// Copyright 2021 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/resolver/resolver_test_helper.h"

namespace tint {
namespace resolver {
namespace {

/// @return the element type of `type` for vec and mat, otherwise `type` itself
type::Type* ElementTypeOf(type::Type* type) {
  if (auto* v = type->As<type::Vector>()) {
    return v->type();
  }
  if (auto* m = type->As<type::Matrix>()) {
    return m->type();
  }
  return type;
}

class ResolverTypeConstructorValidationTest : public resolver::TestHelper,
                                              public testing::Test {};

namespace InferTypeTest {
struct Params {
  create_type_func_ptr create_rhs_type;
};

// Helpers and typedefs
using i32 = ProgramBuilder::i32;
using u32 = ProgramBuilder::u32;
using f32 = ProgramBuilder::f32;

TEST_F(ResolverTypeConstructorValidationTest, InferTypeTest_Simple) {
  // var a = 1;
  // var b = a;
  auto sc = ast::StorageClass::kFunction;
  auto* a = Var("a", nullptr, sc, Expr(1));
  auto* b = Var("b", nullptr, sc, Expr("a"));
  auto* a_ident = Expr("a");
  auto* b_ident = Expr("b");

  WrapInFunction(Decl(a), Decl(b), Assign(a_ident, a_ident),
                 Assign(b_ident, b_ident));

  ASSERT_TRUE(r()->Resolve()) << r()->error();
  ASSERT_EQ(TypeOf(a_ident), ty.pointer(ty.i32(), sc));
  ASSERT_EQ(TypeOf(b_ident), ty.pointer(ty.i32(), sc));
}

using InferTypeTest_FromConstructorExpression = ResolverTestWithParam<Params>;
TEST_P(InferTypeTest_FromConstructorExpression, All) {
  // e.g. for vec3<f32>
  // {
  //   var a = vec3<f32>(0.0, 0.0, 0.0)
  // }
  auto& params = GetParam();

  auto* rhs_type = params.create_rhs_type(ty);
  auto* constructor_expr = ConstructValueFilledWith(rhs_type, 0);

  auto sc = ast::StorageClass::kFunction;
  auto* a = Var("a", nullptr, sc, constructor_expr);
  // Self-assign 'a' to force the expression to be resolved so we can test its
  // type below
  auto* a_ident = Expr("a");
  WrapInFunction(Decl(a), Assign(a_ident, a_ident));

  ASSERT_TRUE(r()->Resolve()) << r()->error();
  ASSERT_EQ(TypeOf(a_ident), ty.pointer(rhs_type, sc));
}

static constexpr Params from_constructor_expression_cases[] = {
    Params{ty_bool_},
    Params{ty_i32},
    Params{ty_u32},
    Params{ty_f32},
    Params{ty_vec3<i32>},
    Params{ty_vec3<u32>},
    Params{ty_vec3<f32>},
    Params{ty_mat3x3<i32>},
    Params{ty_mat3x3<u32>},
    Params{ty_mat3x3<f32>},
    Params{ty_alias<ty_bool_>},
    Params{ty_alias<ty_i32>},
    Params{ty_alias<ty_u32>},
    Params{ty_alias<ty_f32>},
    Params{ty_alias<ty_vec3<i32>>},
    Params{ty_alias<ty_vec3<u32>>},
    Params{ty_alias<ty_vec3<f32>>},
    Params{ty_alias<ty_mat3x3<i32>>},
    Params{ty_alias<ty_mat3x3<u32>>},
    Params{ty_alias<ty_mat3x3<f32>>},
};
INSTANTIATE_TEST_SUITE_P(ResolverTypeConstructorValidationTest,
                         InferTypeTest_FromConstructorExpression,
                         testing::ValuesIn(from_constructor_expression_cases));

using InferTypeTest_FromArithmeticExpression = ResolverTestWithParam<Params>;
TEST_P(InferTypeTest_FromArithmeticExpression, All) {
  // e.g. for vec3<f32>
  // {
  //   var a = vec3<f32>(2.0, 2.0, 2.0) * 3.0;
  // }
  auto& params = GetParam();

  auto* rhs_type = params.create_rhs_type(ty);

  auto* arith_lhs_expr = ConstructValueFilledWith(rhs_type, 2);
  auto* arith_rhs_expr = ConstructValueFilledWith(ElementTypeOf(rhs_type), 3);
  auto* constructor_expr = Mul(arith_lhs_expr, arith_rhs_expr);

  auto sc = ast::StorageClass::kFunction;
  auto* a = Var("a", nullptr, sc, constructor_expr);
  // Self-assign 'a' to force the expression to be resolved so we can test its
  // type below
  auto* a_ident = Expr("a");
  WrapInFunction(Decl(a), Assign(a_ident, a_ident));

  ASSERT_TRUE(r()->Resolve()) << r()->error();
  ASSERT_EQ(TypeOf(a_ident), ty.pointer(rhs_type, sc));
}
static constexpr Params from_arithmetic_expression_cases[] = {
    Params{ty_i32},       Params{ty_u32},         Params{ty_f32},
    Params{ty_vec3<f32>}, Params{ty_mat3x3<f32>},

    // TODO(amaiorano): Uncomment once https://crbug.com/tint/680 is fixed
    // Params{ty_alias<ty_i32>},
    // Params{ty_alias<ty_u32>},
    // Params{ty_alias<ty_f32>},
    // Params{ty_alias<ty_vec3<f32>>},
    // Params{ty_alias<ty_mat3x3<f32>>},
};
INSTANTIATE_TEST_SUITE_P(ResolverTypeConstructorValidationTest,
                         InferTypeTest_FromArithmeticExpression,
                         testing::ValuesIn(from_arithmetic_expression_cases));

using InferTypeTest_FromCallExpression = ResolverTestWithParam<Params>;
TEST_P(InferTypeTest_FromCallExpression, All) {
  // e.g. for vec3<f32>
  //
  // fn foo() -> vec3<f32> {
  //   return vec3<f32>(0.0, 0.0, 0.0);
  // }
  //
  // fn bar() -> void
  // {
  //   var a = foo();
  // }
  auto& params = GetParam();

  auto* rhs_type = params.create_rhs_type(ty);

  Func("foo", {}, rhs_type, {Return(ConstructValueFilledWith(rhs_type, 0))},
       {});
  auto* constructor_expr = Call(Expr("foo"));

  auto sc = ast::StorageClass::kFunction;
  auto* a = Var("a", nullptr, sc, constructor_expr);
  // Self-assign 'a' to force the expression to be resolved so we can test its
  // type below
  auto* a_ident = Expr("a");
  WrapInFunction(Decl(a), Assign(a_ident, a_ident));

  ASSERT_TRUE(r()->Resolve()) << r()->error();
  ASSERT_EQ(TypeOf(a_ident), ty.pointer(rhs_type, sc));
}
static constexpr Params from_call_expression_cases[] = {
    Params{ty_bool_},
    Params{ty_i32},
    Params{ty_u32},
    Params{ty_f32},
    Params{ty_vec3<i32>},
    Params{ty_vec3<u32>},
    Params{ty_vec3<f32>},
    Params{ty_mat3x3<i32>},
    Params{ty_mat3x3<u32>},
    Params{ty_mat3x3<f32>},
    Params{ty_alias<ty_bool_>},
    Params{ty_alias<ty_i32>},
    Params{ty_alias<ty_u32>},
    Params{ty_alias<ty_f32>},
    Params{ty_alias<ty_vec3<i32>>},
    Params{ty_alias<ty_vec3<u32>>},
    Params{ty_alias<ty_vec3<f32>>},
    Params{ty_alias<ty_mat3x3<i32>>},
    Params{ty_alias<ty_mat3x3<u32>>},
    Params{ty_alias<ty_mat3x3<f32>>},
};
INSTANTIATE_TEST_SUITE_P(ResolverTypeConstructorValidationTest,
                         InferTypeTest_FromCallExpression,
                         testing::ValuesIn(from_call_expression_cases));

}  // namespace InferTypeTest

}  // namespace
}  // namespace resolver
}  // namespace tint