package handlers

import (
	"log/slog"
	"net/http"
	"testing"

	"github.com/davidbyttow/govips/v2/vips"

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

// jxlType is the content type of JPEG XL.
const jxlType = "image/jxl"

// TestFormatForAccept_JPEGXL verifies that the format auto chooses JPEG XL
// when Accept names image/jxl, ahead of AVIF whatever their q, and AVIF when
// Accept refuses JPEG XL with q=0.
func TestFormatForAccept_JPEGXL(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name   string
		accept string
		want   imgcache.ImageFormat
	}{
		{"JPEG XL-capable browser",
			"image/jxl,image/avif,image/webp,image/*,*/*;q=0.8", imgcache.FormatJXL},
		{"JPEG XL only", jxlType, imgcache.FormatJXL},
		{"JPEG XL with a lower q than AVIF", "image/avif,image/jxl;q=0.5",
			imgcache.FormatJXL},
		{"q=0 on JPEG XL", "image/jxl;q=0,image/avif,*/*", imgcache.FormatAVIF},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			got, err := formatForAccept(tt.accept)
			if got != tt.want || err != nil {
				t.Errorf("formatForAccept(%q) = %q, %v, want %q",
					tt.accept, got, err, tt.want)
			}
		})
	}
}

// TestFormatAuto_JPEGXL requests an auto URL on each image route with an
// Accept header that names image/jxl, and checks that the answer is a JPEG XL
// image.
func TestFormatAuto_JPEGXL(t *testing.T) {
	t.Parallel()

	h, srv := newSignedHostServer(t, slog.New(slog.DiscardHandler))
	signedURL, encryptedURL := autoPhotoURLs(t, h)

	for _, target := range []string{signedURL, encryptedURL} {
		rec := requestImage(t, srv, http.MethodGet, target,
			"image/jxl,image/avif,image/webp,*/*;q=0.8")
		gotType := rec.Header().Get("Content-Type")

		if rec.Code != http.StatusOK || gotType != jxlType {
			t.Errorf("%s: %d %s, want 200 %s; body %s",
				target, rec.Code, gotType, jxlType, rec.Body)

			continue
		}

		if got := vips.DetermineImageType(rec.Body.Bytes()); got != vips.ImageTypeJXL {
			t.Errorf("%s: body is %s, want jxl", target, vips.ImageTypes[got])
		}
	}
}