// Copyright 2022 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "gmock/gmock.h"
#include "src/tint/writer/glsl/test_helper.h"

using ::testing::HasSubstr;

namespace tint {
namespace writer {
namespace glsl {
namespace {

using GlslGeneratorImplTest_StorageBuffer = TestHelper;

void TestAlign(ProgramBuilder* ctx) {
  // struct Nephews {
  //   @align(256) huey  : f32;
  //   @align(256) dewey : f32;
  //   @align(256) louie : f32;
  // };
  // @group(0) @binding(0) var<storage, read_write> nephews : Nephews;
  auto* nephews = ctx->Structure(
      "Nephews",
      {
          ctx->Member("huey", ctx->ty.f32(), {ctx->MemberAlign(256)}),
          ctx->Member("dewey", ctx->ty.f32(), {ctx->MemberAlign(256)}),
          ctx->Member("louie", ctx->ty.f32(), {ctx->MemberAlign(256)}),
      });
  ctx->Global("nephews", ctx->ty.Of(nephews), ast::StorageClass::kStorage,
              ast::AttributeList{
                  ctx->create<ast::BindingAttribute>(0),
                  ctx->create<ast::GroupAttribute>(0),
              });
}

TEST_F(GlslGeneratorImplTest_StorageBuffer, Align) {
  TestAlign(this);

  GeneratorImpl& gen = Build();

  // TODO(crbug.com/tint/1421) offsets do not currently work on GLSL ES.
  // They will likely require manual padding.
  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#version 310 es

struct Nephews {
  float huey;
  float dewey;
  float louie;
};

layout(binding = 0, std430) buffer Nephews_1 {
  float huey;
  float dewey;
  float louie;
} nephews;
)");
}

TEST_F(GlslGeneratorImplTest_StorageBuffer, Align_Desktop) {
  TestAlign(this);

  GeneratorImpl& gen = Build(Version(Version::Standard::kDesktop, 4, 4));

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#version 440

struct Nephews {
  float huey;
  float dewey;
  float louie;
};

layout(binding = 0, std430) buffer Nephews_1 {
  float huey;
  layout(offset=256) float dewey;
  layout(offset=512) float louie;
} nephews;
)");
}

}  // namespace
}  // namespace glsl
}  // namespace writer
}  // namespace tint