// 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/float_literal.h"
#include "src/ast/module.h"
#include "src/ast/scalar_constructor_expression.h"
#include "src/ast/sint_literal.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/u32_type.h"
#include "src/ast/type/vector_type.h"
#include "src/ast/type_constructor_expression.h"
#include "src/ast/uint_literal.h"
#include "src/writer/msl/generator_impl.h"

namespace tint {
namespace writer {
namespace msl {
namespace {

using MslGeneratorImplTest = testing::Test;

TEST_F(MslGeneratorImplTest, EmitConstructor_Bool) {
  ast::type::BoolType bool_type;
  auto lit = std::make_unique<ast::BoolLiteral>(&bool_type, false);
  ast::ScalarConstructorExpression expr(std::move(lit));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "false");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Int) {
  ast::type::I32Type i32;
  auto lit = std::make_unique<ast::SintLiteral>(&i32, -12345);
  ast::ScalarConstructorExpression expr(std::move(lit));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "-12345");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_UInt) {
  ast::type::U32Type u32;
  auto lit = std::make_unique<ast::UintLiteral>(&u32, 56779);
  ast::ScalarConstructorExpression expr(std::move(lit));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "56779u");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Float) {
  ast::type::F32Type f32;
  // Use a number close to 1<<30 but whose decimal representation ends in 0.
  auto lit = std::make_unique<ast::FloatLiteral>(&f32, float((1 << 30) - 4));
  ast::ScalarConstructorExpression expr(std::move(lit));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "1.07374182e+09f");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Float) {
  ast::type::F32Type f32;

  auto lit = std::make_unique<ast::FloatLiteral>(&f32, -1.2e-5);
  ast::ExpressionList values;
  values.push_back(
      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));

  ast::TypeConstructorExpression expr(&f32, std::move(values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "float(-1.20000004e-05f)");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Bool) {
  ast::type::BoolType b;

  auto lit = std::make_unique<ast::BoolLiteral>(&b, true);
  ast::ExpressionList values;
  values.push_back(
      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));

  ast::TypeConstructorExpression expr(&b, std::move(values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "bool(true)");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Int) {
  ast::type::I32Type i32;

  auto lit = std::make_unique<ast::SintLiteral>(&i32, -12345);
  ast::ExpressionList values;
  values.push_back(
      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));

  ast::TypeConstructorExpression expr(&i32, std::move(values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "int(-12345)");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Uint) {
  ast::type::U32Type u32;

  auto lit = std::make_unique<ast::UintLiteral>(&u32, 12345);
  ast::ExpressionList values;
  values.push_back(
      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit)));

  ast::TypeConstructorExpression expr(&u32, std::move(values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "uint(12345u)");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Vec) {
  ast::type::F32Type f32;
  ast::type::VectorType vec(&f32, 3);

  auto lit1 = std::make_unique<ast::FloatLiteral>(&f32, 1.f);
  auto lit2 = std::make_unique<ast::FloatLiteral>(&f32, 2.f);
  auto lit3 = std::make_unique<ast::FloatLiteral>(&f32, 3.f);
  ast::ExpressionList values;
  values.push_back(
      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit1)));
  values.push_back(
      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit2)));
  values.push_back(
      std::make_unique<ast::ScalarConstructorExpression>(std::move(lit3)));

  ast::TypeConstructorExpression expr(&vec, std::move(values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "float3(1.00000000f, 2.00000000f, 3.00000000f)");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Vec_Empty) {
  ast::type::F32Type f32;
  ast::type::VectorType vec(&f32, 3);

  ast::ExpressionList values;
  ast::TypeConstructorExpression expr(&vec, std::move(values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), "float3(0.0f)");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Mat) {
  ast::type::F32Type f32;
  ast::type::MatrixType mat(&f32, 3, 2);  // 3 ROWS, 2 COLUMNS
  ast::type::VectorType vec(&f32, 3);

  // WGSL matrix is mat2x3 (it flips for AST, sigh). With a type constructor
  // of <vec3, vec3>

  ast::ExpressionList mat_values;

  for (size_t i = 0; i < 2; i++) {
    auto lit1 = std::make_unique<ast::FloatLiteral>(
        &f32, static_cast<float>(1 + (i * 2)));
    auto lit2 = std::make_unique<ast::FloatLiteral>(
        &f32, static_cast<float>(2 + (i * 2)));
    auto lit3 = std::make_unique<ast::FloatLiteral>(
        &f32, static_cast<float>(3 + (i * 2)));

    ast::ExpressionList values;
    values.push_back(
        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit1)));
    values.push_back(
        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit2)));
    values.push_back(
        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit3)));

    mat_values.push_back(std::make_unique<ast::TypeConstructorExpression>(
        &vec, std::move(values)));
  }

  ast::TypeConstructorExpression expr(&mat, std::move(mat_values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();

  // A matrix of type T with n columns and m rows can also be constructed from
  // n vectors of type T with m components.
  EXPECT_EQ(
      g.result(),
      std::string("float2x3(float3(1.00000000f, 2.00000000f, 3.00000000f), ") +
          "float3(3.00000000f, 4.00000000f, 5.00000000f))");
}

TEST_F(MslGeneratorImplTest, EmitConstructor_Type_Array) {
  ast::type::F32Type f32;
  ast::type::VectorType vec(&f32, 3);
  ast::type::ArrayType ary(&vec, 3);

  ast::ExpressionList ary_values;

  for (size_t i = 0; i < 3; i++) {
    auto lit1 = std::make_unique<ast::FloatLiteral>(
        &f32, static_cast<float>(1 + (i * 3)));
    auto lit2 = std::make_unique<ast::FloatLiteral>(
        &f32, static_cast<float>(2 + (i * 3)));
    auto lit3 = std::make_unique<ast::FloatLiteral>(
        &f32, static_cast<float>(3 + (i * 3)));

    ast::ExpressionList values;
    values.push_back(
        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit1)));
    values.push_back(
        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit2)));
    values.push_back(
        std::make_unique<ast::ScalarConstructorExpression>(std::move(lit3)));

    ary_values.push_back(std::make_unique<ast::TypeConstructorExpression>(
        &vec, std::move(values)));
  }

  ast::TypeConstructorExpression expr(&ary, std::move(ary_values));

  ast::Module m;
  GeneratorImpl g(&m);
  ASSERT_TRUE(g.EmitConstructor(&expr)) << g.error();
  EXPECT_EQ(g.result(), std::string("{") +
                            "float3(1.00000000f, 2.00000000f, 3.00000000f), " +
                            "float3(4.00000000f, 5.00000000f, 6.00000000f), " +
                            "float3(7.00000000f, 8.00000000f, 9.00000000f)}");
}

// TODO(dsinclair): Add struct constructor test.
TEST_F(MslGeneratorImplTest, DISABLED_EmitConstructor_Type_Struct) {}

}  // namespace
}  // namespace msl
}  // namespace writer
}  // namespace tint