package server

import (
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"sneak.berlin/go/pixa/internal/encurl"
	"sneak.berlin/go/pixa/internal/imgcache"
)

// svgServedAsAVIF is an SVG whose first bytes pass the first-bytes check for
// AVIF: its XML comment puts "ftypavis" at bytes 4 to 11, where an AVIF file
// has its ftyp box and brand. libvips would load it as SVG.
const svgServedAsAVIF = `<!--ftypavis--><svg xmlns="http://www.w3.org/2000/svg" ` +
	`width="64" height="48"><rect width="64" height="48"/></svg>`

// TestImageProxyRefusesSVGServedAsAVIF requests svgServedAsAVIF, which the
// upstream answers as image/avif, through both image routes, resized as PNG
// and in its own format (orig). Each request is answered 415, as for an SVG
// source, never with an image.
func TestImageProxyRefusesSVGServedAsAVIF(t *testing.T) {
	t.Parallel()

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

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

	generator, err := encurl.NewGenerator(testSigningKey)
	if err != nil {
		t.Fatalf("encurl.NewGenerator: %v", err)
	}

	encryptedURL := func(format imgcache.ImageFormat) string {
		token, err := generator.Generate(&encurl.Payload{
			SourceHost: upstreamHost, SourcePath: "/drawing.avif",
			Width: 32, Height: 24, Format: format,
		})
		if err != nil {
			t.Fatalf("encurl Generate: %v", err)
		}

		return "/v1/e/" + token + "/drawing." + string(format)
	}

	for _, target := range []string{
		"/v1/image/" + upstreamHost + "/drawing.avif/32x24.png",
		"/v1/image/" + upstreamHost + "/drawing.avif/64x48.orig",
		encryptedURL(imgcache.FormatPNG),
		encryptedURL(imgcache.FormatOriginal),
	} {
		rec := httptest.NewRecorder()
		s.ServeHTTP(rec, httptest.NewRequestWithContext(
			t.Context(), http.MethodGet, target, nil))
		t.Logf("GET %s: %d, Content-Type %s, body %q",
			target, rec.Code, rec.Header().Get("Content-Type"), rec.Body.String())

		if rec.Code != http.StatusUnsupportedMediaType ||
			!strings.Contains(rec.Body.String(), "unsupported source format") {
			t.Errorf("GET %s: %d %q, want %d unsupported source format",
				target, rec.Code, rec.Body.String(), http.StatusUnsupportedMediaType)
		}
	}
}