// 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 <memory>

#include "gtest/gtest.h"
#include "src/tint/lang/base/builtin/address_space.h"
#include "src/tint/lang/base/builtin/builtin_value.h"
#include "src/tint/lang/base/type/f32.h"
#include "src/tint/lang/base/type/vector.h"
#include "src/tint/lang/wgsl/ast/builtin_attribute.h"
#include "src/tint/lang/wgsl/ast/location_attribute.h"
#include "src/tint/lang/wgsl/ast/return_statement.h"
#include "src/tint/lang/wgsl/ast/stage_attribute.h"
#include "src/tint/lang/wgsl/ast/variable.h"
#include "src/tint/program.h"
#include "src/tint/writer/spirv/builder.h"
#include "src/tint/writer/spirv/spv_dump.h"
#include "src/tint/writer/spirv/test_helper.h"

namespace tint::writer::spirv {
namespace {

using namespace tint::builtin::fluent_types;  // NOLINT
using namespace tint::number_suffixes;        // NOLINT

using BuilderTest = TestHelper;

TEST_F(BuilderTest, EntryPoint_Parameters) {
    // @fragment
    // fn frag_main(@builtin(position) coord : vec4<f32>,
    //              @location(1) loc1 : f32) {
    //   var col : f32 = (coord.x * loc1);
    // }
    auto* coord = Param("coord", ty.vec4<f32>(),
                        utils::Vector{
                            Builtin(builtin::BuiltinValue::kPosition),
                        });
    auto* loc1 = Param("loc1", ty.f32(),
                       utils::Vector{
                           Location(1_u),
                       });
    auto* mul = Mul(Expr(MemberAccessor("coord", "x")), Expr("loc1"));
    auto* col = Var("col", ty.f32(), mul);
    Func("frag_main", utils::Vector{coord, loc1}, ty.void_(), utils::Vector{WrapInStatement(col)},
         utils::Vector{
             Stage(ast::PipelineStage::kFragment),
         });

    spirv::Builder& b = SanitizeAndBuild();

    ASSERT_TRUE(b.Build());

    // Test that "coord" and "loc1" get hoisted out to global variables with the
    // Input address space, retaining their decorations.
    EXPECT_EQ(DumpBuilder(b), R"(OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %19 "frag_main" %1 %5
OpExecutionMode %19 OriginUpperLeft
OpName %1 "coord_1"
OpName %5 "loc1_1"
OpName %9 "frag_main_inner"
OpName %10 "coord"
OpName %11 "loc1"
OpName %15 "col"
OpName %19 "frag_main"
OpDecorate %1 BuiltIn FragCoord
OpDecorate %5 Location 1
%4 = OpTypeFloat 32
%3 = OpTypeVector %4 4
%2 = OpTypePointer Input %3
%1 = OpVariable %2 Input
%6 = OpTypePointer Input %4
%5 = OpVariable %6 Input
%8 = OpTypeVoid
%7 = OpTypeFunction %8 %3 %4
%16 = OpTypePointer Function %4
%17 = OpConstantNull %4
%18 = OpTypeFunction %8
%9 = OpFunction %8 None %7
%10 = OpFunctionParameter %3
%11 = OpFunctionParameter %4
%12 = OpLabel
%15 = OpVariable %16 Function %17
%13 = OpCompositeExtract %4 %10 0
%14 = OpFMul %4 %13 %11
OpStore %15 %14
OpReturn
OpFunctionEnd
%19 = OpFunction %8 None %18
%20 = OpLabel
%22 = OpLoad %3 %1
%23 = OpLoad %4 %5
%21 = OpFunctionCall %8 %9 %22 %23
OpReturn
OpFunctionEnd
)");

    Validate(b);
}

TEST_F(BuilderTest, EntryPoint_ReturnValue) {
    // @fragment
    // fn frag_main(@location(0) @interpolate(flat) loc_in : u32)
    //     -> @location(0) f32 {
    //   if (loc_in > 10) {
    //     return 0.5;
    //   }
    //   return 1.0;
    // }
    auto* loc_in = Param("loc_in", ty.u32(),
                         utils::Vector{
                             Location(0_a),
                             Flat(),
                         });
    auto* cond =
        create<ast::BinaryExpression>(ast::BinaryOp::kGreaterThan, Expr("loc_in"), Expr(10_u));
    Func("frag_main", utils::Vector{loc_in}, ty.f32(),
         utils::Vector{
             If(cond, Block(Return(0.5_f))),
             Return(1_f),
         },
         utils::Vector{
             Stage(ast::PipelineStage::kFragment),
         },
         utils::Vector{
             Location(0_a),
         });

    spirv::Builder& b = SanitizeAndBuild();

    ASSERT_TRUE(b.Build());

    // Test that the return value gets hoisted out to a global variable with the
    // Output address space, and the return statements are replaced with stores.
    EXPECT_EQ(DumpBuilder(b), R"(OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %21 "frag_main" %1 %4
OpExecutionMode %21 OriginUpperLeft
OpName %1 "loc_in_1"
OpName %4 "value"
OpName %9 "frag_main_inner"
OpName %10 "loc_in"
OpName %21 "frag_main"
OpDecorate %1 Location 0
OpDecorate %1 Flat
OpDecorate %4 Location 0
%3 = OpTypeInt 32 0
%2 = OpTypePointer Input %3
%1 = OpVariable %2 Input
%6 = OpTypeFloat 32
%5 = OpTypePointer Output %6
%7 = OpConstantNull %6
%4 = OpVariable %5 Output %7
%8 = OpTypeFunction %6 %3
%12 = OpConstant %3 10
%14 = OpTypeBool
%17 = OpConstant %6 0.5
%18 = OpConstant %6 1
%20 = OpTypeVoid
%19 = OpTypeFunction %20
%9 = OpFunction %6 None %8
%10 = OpFunctionParameter %3
%11 = OpLabel
%13 = OpUGreaterThan %14 %10 %12
OpSelectionMerge %15 None
OpBranchConditional %13 %16 %15
%16 = OpLabel
OpReturnValue %17
%15 = OpLabel
OpReturnValue %18
OpFunctionEnd
%21 = OpFunction %20 None %19
%22 = OpLabel
%24 = OpLoad %3 %1
%23 = OpFunctionCall %6 %9 %24
OpStore %4 %23
OpReturn
OpFunctionEnd
)");

    Validate(b);
}

TEST_F(BuilderTest, EntryPoint_SharedStruct) {
    // struct Interface {
    //   @location(1) value : f32;
    //   @builtin(position) pos : vec4<f32>;
    // };
    //
    // @vertex
    // fn vert_main() -> Interface {
    //   return Interface(42.0, vec4<f32>());
    // }
    //
    // @fragment
    // fn frag_main(inputs : Interface) -> @builtin(frag_depth) f32 {
    //   return inputs.value;
    // }

    auto* interface = Structure(
        "Interface",
        utils::Vector{
            Member("value", ty.f32(), utils::Vector{Location(1_u)}),
            Member("pos", ty.vec4<f32>(), utils::Vector{Builtin(builtin::BuiltinValue::kPosition)}),
        });

    auto* vert_retval = Call(ty.Of(interface), 42_f, Call<vec4<f32>>());
    Func("vert_main", utils::Empty, ty.Of(interface), utils::Vector{Return(vert_retval)},
         utils::Vector{
             Stage(ast::PipelineStage::kVertex),
         });

    auto* frag_inputs = Param("inputs", ty.Of(interface));
    Func("frag_main", utils::Vector{frag_inputs}, ty.f32(),
         utils::Vector{
             Return(MemberAccessor(Expr("inputs"), "value")),
         },
         utils::Vector{Stage(ast::PipelineStage::kFragment)},
         utils::Vector{
             Builtin(builtin::BuiltinValue::kFragDepth),
         });

    spirv::Builder& b = SanitizeAndBuild();

    ASSERT_TRUE(b.Build()) << b.Diagnostics();

    EXPECT_EQ(DumpBuilder(b), R"(OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Vertex %23 "vert_main" %1 %5 %9
OpEntryPoint Fragment %34 "frag_main" %10 %12 %14
OpExecutionMode %34 OriginUpperLeft
OpExecutionMode %34 DepthReplacing
OpName %1 "value_1"
OpName %5 "pos_1"
OpName %9 "vertex_point_size"
OpName %10 "value_2"
OpName %12 "pos_2"
OpName %14 "value_3"
OpName %16 "Interface"
OpMemberName %16 0 "value"
OpMemberName %16 1 "pos"
OpName %17 "vert_main_inner"
OpName %23 "vert_main"
OpName %30 "frag_main_inner"
OpName %31 "inputs"
OpName %34 "frag_main"
OpDecorate %1 Location 1
OpDecorate %5 BuiltIn Position
OpDecorate %9 BuiltIn PointSize
OpDecorate %10 Location 1
OpDecorate %12 BuiltIn FragCoord
OpDecorate %14 BuiltIn FragDepth
OpMemberDecorate %16 0 Offset 0
OpMemberDecorate %16 1 Offset 16
%3 = OpTypeFloat 32
%2 = OpTypePointer Output %3
%4 = OpConstantNull %3
%1 = OpVariable %2 Output %4
%7 = OpTypeVector %3 4
%6 = OpTypePointer Output %7
%8 = OpConstantNull %7
%5 = OpVariable %6 Output %8
%9 = OpVariable %2 Output %4
%11 = OpTypePointer Input %3
%10 = OpVariable %11 Input
%13 = OpTypePointer Input %7
%12 = OpVariable %13 Input
%14 = OpVariable %2 Output %4
%16 = OpTypeStruct %3 %7
%15 = OpTypeFunction %16
%19 = OpConstant %3 42
%20 = OpConstantComposite %16 %19 %8
%22 = OpTypeVoid
%21 = OpTypeFunction %22
%28 = OpConstant %3 1
%29 = OpTypeFunction %3 %16
%17 = OpFunction %16 None %15
%18 = OpLabel
OpReturnValue %20
OpFunctionEnd
%23 = OpFunction %22 None %21
%24 = OpLabel
%25 = OpFunctionCall %16 %17
%26 = OpCompositeExtract %3 %25 0
OpStore %1 %26
%27 = OpCompositeExtract %7 %25 1
OpStore %5 %27
OpStore %9 %28
OpReturn
OpFunctionEnd
%30 = OpFunction %3 None %29
%31 = OpFunctionParameter %16
%32 = OpLabel
%33 = OpCompositeExtract %3 %31 0
OpReturnValue %33
OpFunctionEnd
%34 = OpFunction %22 None %21
%35 = OpLabel
%37 = OpLoad %3 %10
%38 = OpLoad %7 %12
%39 = OpCompositeConstruct %16 %37 %38
%36 = OpFunctionCall %3 %30 %39
OpStore %14 %36
OpReturn
OpFunctionEnd
)");

    Validate(b);
}

TEST_F(BuilderTest, SampleIndex_SampleRateShadingCapability) {
    Func("main",
         utils::Vector{Param("sample_index", ty.u32(),
                             utils::Vector{Builtin(builtin::BuiltinValue::kSampleIndex)})},
         ty.void_(), utils::Empty,
         utils::Vector{
             Stage(ast::PipelineStage::kFragment),
         });

    spirv::Builder& b = SanitizeAndBuild();

    ASSERT_TRUE(b.Build()) << b.Diagnostics();

    // Make sure we generate the SampleRateShading capability.
    EXPECT_EQ(DumpInstructions(b.Module().Capabilities()),
              R"(OpCapability Shader
OpCapability SampleRateShading
)");
    EXPECT_EQ(DumpInstructions(b.Module().Annots()), R"(OpDecorate %1 BuiltIn SampleId
OpDecorate %1 Flat
)");
}

}  // namespace
}  // namespace tint::writer::spirv