / 100
+	return "[" + strings.Repeat("#", filled) + strings.Repeat("-", width-filled) + "]"
+}
+
+func formatBytes(bytes int64) string {
+	const mb = 1024 * 1024
+	if bytes >= mb {
+		return fmt.Sprintf("%.1f MB", float64(bytes)/mb)
+	}
+	return fmt.Sprintf("%.0f KB", float64(bytes)/1024)
+}
+
+func emitAssetProgress(events chan<- Event, format string, args ...any) {
+	if events != nil {
+		events <- Event{Line: fmt.Sprintf(format, args...)}
 	}
-	return extractZip(path, configDir)
 }
 
 func extractZip(zipPath, dst string) error {

setup/internal/installer/runner.go

@@ -86,7 +86,7 @@ func (r *Runner) install(ctx context.Context, cfg Config, sourceConfigDir string
 	}
 
 	r.emit("Checking for world assets")
-	if err := DownloadLimboAssets(ctx, cfg.InstallDir); err != nil {
+	if err := DownloadLimboAssets(ctx, cfg.InstallDir, r.Events); err != nil {
 		r.emit("asset import failed: %v", err)
 		r.emit("Manual fallback: %s", LimboAssetsManualHint())
 	} else {