// 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 "gmock/gmock.h"
#include "src/tint/ast/call_statement.h"
#include "src/tint/ast/stage_attribute.h"
#include "src/tint/ast/variable_decl_statement.h"
#include "src/tint/writer/msl/test_helper.h"

namespace tint::writer::msl {
namespace {

using ::testing::HasSubstr;

using MslSanitizerTest = TestHelper;

TEST_F(MslSanitizerTest, Call_ArrayLength) {
    auto* s = Structure("my_struct", {Member(0, "a", ty.array<f32>(4))});
    Global("b", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
           ast::AttributeList{
               create<ast::BindingAttribute>(1),
               create<ast::GroupAttribute>(2),
           });

    Func("a_func", ast::VariableList{}, ty.void_(),
         ast::StatementList{
             Decl(Var("len", ty.u32(), ast::StorageClass::kNone,
                      Call("arrayLength", AddressOf(MemberAccessor("b", "a"))))),
         },
         ast::AttributeList{
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

    ASSERT_TRUE(gen.Generate()) << gen.error();

    auto got = gen.result();
    auto* expect = R"(#include <metal_stdlib>

using namespace metal;
struct tint_symbol {
  /* 0x0000 */ uint4 buffer_size[1];
};

struct my_struct {
  float a[1];
};

fragment void a_func(const constant tint_symbol* tint_symbol_2 [[buffer(30)]]) {
  uint len = (((*(tint_symbol_2)).buffer_size[0u][1u] - 0u) / 4u);
  return;
}

)";
    EXPECT_EQ(expect, got);
}

TEST_F(MslSanitizerTest, Call_ArrayLength_OtherMembersInStruct) {
    auto* s = Structure("my_struct", {
                                         Member(0, "z", ty.f32()),
                                         Member(4, "a", ty.array<f32>(4)),
                                     });
    Global("b", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
           ast::AttributeList{
               create<ast::BindingAttribute>(1),
               create<ast::GroupAttribute>(2),
           });

    Func("a_func", ast::VariableList{}, ty.void_(),
         ast::StatementList{
             Decl(Var("len", ty.u32(), ast::StorageClass::kNone,
                      Call("arrayLength", AddressOf(MemberAccessor("b", "a"))))),
         },
         ast::AttributeList{
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

    ASSERT_TRUE(gen.Generate()) << gen.error();

    auto got = gen.result();
    auto* expect = R"(#include <metal_stdlib>

using namespace metal;
struct tint_symbol {
  /* 0x0000 */ uint4 buffer_size[1];
};

struct my_struct {
  float z;
  float a[1];
};

fragment void a_func(const constant tint_symbol* tint_symbol_2 [[buffer(30)]]) {
  uint len = (((*(tint_symbol_2)).buffer_size[0u][1u] - 4u) / 4u);
  return;
}

)";

    EXPECT_EQ(expect, got);
}

TEST_F(MslSanitizerTest, Call_ArrayLength_ViaLets) {
    auto* s = Structure("my_struct", {Member(0, "a", ty.array<f32>(4))});
    Global("b", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
           ast::AttributeList{
               create<ast::BindingAttribute>(1),
               create<ast::GroupAttribute>(2),
           });

    auto* p = Let("p", nullptr, AddressOf("b"));
    auto* p2 = Let("p2", nullptr, AddressOf(MemberAccessor(Deref(p), "a")));

    Func("a_func", ast::VariableList{}, ty.void_(),
         ast::StatementList{
             Decl(p),
             Decl(p2),
             Decl(Var("len", ty.u32(), ast::StorageClass::kNone, Call("arrayLength", p2))),
         },
         ast::AttributeList{
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

    ASSERT_TRUE(gen.Generate()) << gen.error();

    auto got = gen.result();
    auto* expect = R"(#include <metal_stdlib>

using namespace metal;
struct tint_symbol {
  /* 0x0000 */ uint4 buffer_size[1];
};

struct my_struct {
  float a[1];
};

fragment void a_func(const constant tint_symbol* tint_symbol_2 [[buffer(30)]]) {
  uint len = (((*(tint_symbol_2)).buffer_size[0u][1u] - 0u) / 4u);
  return;
}

)";

    EXPECT_EQ(expect, got);
}

TEST_F(MslSanitizerTest, Call_ArrayLength_ArrayLengthFromUniform) {
    auto* s = Structure("my_struct", {Member(0, "a", ty.array<f32>(4))});
    Global("b", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
           ast::AttributeList{
               create<ast::BindingAttribute>(1),
               create<ast::GroupAttribute>(0),
           });
    Global("c", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
           ast::AttributeList{
               create<ast::BindingAttribute>(2),
               create<ast::GroupAttribute>(0),
           });

    Func("a_func", ast::VariableList{}, ty.void_(),
         ast::StatementList{
             Decl(Var("len", ty.u32(), ast::StorageClass::kNone,
                      Add(Call("arrayLength", AddressOf(MemberAccessor("b", "a"))),
                          Call("arrayLength", AddressOf(MemberAccessor("c", "a")))))),
         },
         ast::AttributeList{
             Stage(ast::PipelineStage::kFragment),
         });

    Options options;
    options.array_length_from_uniform.ubo_binding = {0, 29};
    options.array_length_from_uniform.bindpoint_to_size_index.emplace(sem::BindingPoint{0, 1}, 7u);
    options.array_length_from_uniform.bindpoint_to_size_index.emplace(sem::BindingPoint{0, 2}, 2u);
    GeneratorImpl& gen = SanitizeAndBuild(options);

    ASSERT_TRUE(gen.Generate()) << gen.error();

    auto got = gen.result();
    auto* expect = R"(#include <metal_stdlib>

using namespace metal;
struct tint_symbol {
  /* 0x0000 */ uint4 buffer_size[2];
};

struct my_struct {
  float a[1];
};

fragment void a_func(const constant tint_symbol* tint_symbol_2 [[buffer(29)]]) {
  uint len = ((((*(tint_symbol_2)).buffer_size[1u][3u] - 0u) / 4u) + (((*(tint_symbol_2)).buffer_size[0u][2u] - 0u) / 4u));
  return;
}

)";
    EXPECT_EQ(expect, got);
}

TEST_F(MslSanitizerTest, Call_ArrayLength_ArrayLengthFromUniformMissingBinding) {
    auto* s = Structure("my_struct", {Member(0, "a", ty.array<f32>(4))});
    Global("b", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
           ast::AttributeList{
               create<ast::BindingAttribute>(1),
               create<ast::GroupAttribute>(0),
           });
    Global("c", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
           ast::AttributeList{
               create<ast::BindingAttribute>(2),
               create<ast::GroupAttribute>(0),
           });

    Func("a_func", ast::VariableList{}, ty.void_(),
         ast::StatementList{
             Decl(Var("len", ty.u32(), ast::StorageClass::kNone,
                      Add(Call("arrayLength", AddressOf(MemberAccessor("b", "a"))),
                          Call("arrayLength", AddressOf(MemberAccessor("c", "a")))))),
         },
         ast::AttributeList{
             Stage(ast::PipelineStage::kFragment),
         });

    Options options;
    options.array_length_from_uniform.ubo_binding = {0, 29};
    options.array_length_from_uniform.bindpoint_to_size_index.emplace(sem::BindingPoint{0, 2}, 2u);
    GeneratorImpl& gen = SanitizeAndBuild(options);

    ASSERT_FALSE(gen.Generate());
    EXPECT_THAT(gen.error(), HasSubstr("Unable to translate builtin: arrayLength"));
}

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