refactor(random)!: configure the renderer by base URL as RENDERER_URL

The bot now takes the renderer's base URL and appends each /api/<name>
route itself, instead of taking the full /api/gif endpoint and swapping
its last path segment for /gacha and /genshin. The client, its files, and
its errors are named after the renderer rather than wheelofnames; the
/wheelofnames command keeps its name.

BREAKING CHANGE: WHEELOFNAMES_API_URL is replaced by RENDERER_URL, which
holds the base URL (e.g. http://renderer:3000) rather than the /api/gif
endpoint. compose.yml sets it, so Coolify needs no value.

internal/modules/random/gacha_command.go

@@ -100,7 +100,7 @@ func newGachaCommand(name string, visibility modules.Visibility, description, us
 			placeholder := sendRenderPlaceholder(ctx, b, update.Message, gachaPlaceholder)
 			animation, err := renderGachaAnimation(ctx, style, options[winner].Label, options[winner].Rarity)
 			if err != nil {
-				if !errors.Is(err, errWheelAPINotConfigured) {
+				if !errors.Is(err, errRendererNotConfigured) {
 					log.Warn("gacha remote render failed", "command", name, "err", err)
 				}
 				return replaceWheelPlaceholder(ctx, b, update.Message, placeholder, results[winner])

internal/modules/random/gacha_command_test.go

@@ -54,7 +54,7 @@ func TestGacha_NotConfiguredRepliesWithStars(t *testing.T) {
 }
 
 func TestGacha_UsesRemoteAPIWhenConfigured(t *testing.T) {
-	var got gachaAPIRequest
+	var got gachaRenderRequest
 	var gotPath, gotAuthorization string
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		gotPath = r.URL.Path
@@ -66,7 +66,7 @@ func TestGacha_UsesRemoteAPIWhenConfigured(t *testing.T) {
 		_, _ = w.Write(mp4Bytes)
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	rb.Bot.ProcessUpdate(context.Background(), testutil.NewPrivateMessage(7, "/gacha 4* Pho"))
@@ -77,7 +77,7 @@ func TestGacha_UsesRemoteAPIWhenConfigured(t *testing.T) {
 	if gotAuthorization != "" {
 		t.Fatalf("Authorization = %q, want none", gotAuthorization)
 	}
-	want := gachaAPIRequest{Label: "Pho", Rarity: 4, FPS: gachaRemoteFPS, Width: gachaRemoteWidth}
+	want := gachaRenderRequest{Label: "Pho", Rarity: 4, FPS: gachaRemoteFPS, Width: gachaRemoteWidth}
 	if got != want {
 		t.Fatalf("request = %+v, want %+v", got, want)
 	}
@@ -111,7 +111,7 @@ func TestGacha_RemoteFailureFallsBackToText(t *testing.T) {
 		http.Error(w, "no", http.StatusInternalServerError)
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	rb.Bot.ProcessUpdate(context.Background(), testutil.NewPrivateMessage(7, "/gacha 3* Rice"))
@@ -131,7 +131,7 @@ func TestGacha_SendAnimationFailureFallsBackToText(t *testing.T) {
 		_, _ = w.Write(mp4Bytes)
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	rb.FailMethod("sendAnimation", http.StatusInternalServerError, "")
@@ -149,7 +149,7 @@ func TestGacha_ForwardsMessageThreadID(t *testing.T) {
 		_, _ = w.Write(mp4Bytes)
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	update := testutil.NewSupergroupMessage(-100, 7, "/gacha 3* Rice")
@@ -175,7 +175,7 @@ func TestGacha_ForwardsMessageThreadID(t *testing.T) {
 
 func TestGenshin_UsesGenshinRendererAndAnyoneCanRunIt(t *testing.T) {
 	var gotPath string
-	var got gachaAPIRequest
+	var got gachaRenderRequest
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		gotPath = r.URL.Path
 		if err := json.NewDecoder(r.Body).Decode(&got); err != nil {
@@ -185,7 +185,7 @@ func TestGenshin_UsesGenshinRendererAndAnyoneCanRunIt(t *testing.T) {
 		_, _ = w.Write(mp4Bytes)
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	// 7 is neither the owner (999) nor an admin.
 	rb := installRandom(t, 999)
@@ -194,7 +194,7 @@ func TestGenshin_UsesGenshinRendererAndAnyoneCanRunIt(t *testing.T) {
 	if gotPath != "/api/genshin" {
 		t.Fatalf("path = %q, want /api/genshin", gotPath)
 	}
-	if want := (gachaAPIRequest{Label: "Bún bò", Rarity: 5, FPS: gachaRemoteFPS, Width: gachaRemoteWidth}); got != want {
+	if want := (gachaRenderRequest{Label: "Bún bò", Rarity: 5, FPS: gachaRemoteFPS, Width: gachaRemoteWidth}); got != want {
 		t.Fatalf("request = %+v, want %+v", got, want)
 	}
 	var animation *testutil.SentCall

internal/modules/random/gacha_render.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"net/url"
 	"strings"
 )
 
@@ -15,8 +14,8 @@ const (
 	gachaRemoteHeight = 360
 )
 
-// gachaStyle is one wish animation the renderer serves: its path next to
-// /api/gif, the clip length in seconds, and the frame size it renders for a
+// gachaStyle is one wish animation the renderer serves: its route name under
+// /api, the clip length in seconds, and the frame size it renders for a
 // gachaRemoteWidth request.
 type gachaStyle struct {
 	Path     string
@@ -31,49 +30,34 @@ var (
 	gachaStyleGenshin  = gachaStyle{Path: "genshin", Duration: 7, Width: gachaRemoteWidth, Height: gachaRemoteHeight}
 )
 
-type gachaAPIRequest struct {
+type gachaRenderRequest struct {
 	Label  string `json:"label"`
 	Rarity int    `json:"rarity"`
 	FPS    int    `json:"fps"`
 	Width  int    `json:"width"`
 }
 
-// gachaAPIEndpoint derives a wish renderer from the configured wheel
-// endpoint: the same service serves /api/gacha and /api/genshin next to
-// /api/gif, so the last path segment is swapped and no second URL needs
-// configuring.
-func gachaAPIEndpoint(rawURL, path string) (*url.URL, error) {
-	endpoint, err := wheelAPIEndpoint(rawURL)
-	if err != nil {
-		return nil, err
-	}
-	base := *endpoint
-	base.Path = strings.TrimSuffix(base.Path, "/")
-	base.RawPath = ""
-	return base.ResolveReference(&url.URL{Path: path}), nil
-}
-
-// RenderGacha returns the MP4 wish animation at path revealing label at
+// RenderGacha returns the MP4 wish animation named path revealing label at
 // rarity stars.
-func (c wheelAPIClient) RenderGacha(ctx context.Context, path, label string, rarity int) ([]byte, error) {
-	endpoint, err := gachaAPIEndpoint(c.URL, path)
+func (c rendererClient) RenderGacha(ctx context.Context, path, label string, rarity int) ([]byte, error) {
+	endpoint, err := c.endpoint(path)
 	if err != nil {
 		return nil, err
 	}
 	if strings.TrimSpace(label) == "" {
-		return nil, fmt.Errorf("gacha api label empty")
+		return nil, fmt.Errorf("renderer gacha label empty")
 	}
 	if rarity < gachaMinRarity || rarity > gachaMaxRarity {
-		return nil, fmt.Errorf("gacha api rarity %d out of range", rarity)
+		return nil, fmt.Errorf("renderer gacha rarity %d out of range", rarity)
 	}
-	body, err := json.Marshal(gachaAPIRequest{
+	body, err := json.Marshal(gachaRenderRequest{
 		Label:  label,
 		Rarity: rarity,
 		FPS:    gachaRemoteFPS,
 		Width:  gachaRemoteWidth,
 	})
 	if err != nil {
-		return nil, fmt.Errorf("gacha api request encode failed: %w", err)
+		return nil, fmt.Errorf("renderer gacha request encode failed: %w", err)
 	}
 	return c.post(ctx, endpoint, body, "video/mp4", isMP4)
 }
@@ -83,12 +67,12 @@ func isMP4(data []byte) bool {
 	return len(data) >= 8 && bytes.Equal(data[4:8], []byte("ftyp"))
 }
 
-func renderGachaAnimation(ctx context.Context, style gachaStyle, label string, rarity int) (wheelAnimation, error) {
-	data, err := newWheelAPIClientFromEnv().RenderGacha(ctx, style.Path, label, rarity)
+func renderGachaAnimation(ctx context.Context, style gachaStyle, label string, rarity int) (renderedAnimation, error) {
+	data, err := newRendererClientFromEnv().RenderGacha(ctx, style.Path, label, rarity)
 	if err != nil {
-		return wheelAnimation{}, err
+		return renderedAnimation{}, err
 	}
-	return wheelAnimation{
+	return renderedAnimation{
 		Data:     data,
 		Duration: style.Duration,
 		Width:    style.Width,

internal/modules/random/gacha_render_test.go

@@ -7,27 +7,28 @@ import (
 	"testing"
 )
 
-func TestGachaAPIEndpoint_SwapsLastPathSegment(t *testing.T) {
+func TestRendererClient_EndpointJoinsAPIRoute(t *testing.T) {
 	for raw, want := range map[string]string{
-		"https://render.example/api/gif":  "https://render.example/api/gacha",
-		"https://render.example/api/gif/": "https://render.example/api/gacha",
-		"http://10.0.0.5:3000/api/gif":    "http://10.0.0.5:3000/api/gacha",
+		"http://renderer:3000":            "http://renderer:3000/api/gacha",
+		"http://renderer:3000/":           "http://renderer:3000/api/gacha",
+		"https://render.example/proxied":  "https://render.example/proxied/api/gacha",
+		"https://render.example/proxied/": "https://render.example/proxied/api/gacha",
 	} {
-		got, err := gachaAPIEndpoint(raw, "gacha")
+		got, err := rendererClient{BaseURL: raw}.endpoint("gacha")
 		if err != nil {
-			t.Fatalf("gachaAPIEndpoint(%q): %v", raw, err)
+			t.Fatalf("endpoint(%q): %v", raw, err)
 		}
 		if got.String() != want {
-			t.Errorf("gachaAPIEndpoint(%q) = %q, want %q", raw, got, want)
+			t.Errorf("endpoint(%q) = %q, want %q", raw, got, want)
 		}
 	}
-	if _, err := gachaAPIEndpoint("", "gacha"); err != errWheelAPINotConfigured {
-		t.Fatalf("empty url err = %v, want errWheelAPINotConfigured", err)
+	if _, err := (rendererClient{}).endpoint("gacha"); err != errRendererNotConfigured {
+		t.Fatalf("empty url err = %v, want errRendererNotConfigured", err)
 	}
 }
 
-func TestWheelAPIClient_RenderGachaRejectsInvalidInput(t *testing.T) {
-	client := wheelAPIClient{URL: "https://example.com/api/gif"}
+func TestRendererClient_RenderGachaRejectsInvalidInput(t *testing.T) {
+	client := rendererClient{BaseURL: "https://example.com"}
 	for _, tc := range []struct {
 		name   string
 		label  string
@@ -45,7 +46,7 @@ func TestWheelAPIClient_RenderGachaRejectsInvalidInput(t *testing.T) {
 	}
 }
 
-func TestWheelAPIClient_RenderGachaReturnsErrorsForBadResponses(t *testing.T) {
+func TestRendererClient_RenderGachaReturnsErrorsForBadResponses(t *testing.T) {
 	for _, tc := range []struct {
 		name        string
 		status      int
@@ -65,7 +66,7 @@ func TestWheelAPIClient_RenderGachaReturnsErrorsForBadResponses(t *testing.T) {
 			}))
 			defer server.Close()
 
-			client := wheelAPIClient{HTTP: server.Client(), URL: server.URL + "/api/gif"}
+			client := rendererClient{HTTP: server.Client(), BaseURL: server.URL}
 			if _, err := client.RenderGacha(context.Background(), "gacha", "a", 3); err == nil {
 				t.Fatal("RenderGacha returned nil error")
 			}

internal/modules/random/handlers_test.go

@@ -115,7 +115,7 @@ func TestWheelOfNames_ResultCaptionPadsShortWinnerToLongestOption(t *testing.T)
 }
 
 func TestWheelOfNames_UsesRemoteAPIWhenConfigured(t *testing.T) {
-	var got wheelAPIRequest
+	var got wheelRenderRequest
 	var gotAuthorization string
 	var calls int
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -131,7 +131,7 @@ func TestWheelOfNames_UsesRemoteAPIWhenConfigured(t *testing.T) {
 		_, _ = w.Write([]byte("GIF89a-remote"))
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	rb.Bot.ProcessUpdate(context.Background(), testutil.NewPrivateMessage(7, "/wheelofnames Alice, Bob, Carol"))
@@ -191,7 +191,7 @@ func TestWheelOfNames_RemoteFailureFallsBackToRandomReply(t *testing.T) {
 		http.Error(w, "no", http.StatusInternalServerError)
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	rb.Bot.ProcessUpdate(context.Background(), testutil.NewPrivateMessage(7, "/wheelofnames Alice"))
@@ -221,7 +221,7 @@ func TestWheelOfNames_PlaceholderEditFailureFallsBackToReply(t *testing.T) {
 		http.Error(w, "no", http.StatusInternalServerError)
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	rb.FailMethod("editMessageText", http.StatusInternalServerError, "")
@@ -254,7 +254,7 @@ func TestWheelOfNames_SendAnimationFailureFallsBackToRandomReply(t *testing.T) {
 		_, _ = w.Write([]byte("GIF89a-remote"))
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	rb.FailMethod("sendAnimation", http.StatusInternalServerError, "")
@@ -283,7 +283,7 @@ func TestWheelOfNames_ForwardsMessageThreadID(t *testing.T) {
 		_, _ = w.Write([]byte("GIF89a-remote"))
 	}))
 	defer server.Close()
-	t.Setenv(wheelOfNamesAPIURLEnv, server.URL+"/api/gif")
+	t.Setenv(rendererURLEnv, server.URL)
 
 	rb := installRandom(t, 999)
 	update := testutil.NewSupergroupMessage(-100, 7, "/wheelofnames Alice")

internal/modules/random/random.go

@@ -1,7 +1,7 @@
 // Package random groups the commands that pick one option at random: /random
 // (plain text pick), /wheelofnames (wheel GIF when a renderer is configured),
 // /gacha (card-pack wish MP4), and the unlisted /genshin (Genshin-style meteor
-// wish MP4). The animated commands share the optional wheelofnames renderer and
+// wish MP4). The animated commands share the optional renderer service and
 // fall back to a text reply without it.
 package random
 

internal/modules/random/renderer_client.go

@@ -0,0 +1,196 @@
+package random
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"net/http"
+	"net/url"
+	"os"
+	"strings"
+	"time"
+)
+
+const (
+	// rendererURLEnv holds the renderer's base URL, e.g. http://renderer:3000.
+	// The standard renderer is the renderer/ service in this repository, wired
+	// in by compose.yml and reachable only on the compose network, so requests
+	// carry no credentials. The client appends each animation's /api/<name>
+	// path itself.
+	rendererURLEnv = "RENDERER_URL"
+
+	rendererMaxBytes = 12 << 20
+	rendererTimeout  = 30 * time.Second
+
+	wheelRemoteDurationMs = 6000
+	wheelRemoteHoldMs     = 1000
+	wheelRemoteFPS        = 20
+	wheelRemoteSize       = 512
+	wheelRemoteTheme      = "classic"
+	wheelRemoteDuration   = (wheelRemoteDurationMs + wheelRemoteHoldMs) / 1000
+)
+
+var errRendererNotConfigured = errors.New("renderer not configured")
+
+// rendererClient calls the animation renderer. BaseURL is the service root;
+// every animation lives under its /api path.
+type rendererClient struct {
+	HTTP    *http.Client
+	BaseURL string
+}
+
+type wheelRenderRequest struct {
+	Options     []string `json:"options"`
+	WinnerIndex int      `json:"winnerIndex"`
+	DurationMs  int      `json:"durationMs"`
+	HoldMs      int      `json:"holdMs"`
+	FPS         int      `json:"fps"`
+	Size        int      `json:"size"`
+	Theme       string   `json:"theme"`
+}
+
+// renderedAnimation is a rendered clip plus the metadata Telegram's
+// sendAnimation wants.
+type renderedAnimation struct {
+	Data     []byte
+	Duration int
+	Width    int
+	Height   int
+}
+
+func newRendererClientFromEnv() rendererClient {
+	return rendererClient{
+		BaseURL: strings.TrimSpace(os.Getenv(rendererURLEnv)),
+	}
+}
+
+// RenderWheel returns the wheel-of-names GIF landing on options[winner].
+func (c rendererClient) RenderWheel(ctx context.Context, options []string, winner int) ([]byte, error) {
+	endpoint, err := c.endpoint("gif")
+	if err != nil {
+		return nil, err
+	}
+	if len(options) == 0 {
+		return nil, fmt.Errorf("renderer wheel options empty")
+	}
+	if winner < 0 || winner >= len(options) {
+		return nil, fmt.Errorf("renderer wheel winner index %d out of range %d", winner, len(options))
+	}
+
+	body, err := json.Marshal(wheelRenderRequest{
+		Options:     options,
+		WinnerIndex: winner,
+		DurationMs:  wheelRemoteDurationMs,
+		HoldMs:      wheelRemoteHoldMs,
+		FPS:         wheelRemoteFPS,
+		Size:        wheelRemoteSize,
+		Theme:       wheelRemoteTheme,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("renderer wheel request encode failed: %w", err)
+	}
+
+	return c.post(ctx, endpoint, body, "image/gif", isWheelGIF)
+}
+
+// post sends one JSON render request to endpoint and returns the response
+// body once it is a 2xx of the expected media type that passes isValid.
+func (c rendererClient) post(ctx context.Context, endpoint *url.URL, body []byte, mediaType string, isValid func([]byte) bool) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint.String(), bytes.NewReader(body))
+	if err != nil {
+		return nil, fmt.Errorf("renderer request build failed: %w", err)
+	}
+	req.Header.Set("Accept", mediaType)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.httpClient().Do(req)
+	if err != nil {
+		return nil, errors.New("renderer request failed")
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusMultipleChoices {
+		return nil, fmt.Errorf("renderer status %d", resp.StatusCode)
+	}
+	if err := requireContentType(resp.Header.Get("Content-Type"), mediaType); err != nil {
+		return nil, err
+	}
+
+	data, err := io.ReadAll(io.LimitReader(resp.Body, rendererMaxBytes+1))
+	if err != nil {
+		return nil, fmt.Errorf("renderer response read failed: %w", err)
+	}
+	if len(data) > rendererMaxBytes {
+		return nil, fmt.Errorf("renderer response too large")
+	}
+	if len(data) == 0 {
+		return nil, fmt.Errorf("renderer response empty")
+	}
+	if !isValid(data) {
+		return nil, fmt.Errorf("renderer response is not %s", mediaType)
+	}
+	return data, nil
+}
+
+func (c rendererClient) httpClient() *http.Client {
+	if c.HTTP != nil {
+		return c.HTTP
+	}
+	return &http.Client{Timeout: rendererTimeout}
+}
+
+// endpoint resolves the renderer route /api/<name> under BaseURL. A path
+// prefix on BaseURL is kept, so a renderer mounted below a reverse-proxy path
+// still works.
+func (c rendererClient) endpoint(name string) (*url.URL, error) {
+	base, err := rendererBaseURL(c.BaseURL)
+	if err != nil {
+		return nil, err
+	}
+	return base.JoinPath("api", name), nil
+}
+
+// rendererBaseURL validates the configured base URL.
+func rendererBaseURL(rawURL string) (*url.URL, error) {
+	rawURL = strings.TrimSpace(rawURL)
+	if rawURL == "" {
+		return nil, errRendererNotConfigured
+	}
+	base, err := url.Parse(rawURL)
+	if err != nil || base.Scheme == "" || base.Host == "" {
+		return nil, fmt.Errorf("renderer url invalid")
+	}
+	if base.Scheme != "http" && base.Scheme != "https" {
+		return nil, fmt.Errorf("renderer url scheme %q unsupported", base.Scheme)
+	}
+	return base, nil
+}
+
+func requireContentType(contentType, want string) error {
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err != nil || mediaType != want {
+		return fmt.Errorf("renderer content type %q unsupported", contentType)
+	}
+	return nil
+}
+
+func isWheelGIF(data []byte) bool {
+	return bytes.HasPrefix(data, []byte("GIF87a")) || bytes.HasPrefix(data, []byte("GIF89a"))
+}
+
+func renderWheelOfNamesAnimation(ctx context.Context, options []string, winner int) (renderedAnimation, error) {
+	data, err := newRendererClientFromEnv().RenderWheel(ctx, options, winner)
+	if err != nil {
+		return renderedAnimation{}, err
+	}
+	return renderedAnimation{
+		Data:     data,
+		Duration: wheelRemoteDuration,
+		Width:    wheelRemoteSize,
+		Height:   wheelRemoteSize,
+	}, nil
+}

internal/modules/random/renderer_client_test.go

@@ -11,8 +11,8 @@ import (
 	"testing"
 )
 
-func TestWheelAPIClient_RenderValidRequest(t *testing.T) {
-	var got wheelAPIRequest
+func TestRendererClient_RenderValidRequest(t *testing.T) {
+	var got wheelRenderRequest
 	var gotAccept string
 	var gotContentType string
 	var gotMethod string
@@ -30,13 +30,13 @@ func TestWheelAPIClient_RenderValidRequest(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := wheelAPIClient{
-		HTTP: server.Client(),
-		URL:  server.URL + "/api/gif",
+	client := rendererClient{
+		HTTP:    server.Client(),
+		BaseURL: server.URL,
 	}
-	data, err := client.Render(context.Background(), []string{"alice", "bob", "carol"}, 1)
+	data, err := client.RenderWheel(context.Background(), []string{"alice", "bob", "carol"}, 1)
 	if err != nil {
-		t.Fatalf("Render: %v", err)
+		t.Fatalf("RenderWheel: %v", err)
 	}
 	if !bytes.Equal(data, []byte("GIF89a-remote")) {
 		t.Fatalf("data = %q, want remote GIF bytes", data)
@@ -63,7 +63,7 @@ func TestWheelAPIClient_RenderValidRequest(t *testing.T) {
 }
 
 // The renderer is internal to the compose network; the bot sends no credentials.
-func TestWheelAPIClient_RenderSendsNoAuthorization(t *testing.T) {
+func TestRendererClient_RenderSendsNoAuthorization(t *testing.T) {
 	var gotAuthorization string
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		gotAuthorization = r.Header.Get("Authorization")
@@ -72,45 +72,45 @@ func TestWheelAPIClient_RenderSendsNoAuthorization(t *testing.T) {
 	}))
 	defer server.Close()
 
-	client := wheelAPIClient{HTTP: server.Client(), URL: server.URL + "/api/gif"}
-	if _, err := client.Render(context.Background(), []string{"alice"}, 0); err != nil {
-		t.Fatalf("Render: %v", err)
+	client := rendererClient{HTTP: server.Client(), BaseURL: server.URL}
+	if _, err := client.RenderWheel(context.Background(), []string{"alice"}, 0); err != nil {
+		t.Fatalf("RenderWheel: %v", err)
 	}
 	if gotAuthorization != "" {
 		t.Fatalf("Authorization = %q, want empty", gotAuthorization)
 	}
 }
 
-func TestWheelAPIClient_RenderNotConfigured(t *testing.T) {
-	client := wheelAPIClient{}
-	_, err := client.Render(context.Background(), []string{"alice"}, 0)
-	if !errors.Is(err, errWheelAPINotConfigured) {
-		t.Fatalf("Render error = %v, want errWheelAPINotConfigured", err)
+func TestRendererClient_RenderNotConfigured(t *testing.T) {
+	client := rendererClient{}
+	_, err := client.RenderWheel(context.Background(), []string{"alice"}, 0)
+	if !errors.Is(err, errRendererNotConfigured) {
+		t.Fatalf("RenderWheel error = %v, want errRendererNotConfigured", err)
 	}
 }
 
-func TestWheelAPIClient_RenderRejectsInvalidInput(t *testing.T) {
-	client := wheelAPIClient{URL: "https://example.com/api/gif"}
+func TestRendererClient_RenderRejectsInvalidInput(t *testing.T) {
+	client := rendererClient{BaseURL: "https://example.com"}
 	for _, tc := range []struct {
 		name    string
 		url     string
 		options []string
 		winner  int
 	}{
-		{name: "bad scheme", url: "ftp://example.com/api/gif", options: []string{"alice"}, winner: 0},
-		{name: "empty options", url: "https://example.com/api/gif", options: nil, winner: 0},
-		{name: "winner out of range", url: "https://example.com/api/gif", options: []string{"alice"}, winner: 1},
+		{name: "bad scheme", url: "ftp://example.com", options: []string{"alice"}, winner: 0},
+		{name: "empty options", url: "https://example.com", options: nil, winner: 0},
+		{name: "winner out of range", url: "https://example.com", options: []string{"alice"}, winner: 1},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			client.URL = tc.url
-			if _, err := client.Render(context.Background(), tc.options, tc.winner); err == nil {
-				t.Fatalf("Render returned nil error")
+			client.BaseURL = tc.url
+			if _, err := client.RenderWheel(context.Background(), tc.options, tc.winner); err == nil {
+				t.Fatalf("RenderWheel returned nil error")
 			}
 		})
 	}
 }
 
-func TestWheelAPIClient_RenderReturnsErrorsForBadResponses(t *testing.T) {
+func TestRendererClient_RenderReturnsErrorsForBadResponses(t *testing.T) {
 	for _, tc := range []struct {
 		name        string
 		status      int
@@ -131,35 +131,35 @@ func TestWheelAPIClient_RenderReturnsErrorsForBadResponses(t *testing.T) {
 			}))
 			defer server.Close()
 
-			client := wheelAPIClient{HTTP: server.Client(), URL: server.URL + "/api/gif"}
-			if _, err := client.Render(context.Background(), []string{"alice"}, 0); err == nil {
-				t.Fatalf("Render returned nil error")
+			client := rendererClient{HTTP: server.Client(), BaseURL: server.URL}
+			if _, err := client.RenderWheel(context.Background(), []string{"alice"}, 0); err == nil {
+				t.Fatalf("RenderWheel returned nil error")
 			}
 		})
 	}
 }
 
-func TestWheelAPIClient_RenderRejectsOversizedResponse(t *testing.T) {
+func TestRendererClient_RenderRejectsOversizedResponse(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Content-Type", "image/gif")
-		_, _ = w.Write(bytes.Repeat([]byte("a"), int(wheelRemoteMaxBytes)+1))
+		_, _ = w.Write(bytes.Repeat([]byte("a"), int(rendererMaxBytes)+1))
 	}))
 	defer server.Close()
 
-	client := wheelAPIClient{HTTP: server.Client(), URL: server.URL + "/api/gif"}
-	if _, err := client.Render(context.Background(), []string{"alice"}, 0); err == nil {
-		t.Fatalf("Render returned nil error")
+	client := rendererClient{HTTP: server.Client(), BaseURL: server.URL}
+	if _, err := client.RenderWheel(context.Background(), []string{"alice"}, 0); err == nil {
+		t.Fatalf("RenderWheel returned nil error")
 	}
 }
 
-func TestWheelAPIClient_DefaultHTTPClientHasTimeout(t *testing.T) {
-	client := wheelAPIClient{}
-	if got := client.httpClient().Timeout; got != wheelRemoteTimeout {
-		t.Fatalf("timeout = %s, want %s", got, wheelRemoteTimeout)
+func TestRendererClient_DefaultHTTPClientHasTimeout(t *testing.T) {
+	client := rendererClient{}
+	if got := client.httpClient().Timeout; got != rendererTimeout {
+		t.Fatalf("timeout = %s, want %s", got, rendererTimeout)
 	}
 }
 
-func assertWheelRemoteDefaults(t *testing.T, got wheelAPIRequest) {
+func assertWheelRemoteDefaults(t *testing.T, got wheelRenderRequest) {
 	t.Helper()
 	if got.DurationMs != wheelRemoteDurationMs {
 		t.Fatalf("durationMs = %d, want %d", got.DurationMs, wheelRemoteDurationMs)

internal/modules/random/wheelofnames_api_client.go

@@ -1,179 +0,0 @@
-package random
-
-import (
-	"bytes"
-	"context"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-	"mime"
-	"net/http"
-	"net/url"
-	"os"
-	"strings"
-	"time"
-)
-
-const (
-	// The standard renderer is the renderer/ service in this repository, wired
-	// in by compose.yml and reachable only on the compose network, so requests
-	// carry no credentials. Operators may point this to any service that
-	// implements the same /api/gif contract.
-	wheelOfNamesAPIURLEnv = "WHEELOFNAMES_API_URL"
-
-	wheelRemoteDurationMs = 6000
-	wheelRemoteHoldMs     = 1000
-	wheelRemoteFPS        = 20
-	wheelRemoteSize       = 512
-	wheelRemoteTheme      = "classic"
-	wheelRemoteDuration   = (wheelRemoteDurationMs + wheelRemoteHoldMs) / 1000
-	wheelRemoteMaxBytes   = 12 << 20
-	wheelRemoteTimeout    = 30 * time.Second
-)
-
-var errWheelAPINotConfigured = errors.New("wheelofnames api not configured")
-
-type wheelAPIClient struct {
-	HTTP *http.Client
-	URL  string
-}
-
-type wheelAPIRequest struct {
-	Options     []string `json:"options"`
-	WinnerIndex int      `json:"winnerIndex"`
-	DurationMs  int      `json:"durationMs"`
-	HoldMs      int      `json:"holdMs"`
-	FPS         int      `json:"fps"`
-	Size        int      `json:"size"`
-	Theme       string   `json:"theme"`
-}
-
-type wheelAnimation struct {
-	Data     []byte
-	Duration int
-	Width    int
-	Height   int
-}
-
-func newWheelAPIClientFromEnv() wheelAPIClient {
-	return wheelAPIClient{
-		URL: strings.TrimSpace(os.Getenv(wheelOfNamesAPIURLEnv)),
-	}
-}
-
-func (c wheelAPIClient) Render(ctx context.Context, options []string, winner int) ([]byte, error) {
-	endpoint, err := wheelAPIEndpoint(c.URL)
-	if err != nil {
-		return nil, err
-	}
-	if len(options) == 0 {
-		return nil, fmt.Errorf("wheelofnames api options empty")
-	}
-	if winner < 0 || winner >= len(options) {
-		return nil, fmt.Errorf("wheelofnames api winner index %d out of range %d", winner, len(options))
-	}
-
-	body, err := json.Marshal(wheelAPIRequest{
-		Options:     options,
-		WinnerIndex: winner,
-		DurationMs:  wheelRemoteDurationMs,
-		HoldMs:      wheelRemoteHoldMs,
-		FPS:         wheelRemoteFPS,
-		Size:        wheelRemoteSize,
-		Theme:       wheelRemoteTheme,
-	})
-	if err != nil {
-		return nil, fmt.Errorf("wheelofnames api request encode failed: %w", err)
-	}
-
-	return c.post(ctx, endpoint, body, "image/gif", isWheelGIF)
-}
-
-// post sends one JSON render request to endpoint and returns the response
-// body once it is a 2xx of the expected media type that passes isValid. The
-// gif and gacha renderers share it because they live on the same service.
-func (c wheelAPIClient) post(ctx context.Context, endpoint *url.URL, body []byte, mediaType string, isValid func([]byte) bool) ([]byte, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint.String(), bytes.NewReader(body))
-	if err != nil {
-		return nil, fmt.Errorf("wheelofnames api request build failed: %w", err)
-	}
-	req.Header.Set("Accept", mediaType)
-	req.Header.Set("Content-Type", "application/json")
-
-	resp, err := c.httpClient().Do(req)
-	if err != nil {
-		return nil, errors.New("wheelofnames api request failed")
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusMultipleChoices {
-		return nil, fmt.Errorf("wheelofnames api status %d", resp.StatusCode)
-	}
-	if err := requireContentType(resp.Header.Get("Content-Type"), mediaType); err != nil {
-		return nil, err
-	}
-
-	data, err := io.ReadAll(io.LimitReader(resp.Body, wheelRemoteMaxBytes+1))
-	if err != nil {
-		return nil, fmt.Errorf("wheelofnames api response read failed: %w", err)
-	}
-	if len(data) > wheelRemoteMaxBytes {
-		return nil, fmt.Errorf("wheelofnames api response too large")
-	}
-	if len(data) == 0 {
-		return nil, fmt.Errorf("wheelofnames api response empty")
-	}
-	if !isValid(data) {
-		return nil, fmt.Errorf("wheelofnames api response is not %s", mediaType)
-	}
-	return data, nil
-}
-
-func (c wheelAPIClient) httpClient() *http.Client {
-	if c.HTTP != nil {
-		return c.HTTP
-	}
-	return &http.Client{Timeout: wheelRemoteTimeout}
-}
-
-func wheelAPIEndpoint(rawURL string) (*url.URL, error) {
-	rawURL = strings.TrimSpace(rawURL)
-	if rawURL == "" {
-		return nil, errWheelAPINotConfigured
-	}
-	endpoint, err := url.Parse(rawURL)
-	if err != nil || endpoint.Scheme == "" || endpoint.Host == "" {
-		return nil, fmt.Errorf("wheelofnames api url invalid")
-	}
-	if endpoint.Scheme != "http" && endpoint.Scheme != "https" {
-		return nil, fmt.Errorf("wheelofnames api url scheme %q unsupported", endpoint.Scheme)
-	}
-	return endpoint, nil
-}
-
-func requireContentType(contentType, want string) error {
-	mediaType, _, err := mime.ParseMediaType(contentType)
-	if err != nil || mediaType != want {
-		return fmt.Errorf("wheelofnames api content type %q unsupported", contentType)
-	}
-	return nil
-}
-
-func isWheelGIF(data []byte) bool {
-	return bytes.HasPrefix(data, []byte("GIF87a")) || bytes.HasPrefix(data, []byte("GIF89a"))
-}
-
-func renderWheelOfNamesAnimation(ctx context.Context, options []string, winner int) (wheelAnimation, error) {
-	client := newWheelAPIClientFromEnv()
-	data, err := client.Render(ctx, options, winner)
-	if err != nil {
-		return wheelAnimation{}, err
-	}
-	return wheelAnimation{
-		Data:     data,
-		Duration: wheelRemoteDuration,
-		Width:    wheelRemoteSize,
-		Height:   wheelRemoteSize,
-	}, nil
-}

internal/modules/random/wheelofnames_command.go

@@ -38,7 +38,7 @@ func wheelOfNamesCommand() modules.Command {
 			placeholder := sendRenderPlaceholder(ctx, b, update.Message, wheelPlaceholder)
 			animation, err := renderWheelOfNamesAnimation(ctx, options, winner)
 			if err != nil {
-				if !errors.Is(err, errWheelAPINotConfigured) {
+				if !errors.Is(err, errRendererNotConfigured) {
 					log.Warn("wheelofnames remote render failed", "err", err)
 				}
 				return replaceWheelPlaceholder(ctx, b, update.Message, placeholder, options[winner])
@@ -81,12 +81,12 @@ const wheelPlaceholder = "Spinning..."
 // is immediate, and a placeholder would only flash. A failed placeholder is
 // non-fatal — the pick still resolves, just without the holding message.
 func sendRenderPlaceholder(ctx context.Context, b *bot.Bot, msg *models.Message, text string) int {
-	if _, err := wheelAPIEndpoint(newWheelAPIClientFromEnv().URL); err != nil {
+	if _, err := rendererBaseURL(newRendererClientFromEnv().BaseURL); err != nil {
 		return 0
 	}
 	id, err := chathelper.SendText(ctx, b, msg, text)
 	if err != nil {
-		log.Warn("wheelofnames placeholder send failed", "chat", msg.Chat.ID, "err", err)
+		log.Warn("render placeholder send failed", "chat", msg.Chat.ID, "err", err)
 		return 0
 	}
 	return id
@@ -101,7 +101,7 @@ func replaceWheelPlaceholder(ctx context.Context, b *bot.Bot, msg *models.Messag
 		if err == nil {
 			return nil
 		}
-		log.Warn("wheelofnames placeholder edit failed", "chat", msg.Chat.ID, "err", err)
+		log.Warn("render placeholder edit failed", "chat", msg.Chat.ID, "err", err)
 	}
 	return chathelper.Reply(ctx, b, msg, winner)
 }