// 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 "src/validator_impl.h"

#include "gtest/gtest.h"
#include "spirv/unified1/GLSL.std.450.h"
#include "src/ast/array_accessor_expression.h"
#include "src/ast/as_expression.h"
#include "src/ast/assignment_statement.h"
#include "src/ast/binary_expression.h"
#include "src/ast/bool_literal.h"
#include "src/ast/break_statement.h"
#include "src/ast/call_expression.h"
#include "src/ast/case_statement.h"
#include "src/ast/cast_expression.h"
#include "src/ast/continue_statement.h"
#include "src/ast/else_statement.h"
#include "src/ast/float_literal.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/if_statement.h"
#include "src/ast/int_literal.h"
#include "src/ast/loop_statement.h"
#include "src/ast/member_accessor_expression.h"
#include "src/ast/return_statement.h"
#include "src/ast/scalar_constructor_expression.h"
#include "src/ast/sint_literal.h"
#include "src/ast/struct.h"
#include "src/ast/struct_member.h"
#include "src/ast/switch_statement.h"
#include "src/ast/type/alias_type.h"
#include "src/ast/type/array_type.h"
#include "src/ast/type/bool_type.h"
#include "src/ast/type/f32_type.h"
#include "src/ast/type/i32_type.h"
#include "src/ast/type/matrix_type.h"
#include "src/ast/type/pointer_type.h"
#include "src/ast/type/struct_type.h"
#include "src/ast/type/vector_type.h"
#include "src/ast/type_constructor_expression.h"
#include "src/ast/variable.h"
#include "src/ast/variable_decl_statement.h"
#include "src/type_determiner.h"

namespace tint {
namespace {

class TypeDeterminerHelper {
 public:
  TypeDeterminerHelper()
      : td_(std::make_unique<TypeDeterminer>(&ctx_, &mod_)) {}

  TypeDeterminer* td() const { return td_.get(); }
  ast::Module* mod() { return &mod_; }

 private:
  Context ctx_;
  ast::Module mod_;
  std::unique_ptr<TypeDeterminer> td_;
};

class ValidatorTest : public TypeDeterminerHelper, public testing::Test {};

TEST_F(ValidatorTest, Import) {
  ast::Module m;
  m.AddImport(std::make_unique<ast::Import>("GLSL.std.450", "glsl"));

  tint::ValidatorImpl v;
  EXPECT_TRUE(v.CheckImports(&m));
}

TEST_F(ValidatorTest, Import_Fail_NotGLSL) {
  ast::Module m;
  m.AddImport(
      std::make_unique<ast::Import>(Source{12, 34}, "not.GLSL", "glsl"));

  tint::ValidatorImpl v;
  EXPECT_FALSE(v.CheckImports(&m));
  ASSERT_TRUE(v.has_error());
  EXPECT_EQ(v.error(), "12:34: v-0001: unknown import: not.GLSL");
}

TEST_F(ValidatorTest, Import_Fail_Typo) {
  ast::Module m;
  m.AddImport(
      std::make_unique<ast::Import>(Source{12, 34}, "GLSL.std.4501", "glsl"));

  tint::ValidatorImpl v;
  EXPECT_FALSE(v.CheckImports(&m));
  ASSERT_TRUE(v.has_error());
  EXPECT_EQ(v.error(), "12:34: v-0001: unknown import: GLSL.std.4501");
}

TEST_F(ValidatorTest, DISABLED_AssignToScalar_Fail) {
  // 1 = my_var;
  ast::type::I32Type i32;

  auto lhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 1));
  auto rhs = std::make_unique<ast::IdentifierExpression>("my_var");
  ast::AssignmentStatement assign(Source{12, 34}, std::move(lhs),
                                  std::move(rhs));

  tint::ValidatorImpl v;
  // TODO(sarahM0): Invalidate assignment to scalar.
  ASSERT_TRUE(v.has_error());
  // TODO(sarahM0): figure out what should be the error number.
  EXPECT_EQ(v.error(), "12:34: v-000x: invalid assignment");
}

TEST_F(ValidatorTest, UsingUndefinedVariable_Fail) {
  // b = 2;
  ast::type::I32Type i32;

  auto lhs = std::make_unique<ast::IdentifierExpression>(Source{12, 34}, "b");
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2));
  auto assign = std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs));

  EXPECT_TRUE(td()->DetermineResultType(assign.get())) << td()->error();
  tint::ValidatorImpl v;
  EXPECT_FALSE(v.ValidateStatement(assign.get()));
  EXPECT_EQ(v.error(), "12:34: v-0006: 'b' is not declared");
}

TEST_F(ValidatorTest, UsingUndefinedVariableInBlockStatement_Fail) {
  // {
  //  b = 2;
  // }
  ast::type::I32Type i32;

  auto lhs = std::make_unique<ast::IdentifierExpression>(Source{12, 34}, "b");
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2));

  auto body = std::make_unique<ast::BlockStatement>();
  body->append(std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs)));

  EXPECT_TRUE(td()->DetermineStatements(body.get())) << td()->error();
  tint::ValidatorImpl v;
  EXPECT_FALSE(v.ValidateStatements(body.get()));
  EXPECT_EQ(v.error(), "12:34: v-0006: 'b' is not declared");
}

TEST_F(ValidatorTest, AssignCompatibleTypes_Pass) {
  // var a :i32 = 2;
  // a = 2
  ast::type::I32Type i32;
  auto var =
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &i32);
  var->set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2)));

  auto lhs = std::make_unique<ast::IdentifierExpression>("a");
  auto* lhs_ptr = lhs.get();
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2));
  auto* rhs_ptr = rhs.get();

  ast::AssignmentStatement assign(Source{12, 34}, std::move(lhs),
                                  std::move(rhs));
  td()->RegisterVariableForTesting(var.get());
  EXPECT_TRUE(td()->DetermineResultType(&assign)) << td()->error();
  ASSERT_NE(lhs_ptr->result_type(), nullptr);
  ASSERT_NE(rhs_ptr->result_type(), nullptr);
  tint::ValidatorImpl v;
  EXPECT_TRUE(v.ValidateResultTypes(&assign));
}

TEST_F(ValidatorTest, AssignIncompatibleTypes_Fail) {
  // {
  //  var a :i32 = 2;
  //  a = 2.3;
  // }
  ast::type::F32Type f32;
  ast::type::I32Type i32;

  auto var =
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &i32);
  var->set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2)));
  auto lhs = std::make_unique<ast::IdentifierExpression>("a");
  auto* lhs_ptr = lhs.get();
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 2.3f));
  auto* rhs_ptr = rhs.get();

  ast::AssignmentStatement assign(Source{12, 34}, std::move(lhs),
                                  std::move(rhs));
  td()->RegisterVariableForTesting(var.get());
  EXPECT_TRUE(td()->DetermineResultType(&assign)) << td()->error();
  ASSERT_NE(lhs_ptr->result_type(), nullptr);
  ASSERT_NE(rhs_ptr->result_type(), nullptr);

  tint::ValidatorImpl v;
  EXPECT_FALSE(v.ValidateResultTypes(&assign));
  ASSERT_TRUE(v.has_error());
  // TODO(sarahM0): figure out what should be the error number.
  EXPECT_EQ(v.error(),
            "12:34: v-000x: invalid assignment of '__i32' to '__f32'");
}

TEST_F(ValidatorTest, AssignCompatibleTypesInBlockStatement_Pass) {
  // {
  //  var a :i32 = 2;
  //  a = 2
  // }
  ast::type::I32Type i32;
  auto var =
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &i32);
  var->set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2)));

  auto lhs = std::make_unique<ast::IdentifierExpression>("a");
  auto* lhs_ptr = lhs.get();
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2));
  auto* rhs_ptr = rhs.get();

  auto body = std::make_unique<ast::BlockStatement>();
  body->append(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
  body->append(std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs)));

  EXPECT_TRUE(td()->DetermineStatements(body.get())) << td()->error();
  ASSERT_NE(lhs_ptr->result_type(), nullptr);
  ASSERT_NE(rhs_ptr->result_type(), nullptr);

  tint::ValidatorImpl v;
  EXPECT_TRUE(v.ValidateStatements(body.get()));
}

TEST_F(ValidatorTest, AssignIncompatibleTypesInBlockStatement_Fail) {
  // {
  //  var a :i32 = 2;
  //  a = 2.3;
  // }
  ast::type::F32Type f32;
  ast::type::I32Type i32;

  auto var =
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &i32);
  var->set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2)));
  auto lhs = std::make_unique<ast::IdentifierExpression>("a");
  auto* lhs_ptr = lhs.get();
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 2.3f));
  auto* rhs_ptr = rhs.get();

  ast::BlockStatement block;
  block.append(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
  block.append(std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs)));

  EXPECT_TRUE(td()->DetermineStatements(&block)) << td()->error();
  ASSERT_NE(lhs_ptr->result_type(), nullptr);
  ASSERT_NE(rhs_ptr->result_type(), nullptr);

  tint::ValidatorImpl v;
  EXPECT_FALSE(v.ValidateStatements(&block));
  ASSERT_TRUE(v.has_error());
  // TODO(sarahM0): figure out what should be the error number.
  EXPECT_EQ(v.error(),
            "12:34: v-000x: invalid assignment of '__i32' to '__f32'");
}

TEST_F(ValidatorTest, UnsingUndefinedVariableGlobalVariable_Fail) {
  ast::type::F32Type f32;
  auto global_var = std::make_unique<ast::Variable>(
      "global_var", ast::StorageClass::kPrivate, &f32);
  global_var->set_constructor(
      std::make_unique<ast::ScalarConstructorExpression>(
          std::make_unique<ast::FloatLiteral>(&f32, 2.1)));
  mod()->AddGlobalVariable(std::move(global_var));

  auto lhs = std::make_unique<ast::IdentifierExpression>(Source{12, 34},
                                                         "not_global_var");
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 3.14f));

  ast::VariableList params;
  auto func =
      std::make_unique<ast::Function>("my_func", std::move(params), &f32);

  auto body = std::make_unique<ast::BlockStatement>();
  body->append(std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs)));
  func->set_body(std::move(body));
  mod()->AddFunction(std::move(func));

  tint::ValidatorImpl v;
  EXPECT_FALSE(v.Validate(mod()));
  EXPECT_EQ(v.error(), "12:34: v-0006: 'not_global_var' is not declared");
}

TEST_F(ValidatorTest, UnsingUndefinedVariableGlobalVariable_Pass) {
  ast::type::F32Type f32;
  auto global_var = std::make_unique<ast::Variable>(
      "global_var", ast::StorageClass::kPrivate, &f32);
  global_var->set_constructor(
      std::make_unique<ast::ScalarConstructorExpression>(
          std::make_unique<ast::FloatLiteral>(&f32, 2.1)));
  mod()->AddGlobalVariable(std::move(global_var));

  auto lhs = std::make_unique<ast::IdentifierExpression>("global_var");
  auto* lhs_ptr = lhs.get();
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 3.14f));
  auto* rhs_ptr = rhs.get();

  ast::VariableList params;
  auto func =
      std::make_unique<ast::Function>("my_func", std::move(params), &f32);

  auto body = std::make_unique<ast::BlockStatement>();
  body->append(std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs)));
  func->set_body(std::move(body));
  auto* func_ptr = func.get();
  mod()->AddFunction(std::move(func));

  EXPECT_TRUE(td()->Determine()) << td()->error();
  EXPECT_TRUE(td()->DetermineFunction(func_ptr)) << td()->error();
  tint::ValidatorImpl v;
  ASSERT_NE(lhs_ptr->result_type(), nullptr);
  ASSERT_NE(rhs_ptr->result_type(), nullptr);
  EXPECT_TRUE(v.Validate(mod())) << v.error();
}

TEST_F(ValidatorTest, UnsingUndefinedVariableInnerScope_Fail) {
  // {
  // if (true) { var a : f32 = 2.0; }
  // a = 3.14;
  // }
  ast::type::F32Type f32;
  auto var =
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &f32);
  var->set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 2.0)));

  ast::type::BoolType bool_type;
  auto cond = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::BoolLiteral>(&bool_type, true));
  auto body = std::make_unique<ast::BlockStatement>();
  body->append(std::make_unique<ast::VariableDeclStatement>(std::move(var)));

  auto lhs = std::make_unique<ast::IdentifierExpression>(Source{12, 34}, "a");
  auto* lhs_ptr = lhs.get();
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 3.14f));
  auto* rhs_ptr = rhs.get();

  auto outer_body = std::make_unique<ast::BlockStatement>();
  outer_body->append(
      std::make_unique<ast::IfStatement>(std::move(cond), std::move(body)));
  outer_body->append(std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs)));

  EXPECT_TRUE(td()->DetermineStatements(outer_body.get())) << td()->error();
  tint::ValidatorImpl v;
  ASSERT_NE(lhs_ptr->result_type(), nullptr);
  ASSERT_NE(rhs_ptr->result_type(), nullptr);
  EXPECT_FALSE(v.ValidateStatements(outer_body.get()));
  EXPECT_EQ(v.error(), "12:34: v-0006: 'a' is not declared");
}

TEST_F(ValidatorTest, UnsingUndefinedVariableOuterScope_Pass) {
  // {
  // var a : f32 = 2.0;
  // if (true) { a = 3.14; }
  // }
  ast::type::F32Type f32;
  auto var =
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &f32);
  var->set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 2.0)));

  auto lhs = std::make_unique<ast::IdentifierExpression>(Source{12, 34}, "a");
  auto* lhs_ptr = lhs.get();
  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 3.14f));
  auto* rhs_ptr = rhs.get();
  ast::type::BoolType bool_type;
  auto cond = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::BoolLiteral>(&bool_type, true));
  auto body = std::make_unique<ast::BlockStatement>();
  body->append(std::make_unique<ast::AssignmentStatement>(
      Source{12, 34}, std::move(lhs), std::move(rhs)));

  auto outer_body = std::make_unique<ast::BlockStatement>();
  outer_body->append(
      std::make_unique<ast::VariableDeclStatement>(std::move(var)));
  outer_body->append(
      std::make_unique<ast::IfStatement>(std::move(cond), std::move(body)));
  EXPECT_TRUE(td()->DetermineStatements(outer_body.get())) << td()->error();
  tint::ValidatorImpl v;
  ASSERT_NE(lhs_ptr->result_type(), nullptr);
  ASSERT_NE(rhs_ptr->result_type(), nullptr);
  EXPECT_TRUE(v.ValidateStatements(outer_body.get())) << v.error();
}

TEST_F(ValidatorTest, DISABLED_AssignToConstant_Fail) {
  // v-0021: Cannot re-assign a constant.
  // const a :i32 = 1;
  // a = 2;
  ast::type::I32Type i32;

  ast::Variable var("a", ast::StorageClass::kPrivate, &i32);
  var.set_constructor(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 1)));
  var.set_is_const(true);
  auto lhs = std::make_unique<ast::IdentifierExpression>("a");

  auto rhs = std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::SintLiteral>(&i32, 2));

  ast::AssignmentStatement assign(std::move(lhs), std::move(rhs));

  tint::ValidatorImpl v;
  // TODO(SarahM0): Invalidate assignments to a constant.
  ASSERT_TRUE(v.has_error());
  EXPECT_EQ(v.error(), "2:1: v-0021: cannot re-assign a constant");
}

}  // namespace
}  // namespace tint