// 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 "gtest/gtest.h"
#include "src/ast/assignment_statement.h"
#include "src/ast/block_statement.h"
#include "src/ast/float_literal.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/scalar_constructor_expression.h"
#include "src/ast/type/f32_type.h"
#include "src/ast/variable_decl_statement.h"
#include "src/context.h"
#include "src/type_determiner.h"
#include "src/writer/spirv/builder.h"
#include "src/writer/spirv/spv_dump.h"

namespace tint {
namespace writer {
namespace spirv {
namespace {

using BuilderTest = testing::Test;

TEST_F(BuilderTest, Block) {
  ast::type::F32Type f32;

  // Note, this test uses shadow variables which aren't allowed in WGSL but
  // serves to prove the block code is pushing new scopes as needed.
  ast::BlockStatement outer;

  outer.append(std::make_unique<ast::VariableDeclStatement>(
      std::make_unique<ast::Variable>("var", ast::StorageClass::kFunction,
                                      &f32)));
  outer.append(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("var"),
      std::make_unique<ast::ScalarConstructorExpression>(
          std::make_unique<ast::FloatLiteral>(&f32, 1.0f))));

  auto inner = std::make_unique<ast::BlockStatement>();
  inner->append(std::make_unique<ast::VariableDeclStatement>(
      std::make_unique<ast::Variable>("var", ast::StorageClass::kFunction,
                                      &f32)));
  inner->append(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("var"),
      std::make_unique<ast::ScalarConstructorExpression>(
          std::make_unique<ast::FloatLiteral>(&f32, 2.0f))));

  outer.append(std::move(inner));
  outer.append(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("var"),
      std::make_unique<ast::ScalarConstructorExpression>(
          std::make_unique<ast::FloatLiteral>(&f32, 3.0f))));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  ASSERT_TRUE(td.DetermineResultType(&outer)) << td.error();

  Builder b(&mod);
  b.push_function(Function{});
  ASSERT_FALSE(b.has_error()) << b.error();

  EXPECT_TRUE(b.GenerateStatement(&outer)) << b.error();
  EXPECT_FALSE(b.has_error());

  EXPECT_EQ(DumpInstructions(b.types()), R"(%3 = OpTypeFloat 32
%2 = OpTypePointer Function %3
%4 = OpConstantNull %3
%5 = OpConstant %3 1
%7 = OpConstant %3 2
%8 = OpConstant %3 3
)");

  EXPECT_EQ(DumpInstructions(b.functions()[0].variables()),
            R"(%1 = OpVariable %2 Function %4
%6 = OpVariable %2 Function %4
)");

  EXPECT_EQ(DumpInstructions(b.functions()[0].instructions()), R"(OpStore %1 %5
OpStore %6 %7
OpStore %1 %8
)");
}

}  // namespace
}  // namespace spirv
}  // namespace writer
}  // namespace tint