package server

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"testing"

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

// TestImageProxyRefusesFitOutsideAboveMaximum requests sizes with fit=outside
// through both image routes. fit=outside scales the source to cover the size,
// and so past it on one side: a size for which that side would be above 8192
// is refused with 400 and the JSON error body, whether it is the width or the
// height, and a size for which it stays within 8192 is served at the scaled
// size.
func TestImageProxyRefusesFitOutsideAboveMaximum(t *testing.T) {
	t.Parallel()

	// The upstream paths of the sources
	const (
		widePath   = "/wide.png"
		rowPath    = "/row.png"
		columnPath = "/column.png"
	)

	sources := map[string][]byte{
		widePath:   encodeTestPNG(t, 3000, 600),
		rowPath:    encodeTestPNG(t, 8192, 1),
		columnPath: encodeTestPNG(t, 1, 8192),
	}

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

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

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

	tests := []struct {
		path          string
		width, height int
		// wantWidth and wantHeight are the served image's, 0 for a refusal
		wantWidth, wantHeight int
	}{
		{widePath, 1, 8192, 0, 0},
		{rowPath, 1, 8192, 0, 0},
		{columnPath, 8192, 1, 0, 0},
		{widePath, 1, 1200, 6000, 1200},
	}

	for _, tt := range tests {
		token, err := generator.Generate(&encurl.Payload{
			SourceHost: upstreamHost, SourcePath: tt.path,
			Width: tt.width, Height: tt.height, Format: imgcache.FormatJPEG,
			FitMode: imgcache.FitOutside,
		})
		if err != nil {
			t.Fatalf("encurl Generate: %v", err)
		}

		size := fmt.Sprintf("%dx%d", tt.width, tt.height)

		for _, target := range []string{
			"/v1/image/" + upstreamHost + tt.path + "/" + size +
				".jpeg?fit=outside",
			"/v1/e/" + token + "/img.jpg",
		} {
			rec := httptest.NewRecorder()
			s.ServeHTTP(rec, httptest.NewRequestWithContext(
				t.Context(), http.MethodGet, target, nil))
			t.Logf("GET %s: %d, Content-Type %s",
				target, rec.Code, rec.Header().Get("Content-Type"))

			if tt.wantWidth == 0 {
				checkSizeRefused(t, rec)
			} else {
				checkServedSize(t, rec, tt.wantWidth, tt.wantHeight)
			}
		}
	}
}