// 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/ast/stage_decoration.h"
#include "src/ast/struct_block_decoration.h"
#include "src/ast/variable_decl_statement.h"
#include "src/writer/msl/test_helper.h"

namespace tint {
namespace writer {
namespace msl {
namespace {

using MslGeneratorImplTest = TestHelper;

TEST_F(MslGeneratorImplTest, Emit_Function) {
  Func("my_func", ast::VariableList{}, ty.void_(),
       ast::StatementList{
           Return(),
       },
       {});

  GeneratorImpl& gen = Build();

  gen.increment_indent();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(  #include <metal_stdlib>

  using namespace metal;
  void my_func() {
    return;
  }

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_WithParams) {
  ast::VariableList params;
  params.push_back(Param("a", ty.f32()));
  params.push_back(Param("b", ty.i32()));

  Func("my_func", params, ty.void_(),
       ast::StatementList{
           Return(),
       },
       {});

  GeneratorImpl& gen = Build();

  gen.increment_indent();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(  #include <metal_stdlib>

  using namespace metal;
  void my_func(float a, int b) {
    return;
  }

)");
}

TEST_F(MslGeneratorImplTest, Emit_Decoration_EntryPoint_NoReturn_Void) {
  Func("main", ast::VariableList{}, ty.void_(),
       ast::StatementList{/* no explicit return */},
       {Stage(ast::PipelineStage::kFragment)});

  GeneratorImpl& gen = Build();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
fragment void main() {
  return;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Decoration_EntryPoint_WithInOutVars) {
  // fn frag_main(@location(0) foo : f32) -> @location(1) f32 {
  //   return foo;
  // }
  auto* foo_in = Param("foo", ty.f32(), {Location(0)});
  Func("frag_main", ast::VariableList{foo_in}, ty.f32(), {Return("foo")},
       {Stage(ast::PipelineStage::kFragment)}, {Location(1)});

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct tint_symbol_1 {
  float foo [[user(locn0)]];
};
struct tint_symbol_2 {
  float value [[color(1)]];
};

float frag_main_inner(float foo) {
  return foo;
}

fragment tint_symbol_2 frag_main(tint_symbol_1 tint_symbol [[stage_in]]) {
  float const inner_result = frag_main_inner(tint_symbol.foo);
  tint_symbol_2 wrapper_result = {};
  wrapper_result.value = inner_result;
  return wrapper_result;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Decoration_EntryPoint_WithInOut_Builtins) {
  // fn frag_main(@position(0) coord : vec4<f32>) -> @frag_depth f32 {
  //   return coord.x;
  // }
  auto* coord_in =
      Param("coord", ty.vec4<f32>(), {Builtin(ast::Builtin::kPosition)});
  Func("frag_main", ast::VariableList{coord_in}, ty.f32(),
       {Return(MemberAccessor("coord", "x"))},
       {Stage(ast::PipelineStage::kFragment)},
       {Builtin(ast::Builtin::kFragDepth)});

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct tint_symbol {
  float value [[depth(any)]];
};

float frag_main_inner(float4 coord) {
  return coord[0];
}

fragment tint_symbol frag_main(float4 coord [[position]]) {
  float const inner_result = frag_main_inner(coord);
  tint_symbol wrapper_result = {};
  wrapper_result.value = inner_result;
  return wrapper_result;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Decoration_EntryPoint_SharedStruct_DifferentStages) {
  // struct Interface {
  //   @location(1) col1 : f32;
  //   @location(2) col2 : f32;
  //   @builtin(position) pos : vec4<f32>;
  // };
  // fn vert_main() -> Interface {
  //   return Interface(0.4, 0.6, vec4<f32>());
  // }
  // fn frag_main(colors : Interface) {
  //   const r = colors.col1;
  //   const g = colors.col2;
  // }
  auto* interface_struct = Structure(
      "Interface",
      {
          Member("col1", ty.f32(), {Location(1)}),
          Member("col2", ty.f32(), {Location(2)}),
          Member("pos", ty.vec4<f32>(), {Builtin(ast::Builtin::kPosition)}),
      });

  Func("vert_main", {}, ty.Of(interface_struct),
       {Return(Construct(ty.Of(interface_struct), Expr(0.5f), Expr(0.25f),
                         Construct(ty.vec4<f32>())))},
       {Stage(ast::PipelineStage::kVertex)});

  Func("frag_main", {Param("colors", ty.Of(interface_struct))}, ty.void_(),
       {
           WrapInStatement(
               Const("r", ty.f32(), MemberAccessor("colors", "col1"))),
           WrapInStatement(
               Const("g", ty.f32(), MemberAccessor("colors", "col2"))),
       },
       {Stage(ast::PipelineStage::kFragment)});

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct Interface {
  float col1;
  float col2;
  float4 pos;
};
struct tint_symbol {
  float col1 [[user(locn1)]];
  float col2 [[user(locn2)]];
  float4 pos [[position]];
};
struct tint_symbol_2 {
  float col1 [[user(locn1)]];
  float col2 [[user(locn2)]];
};

Interface vert_main_inner() {
  Interface const tint_symbol_3 = {.col1=0.5f, .col2=0.25f, .pos=float4()};
  return tint_symbol_3;
}

vertex tint_symbol vert_main() {
  Interface const inner_result = vert_main_inner();
  tint_symbol wrapper_result = {};
  wrapper_result.col1 = inner_result.col1;
  wrapper_result.col2 = inner_result.col2;
  wrapper_result.pos = inner_result.pos;
  return wrapper_result;
}

void frag_main_inner(Interface colors) {
  float const r = colors.col1;
  float const g = colors.col2;
}

fragment void frag_main(float4 pos [[position]], tint_symbol_2 tint_symbol_1 [[stage_in]]) {
  Interface const tint_symbol_4 = {.col1=tint_symbol_1.col1, .col2=tint_symbol_1.col2, .pos=pos};
  frag_main_inner(tint_symbol_4);
  return;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Decoration_EntryPoint_SharedStruct_HelperFunction) {
  // struct VertexOutput {
  //   @builtin(position) pos : vec4<f32>;
  // };
  // fn foo(x : f32) -> VertexOutput {
  //   return VertexOutput(vec4<f32>(x, x, x, 1.0));
  // }
  // fn vert_main1() -> VertexOutput {
  //   return foo(0.5);
  // }
  // fn vert_main2() -> VertexOutput {
  //   return foo(0.25);
  // }
  auto* vertex_output_struct = Structure(
      "VertexOutput",
      {Member("pos", ty.vec4<f32>(), {Builtin(ast::Builtin::kPosition)})});

  Func("foo", {Param("x", ty.f32())}, ty.Of(vertex_output_struct),
       {Return(Construct(ty.Of(vertex_output_struct),
                         Construct(ty.vec4<f32>(), "x", "x", "x", Expr(1.f))))},
       {});

  Func("vert_main1", {}, ty.Of(vertex_output_struct),
       {Return(Expr(Call("foo", Expr(0.5f))))},
       {Stage(ast::PipelineStage::kVertex)});

  Func("vert_main2", {}, ty.Of(vertex_output_struct),
       {Return(Expr(Call("foo", Expr(0.25f))))},
       {Stage(ast::PipelineStage::kVertex)});

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct VertexOutput {
  float4 pos;
};
struct tint_symbol {
  float4 pos [[position]];
};
struct tint_symbol_1 {
  float4 pos [[position]];
};

VertexOutput foo(float x) {
  VertexOutput const tint_symbol_2 = {.pos=float4(x, x, x, 1.0f)};
  return tint_symbol_2;
}

VertexOutput vert_main1_inner() {
  return foo(0.5f);
}

vertex tint_symbol vert_main1() {
  VertexOutput const inner_result = vert_main1_inner();
  tint_symbol wrapper_result = {};
  wrapper_result.pos = inner_result.pos;
  return wrapper_result;
}

VertexOutput vert_main2_inner() {
  return foo(0.25f);
}

vertex tint_symbol_1 vert_main2() {
  VertexOutput const inner_result_1 = vert_main2_inner();
  tint_symbol_1 wrapper_result_1 = {};
  wrapper_result_1.pos = inner_result_1.pos;
  return wrapper_result_1;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_FunctionDecoration_EntryPoint_With_RW_StorageBuffer) {
  auto* s = Structure("Data",
                      {
                          Member("a", ty.i32()),
                          Member("b", ty.f32()),
                      },
                      {create<ast::StructBlockDecoration>()});

  Global("coord", ty.Of(s), ast::StorageClass::kStorage,
         ast::Access::kReadWrite,
         ast::DecorationList{
             create<ast::BindingDecoration>(0),
             create<ast::GroupDecoration>(0),
         });

  auto* var = Var("v", ty.f32(), ast::StorageClass::kNone,
                  MemberAccessor("coord", "b"));

  Func("frag_main", ast::VariableList{}, ty.void_(),
       ast::StatementList{
           Decl(var),
           Return(),
       },
       {
           Stage(ast::PipelineStage::kFragment),
       });

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct Data {
  /* 0x0000 */ int a;
  /* 0x0004 */ float b;
};

fragment void frag_main(device Data* tint_symbol [[buffer(0)]]) {
  float v = (*(tint_symbol)).b;
  return;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_FunctionDecoration_EntryPoint_With_RO_StorageBuffer) {
  auto* s = Structure("Data",
                      {
                          Member("a", ty.i32()),
                          Member("b", ty.f32()),
                      },
                      {create<ast::StructBlockDecoration>()});

  Global("coord", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
         ast::DecorationList{
             create<ast::BindingDecoration>(0),
             create<ast::GroupDecoration>(0),
         });

  auto* var = Var("v", ty.f32(), ast::StorageClass::kNone,
                  MemberAccessor("coord", "b"));

  Func("frag_main", ast::VariableList{}, ty.void_(),
       ast::StatementList{
           Decl(var),
           Return(),
       },
       {
           Stage(ast::PipelineStage::kFragment),
       });

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct Data {
  /* 0x0000 */ int a;
  /* 0x0004 */ float b;
};

fragment void frag_main(const device Data* tint_symbol [[buffer(0)]]) {
  float v = (*(tint_symbol)).b;
  return;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Decoration_Called_By_EntryPoint_With_Uniform) {
  auto* ubo_ty = Structure("UBO", {Member("coord", ty.vec4<f32>())},
                           {create<ast::StructBlockDecoration>()});
  auto* ubo = Global("ubo", ty.Of(ubo_ty), ast::StorageClass::kUniform,
                     ast::DecorationList{
                         create<ast::BindingDecoration>(0),
                         create<ast::GroupDecoration>(0),
                     });

  Func("sub_func",
       {
           Param("param", ty.f32()),
       },
       ty.f32(),
       {
           Return(MemberAccessor(MemberAccessor(ubo, "coord"), "x")),
       });

  auto* var =
      Var("v", ty.f32(), ast::StorageClass::kNone, Call("sub_func", 1.0f));

  Func("frag_main", {}, ty.void_(),
       {
           Decl(var),
           Return(),
       },
       {
           Stage(ast::PipelineStage::kFragment),
       });

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct UBO {
  /* 0x0000 */ float4 coord;
};

float sub_func(float param, const constant UBO* const tint_symbol) {
  return (*(tint_symbol)).coord[0];
}

fragment void frag_main(const constant UBO* tint_symbol_1 [[buffer(0)]]) {
  float v = sub_func(1.0f, tint_symbol_1);
  return;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_FunctionDecoration_Called_By_EntryPoint_With_RW_StorageBuffer) {
  auto* s = Structure("Data",
                      {
                          Member("a", ty.i32()),
                          Member("b", ty.f32()),
                      },
                      {create<ast::StructBlockDecoration>()});

  Global("coord", ty.Of(s), ast::StorageClass::kStorage,
         ast::Access::kReadWrite,
         ast::DecorationList{
             create<ast::BindingDecoration>(0),
             create<ast::GroupDecoration>(0),
         });

  ast::VariableList params;
  params.push_back(Param("param", ty.f32()));

  auto body = ast::StatementList{Return(MemberAccessor("coord", "b"))};

  Func("sub_func", params, ty.f32(), body, {});

  auto* var =
      Var("v", ty.f32(), ast::StorageClass::kNone, Call("sub_func", 1.0f));

  Func("frag_main", ast::VariableList{}, ty.void_(),
       ast::StatementList{
           Decl(var),
           Return(),
       },
       {
           Stage(ast::PipelineStage::kFragment),
       });

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct Data {
  /* 0x0000 */ int a;
  /* 0x0004 */ float b;
};

float sub_func(float param, device Data* const tint_symbol) {
  return (*(tint_symbol)).b;
}

fragment void frag_main(device Data* tint_symbol_1 [[buffer(0)]]) {
  float v = sub_func(1.0f, tint_symbol_1);
  return;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_FunctionDecoration_Called_By_EntryPoint_With_RO_StorageBuffer) {
  auto* s = Structure("Data",
                      {
                          Member("a", ty.i32()),
                          Member("b", ty.f32()),
                      },
                      {create<ast::StructBlockDecoration>()});

  Global("coord", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kRead,
         ast::DecorationList{
             create<ast::BindingDecoration>(0),
             create<ast::GroupDecoration>(0),
         });

  ast::VariableList params;
  params.push_back(Param("param", ty.f32()));

  auto body = ast::StatementList{Return(MemberAccessor("coord", "b"))};

  Func("sub_func", params, ty.f32(), body, {});

  auto* var =
      Var("v", ty.f32(), ast::StorageClass::kNone, Call("sub_func", 1.0f));

  Func("frag_main", ast::VariableList{}, ty.void_(),
       ast::StatementList{
           Decl(var),
           Return(),
       },
       {
           Stage(ast::PipelineStage::kFragment),
       });

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct Data {
  /* 0x0000 */ int a;
  /* 0x0004 */ float b;
};

float sub_func(float param, const device Data* const tint_symbol) {
  return (*(tint_symbol)).b;
}

fragment void frag_main(const device Data* tint_symbol_1 [[buffer(0)]]) {
  float v = sub_func(1.0f, tint_symbol_1);
  return;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_WithArrayParams) {
  ast::VariableList params;
  params.push_back(Param("a", ty.array<f32, 5>()));

  Func("my_func", params, ty.void_(),
       {
           Return(),
       });

  GeneratorImpl& gen = SanitizeAndBuild();

  gen.increment_indent();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(  #include <metal_stdlib>

  using namespace metal;
  struct tint_array_wrapper {
    float arr[5];
  };

  void my_func(tint_array_wrapper a) {
    return;
  }

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_WithArrayReturn) {
  Func("my_func", {}, ty.array<f32, 5>(),
       {
           Return(Construct(ty.array<f32, 5>())),
       });

  GeneratorImpl& gen = SanitizeAndBuild();

  gen.increment_indent();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(  #include <metal_stdlib>

  using namespace metal;
  struct tint_array_wrapper {
    float arr[5];
  };

  tint_array_wrapper my_func() {
    tint_array_wrapper const tint_symbol = {.arr={}};
    return tint_symbol;
  }

)");
}

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

  auto* s = Structure("Data", {Member("d", ty.f32())},
                      {create<ast::StructBlockDecoration>()});

  Global("data", ty.Of(s), ast::StorageClass::kStorage, ast::Access::kReadWrite,
         ast::DecorationList{
             create<ast::BindingDecoration>(0),
             create<ast::GroupDecoration>(0),
         });

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

    Func("a", ast::VariableList{}, ty.void_(),
         ast::StatementList{
             Decl(var),
             Return(),
         },
         {
             Stage(ast::PipelineStage::kCompute),
             WorkgroupSize(1),
         });
  }

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

    Func("b", ast::VariableList{}, ty.void_(),
         ast::StatementList{Decl(var), Return()},
         {
             Stage(ast::PipelineStage::kCompute),
             WorkgroupSize(1),
         });
  }

  GeneratorImpl& gen = SanitizeAndBuild();

  ASSERT_TRUE(gen.Generate()) << gen.error();
  EXPECT_EQ(gen.result(), R"(#include <metal_stdlib>

using namespace metal;
struct Data {
  /* 0x0000 */ float d;
};

kernel void a(device Data* tint_symbol [[buffer(0)]]) {
  float v = (*(tint_symbol)).d;
  return;
}

kernel void b(device Data* tint_symbol_1 [[buffer(0)]]) {
  float v = (*(tint_symbol_1)).d;
  return;
}

)");
}

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