//--------------------------------------------------------------------------------------
// File: PBREffectFactory.cpp
//
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.
//
// http://go.microsoft.com/fwlink/?LinkId=248929
//--------------------------------------------------------------------------------------

#include "pch.h"
#include "Effects.h"
#include "DemandCreate.h"
#include "SharedResourcePool.h"

#include "DDSTextureLoader.h"
#include "WICTextureLoader.h"

using namespace DirectX;
using Microsoft::WRL::ComPtr;

// Internal PBREffectFactory implementation class. Only one of these helpers is allocated
// per D3D device, even if there are multiple public facing PBREffectFactory instances.
class PBREffectFactory::Impl
{
public:
    Impl(_In_ ID3D11Device* device)
        : mPath{},
        mDevice(device),
        mSharing(true),
        mForceSRGB(false)
    {}

    std::shared_ptr<IEffect> CreateEffect(_In_ IEffectFactory* factory, _In_ const IEffectFactory::EffectInfo& info, _In_opt_ ID3D11DeviceContext* deviceContext);
    void CreateTexture(_In_z_ const wchar_t* texture, _In_opt_ ID3D11DeviceContext* deviceContext, _Outptr_ ID3D11ShaderResourceView** textureView);

    void ReleaseCache();
    void SetSharing(bool enabled) noexcept { mSharing = enabled; }
    void EnableForceSRGB(bool forceSRGB) noexcept { mForceSRGB = forceSRGB; }

    static SharedResourcePool<ID3D11Device*, Impl> instancePool;

    wchar_t mPath[MAX_PATH];

    ComPtr<ID3D11Device> mDevice;

private:
    using EffectCache = std::map< std::wstring, std::shared_ptr<IEffect> >;
    using TextureCache = std::map< std::wstring, ComPtr<ID3D11ShaderResourceView> >;

    EffectCache  mEffectCache;
    TextureCache mTextureCache;

    bool mSharing;
    bool mForceSRGB;

    std::mutex mutex;
};


// Global instance pool.
SharedResourcePool<ID3D11Device*, PBREffectFactory::Impl> PBREffectFactory::Impl::instancePool;


_Use_decl_annotations_
std::shared_ptr<IEffect> PBREffectFactory::Impl::CreateEffect(IEffectFactory* factory, const IEffectFactory::EffectInfo& info, ID3D11DeviceContext* deviceContext)
{
    if (mSharing && info.name && *info.name)
    {
        auto it = mEffectCache.find(info.name);
        if (mSharing && it != mEffectCache.end())
        {
            return it->second;
        }
    }

    auto effect = std::make_shared<PBREffect>(mDevice.Get());

    // We don't use EnableDefaultLighting generally for PBR as it uses Image-Based Lighting instead.

    effect->SetAlpha(info.alpha);

    ComPtr<ID3D11ShaderResourceView> albetoSrv;
    if (info.diffuseTexture && *info.diffuseTexture)
    {
        factory->CreateTexture(info.diffuseTexture, deviceContext, albetoSrv.GetAddressOf());
    }

    ComPtr<ID3D11ShaderResourceView> normalSrv;
    if (info.normalTexture && *info.normalTexture)
    {
        factory->CreateTexture(info.normalTexture, deviceContext, normalSrv.GetAddressOf());
    }

    ComPtr<ID3D11ShaderResourceView> rmaSrv;
    if (info.specularTexture && *info.specularTexture)
    {
        // We use the specular texture for the roughness/metalness/ambient-occlusion texture
        factory->CreateTexture(info.specularTexture, deviceContext, rmaSrv.GetAddressOf());
    }

    effect->SetSurfaceTextures(albetoSrv.Get(), normalSrv.Get(), rmaSrv.Get());

    if (info.emissiveTexture && *info.emissiveTexture)
    {
        ComPtr<ID3D11ShaderResourceView> srv;
        factory->CreateTexture(info.emissiveTexture, deviceContext, srv.GetAddressOf());

        effect->SetEmissiveTexture(srv.Get());
    }

    if (info.biasedVertexNormals)
    {
        effect->SetBiasedVertexNormals(true);
    }

    if (mSharing && info.name && *info.name)
    {
        std::lock_guard<std::mutex> lock(mutex);
        EffectCache::value_type v(info.name, effect);
        mEffectCache.insert(v);
    }

    return std::move(effect);
}

_Use_decl_annotations_
void PBREffectFactory::Impl::CreateTexture(const wchar_t* name, ID3D11DeviceContext* deviceContext, ID3D11ShaderResourceView** textureView)
{
    if (!name || !textureView)
        throw std::exception("invalid arguments");

#if defined(_XBOX_ONE) && defined(_TITLE)
    UNREFERENCED_PARAMETER(deviceContext);
#endif

    auto it = mTextureCache.find(name);

    if (mSharing && it != mTextureCache.end())
    {
        ID3D11ShaderResourceView* srv = it->second.Get();
        srv->AddRef();
        *textureView = srv;
    }
    else
    {
        wchar_t fullName[MAX_PATH] = {};
        wcscpy_s(fullName, mPath);
        wcscat_s(fullName, name);

        WIN32_FILE_ATTRIBUTE_DATA fileAttr = {};
        if (!GetFileAttributesExW(fullName, GetFileExInfoStandard, &fileAttr))
        {
            // Try Current Working Directory (CWD)
            wcscpy_s(fullName, name);
            if (!GetFileAttributesExW(fullName, GetFileExInfoStandard, &fileAttr))
            {
                DebugTrace("ERROR: PBREffectFactory could not find texture file '%ls'\n", name);
                throw std::exception("CreateTexture");
            }
        }

        wchar_t ext[_MAX_EXT];
        _wsplitpath_s(name, nullptr, 0, nullptr, 0, nullptr, 0, ext, _MAX_EXT);

        if (_wcsicmp(ext, L".dds") == 0)
        {
            HRESULT hr = CreateDDSTextureFromFileEx(
                mDevice.Get(), fullName, 0,
                D3D11_USAGE_DEFAULT, D3D11_BIND_SHADER_RESOURCE, 0, 0,
                mForceSRGB, nullptr, textureView);
            if (FAILED(hr))
            {
                DebugTrace("ERROR: CreateDDSTextureFromFile failed (%08X) for '%ls'\n",
                    static_cast<unsigned int>(hr), fullName);
                throw std::exception("CreateDDSTextureFromFile");
            }
        }
    #if !defined(_XBOX_ONE) || !defined(_TITLE)
        else if (deviceContext)
        {
            std::lock_guard<std::mutex> lock(mutex);
            HRESULT hr = CreateWICTextureFromFileEx(
                mDevice.Get(), deviceContext, fullName, 0,
                D3D11_USAGE_DEFAULT, D3D11_BIND_SHADER_RESOURCE, 0, 0,
                mForceSRGB ? WIC_LOADER_FORCE_SRGB : WIC_LOADER_DEFAULT, nullptr, textureView);
            if (FAILED(hr))
            {
                DebugTrace("ERROR: CreateWICTextureFromFile failed (%08X) for '%ls'\n",
                    static_cast<unsigned int>(hr), fullName);
                throw std::exception("CreateWICTextureFromFile");
            }
        }
    #endif
        else
        {
            HRESULT hr = CreateWICTextureFromFileEx(
                mDevice.Get(), fullName, 0,
                D3D11_USAGE_DEFAULT, D3D11_BIND_SHADER_RESOURCE, 0, 0,
                mForceSRGB ? WIC_LOADER_FORCE_SRGB : WIC_LOADER_DEFAULT, nullptr, textureView);
            if (FAILED(hr))
            {
                DebugTrace("ERROR: CreateWICTextureFromFile failed (%08X) for '%ls'\n",
                    static_cast<unsigned int>(hr), fullName);
                throw std::exception("CreateWICTextureFromFile");
            }
        }

        if (mSharing && *name && it == mTextureCache.end())
        {
            std::lock_guard<std::mutex> lock(mutex);
            TextureCache::value_type v(name, *textureView);
            mTextureCache.insert(v);
        }
    }
}

void PBREffectFactory::Impl::ReleaseCache()
{
    std::lock_guard<std::mutex> lock(mutex);
    mEffectCache.clear();
    mTextureCache.clear();
}



//--------------------------------------------------------------------------------------
// PBREffectFactory
//--------------------------------------------------------------------------------------

PBREffectFactory::PBREffectFactory(_In_ ID3D11Device* device)
    : pImpl(Impl::instancePool.DemandCreate(device))
{
}

PBREffectFactory::~PBREffectFactory()
{
}


PBREffectFactory::PBREffectFactory(PBREffectFactory&& moveFrom) noexcept
    : pImpl(std::move(moveFrom.pImpl))
{
}

PBREffectFactory& PBREffectFactory::operator= (PBREffectFactory&& moveFrom) noexcept
{
    pImpl = std::move(moveFrom.pImpl);
    return *this;
}

_Use_decl_annotations_
std::shared_ptr<IEffect> PBREffectFactory::CreateEffect(const EffectInfo& info, ID3D11DeviceContext* deviceContext)
{
    return pImpl->CreateEffect(this, info, deviceContext);
}

_Use_decl_annotations_
void PBREffectFactory::CreateTexture(const wchar_t* name, ID3D11DeviceContext* deviceContext, ID3D11ShaderResourceView** textureView)
{
    return pImpl->CreateTexture(name, deviceContext, textureView);
}

void PBREffectFactory::ReleaseCache()
{
    pImpl->ReleaseCache();
}

void PBREffectFactory::SetSharing(bool enabled) noexcept
{
    pImpl->SetSharing(enabled);
}

void PBREffectFactory::EnableForceSRGB(bool forceSRGB) noexcept
{
    pImpl->EnableForceSRGB(forceSRGB);
}

void PBREffectFactory::SetDirectory(_In_opt_z_ const wchar_t* path) noexcept
{
    if (path && *path != 0)
    {
        wcscpy_s(pImpl->mPath, path);
        size_t len = wcsnlen(pImpl->mPath, MAX_PATH);
        if (len > 0 && len < (MAX_PATH - 1))
        {
            // Ensure it has a trailing slash
            if (pImpl->mPath[len - 1] != L'\\')
            {
                pImpl->mPath[len] = L'\\';
                pImpl->mPath[len + 1] = 0;
            }
        }
    }
    else
        *pImpl->mPath = 0;
}

ID3D11Device* PBREffectFactory::GetDevice() const noexcept
{
    return pImpl->mDevice.Get();
}