Show poster thumbnails in the detail panes

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
2026-10-20 21:47:50 +02:00
parent ff204655d3
commit a4303ed3ca
15 changed files with 724 additions and 22 deletions
@@ -0,0 +1,120 @@
+package arr
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const maxImageBytes = 8 << 20
+
+// Poster returns a key identifying the poster among cached images and a
+// function that downloads it, or ok=false when there is none.
+//
+// Library items have a copy on the Radarr/Sonarr server, which is fetched
+// with the API key (preferring the small -250 variant). Titles that are not
+// in the library yet only have the remote URL of the metadata provider; that
+// is fetched without the API key.
+func (c *Client) Poster(images []Image, inLibrary bool) (key string, fetch func(ctx context.Context) ([]byte, error), ok bool) {
+	for _, img := range images {
+		if img.CoverType != "poster" {
+			continue
+		}
+		if inLibrary && img.URL != "" {
+			local := img.URL
+			return c.baseURL + "|" + local, func(ctx context.Context) ([]byte, error) {
+				// MediaCover has poster-250.jpg next to poster.jpg; fall back to the original.
+				if small := smallVariant(local); small != local {
+					if data, err := c.GetBytes(ctx, small); err == nil {
+						return data, nil
+					}
+				}
+				return c.GetBytes(ctx, local)
+			}, true
+		}
+		if img.RemoteURL != "" {
+			remote := img.RemoteURL
+			return remote, func(ctx context.Context) ([]byte, error) { return FetchURL(ctx, remote) }, true
+		}
+	}
+	return "", nil, false
+}
+
+// smallVariant turns /MediaCover/1/poster.jpg?x into /MediaCover/1/poster-250.jpg?x.
+func smallVariant(p string) string {
+	path, query, hasQuery := strings.Cut(p, "?")
+	if !strings.HasSuffix(path, "/poster.jpg") {
+		return p
+	}
+	path = strings.TrimSuffix(path, ".jpg") + "-250.jpg"
+	if hasQuery {
+		return path + "?" + query
+	}
+	return path
+}
+
+// GetBytes downloads a server-relative path such as /MediaCover/1/poster.jpg
+// from the instance, authenticated with the API key.
+func (c *Client) GetBytes(ctx context.Context, ref string) ([]byte, error) {
+	u, err := c.resolve(ref)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("X-Api-Key", c.apiKey)
+	return doImage(c.http, req)
+}
+
+// resolve joins a server-relative path to the base URL. Radarr/Sonarr include
+// their URL base in image paths, so it must not be added twice.
+func (c *Client) resolve(ref string) (string, error) {
+	base, err := url.Parse(c.baseURL)
+	if err != nil {
+		return "", err
+	}
+	if base.Path != "" && base.Path != "/" && strings.HasPrefix(ref, strings.TrimRight(base.Path, "/")+"/") {
+		return base.Scheme + "://" + base.Host + ref, nil
+	}
+	return c.baseURL + ref, nil
+}
+
+var imageClient = &http.Client{Timeout: 20 * time.Second}
+
+// FetchURL downloads a public image. No credentials are sent.
+func FetchURL(ctx context.Context, rawURL string) ([]byte, error) {
+	u, err := url.Parse(rawURL)
+	if err != nil || (u.Scheme != "http" && u.Scheme != "https") {
+		return nil, fmt.Errorf("unsupported image URL")
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
+	if err != nil {
+		return nil, err
+	}
+	return doImage(imageClient, req)
+}
+
+func doImage(client *http.Client, req *http.Request) ([]byte, error) {
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, stripURL(err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("image: HTTP %d", resp.StatusCode)
+	}
+	data, err := io.ReadAll(io.LimitReader(resp.Body, maxImageBytes+1))
+	if err != nil {
+		return nil, err
+	}
+	if len(data) > maxImageBytes {
+		return nil, fmt.Errorf("image larger than %d MB", maxImageBytes>>20)
+	}
+	return data, nil
+}
@@ -0,0 +1,96 @@
+package arr
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestSmallVariant(t *testing.T) {
+	for in, want := range map[string]string{
+		"/MediaCover/1/poster.jpg?lastWrite=5": "/MediaCover/1/poster-250.jpg?lastWrite=5",
+		"/MediaCover/1/poster.jpg":             "/MediaCover/1/poster-250.jpg",
+		"/MediaCover/1/fanart.jpg":             "/MediaCover/1/fanart.jpg",
+	} {
+		if got := smallVariant(in); got != want {
+			t.Errorf("smallVariant(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestPosterLocalUsesAPIKey(t *testing.T) {
+	var paths []string
+	var keys []string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		paths = append(paths, r.URL.RequestURI())
+		keys = append(keys, r.Header.Get("X-Api-Key"))
+		if r.URL.Path == "/MediaCover/1/poster-250.jpg" {
+			http.NotFound(w, r) // no small variant: fall back to the original
+			return
+		}
+		w.Write([]byte("IMG"))
+	}))
+	defer srv.Close()
+
+	c := NewClient(srv.URL, "secret")
+	imgs := []Image{{CoverType: "fanart", URL: "/MediaCover/1/fanart.jpg"}, {CoverType: "poster", URL: "/MediaCover/1/poster.jpg?lastWrite=1", RemoteURL: "https://remote/p.jpg"}}
+	key, fetch, ok := c.Poster(imgs, true)
+	if !ok || key == "" {
+		t.Fatal("no poster")
+	}
+	data, err := fetch(context.Background())
+	if err != nil || string(data) != "IMG" {
+		t.Fatalf("data=%q err=%v", data, err)
+	}
+	if len(paths) != 2 || paths[0] != "/MediaCover/1/poster-250.jpg?lastWrite=1" || paths[1] != "/MediaCover/1/poster.jpg?lastWrite=1" {
+		t.Errorf("requests = %v", paths)
+	}
+	for _, k := range keys {
+		if k != "secret" {
+			t.Errorf("api key header = %q", k)
+		}
+	}
+}
+
+func TestPosterRemoteSendsNoAPIKey(t *testing.T) {
+	var got string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		got = r.Header.Get("X-Api-Key")
+		w.Write([]byte("IMG"))
+	}))
+	defer srv.Close()
+
+	c := NewClient("http://radarr.invalid", "secret")
+	key, fetch, ok := c.Poster([]Image{{CoverType: "poster", URL: "/MediaCover/0/poster.jpg", RemoteURL: srv.URL + "/p.jpg"}}, false)
+	if !ok || key != srv.URL+"/p.jpg" {
+		t.Fatalf("key=%q ok=%v", key, ok)
+	}
+	if _, err := fetch(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	if got != "" {
+		t.Errorf("the API key leaked to a remote image host: %q", got)
+	}
+	if _, _, ok := c.Poster([]Image{{CoverType: "banner", RemoteURL: "x"}}, false); ok {
+		t.Error("only posters count")
+	}
+	if _, err := FetchURL(context.Background(), "file:///etc/passwd"); err == nil {
+		t.Error("non-http schemes must be refused")
+	}
+}
+
+func TestResolveURLBase(t *testing.T) {
+	c := NewClient("http://host:7878/radarr", "k")
+	for ref, want := range map[string]string{
+		"/radarr/MediaCover/1/poster.jpg": "http://host:7878/radarr/MediaCover/1/poster.jpg",
+		"/MediaCover/1/poster.jpg":        "http://host:7878/radarr/MediaCover/1/poster.jpg",
+	} {
+		if got, _ := c.resolve(ref); got != want {
+			t.Errorf("resolve(%q) = %q, want %q", ref, got, want)
+		}
+	}
+	if got, _ := NewClient("http://host", "k").resolve("/MediaCover/1/poster.jpg"); got != "http://host/MediaCover/1/poster.jpg" {
+		t.Errorf("no url base: %q", got)
+	}
+}