// 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/ast/builtin_texture_helper_test.h"
#include "src/resolver/resolver_test_helper.h"

namespace tint {
namespace resolver {
namespace {

using ResolverBuiltinValidationTest = ResolverTest;

TEST_F(ResolverBuiltinValidationTest,
       FunctionTypeMustMatchReturnStatementType_void_fail) {
  // fn func { return workgroupBarrier(); }
  Func("func", {}, ty.void_(),
       {
           Return(Call(Source{Source::Location{12, 34}}, "workgroupBarrier")),
       });

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(r()->error(),
            "12:34 error: builtin 'workgroupBarrier' does not return a value");
}

TEST_F(ResolverBuiltinValidationTest, InvalidPipelineStageDirect) {
  // @stage(compute) @workgroup_size(1) fn func { return dpdx(1.0); }

  auto* dpdx = create<ast::CallExpression>(Source{{3, 4}}, Expr("dpdx"),
                                           ast::ExpressionList{Expr(1.0f)});
  Func(Source{{1, 2}}, "func", ast::VariableList{}, ty.void_(),
       {CallStmt(dpdx)},
       {Stage(ast::PipelineStage::kCompute), WorkgroupSize(1)});

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(r()->error(),
            "3:4 error: built-in cannot be used by compute pipeline stage");
}

TEST_F(ResolverBuiltinValidationTest, InvalidPipelineStageIndirect) {
  // fn f0 { return dpdx(1.0); }
  // fn f1 { f0(); }
  // fn f2 { f1(); }
  // @stage(compute) @workgroup_size(1) fn main { return f2(); }

  auto* dpdx = create<ast::CallExpression>(Source{{3, 4}}, Expr("dpdx"),
                                           ast::ExpressionList{Expr(1.0f)});
  Func(Source{{1, 2}}, "f0", {}, ty.void_(), {CallStmt(dpdx)});

  Func(Source{{3, 4}}, "f1", {}, ty.void_(), {CallStmt(Call("f0"))});

  Func(Source{{5, 6}}, "f2", {}, ty.void_(), {CallStmt(Call("f1"))});

  Func(Source{{7, 8}}, "main", {}, ty.void_(), {CallStmt(Call("f2"))},
       {Stage(ast::PipelineStage::kCompute), WorkgroupSize(1)});

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(r()->error(),
            R"(3:4 error: built-in cannot be used by compute pipeline stage
1:2 note: called by function 'f0'
3:4 note: called by function 'f1'
5:6 note: called by function 'f2'
7:8 note: called by entry point 'main')");
}

TEST_F(ResolverBuiltinValidationTest, BuiltinRedeclaredAsFunction) {
  Func(Source{{12, 34}}, "mix", {}, ty.i32(), {});

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(
      r()->error(),
      R"(12:34 error: 'mix' is a builtin and cannot be redeclared as a function)");
}

TEST_F(ResolverBuiltinValidationTest, BuiltinRedeclaredAsGlobalLet) {
  GlobalConst(Source{{12, 34}}, "mix", ty.i32(), Expr(1));

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(
      r()->error(),
      R"(12:34 error: 'mix' is a builtin and cannot be redeclared as a module-scope let)");
}

TEST_F(ResolverBuiltinValidationTest, BuiltinRedeclaredAsGlobalVar) {
  Global(Source{{12, 34}}, "mix", ty.i32(), Expr(1),
         ast::StorageClass::kPrivate);

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(
      r()->error(),
      R"(12:34 error: 'mix' is a builtin and cannot be redeclared as a module-scope var)");
}

TEST_F(ResolverBuiltinValidationTest, BuiltinRedeclaredAsAlias) {
  Alias(Source{{12, 34}}, "mix", ty.i32());

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(
      r()->error(),
      R"(12:34 error: 'mix' is a builtin and cannot be redeclared as an alias)");
}

TEST_F(ResolverBuiltinValidationTest, BuiltinRedeclaredAsStruct) {
  Structure(Source{{12, 34}}, "mix", {Member("m", ty.i32())});

  EXPECT_FALSE(r()->Resolve());
  EXPECT_EQ(
      r()->error(),
      R"(12:34 error: 'mix' is a builtin and cannot be redeclared as a struct)");
}

namespace texture_constexpr_args {

using TextureOverloadCase = ast::builtin::test::TextureOverloadCase;
using ValidTextureOverload = ast::builtin::test::ValidTextureOverload;
using TextureKind = ast::builtin::test::TextureKind;
using TextureDataType = ast::builtin::test::TextureDataType;
using u32 = ProgramBuilder::u32;
using i32 = ProgramBuilder::i32;
using f32 = ProgramBuilder::f32;

static std::vector<TextureOverloadCase> TextureCases(
    std::unordered_set<ValidTextureOverload> overloads) {
  std::vector<TextureOverloadCase> cases;
  for (auto c : TextureOverloadCase::ValidCases()) {
    if (overloads.count(c.overload)) {
      cases.push_back(c);
    }
  }
  return cases;
}

enum class Position {
  kFirst,
  kLast,
};

struct Parameter {
  const char* const name;
  const Position position;
  int min;
  int max;
};

class Constexpr {
 public:
  enum class Kind {
    kScalar,
    kVec2,
    kVec3,
    kVec3_Scalar_Vec2,
    kVec3_Vec2_Scalar,
    kEmptyVec2,
    kEmptyVec3,
  };

  Constexpr(int32_t invalid_idx,
            Kind k,
            int32_t x = 0,
            int32_t y = 0,
            int32_t z = 0)
      : invalid_index(invalid_idx), kind(k), values{x, y, z} {}

  const ast::Expression* operator()(Source src, ProgramBuilder& b) {
    switch (kind) {
      case Kind::kScalar:
        return b.Expr(src, values[0]);
      case Kind::kVec2:
        return b.Construct(src, b.ty.vec2<i32>(), values[0], values[1]);
      case Kind::kVec3:
        return b.Construct(src, b.ty.vec3<i32>(), values[0], values[1],
                           values[2]);
      case Kind::kVec3_Scalar_Vec2:
        return b.Construct(src, b.ty.vec3<i32>(), values[0],
                           b.vec2<i32>(values[1], values[2]));
      case Kind::kVec3_Vec2_Scalar:
        return b.Construct(src, b.ty.vec3<i32>(),
                           b.vec2<i32>(values[0], values[1]), values[2]);
      case Kind::kEmptyVec2:
        return b.Construct(src, b.ty.vec2<i32>());
      case Kind::kEmptyVec3:
        return b.Construct(src, b.ty.vec3<i32>());
    }
    return nullptr;
  }

  static const constexpr int32_t kValid = -1;
  const int32_t invalid_index;  // Expected error value, or kValid
  const Kind kind;
  const std::array<int32_t, 3> values;
};

static std::ostream& operator<<(std::ostream& out, Parameter param) {
  return out << param.name;
}

static std::ostream& operator<<(std::ostream& out, Constexpr expr) {
  switch (expr.kind) {
    case Constexpr::Kind::kScalar:
      return out << expr.values[0];
    case Constexpr::Kind::kVec2:
      return out << "vec2(" << expr.values[0] << ", " << expr.values[1] << ")";
    case Constexpr::Kind::kVec3:
      return out << "vec3(" << expr.values[0] << ", " << expr.values[1] << ", "
                 << expr.values[2] << ")";
    case Constexpr::Kind::kVec3_Scalar_Vec2:
      return out << "vec3(" << expr.values[0] << ", vec2(" << expr.values[1]
                 << ", " << expr.values[2] << "))";
    case Constexpr::Kind::kVec3_Vec2_Scalar:
      return out << "vec3(vec2(" << expr.values[0] << ", " << expr.values[1]
                 << "), " << expr.values[2] << ")";
    case Constexpr::Kind::kEmptyVec2:
      return out << "vec2()";
    case Constexpr::Kind::kEmptyVec3:
      return out << "vec3()";
  }
  return out;
}

using BuiltinTextureConstExprArgValidationTest = ResolverTestWithParam<
    std::tuple<TextureOverloadCase, Parameter, Constexpr>>;

TEST_P(BuiltinTextureConstExprArgValidationTest, Immediate) {
  auto& p = GetParam();
  auto overload = std::get<0>(p);
  auto param = std::get<1>(p);
  auto expr = std::get<2>(p);

  overload.BuildTextureVariable(this);
  overload.BuildSamplerVariable(this);

  auto args = overload.args(this);
  auto*& arg_to_replace =
      (param.position == Position::kFirst) ? args.front() : args.back();

  // BuildTextureVariable() uses a Literal for scalars, and a CallExpression for
  // a vector constructor.
  bool is_vector = arg_to_replace->Is<ast::CallExpression>();

  // Make the expression to be replaced, reachable. This keeps the resolver
  // happy.
  WrapInFunction(arg_to_replace);

  arg_to_replace = expr(Source{{12, 34}}, *this);

  // Call the builtin with the constexpr argument replaced
  Func("func", {}, ty.void_(), {CallStmt(Call(overload.function, args))},
       {Stage(ast::PipelineStage::kFragment)});

  if (expr.invalid_index == Constexpr::kValid) {
    EXPECT_TRUE(r()->Resolve()) << r()->error();
  } else {
    EXPECT_FALSE(r()->Resolve());
    std::stringstream err;
    if (is_vector) {
      err << "12:34 error: each component of the " << param.name
          << " argument must be at least " << param.min << " and at most "
          << param.max << ". " << param.name << " component "
          << expr.invalid_index << " is "
          << std::to_string(expr.values[expr.invalid_index]);
    } else {
      err << "12:34 error: the " << param.name << " argument must be at least "
          << param.min << " and at most " << param.max << ". " << param.name
          << " is " << std::to_string(expr.values[expr.invalid_index]);
    }
    EXPECT_EQ(r()->error(), err.str());
  }
}

TEST_P(BuiltinTextureConstExprArgValidationTest, GlobalConst) {
  auto& p = GetParam();
  auto overload = std::get<0>(p);
  auto param = std::get<1>(p);
  auto expr = std::get<2>(p);

  // Build the global texture and sampler variables
  overload.BuildTextureVariable(this);
  overload.BuildSamplerVariable(this);

  // Build the module-scope let 'G' with the offset value
  GlobalConst("G", nullptr, expr({}, *this));

  auto args = overload.args(this);
  auto*& arg_to_replace =
      (param.position == Position::kFirst) ? args.front() : args.back();

  // Make the expression to be replaced, reachable. This keeps the resolver
  // happy.
  WrapInFunction(arg_to_replace);

  arg_to_replace = Expr(Source{{12, 34}}, "G");

  // Call the builtin with the constexpr argument replaced
  Func("func", {}, ty.void_(), {CallStmt(Call(overload.function, args))},
       {Stage(ast::PipelineStage::kFragment)});

  EXPECT_FALSE(r()->Resolve());
  std::stringstream err;
  err << "12:34 error: the " << param.name
      << " argument must be a const_expression";
  EXPECT_EQ(r()->error(), err.str());
}

INSTANTIATE_TEST_SUITE_P(
    Offset2D,
    BuiltinTextureConstExprArgValidationTest,
    testing::Combine(
        testing::ValuesIn(TextureCases({
            ValidTextureOverload::kSample2dOffsetF32,
            ValidTextureOverload::kSample2dArrayOffsetF32,
            ValidTextureOverload::kSampleDepth2dOffsetF32,
            ValidTextureOverload::kSampleDepth2dArrayOffsetF32,
            ValidTextureOverload::kSampleBias2dOffsetF32,
            ValidTextureOverload::kSampleBias2dArrayOffsetF32,
            ValidTextureOverload::kSampleLevel2dOffsetF32,
            ValidTextureOverload::kSampleLevel2dArrayOffsetF32,
            ValidTextureOverload::kSampleLevelDepth2dOffsetF32,
            ValidTextureOverload::kSampleLevelDepth2dArrayOffsetF32,
            ValidTextureOverload::kSampleGrad2dOffsetF32,
            ValidTextureOverload::kSampleGrad2dArrayOffsetF32,
            ValidTextureOverload::kSampleCompareDepth2dOffsetF32,
            ValidTextureOverload::kSampleCompareDepth2dArrayOffsetF32,
            ValidTextureOverload::kSampleCompareLevelDepth2dOffsetF32,
            ValidTextureOverload::kSampleCompareLevelDepth2dArrayOffsetF32,
        })),
        testing::Values(Parameter{"offset", Position::kLast, -8, 7}),
        testing::Values(
            Constexpr{Constexpr::kValid, Constexpr::Kind::kEmptyVec2},
            Constexpr{Constexpr::kValid, Constexpr::Kind::kVec2, -1, 1},
            Constexpr{Constexpr::kValid, Constexpr::Kind::kVec2, 7, -8},
            Constexpr{0, Constexpr::Kind::kVec2, 8, 0},
            Constexpr{1, Constexpr::Kind::kVec2, 0, 8},
            Constexpr{0, Constexpr::Kind::kVec2, -9, 0},
            Constexpr{1, Constexpr::Kind::kVec2, 0, -9},
            Constexpr{0, Constexpr::Kind::kVec2, 8, 8},
            Constexpr{0, Constexpr::Kind::kVec2, -9, -9})));

INSTANTIATE_TEST_SUITE_P(
    Offset3D,
    BuiltinTextureConstExprArgValidationTest,
    testing::Combine(
        testing::ValuesIn(TextureCases({
            ValidTextureOverload::kSample3dOffsetF32,
            ValidTextureOverload::kSampleBias3dOffsetF32,
            ValidTextureOverload::kSampleLevel3dOffsetF32,
            ValidTextureOverload::kSampleGrad3dOffsetF32,
        })),
        testing::Values(Parameter{"offset", Position::kLast, -8, 7}),
        testing::Values(
            Constexpr{Constexpr::kValid, Constexpr::Kind::kEmptyVec3},
            Constexpr{Constexpr::kValid, Constexpr::Kind::kVec3, 0, 0, 0},
            Constexpr{Constexpr::kValid, Constexpr::Kind::kVec3, 7, -8, 7},
            Constexpr{0, Constexpr::Kind::kVec3, 10, 0, 0},
            Constexpr{1, Constexpr::Kind::kVec3, 0, 10, 0},
            Constexpr{2, Constexpr::Kind::kVec3, 0, 0, 10},
            Constexpr{0, Constexpr::Kind::kVec3, 10, 11, 12},
            Constexpr{0, Constexpr::Kind::kVec3_Scalar_Vec2, 10, 0, 0},
            Constexpr{1, Constexpr::Kind::kVec3_Scalar_Vec2, 0, 10, 0},
            Constexpr{2, Constexpr::Kind::kVec3_Scalar_Vec2, 0, 0, 10},
            Constexpr{0, Constexpr::Kind::kVec3_Scalar_Vec2, 10, 11, 12},
            Constexpr{0, Constexpr::Kind::kVec3_Vec2_Scalar, 10, 0, 0},
            Constexpr{1, Constexpr::Kind::kVec3_Vec2_Scalar, 0, 10, 0},
            Constexpr{2, Constexpr::Kind::kVec3_Vec2_Scalar, 0, 0, 10},
            Constexpr{0, Constexpr::Kind::kVec3_Vec2_Scalar, 10, 11, 12})));

INSTANTIATE_TEST_SUITE_P(
    Component,
    BuiltinTextureConstExprArgValidationTest,
    testing::Combine(
        testing::ValuesIn(
            TextureCases({ValidTextureOverload::kGather2dF32,
                          ValidTextureOverload::kGather2dOffsetF32,
                          ValidTextureOverload::kGather2dArrayF32,
                          ValidTextureOverload::kGather2dArrayOffsetF32,
                          ValidTextureOverload::kGatherCubeF32,
                          ValidTextureOverload::kGatherCubeArrayF32})),
        testing::Values(Parameter{"component", Position::kFirst, 0, 3}),
        testing::Values(
            Constexpr{Constexpr::kValid, Constexpr::Kind::kScalar, 0},
            Constexpr{Constexpr::kValid, Constexpr::Kind::kScalar, 1},
            Constexpr{Constexpr::kValid, Constexpr::Kind::kScalar, 2},
            Constexpr{Constexpr::kValid, Constexpr::Kind::kScalar, 3},
            Constexpr{0, Constexpr::Kind::kScalar, 4},
            Constexpr{0, Constexpr::Kind::kScalar, 123},
            Constexpr{0, Constexpr::Kind::kScalar, -1})));

}  // namespace texture_constexpr_args

}  // namespace
}  // namespace resolver
}  // namespace tint