package renderer

import (
	"errors"
	"strconv"
	"testing"

	"github.com/christerso/vulkan-go/vk"
)

func TestValidateFramePayload(t *testing.T) {
	tests := []struct {
		name       string
		payloadLen int
		width      uint32
		height     uint32
		stride     uint32
		wantSize   vk.DeviceSize
		wantErr    bool
	}{
		{
			name:       "valid frame",
			payloadLen: 5120 * 1080,
			width:      1920,
			height:     1080,
			stride:     5120,
			wantSize:   vk.DeviceSize(5120 * 1080),
		},
		{
			name:       "payload may be larger than frame",
			payloadLen: 5120*1080 + 128,
			width:      1920,
			height:     1080,
			stride:     5120,
			wantSize:   vk.DeviceSize(5120 * 1080),
		},
		{
			name:       "zero width",
			payloadLen: 100,
			height:     10,
			stride:     10,
			wantErr:    true,
		},
		{
			name:       "zero height",
			payloadLen: 100,
			width:      10,
			stride:     10,
			wantErr:    true,
		},
		{
			name:       "zero stride",
			payloadLen: 100,
			width:      10,
			height:     10,
			wantErr:    true,
		},
		{
			name:       "payload is too small",
			payloadLen: 99,
			width:      10,
			height:     10,
			stride:     10,
			wantErr:    true,
		},
		{
			name:       "negative payload length",
			payloadLen: -1,
			width:      10,
			height:     10,
			stride:     10,
			wantErr:    true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := validateFramePayload(
				tt.payloadLen,
				tt.width,
				tt.height,
				tt.stride,
			)

			if tt.wantErr {
				if !errors.Is(err, ErrInvalidVideoFrame) {
					t.Fatalf("validateFramePayload() error = %v, want %v", err, ErrInvalidVideoFrame)
				}
				return
			}
			if err != nil {
				t.Fatalf("validateFramePayload() error = %v, want nil", err)
			}
			if got != tt.wantSize {
				t.Errorf("validateFramePayload() size = %d, want %d", got, tt.wantSize)
			}
		})
	}
}

func TestValidateFramePayloadUses64BitSize(t *testing.T) {
	if strconv.IntSize < 64 {
		t.Skip("test requires a 64-bit int")
	}

	stride := ^uint32(0)
	height := uint32(2)
	required := uint64(stride) * uint64(height)

	got, err := validateFramePayload(
		int(required),
		1,
		height,
		stride,
	)
	if err != nil {
		t.Fatalf("validateFramePayload() error = %v, want nil", err)
	}
	if uint64(got) != required {
		t.Fatalf("validateFramePayload() size = %d, want %d", got, required)
	}
}