package server

import (
	"net/http"
	"net/http/httptest"
	"slices"
	"testing"
)

// TestFormatAutoVaryNextToOrigin requests an image URL with the format auto
// through the server's routes and verifies that the answer carries
// Vary: Accept next to the Vary: Origin the CORS middleware sends.
func TestFormatAutoVaryNextToOrigin(t *testing.T) {
	t.Parallel()

	source := encodeTestPNG(t, 64, 48)

	upstream := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			w.Header().Set("Content-Type", "image/png")
			_, _ = w.Write(source)
		}))
	t.Cleanup(upstream.Close)

	s, _, _ := startImageProxy(t, upstream)

	req := httptest.NewRequestWithContext(t.Context(), http.MethodGet,
		"/v1/image/"+upstreamHost+"/photo.png/32x24.auto", nil)
	req.Header.Set("Origin", "https://app.example.com")
	req.Header.Set("Accept", "image/webp")

	rec := httptest.NewRecorder()
	s.ServeHTTP(rec, req)

	vary := rec.Header().Values("Vary")
	t.Logf("status %d, Content-Type %s, Vary %v",
		rec.Code, rec.Header().Get("Content-Type"), vary)

	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
	}

	if want := []string{"Origin", "Accept"}; !slices.Equal(vary, want) {
		t.Errorf("Vary = %v, want %v", vary, want)
	}
}