// Copyright 2023 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 <string>

#include "gtest/gtest-spi.h"
#include "src/tint/lang/core/ir/function.h"
#include "src/tint/lang/core/ir/ir_helper_test.h"

namespace tint::core::ir {
namespace {

using namespace tint::core::number_suffixes;  // NOLINT
using IR_FunctionTest = IRTestHelper;

TEST_F(IR_FunctionTest, Fail_NullReturnType) {
    EXPECT_FATAL_FAILURE(
        {
            Module mod;
            Builder b{mod};
            b.Function("my_func", nullptr);
        },
        "");
}

TEST_F(IR_FunctionTest, Fail_DoubleReturnBuiltin) {
    EXPECT_FATAL_FAILURE(
        {
            Module mod;
            Builder b{mod};
            auto* f = b.Function("my_func", mod.Types().void_());
            f->SetReturnBuiltin(Function::ReturnBuiltin::kFragDepth);
            f->SetReturnBuiltin(Function::ReturnBuiltin::kPosition);
        },
        "");
}

TEST_F(IR_FunctionTest, Fail_NullParam) {
    EXPECT_FATAL_FAILURE(
        {
            Module mod;
            Builder b{mod};
            auto* f = b.Function("my_func", mod.Types().void_());
            f->SetParams({nullptr});
        },
        "");
}

TEST_F(IR_FunctionTest, Fail_NullBlock) {
    EXPECT_FATAL_FAILURE(
        {
            Module mod;
            Builder b{mod};
            auto* f = b.Function("my_func", mod.Types().void_());
            f->SetBlock(nullptr);
        },
        "");
}

TEST_F(IR_FunctionTest, Clone) {
    auto* f =
        b.Function("my_func", mod.Types().i32(), Function::PipelineStage::kCompute, {{2, 3, 4}});
    f->SetReturnBuiltin(Function::ReturnBuiltin::kFragDepth);
    f->SetReturnLocation(
        1, Interpolation{core::InterpolationType::kFlat, core::InterpolationSampling::kCentroid});
    f->SetReturnInvariant(true);

    auto* param1 = b.FunctionParam("a", mod.Types().i32());
    auto* param2 = b.FunctionParam("b", mod.Types().f32());
    f->SetParams({param1, param2});

    auto* new_param1 = clone_ctx.Clone(param1);
    auto* new_param2 = clone_ctx.Clone(param2);
    auto* new_f = clone_ctx.Clone(f);

    EXPECT_NE(f, new_f);
    EXPECT_EQ(std::string("my_func"), mod.NameOf(new_f).Name());

    EXPECT_EQ(Function::PipelineStage::kCompute, new_f->Stage());
    EXPECT_TRUE(new_f->WorkgroupSize().has_value());
    auto wg = new_f->WorkgroupSize().value();
    EXPECT_EQ(2u, wg[0]);
    EXPECT_EQ(3u, wg[1]);
    EXPECT_EQ(4u, wg[2]);

    EXPECT_EQ(mod.Types().i32(), new_f->ReturnType());

    EXPECT_TRUE(new_f->ReturnBuiltin().has_value());
    EXPECT_EQ(Function::ReturnBuiltin::kFragDepth, new_f->ReturnBuiltin().value());

    EXPECT_TRUE(new_f->ReturnLocation().has_value());
    auto loc = new_f->ReturnLocation().value();
    EXPECT_EQ(1u, loc.value);
    EXPECT_EQ(core::InterpolationType::kFlat, loc.interpolation->type);
    EXPECT_EQ(core::InterpolationSampling::kCentroid, loc.interpolation->sampling);

    EXPECT_TRUE(new_f->ReturnInvariant());

    EXPECT_EQ(2u, new_f->Params().Length());
    EXPECT_EQ(new_param1, new_f->Params()[0]);
    EXPECT_EQ(new_param2, new_f->Params()[1]);

    // Cloned functions are not automatically added to the module.
    EXPECT_EQ(mod.functions.Length(), 1u);
}

TEST_F(IR_FunctionTest, CloneWithExits) {
    auto* f = b.Function("my_func", mod.Types().void_());
    b.Append(f->Block(), [&] { b.Return(f); });

    auto* new_f = clone_ctx.Clone(f);
    EXPECT_EQ(1u, new_f->Block()->Length());
    EXPECT_TRUE(new_f->Block()->Front()->Is<Return>());
    EXPECT_EQ(new_f, new_f->Block()->Front()->As<Return>()->Func());
}

}  // namespace
}  // namespace tint::core::ir