// Copyright 2017 The Dawn & Tint Authors
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "dawn/samples/SampleUtils.h"

#include <algorithm>
#include <cstring>
#include <iostream>
#include <memory>
#include <string>
#include <string_view>
#include <utility>
#include <vector>

#include "dawn/common/Assert.h"
#include "dawn/common/Log.h"
#include "dawn/common/Platform.h"
#include "dawn/common/SystemUtils.h"
#include "dawn/utils/CommandLineParser.h"
#include "dawn/utils/SystemUtils.h"
#include "dawn/utils/WGPUHelpers.h"
#include "dawn/webgpu_cpp_print.h"

#ifndef __EMSCRIPTEN__
#include "GLFW/glfw3.h"
#include "dawn/dawn_proc.h"  // nogncheck
#include "dawn/native/DawnNative.h"
#include "webgpu/webgpu_glfw.h"
#else
#include <emscripten/emscripten.h>
#endif  // __EMSCRIPTEN__

// Parsed options.
static wgpu::BackendType backendType = wgpu::BackendType::Undefined;
static wgpu::AdapterType adapterType = wgpu::AdapterType::Unknown;
static std::vector<std::string> enableToggles;
static std::vector<std::string> disableToggles;
#ifndef __EMSCRIPTEN__
static dawn::native::BackendValidationLevel backendValidationLevel;
#endif  // __EMSCRIPTEN__

// Small helper to insert an extension struct into the extension chain.
template <typename T>
void InsertExtensionStruct(T* base, wgpu::ChainedStruct* toInsert) {
    toInsert->nextInChain = base->nextInChain;
    base->nextInChain = toInsert;
}

bool InitSample(int argc, const char** argv) {
    dawn::utils::CommandLineParser opts;
    auto& helpOpt = opts.AddHelp();
    auto& enableTogglesOpt = opts.AddStringList("enable-toggles", "Toggles to enable in Dawn")
                                 .ShortName('e')
                                 .Parameter("comma separated list");
    auto& disableTogglesOpt = opts.AddStringList("disable-toggles", "Toggles to disable in Dawn")
                                  .ShortName('d')
                                  .Parameter("comma separated list");
    auto& backendOpt =
        opts.AddEnum<wgpu::BackendType>({{"d3d11", wgpu::BackendType::D3D11},
                                         {"d3d12", wgpu::BackendType::D3D12},
                                         {"metal", wgpu::BackendType::Metal},
                                         {"null", wgpu::BackendType::Null},
                                         {"opengl", wgpu::BackendType::OpenGL},
                                         {"opengles", wgpu::BackendType::OpenGLES},
                                         {"vulkan", wgpu::BackendType::Vulkan}},
                                        "backend", "The backend to get an adapter from")
            .ShortName('b')
            .Default(wgpu::BackendType::Undefined);
    auto& adapterTypeOpt = opts.AddEnum<wgpu::AdapterType>(
                                   {
                                       {"discrete", wgpu::AdapterType::DiscreteGPU},
                                       {"integrated", wgpu::AdapterType::IntegratedGPU},
                                       {"cpu", wgpu::AdapterType::CPU},
                                   },
                                   "adapter-type", "The type of adapter to request")
                               .ShortName('a')
                               .Default(wgpu::AdapterType::Unknown);
#ifndef __EMSCRIPTEN__
    auto& backendValidationLevelOpt =
        opts.AddEnum<dawn::native::BackendValidationLevel>(
                {
                    {"full", dawn::native::BackendValidationLevel::Full},
                    {"partial", dawn::native::BackendValidationLevel::Partial},
                    {"disabled", dawn::native::BackendValidationLevel::Disabled},
                },
                "enable-backend-validation", "Backend validation layer level")
            .Default(dawn::native::BackendValidationLevel::Disabled);
#endif  // __EMSCRIPTEN__

    auto result = opts.Parse(argc, argv);
    if (!result.success) {
        std::cerr << result.errorMessage << "\n";
        return false;
    }

    if (helpOpt.GetValue()) {
        std::cout << "Usage: " << argv[0] << " <options>\n\noptions\n";
        opts.PrintHelp(std::cout);
        return false;
    }

    backendType = backendOpt.GetValue();
    adapterType = adapterTypeOpt.GetValue();
    enableToggles = enableTogglesOpt.GetOwnedValue();
    disableToggles = disableTogglesOpt.GetOwnedValue();
#ifndef __EMSCRIPTEN__
    backendValidationLevel = backendValidationLevelOpt.GetValue();
#endif  // __EMSCRIPTEN__
    return true;
}

// Global state
static SampleBase* sample = nullptr;

SampleBase::SampleBase() {
    sample = this;
}

SampleBase::SampleBase(uint32_t w, uint32_t h) : width(w), height(h) {
    sample = this;
}

int SampleBase::Run(unsigned int delay) {
    //
    // Early setup stuff
    //

#ifndef __EMSCRIPTEN__
    dawn::ScopedEnvironmentVar angleDefaultPlatform;
    if (dawn::GetEnvironmentVar("ANGLE_DEFAULT_PLATFORM").first.empty()) {
        angleDefaultPlatform.Set("ANGLE_DEFAULT_PLATFORM", "swiftshader");
    }

    dawnProcSetProcs(&dawn::native::GetProcs());

    // Set up this extension struct which will be used three times (instance, adapter, device).
    wgpu::DawnTogglesDescriptor dawnTogglesDesc = {};
    std::vector<const char*> enableToggleNames;
    std::vector<const char*> disabledToggleNames;
    for (const std::string& toggle : enableToggles) {
        enableToggleNames.push_back(toggle.c_str());
    }
    for (const std::string& toggle : disableToggles) {
        disabledToggleNames.push_back(toggle.c_str());
    }
    dawnTogglesDesc.enabledToggles = enableToggleNames.data();
    dawnTogglesDesc.enabledToggleCount = enableToggleNames.size();
    dawnTogglesDesc.disabledToggles = disabledToggleNames.data();
    dawnTogglesDesc.disabledToggleCount = disabledToggleNames.size();
#endif  // __EMSCRIPTEN__

    //
    // Create an instance
    //

    {
        // Base InstanceDescriptor
        wgpu::InstanceDescriptor instanceDescriptor = {};
        static constexpr auto kTimedWaitAny = wgpu::InstanceFeatureName::TimedWaitAny;
        instanceDescriptor.requiredFeatureCount = 1;
        instanceDescriptor.requiredFeatures = &kTimedWaitAny;

#ifndef __EMSCRIPTEN__
        // Add Dawn Toggles
        InsertExtensionStruct(&instanceDescriptor, &dawnTogglesDesc);

        // Add other Dawn instance options
        dawn::native::DawnInstanceDescriptor dawnInstanceDesc;
        InsertExtensionStruct(&instanceDescriptor, &dawnInstanceDesc);
        dawnInstanceDesc.backendValidationLevel = backendValidationLevel;
        // (Note Dawn has a default instance logging callback so we don't need to set one here.)
#endif  // __EMSCRIPTEN__

        sample->instance = wgpu::CreateInstance(&instanceDescriptor);
    }

    //
    // Create an adapter
    //

    {
        // Base RequestAdapterOptions
        wgpu::RequestAdapterOptions adapterOptions = {};
        adapterOptions.backendType = backendType;
        if (backendType != wgpu::BackendType::Undefined) {
            adapterOptions.featureLevel = dawn::utils::BackendRequiresCompat(backendType)
                                              ? wgpu::FeatureLevel::Compatibility
                                              : wgpu::FeatureLevel::Core;
        }

        switch (adapterType) {
            case wgpu::AdapterType::CPU:
                adapterOptions.forceFallbackAdapter = true;
                break;
            case wgpu::AdapterType::DiscreteGPU:
                adapterOptions.powerPreference = wgpu::PowerPreference::HighPerformance;
                break;
            case wgpu::AdapterType::IntegratedGPU:
                adapterOptions.powerPreference = wgpu::PowerPreference::LowPower;
                break;
            case wgpu::AdapterType::Unknown:
                break;
        }

#ifndef __EMSCRIPTEN__
        // Add Dawn Toggles
        InsertExtensionStruct(&adapterOptions, &dawnTogglesDesc);
#endif  // __EMSCRIPTEN__

        // Synchronously create the adapter
        sample->instance.WaitAny(
            sample->instance.RequestAdapter(&adapterOptions, wgpu::CallbackMode::WaitAnyOnly,
                                            [](wgpu::RequestAdapterStatus status,
                                               wgpu::Adapter adapter, wgpu::StringView message) {
                                                if (status != wgpu::RequestAdapterStatus::Success) {
                                                    dawn::ErrorLog()
                                                        << "Failed to get an adapter: " << message;
                                                    return;
                                                }
                                                sample->adapter = std::move(adapter);
                                            }),
            UINT64_MAX);
        if (sample->adapter == nullptr) {
            return 1;
        }
        wgpu::AdapterInfo info;
        sample->adapter.GetInfo(&info);
        dawn::InfoLog() << "Adaptor info:";
        dawn::InfoLog() << "  vendor: \"" << info.vendor << "\"";
        dawn::InfoLog() << "  architecture: \"" << info.architecture << "\"";
        dawn::InfoLog() << "  device: \"" << info.device << "\"";
        dawn::InfoLog() << "  subgroupSizes: { min: " << info.subgroupMinSize
                        << " max: " << info.subgroupMaxSize << " }";
    }

    //
    // Create a device
    //

    {
        // Base DeviceDescriptor
        wgpu::DeviceDescriptor deviceDesc = {};
        deviceDesc.SetDeviceLostCallback(
            wgpu::CallbackMode::AllowSpontaneous,
            [](const wgpu::Device&, wgpu::DeviceLostReason reason, wgpu::StringView message) {
                const char* reasonName = "";
                switch (reason) {
                    case wgpu::DeviceLostReason::Unknown:
                        reasonName = "Unknown";
                        break;
                    case wgpu::DeviceLostReason::Destroyed:
                        reasonName = "Destroyed";
                        break;
                    case wgpu::DeviceLostReason::CallbackCancelled:
                        reasonName = "CallbackCancelled";
                        break;
                    case wgpu::DeviceLostReason::FailedCreation:
                        reasonName = "FailedCreation";
                        break;
                    default:
                        DAWN_UNREACHABLE();
                }
                dawn::ErrorLog() << "Device lost because of " << reasonName << ": " << message;
            });
        deviceDesc.SetUncapturedErrorCallback(
            [](const wgpu::Device&, wgpu::ErrorType type, wgpu::StringView message) {
                const char* errorTypeName = "";
                switch (type) {
                    case wgpu::ErrorType::Validation:
                        errorTypeName = "Validation";
                        break;
                    case wgpu::ErrorType::OutOfMemory:
                        errorTypeName = "Out of memory";
                        break;
                    case wgpu::ErrorType::Internal:
                        errorTypeName = "Internal";
                        break;
                    case wgpu::ErrorType::Unknown:
                        errorTypeName = "Unknown";
                        break;
                    default:
                        DAWN_UNREACHABLE();
                }
                dawn::ErrorLog() << errorTypeName << " error: " << message;
            });

#ifndef __EMSCRIPTEN__
        // Add Dawn Toggles
        InsertExtensionStruct(&deviceDesc, &dawnTogglesDesc);
#endif  // __EMSCRIPTEN__

        // Synchronously create the device
        sample->instance.WaitAny(
            sample->adapter.RequestDevice(
                &deviceDesc, wgpu::CallbackMode::WaitAnyOnly,
                [](wgpu::RequestDeviceStatus status, wgpu::Device device,
                   wgpu::StringView message) {
                    if (status != wgpu::RequestDeviceStatus::Success) {
                        dawn::ErrorLog() << "Failed to get an device: " << message;
                        return;
                    }

#ifndef __EMSCRIPTEN__
                    device.SetLoggingCallback([](wgpu::LoggingType type, wgpu::StringView message) {
                        std::cerr << "Device log (" << type << "): " << message << std::endl;
                    });
#endif  // __EMSCRIPTEN__

                    sample->device = std::move(device);
                    sample->queue = sample->device.GetQueue();
                }),
            UINT64_MAX);
        if (sample->device == nullptr) {
            return 1;
        }
    }

    //
    // Set up and run the sample
    //

#ifndef __EMSCRIPTEN__
    if (!sample->Setup()) {
        dawn::ErrorLog() << "Failed to perform sample setup";
        return 1;
    }

    while (!glfwWindowShouldClose(sample->window)) {
        sample->FrameImpl();
        wgpu::Status presentStatus = sample->surface.Present();
        DAWN_ASSERT(presentStatus == wgpu::Status::Success);
        glfwPollEvents();
        if (delay) {
            dawn::utils::USleep(delay);
        }
    }
#else
    if (sample->Setup()) {
        emscripten_set_main_loop([]() { sample->FrameImpl(); }, 0, false);
    } else {
        dawn::ErrorLog() << "Failed to setup sample";
    }
#endif  // __EMSCRIPTEN__

    return 0;
}

bool SampleBase::Setup() {
#ifndef __EMSCRIPTEN__
    glfwSetErrorCallback([](int code, const char* message) {
        dawn::ErrorLog() << "GLFW error: " << code << " - " << message;
    });

    if (!glfwInit()) {
        return false;
    }

    // Create the test window with no client API.
    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
    window = glfwCreateWindow(width, height, "Dawn window", nullptr, nullptr);
    if (!window) {
        return false;
    }

    // Create the surface.
    surface = wgpu::glfw::CreateSurfaceForWindow(instance, window);
#else
    // Create the surface.
    wgpu::EmscriptenSurfaceSourceCanvasHTMLSelector canvasDesc{};
    canvasDesc.selector = "#canvas";

    wgpu::SurfaceDescriptor surfaceDesc = {};
    surfaceDesc.nextInChain = &canvasDesc;
    surface = instance.CreateSurface(&surfaceDesc);
#endif

    // Configure the surface.
    wgpu::SurfaceCapabilities capabilities;
    surface.GetCapabilities(adapter, &capabilities);
    wgpu::SurfaceConfiguration config = {};
    config.device = device;
    config.format = capabilities.formats[0];
    config.width = width;
    config.height = height;
    DAWN_ASSERT(capabilities.presentModeCount > 0);
    config.presentMode = capabilities.presentModes[0];
    surface.Configure(&config);
    this->preferredSurfaceTextureFormat = capabilities.formats[0];

    return SetupImpl();
}