// 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 "gtest/gtest.h"
#include "src/ast/bool_literal.h"
#include "src/ast/const_initializer_expression.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/relational_expression.h"
#include "src/reader/wgsl/parser_impl.h"

namespace tint {
namespace reader {
namespace wgsl {

using ParserImplTest = testing::Test;

TEST_F(ParserImplTest, ShiftExpression_Parses_ShiftLeft) {
  ParserImpl p{"a << true"};
  auto e = p.shift_expression();
  ASSERT_FALSE(p.has_error()) << p.error();
  ASSERT_NE(e, nullptr);

  ASSERT_TRUE(e->IsRelational());
  auto rel = e->AsRelational();
  EXPECT_EQ(ast::Relation::kShiftLeft, rel->relation());

  ASSERT_TRUE(rel->lhs()->IsIdentifier());
  auto ident = rel->lhs()->AsIdentifier();
  ASSERT_EQ(ident->name().size(), 1);
  EXPECT_EQ(ident->name()[0], "a");

  ASSERT_TRUE(rel->rhs()->IsInitializer());
  ASSERT_TRUE(rel->rhs()->AsInitializer()->IsConstInitializer());
  auto init = rel->rhs()->AsInitializer()->AsConstInitializer();
  ASSERT_TRUE(init->literal()->IsBool());
  ASSERT_TRUE(init->literal()->AsBool()->IsTrue());
}

TEST_F(ParserImplTest, ShiftExpression_Parses_ShiftRight) {
  ParserImpl p{"a >> true"};
  auto e = p.shift_expression();
  ASSERT_FALSE(p.has_error()) << p.error();
  ASSERT_NE(e, nullptr);

  ASSERT_TRUE(e->IsRelational());
  auto rel = e->AsRelational();
  EXPECT_EQ(ast::Relation::kShiftRight, rel->relation());

  ASSERT_TRUE(rel->lhs()->IsIdentifier());
  auto ident = rel->lhs()->AsIdentifier();
  ASSERT_EQ(ident->name().size(), 1);
  EXPECT_EQ(ident->name()[0], "a");

  ASSERT_TRUE(rel->rhs()->IsInitializer());
  ASSERT_TRUE(rel->rhs()->AsInitializer()->IsConstInitializer());
  auto init = rel->rhs()->AsInitializer()->AsConstInitializer();
  ASSERT_TRUE(init->literal()->IsBool());
  ASSERT_TRUE(init->literal()->AsBool()->IsTrue());
}

TEST_F(ParserImplTest, ShiftExpression_Parses_ShiftRightArith) {
  ParserImpl p{"a >>> true"};
  auto e = p.shift_expression();
  ASSERT_FALSE(p.has_error()) << p.error();
  ASSERT_NE(e, nullptr);

  ASSERT_TRUE(e->IsRelational());
  auto rel = e->AsRelational();
  EXPECT_EQ(ast::Relation::kShiftRightArith, rel->relation());

  ASSERT_TRUE(rel->lhs()->IsIdentifier());
  auto ident = rel->lhs()->AsIdentifier();
  ASSERT_EQ(ident->name().size(), 1);
  EXPECT_EQ(ident->name()[0], "a");

  ASSERT_TRUE(rel->rhs()->IsInitializer());
  ASSERT_TRUE(rel->rhs()->AsInitializer()->IsConstInitializer());
  auto init = rel->rhs()->AsInitializer()->AsConstInitializer();
  ASSERT_TRUE(init->literal()->IsBool());
  ASSERT_TRUE(init->literal()->AsBool()->IsTrue());
}

TEST_F(ParserImplTest, ShiftExpression_InvalidLHS) {
  ParserImpl p{"if (a) {} << true"};
  auto e = p.shift_expression();
  ASSERT_FALSE(p.has_error()) << p.error();
  ASSERT_EQ(e, nullptr);
}

TEST_F(ParserImplTest, ShiftExpression_InvalidRHS) {
  ParserImpl p{"true << if (a) {}"};
  auto e = p.shift_expression();
  ASSERT_TRUE(p.has_error());
  ASSERT_EQ(e, nullptr);
  EXPECT_EQ(p.error(), "1:9: unable to parse right side of << expression");
}

TEST_F(ParserImplTest, ShiftExpression_NoOr_ReturnsLHS) {
  ParserImpl p{"a true"};
  auto e = p.shift_expression();
  ASSERT_FALSE(p.has_error()) << p.error();
  ASSERT_NE(e, nullptr);
  ASSERT_TRUE(e->IsIdentifier());
}

}  // namespace wgsl
}  // namespace reader
}  // namespace tint