From 4c4ebc593dc131359849e9e1db32aad113d40603 Mon Sep 17 00:00:00 2001
From: Gabe Farrell <gabe@mnrva.dev>
Date: Sun, 15 Jun 2025 01:02:59 -0400
Subject: [PATCH] feat: re-download missing images on request

---
 CHANGELOG.md                     | 15 ++------------
 engine/handlers/image_handler.go | 34 ++++++++++++++++++++++++++++----
 2 files changed, 32 insertions(+), 17 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a3357e..9eb9f33 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,14 +1,3 @@
-# v0.0.3
-## Features
-- Delete listens from the UI
-
+# v0.0.4
 ## Enhancements
-- Better behaved mobile UI
-- Search now returns 8 items per category instead of 5
-
-## Fixes
-- Many mobile UI fixes
-
-## Updates
-- Refuses a config that changes the MusicBrainz rate limit while using the official MusicBrainz URL
-- Warns when enabling ListenBrainz relay with missing configuration
\ No newline at end of file
+- Re-download images missing from cache on request
diff --git a/engine/handlers/image_handler.go b/engine/handlers/image_handler.go
index 84d8681..8ad1c54 100644
--- a/engine/handlers/image_handler.go
+++ b/engine/handlers/image_handler.go
@@ -2,6 +2,8 @@ package handlers
 
 import (
 	"bytes"
+	"context"
+	"fmt"
 	"net/http"
 	"os"
 	"path"
@@ -47,18 +49,23 @@ func ImageHandler(store db.DB) http.HandlerFunc {
 			fullSizePath := filepath.Join(cfg.ConfigDir(), catalog.ImageCacheDir, string(catalog.ImageSizeFull), filepath.Clean(filename))
 			largeSizePath := filepath.Join(cfg.ConfigDir(), catalog.ImageCacheDir, string(catalog.ImageSizeLarge), filepath.Clean(filename))
 
+			// this if statement flow is terrible but whatever
 			var sourcePath string
 			if _, err = os.Stat(fullSizePath); os.IsNotExist(err) {
 				if _, err = os.Stat(largeSizePath); os.IsNotExist(err) {
-					l.Warn().Msgf("ImageHandler: Could not find requested image %s. Serving default image", imgid.String())
-					serveDefaultImage(w, r, imageSize)
-					return
+					l.Warn().Msgf("ImageHandler: Could not find requested image %s. Attempting to download from source", imgid.String())
+					sourcePath, err = downloadMissingImage(r.Context(), store, imgid)
+					if err != nil {
+						l.Err(err).Msg("ImageHandler: Failed to redownload missing image")
+						w.WriteHeader(http.StatusInternalServerError)
+					}
 				} else if err != nil {
 					l.Err(err).Msg("ImageHandler: Failed to access source image file at large size")
 					w.WriteHeader(http.StatusInternalServerError)
 					return
+				} else {
+					sourcePath = largeSizePath
 				}
-				sourcePath = largeSizePath
 			} else if err != nil {
 				l.Err(err).Msg("ImageHandler: Failed to access source image file at full size")
 				w.WriteHeader(http.StatusInternalServerError)
@@ -139,3 +146,22 @@ func serveDefaultImage(w http.ResponseWriter, r *http.Request, size catalog.Imag
 	l.Debug().Msgf("serveDefaultImage: Successfully serving default image at size '%s'", size)
 	http.ServeFile(w, r, path.Join(cfg.ConfigDir(), catalog.ImageCacheDir, string(size), "default_img"))
 }
+
+// finds the item associated with the image id, downloads it, and saves it in the source path, returning the path to the image
+func downloadMissingImage(ctx context.Context, store db.DB, id uuid.UUID) (string, error) {
+	src, err := store.GetImageSource(ctx, id)
+	if err != nil {
+		return "", fmt.Errorf("downloadMissingImage: store.GetImageSource: %w", err)
+	}
+	var size catalog.ImageSize
+	if cfg.FullImageCacheEnabled() {
+		size = catalog.ImageSizeFull
+	} else {
+		size = catalog.ImageSizeLarge
+	}
+	err = catalog.DownloadAndCacheImage(ctx, id, src, size)
+	if err != nil {
+		return "", fmt.Errorf("downloadMissingImage: catalog.DownloadAndCacheImage: %w", err)
+	}
+	return path.Join(catalog.SourceImageDir(), id.String()), nil
+}