package imageprocessor

import (
	"bytes"
	"errors"
	"testing"
)

// TestImageProcessor_RefusesAVIFAboveMaxPixels verifies that an AVIF output
// of more than MaxAVIFOutputPixels is refused with ErrAVIFOutputTooLarge
// before anything is decoded, whatever size and fit give it, and that an AVIF
// output of at most that many pixels, or one in another format, is not. The
// input is a 64x32 PNG cut off in its pixel data: libvips reads its size from
// its header but fails when it decodes it, so a request that gets that failure
// was not refused, and a refusal came before any decoding.
func TestImageProcessor_RefusesAVIFAboveMaxPixels(t *testing.T) {
	t.Parallel()

	whole := createTestPNG(t, 64, 32)
	cutOff := whole[:len(whole)/2]

	tests := []struct {
		name          string
		format        Format
		width, height int
		fit           FitMode
		refused       bool
	}{
		{"AVIF at the limit", FormatAVIF, 4096, 4096, FitCover, false},
		{"AVIF above the limit", FormatAVIF, 4096, 4097, FitCover, true},
		{"WebP above the AVIF limit", FormatWebP, 4096, 4097, FitCover, false},
		// FitInside does not enlarge, so the output stays 64x32
		{"AVIF inside a larger size", FormatAVIF, 8192, 8192, FitInside, false},
		// FitOutside scales 64x32 by 128 to cover 8192x1: 8192x4096
		{"AVIF outside a smaller size", FormatAVIF, 8192, 1, FitOutside, true},
	}

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

			_, err := New(Params{}).Process(t.Context(), bytes.NewReader(cutOff),
				&Request{
					Size:    Size{Width: tt.width, Height: tt.height},
					Format:  tt.format,
					FitMode: tt.fit,
				})
			t.Logf("Process() error = %v", err)

			if tt.refused {
				if !errors.Is(err, ErrAVIFOutputTooLarge) {
					t.Errorf("Process() error = %v, want %v", err, ErrAVIFOutputTooLarge)
				}

				return
			}

			if err == nil || errors.Is(err, ErrAVIFOutputTooLarge) {
				t.Errorf("Process() error = %v, want the failure to decode "+
					"the cut-off input", err)
			}
		})
	}
}