// 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/type_determiner.h"
#include "src/writer/spirv/builder.h"
#include "src/writer/spirv/spv_dump.h"
#include "src/writer/spirv/test_helper.h"

namespace tint {
namespace writer {
namespace spirv {
namespace {

using BuilderTest = TestHelper;

TEST_F(BuilderTest, Block) {
  ast::type::F32 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(Source{});

  outer.append(create<ast::VariableDeclStatement>(
      Source{},
      create<ast::Variable>(Source{},                          // source
                            "var",                             // name
                            ast::StorageClass::kFunction,      // storage_class
                            &f32,                              // type
                            false,                             // is_const
                            nullptr,                           // constructor
                            ast::VariableDecorationList{})));  // decorations
  outer.append(create<ast::AssignmentStatement>(
      Source{},
      create<ast::IdentifierExpression>(Source{}, mod->RegisterSymbol("var"),
                                        "var"),
      create<ast::ScalarConstructorExpression>(
          Source{}, create<ast::FloatLiteral>(Source{}, &f32, 1.0f))));

  auto* inner = create<ast::BlockStatement>(Source{});
  inner->append(create<ast::VariableDeclStatement>(
      Source{},
      create<ast::Variable>(Source{},                          // source
                            "var",                             // name
                            ast::StorageClass::kFunction,      // storage_class
                            &f32,                              // type
                            false,                             // is_const
                            nullptr,                           // constructor
                            ast::VariableDecorationList{})));  // decorations
  inner->append(create<ast::AssignmentStatement>(
      Source{},
      create<ast::IdentifierExpression>(Source{}, mod->RegisterSymbol("var"),
                                        "var"),
      create<ast::ScalarConstructorExpression>(
          Source{}, create<ast::FloatLiteral>(Source{}, &f32, 2.0f))));

  outer.append(inner);
  outer.append(create<ast::AssignmentStatement>(
      Source{},
      create<ast::IdentifierExpression>(Source{}, mod->RegisterSymbol("var"),
                                        "var"),
      create<ast::ScalarConstructorExpression>(
          Source{}, create<ast::FloatLiteral>(Source{}, &f32, 3.0f))));

  ASSERT_TRUE(td.DetermineResultType(&outer)) << td.error();

  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