// Copyright 2020 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 <memory>
#include <vector>

#include "src/ast/constant_id_decoration.h"
#include "src/ast/float_literal.h"
#include "src/ast/module.h"
#include "src/ast/scalar_constructor_expression.h"
#include "src/ast/type/array_type.h"
#include "src/ast/type/f32_type.h"
#include "src/ast/type_constructor_expression.h"
#include "src/ast/variable.h"
#include "src/writer/hlsl/test_helper.h"

namespace tint {
namespace writer {
namespace hlsl {
namespace {

using HlslGeneratorImplTest_ModuleConstant = TestHelper;

TEST_F(HlslGeneratorImplTest_ModuleConstant, Emit_ModuleConstant) {
  ast::type::F32 f32;
  ast::type::Array ary(&f32, 3, ast::ArrayDecorationList{});

  ast::ExpressionList exprs;
  exprs.push_back(create<ast::ScalarConstructorExpression>(
      create<ast::FloatLiteral>(&f32, 1.0f)));
  exprs.push_back(create<ast::ScalarConstructorExpression>(
      create<ast::FloatLiteral>(&f32, 2.0f)));
  exprs.push_back(create<ast::ScalarConstructorExpression>(
      create<ast::FloatLiteral>(&f32, 3.0f)));

  auto* var = create<ast::Variable>(
      Source{},                                             // source
      "pos",                                                // name
      ast::StorageClass::kNone,                             // storage_class
      &ary,                                                 // type
      true,                                                 // is_const
      create<ast::TypeConstructorExpression>(&ary, exprs),  // constructor
      ast::VariableDecorationList{});                       // decorations

  ASSERT_TRUE(gen.EmitProgramConstVariable(out, var)) << gen.error();
  EXPECT_EQ(result(), "static const float pos[3] = {1.0f, 2.0f, 3.0f};\n");
}

TEST_F(HlslGeneratorImplTest_ModuleConstant, Emit_SpecConstant) {
  ast::type::F32 f32;

  auto* var = create<ast::Variable>(
      Source{},                  // source
      "pos",                     // name
      ast::StorageClass::kNone,  // storage_class
      &f32,                      // type
      true,                      // is_const
      create<ast::ScalarConstructorExpression>(
          create<ast::FloatLiteral>(&f32, 3.0f)),  // constructor
      ast::VariableDecorationList{
          // decorations
          create<ast::ConstantIdDecoration>(23, Source{}),
      });

  ASSERT_TRUE(gen.EmitProgramConstVariable(out, var)) << gen.error();
  EXPECT_EQ(result(), R"(#ifndef WGSL_SPEC_CONSTANT_23
#define WGSL_SPEC_CONSTANT_23 3.0f
#endif
static const float pos = WGSL_SPEC_CONSTANT_23;
#undef WGSL_SPEC_CONSTANT_23
)");
}

TEST_F(HlslGeneratorImplTest_ModuleConstant, Emit_SpecConstant_NoConstructor) {
  ast::type::F32 f32;

  auto* var =
      create<ast::Variable>(Source{},                  // source
                            "pos",                     // name
                            ast::StorageClass::kNone,  // storage_class
                            &f32,                      // type
                            true,                      // is_const
                            nullptr,                   // constructor
                            ast::VariableDecorationList{
                                // decorations
                                create<ast::ConstantIdDecoration>(23, Source{}),
                            });

  ASSERT_TRUE(gen.EmitProgramConstVariable(out, var)) << gen.error();
  EXPECT_EQ(result(), R"(#ifndef WGSL_SPEC_CONSTANT_23
#error spec constant required for constant id 23
#endif
static const float pos = WGSL_SPEC_CONSTANT_23;
#undef WGSL_SPEC_CONSTANT_23
)");
}

}  // namespace
}  // namespace hlsl
}  // namespace writer
}  // namespace tint