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

using namespace tint::number_suffixes;  // NOLINT

namespace tint::writer::glsl {
namespace {

using GlslSanitizerTest = TestHelper;

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

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

    GeneratorImpl& gen = SanitizeAndBuild();

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

    auto got = gen.result();
    auto* expect = R"(#version 310 es
precision mediump float;

layout(binding = 1, std430) buffer my_struct_1 {
  float a[];
} b;
void a_func() {
  uint len = uint(b.a.length());
}

void main() {
  a_func();
  return;
}
)";
    EXPECT_EQ(expect, got);
}

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

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

    GeneratorImpl& gen = SanitizeAndBuild();

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

    auto got = gen.result();
    auto* expect = R"(#version 310 es
precision mediump float;

layout(binding = 1, std430) buffer my_struct_1 {
  float z;
  float a[];
} b;
void a_func() {
  uint len = uint(b.a.length());
}

void main() {
  a_func();
  return;
}
)";

    EXPECT_EQ(expect, got);
}

TEST_F(GlslSanitizerTest, Call_ArrayLength_ViaLets) {
    auto* s = Structure("my_struct", {Member(0, "a", ty.array<f32>(4))});
    GlobalVar("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", {}, ty.void_(),
         {
             Decl(p),
             Decl(p2),
             Decl(Var("len", ty.u32(), ast::StorageClass::kNone, Call("arrayLength", p2))),
         },
         {
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

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

    auto got = gen.result();
    auto* expect = R"(#version 310 es
precision mediump float;

layout(binding = 1, std430) buffer my_struct_1 {
  float a[];
} b;
void a_func() {
  uint len = uint(b.a.length());
}

void main() {
  a_func();
  return;
}
)";

    EXPECT_EQ(expect, got);
}

TEST_F(GlslSanitizerTest, PromoteArrayInitializerToConstVar) {
    auto* array_init = array<i32, 4>(1_i, 2_i, 3_i, 4_i);

    Func("main", {}, ty.void_(),
         {
             Decl(Var("idx", nullptr, Expr(3_i))),
             Decl(Var("pos", ty.i32(), IndexAccessor(array_init, "idx"))),
         },
         {
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

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

    auto got = gen.result();
    auto* expect = R"(#version 310 es
precision mediump float;

void tint_symbol() {
  int idx = 3;
  int tint_symbol_1[4] = int[4](1, 2, 3, 4);
  int pos = tint_symbol_1[idx];
}

void main() {
  tint_symbol();
  return;
}
)";
    EXPECT_EQ(expect, got);
}

TEST_F(GlslSanitizerTest, PromoteStructInitializerToConstVar) {
    auto* str = Structure("S", {
                                   Member("a", ty.i32()),
                                   Member("b", ty.vec3<f32>()),
                                   Member("c", ty.i32()),
                               });
    auto* struct_init = Construct(ty.Of(str), 1_i, vec3<f32>(2_f, 3_f, 4_f), 4_i);
    auto* struct_access = MemberAccessor(struct_init, "b");
    auto* pos = Var("pos", ty.vec3<f32>(), ast::StorageClass::kNone, struct_access);

    Func("main", {}, ty.void_(),
         {
             Decl(pos),
         },
         {
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

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

    auto got = gen.result();
    auto* expect = R"(#version 310 es
precision mediump float;

struct S {
  int a;
  vec3 b;
  int c;
};

void tint_symbol() {
  S tint_symbol_1 = S(1, vec3(2.0f, 3.0f, 4.0f), 4);
  vec3 pos = tint_symbol_1.b;
}

void main() {
  tint_symbol();
  return;
}
)";
    EXPECT_EQ(expect, got);
}

TEST_F(GlslSanitizerTest, InlinePtrLetsBasic) {
    // var v : i32;
    // let p : ptr<function, i32> = &v;
    // let x : i32 = *p;
    auto* v = Var("v", ty.i32());
    auto* p = Let("p", ty.pointer<i32>(ast::StorageClass::kFunction), AddressOf(v));
    auto* x = Var("x", ty.i32(), ast::StorageClass::kNone, Deref(p));

    Func("main", {}, ty.void_(),
         {
             Decl(v),
             Decl(p),
             Decl(x),
         },
         {
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

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

    auto got = gen.result();
    auto* expect = R"(#version 310 es
precision mediump float;

void tint_symbol() {
  int v = 0;
  int x = v;
}

void main() {
  tint_symbol();
  return;
}
)";
    EXPECT_EQ(expect, got);
}

TEST_F(GlslSanitizerTest, InlinePtrLetsComplexChain) {
    // var a : array<mat4x4<f32>, 4u>;
    // let ap : ptr<function, array<mat4x4<f32>, 4u>> = &a;
    // let mp : ptr<function, mat4x4<f32>> = &(*ap)[3i];
    // let vp : ptr<function, vec4<f32>> = &(*mp)[2i];
    // let v : vec4<f32> = *vp;
    auto* a = Var("a", ty.array(ty.mat4x4<f32>(), 4_u));
    auto* ap = Let("ap", ty.pointer(ty.array(ty.mat4x4<f32>(), 4_u), ast::StorageClass::kFunction),
                   AddressOf(a));
    auto* mp = Let("mp", ty.pointer(ty.mat4x4<f32>(), ast::StorageClass::kFunction),
                   AddressOf(IndexAccessor(Deref(ap), 3_i)));
    auto* vp = Let("vp", ty.pointer(ty.vec4<f32>(), ast::StorageClass::kFunction),
                   AddressOf(IndexAccessor(Deref(mp), 2_i)));
    auto* v = Var("v", ty.vec4<f32>(), ast::StorageClass::kNone, Deref(vp));

    Func("main", {}, ty.void_(),
         {
             Decl(a),
             Decl(ap),
             Decl(mp),
             Decl(vp),
             Decl(v),
         },
         {
             Stage(ast::PipelineStage::kFragment),
         });

    GeneratorImpl& gen = SanitizeAndBuild();

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

    auto got = gen.result();
    auto* expect = R"(#version 310 es
precision mediump float;

void tint_symbol() {
  mat4 a[4] = mat4[4](mat4(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f), mat4(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f), mat4(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f), mat4(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f));
  vec4 v = a[3][2];
}

void main() {
  tint_symbol();
  return;
}
)";
    EXPECT_EQ(expect, got);
}

}  // namespace
}  // namespace tint::writer::glsl