// 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.

#ifndef SRC_TINT_WRITER_SPIRV_IR_TEST_HELPER_IR_H_
#define SRC_TINT_WRITER_SPIRV_IR_TEST_HELPER_IR_H_

#include <string>
#include <utility>

#include "gtest/gtest.h"
#include "spirv-tools/libspirv.hpp"
#include "src/tint/ir/builder.h"
#include "src/tint/ir/validate.h"
#include "src/tint/writer/spirv/ir/generator_impl_ir.h"
#include "src/tint/writer/spirv/spv_dump.h"

namespace tint::writer::spirv {

// Helper macro to check whether the SPIR-V output contains an instruction, dumping the full output
// if the instruction was not present.
#define EXPECT_INST(inst) ASSERT_THAT(output_, testing::HasSubstr(inst)) << output_

/// The element type of a test.
enum TestElementType {
    kBool,
    kI32,
    kU32,
    kF32,
    kF16,
};

/// Base helper class for testing the SPIR-V generator implementation.
template <typename BASE>
class SpvGeneratorTestHelperBase : public BASE {
  public:
    SpvGeneratorTestHelperBase() : generator_(&mod, false) {}

    /// The test module.
    ir::Module mod;
    /// The test builder.
    ir::Builder b{mod};
    /// The type manager.
    type::Manager& ty{mod.Types()};

  protected:
    /// The SPIR-V generator.
    GeneratorImplIr generator_;

    /// Validation errors
    std::string err_;

    /// SPIR-V output.
    std::string output_;

    /// @returns the error string from the validation
    std::string Error() const { return err_; }

    /// @returns true if the IR module is valid
    bool IRIsValid() {
        auto res = ir::Validate(mod);
        if (!res) {
            err_ = res.Failure().str();
            return false;
        }
        return true;
    }

    /// Run the generator on the IR module and validate the result.
    /// @returns true if generation and validation succeeded
    bool Generate() {
        if (!generator_.Generate()) {
            err_ = generator_.Diagnostics().str();
            return false;
        }
        if (!Validate()) {
            return false;
        }

        output_ = Disassemble(generator_.Result(), SPV_BINARY_TO_TEXT_OPTION_FRIENDLY_NAMES |
                                                       SPV_BINARY_TO_TEXT_OPTION_INDENT |
                                                       SPV_BINARY_TO_TEXT_OPTION_COMMENT);
        return true;
    }

    /// Validate the generated SPIR-V using the SPIR-V Tools Validator.
    /// @returns true if validation succeeded, false otherwise
    bool Validate() {
        auto binary = generator_.Result();

        std::string spv_errors;
        auto msg_consumer = [&spv_errors](spv_message_level_t level, const char*,
                                          const spv_position_t& position, const char* message) {
            switch (level) {
                case SPV_MSG_FATAL:
                case SPV_MSG_INTERNAL_ERROR:
                case SPV_MSG_ERROR:
                    spv_errors +=
                        "error: line " + std::to_string(position.index) + ": " + message + "\n";
                    break;
                case SPV_MSG_WARNING:
                    spv_errors +=
                        "warning: line " + std::to_string(position.index) + ": " + message + "\n";
                    break;
                case SPV_MSG_INFO:
                    spv_errors +=
                        "info: line " + std::to_string(position.index) + ": " + message + "\n";
                    break;
                case SPV_MSG_DEBUG:
                    break;
            }
        };

        spvtools::SpirvTools tools(SPV_ENV_VULKAN_1_2);
        tools.SetMessageConsumer(msg_consumer);

        auto result = tools.Validate(binary);
        err_ = std::move(spv_errors);
        return result;
    }

    /// @returns the disassembled types from the generated module.
    std::string DumpTypes() { return DumpInstructions(generator_.Module().Types()); }

    /// Helper to make a scalar type corresponding to the element type `type`.
    /// @param type the element type
    /// @returns the scalar type
    const type::Type* MakeScalarType(TestElementType type) {
        switch (type) {
            case kBool:
                return ty.bool_();
            case kI32:
                return ty.i32();
            case kU32:
                return ty.u32();
            case kF32:
                return ty.f32();
            case kF16:
                return ty.f16();
        }
        return nullptr;
    }

    /// Helper to make a vector type corresponding to the element type `type`.
    /// @param type the element type
    /// @returns the vector type
    const type::Type* MakeVectorType(TestElementType type) { return ty.vec2(MakeScalarType(type)); }

    /// Helper to make a scalar value with the scalar type `type`.
    /// @param type the element type
    /// @returns the scalar value
    ir::Value* MakeScalarValue(TestElementType type) {
        switch (type) {
            case kBool:
                return b.Constant(true);
            case kI32:
                return b.Constant(i32(1));
            case kU32:
                return b.Constant(u32(1));
            case kF32:
                return b.Constant(f32(1));
            case kF16:
                return b.Constant(f16(1));
        }
        return nullptr;
    }

    /// Helper to make a vector value with an element type of `type`.
    /// @param type the element type
    /// @returns the vector value
    ir::Value* MakeVectorValue(TestElementType type) {
        switch (type) {
            case kBool:
                return b.Constant(mod.constant_values.Composite(
                    MakeVectorType(type),
                    utils::Vector<const constant::Value*, 2>{mod.constant_values.Get(true),
                                                             mod.constant_values.Get(false)}));
            case kI32:
                return b.Constant(mod.constant_values.Composite(
                    MakeVectorType(type),
                    utils::Vector<const constant::Value*, 2>{mod.constant_values.Get(i32(42)),
                                                             mod.constant_values.Get(i32(-10))}));
            case kU32:
                return b.Constant(mod.constant_values.Composite(
                    MakeVectorType(type),
                    utils::Vector<const constant::Value*, 2>{mod.constant_values.Get(u32(42)),
                                                             mod.constant_values.Get(u32(10))}));
            case kF32:
                return b.Constant(mod.constant_values.Composite(
                    MakeVectorType(type),
                    utils::Vector<const constant::Value*, 2>{mod.constant_values.Get(f32(42)),
                                                             mod.constant_values.Get(f32(-0.5))}));
            case kF16:
                return b.Constant(mod.constant_values.Composite(
                    MakeVectorType(type),
                    utils::Vector<const constant::Value*, 2>{mod.constant_values.Get(f16(42)),
                                                             mod.constant_values.Get(f16(-0.5))}));
        }
        return nullptr;
    }
};

using SpvGeneratorImplTest = SpvGeneratorTestHelperBase<testing::Test>;

template <typename T>
using SpvGeneratorImplTestWithParam = SpvGeneratorTestHelperBase<testing::TestWithParam<T>>;

}  // namespace tint::writer::spirv

#endif  // SRC_TINT_WRITER_SPIRV_IR_TEST_HELPER_IR_H_