// 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/tint/ast/stage_attribute.h"
#include "src/tint/ast/variable_decl_statement.h"
#include "src/tint/ast/workgroup_attribute.h"
#include "src/tint/builtin/builtin_value.h"
#include "src/tint/writer/wgsl/test_helper.h"

using namespace tint::number_suffixes;  // NOLINT

namespace tint::writer::wgsl {
namespace {

using WgslGeneratorImplTest = TestHelper;

TEST_F(WgslGeneratorImplTest, Emit_Function) {
    auto* func = Func("my_func", utils::Empty, ty.void_(),
                      utils::Vector{
                          Return(),
                      });

    GeneratorImpl& gen = Build();

    gen.increment_indent();

    ASSERT_TRUE(gen.EmitFunction(func));
    EXPECT_EQ(gen.result(), R"(  fn my_func() {
    return;
  }
)");
}

TEST_F(WgslGeneratorImplTest, Emit_Function_WithParams) {
    auto* func = Func("my_func",
                      utils::Vector{
                          Param("a", ty.f32()),
                          Param("b", ty.i32()),
                      },
                      ty.void_(),
                      utils::Vector{
                          Return(),
                      });

    GeneratorImpl& gen = Build();

    gen.increment_indent();

    ASSERT_TRUE(gen.EmitFunction(func));
    EXPECT_EQ(gen.result(), R"(  fn my_func(a : f32, b : i32) {
    return;
  }
)");
}

TEST_F(WgslGeneratorImplTest, Emit_Function_WithAttribute_WorkgroupSize) {
    auto* func = Func("my_func", utils::Empty, ty.void_(),
                      utils::Vector{
                          Return(),
                      },
                      utils::Vector{
                          Stage(ast::PipelineStage::kCompute),
                          WorkgroupSize(2_i, 4_i, 6_i),
                      });

    GeneratorImpl& gen = Build();

    gen.increment_indent();

    ASSERT_TRUE(gen.EmitFunction(func));
    EXPECT_EQ(gen.result(), R"(  @compute @workgroup_size(2i, 4i, 6i)
  fn my_func() {
    return;
  }
)");
}

TEST_F(WgslGeneratorImplTest, Emit_Function_WithAttribute_MustUse) {
    auto* func = Func("my_func", utils::Empty, ty.i32(),
                      utils::Vector{
                          Return(1_i),
                      },
                      utils::Vector{
                          MustUse(),
                      });

    GeneratorImpl& gen = Build();

    gen.increment_indent();

    ASSERT_TRUE(gen.EmitFunction(func));
    EXPECT_EQ(gen.result(), R"(  @must_use
  fn my_func() -> i32 {
    return 1i;
  }
)");
}

TEST_F(WgslGeneratorImplTest, Emit_Function_WithAttribute_WorkgroupSize_WithIdent) {
    GlobalConst("height", ty.i32(), Expr(2_i));
    auto* func = Func("my_func", utils::Empty, ty.void_(),
                      utils::Vector{
                          Return(),
                      },
                      utils::Vector{
                          Stage(ast::PipelineStage::kCompute),
                          WorkgroupSize(2_i, "height"),
                      });

    GeneratorImpl& gen = Build();

    gen.increment_indent();

    ASSERT_TRUE(gen.EmitFunction(func));
    EXPECT_EQ(gen.result(), R"(  @compute @workgroup_size(2i, height)
  fn my_func() {
    return;
  }
)");
}

TEST_F(WgslGeneratorImplTest, Emit_Function_EntryPoint_Parameters) {
    auto vec4 = ty.vec4<f32>();
    auto* coord = Param("coord", vec4,
                        utils::Vector{
                            Builtin(builtin::BuiltinValue::kPosition),
                        });
    auto* loc1 = Param("loc1", ty.f32(),
                       utils::Vector{
                           Location(1_a),
                       });
    auto* func = Func("frag_main", utils::Vector{coord, loc1}, ty.void_(), utils::Empty,
                      utils::Vector{
                          Stage(ast::PipelineStage::kFragment),
                      });

    GeneratorImpl& gen = Build();

    gen.increment_indent();

    ASSERT_TRUE(gen.EmitFunction(func));
    EXPECT_EQ(gen.result(), R"(  @fragment
  fn frag_main(@builtin(position) coord : vec4<f32>, @location(1) loc1 : f32) {
  }
)");
}

TEST_F(WgslGeneratorImplTest, Emit_Function_EntryPoint_ReturnValue) {
    auto* func = Func("frag_main", utils::Empty, ty.f32(),
                      utils::Vector{
                          Return(1_f),
                      },
                      utils::Vector{
                          Stage(ast::PipelineStage::kFragment),
                      },
                      utils::Vector{
                          Location(1_a),
                      });

    GeneratorImpl& gen = Build();

    gen.increment_indent();

    ASSERT_TRUE(gen.EmitFunction(func));
    EXPECT_EQ(gen.result(), R"(  @fragment
  fn frag_main() -> @location(1) f32 {
    return 1.0f;
  }
)");
}

// https://crbug.com/tint/297
TEST_F(WgslGeneratorImplTest, Emit_Function_Multiple_EntryPoint_With_Same_ModuleVar) {
    // struct Data {
    //   d : f32;
    // };
    // @binding(0) @group(0) var<storage> data : Data;
    //
    // @compute @workgroup_size(1)
    // fn a() {
    //   return;
    // }
    //
    // @compute @workgroup_size(1)
    // fn b() {
    //   return;
    // }

    auto* s = Structure("Data", utils::Vector{
                                    Member("d", ty.f32()),
                                });

    GlobalVar("data", ty.Of(s), builtin::AddressSpace::kStorage, builtin::Access::kReadWrite,
              Binding(0_a), Group(0_a));

    {
        auto* var = Var("v", ty.f32(), MemberAccessor("data", "d"));

        Func("a", utils::Empty, ty.void_(),
             utils::Vector{
                 Decl(var),
                 Return(),
             },
             utils::Vector{
                 Stage(ast::PipelineStage::kCompute),
                 WorkgroupSize(1_i),
             });
    }

    {
        auto* var = Var("v", ty.f32(), MemberAccessor("data", "d"));

        Func("b", utils::Empty, ty.void_(),
             utils::Vector{
                 Decl(var),
                 Return(),
             },
             utils::Vector{
                 Stage(ast::PipelineStage::kCompute),
                 WorkgroupSize(1_i),
             });
    }

    GeneratorImpl& gen = Build();

    ASSERT_TRUE(gen.Generate()) << gen.error();
    EXPECT_EQ(gen.result(), R"(struct Data {
  d : f32,
}

@binding(0) @group(0) var<storage, read_write> data : Data;

@compute @workgroup_size(1i)
fn a() {
  var v : f32 = data.d;
  return;
}

@compute @workgroup_size(1i)
fn b() {
  var v : f32 = data.d;
  return;
}
)");
}

}  // namespace
}  // namespace tint::writer::wgsl