ParamSerializers.h

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/*
 * Copyright (c) 2018-2019 pongasoft
 *
 * Licensed under the Apache License, Version 2.0 or the MIT license,
 * at your option. You may not use this file except in compliance with
 * one of these licenses. You may obtain copies of the licenses at:
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 * https://opensource.org/licenses/MIT
 *
 * 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.
 *
 * @author Yan Pujante
 */
#pragma once
 
#include <pongasoft/logging/logging.h>
#include <pongasoft/Utils/Constants.h>
#include <pongasoft/Utils/Misc.h>
#include <pongasoft/Utils/Metaprogramming.h>
#include <pluginterfaces/vst/vsttypes.h>
#include <base/source/fstreamer.h>
#include <string>
#include <string_view>
#include <iostream>
#include <memory>
#include <sstream>
#include <map>
#include <vector>
#include <concepts>
 
namespace pongasoft::VST {
 
using namespace Steinberg;
using namespace Steinberg::Vst;

template<typename T>
class IDiscreteConverter
{
public:
  virtual ~IDiscreteConverter() = default;
  virtual int32 getStepCount() const = 0;
  virtual tresult convertFromDiscreteValue(int32 iDiscreteValue, T &oValue) const = 0;
  virtual tresult convertToDiscreteValue(T const &iValue, int32 &oDiscreteValue) const = 0;
};

template<typename T>
class StaticCastDiscreteConverter : public IDiscreteConverter<T>
{
public:
  // Constructor
  explicit StaticCastDiscreteConverter(int32 iStepCount) : fStepCount(iStepCount)
  {
    DCHECK_F(fStepCount > 0);
  }
 
  // getStepCount
  int32 getStepCount() const override { return fStepCount; }
 
  // convertFromDiscreteValue
  tresult convertFromDiscreteValue(int32 iDiscreteValue, T &oValue) const override
  {
    iDiscreteValue = Utils::clamp(iDiscreteValue, Utils::ZERO_INT32, fStepCount);
    oValue = static_cast<T>(iDiscreteValue);
    return kResultOk;
  }
 
  // convertToDiscreteValue
  tresult convertToDiscreteValue(T const &iValue, int32 &oDiscreteValue) const override
  {
    oDiscreteValue = static_cast<int32>(iValue);
    oDiscreteValue = Utils::clamp(oDiscreteValue, Utils::ZERO_INT32, fStepCount);
    return kResultOk;
  }
 
protected:
  int32 fStepCount;
};

template<typename T>
class IParamSerializer
{
public:
  using ParamType = T;

  virtual ~IParamSerializer() = default;

  virtual tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const { return kNotImplemented; }

  virtual tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const { return kNotImplemented; }

  virtual void writeToStream(ParamType const &iValue, std::ostream &oStream) const
  {
    if constexpr(Utils::OstreamWritable<ParamType>)
    {
      oStream << iValue;
    }
  }
 
  virtual std::string toString(ParamType const &iValue, int32 iPrecision) const
  {
    std::ostringstream s;
    if(iPrecision >= 0)
    {
      s.precision(iPrecision);
      s.setf(std::ios::fixed);
    }
    writeToStream(iValue, s);
    return s.str();
  }
};
 
template<typename T, typename ParamType>
concept IsDerivedFromIParamSerializer = std::derived_from<T, IParamSerializer<ParamType>>;

template<typename T>
concept IsIParamSerializer = requires
                             { typename T::ParamType; } &&
                             IsDerivedFromIParamSerializer<T, typename T::ParamType>;

namespace IBStreamHelper {
 
// readDouble - contrary to IBStreamer.readDouble, this method does NOT modify oValue if cannot be read
inline tresult readDouble(IBStreamer &iStreamer, double &oValue)
{
  double value;
  if(!iStreamer.readDouble(value))
    return kResultFalse;
  oValue = value;
  return kResultOk;
}
 
// readFloat - contrary to IBStreamer.readFloat, this method does NOT modify oValue if cannot be read
inline tresult readFloat(IBStreamer &iStreamer, float &oValue)
{
  float value;
  if(!iStreamer.readFloat(value))
    return kResultFalse;
  oValue = value;
  return kResultOk;
}
 
// readFloatArray - contrary to IBStreamer.readFloatArray, this method returns tresult and can use any Int type
template<std::integral Int>
tresult readFloatArray(IBStreamer &iStreamer, float *oValue, Int iCount)
{
  for(Int i = 0; i < iCount; i++)
  {
    if(!iStreamer.readFloat(oValue[i]))
      return kResultFalse;
  }
  return kResultOk;
}
 
 
// readInt64 - contrary to IBStreamer.readInt64, this method does NOT modify oValue if cannot be read
inline tresult readInt64(IBStreamer &iStreamer, int64 &oValue)
{
  int64 value;
  if(!iStreamer.readInt64(value))
    return kResultFalse;
  oValue = value;
  return kResultOk;
}
 
// readInt64 - contrary to IBStreamer.readInt64, this method does NOT modify oValue if cannot be read
inline tresult readInt64u(IBStreamer &iStreamer, uint64 &oValue)
{
  uint64 value;
  if(!iStreamer.readInt64u(value))
    return kResultFalse;
  oValue = value;
  return kResultOk;
}
 
// readInt32 - contrary to IBStreamer.readInt32, this method does NOT modify oValue if cannot be read
inline tresult readInt32(IBStreamer &iStreamer, int32 &oValue)
{
  int32 value;
  if(!iStreamer.readInt32(value))
    return kResultFalse;
  oValue = value;
  return kResultOk;
}
 
// readBool - contrary to IBStreamer.readBool, this method does NOT modify oValue if cannot be read
inline tresult readBool(IBStreamer &iStreamer, bool &oValue)
{
  bool value;
  if(!iStreamer.readBool(value))
    return kResultFalse;
  oValue = value;
  return kResultOk;
}
 
}

class RawParamSerializer : public IParamSerializer<ParamValue>
{
public:
  tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const override
  {
    return IBStreamHelper::readDouble(iStreamer, oValue);
  }
 
  tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const override
  {
    oStreamer.writeDouble(iValue);
    return kResultOk;
  }
};

class DoubleParamSerializer : public IParamSerializer<double>
{
public:
  tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const override
  {
    return IBStreamHelper::readDouble(iStreamer, oValue);
  }
 
  tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const override
  {
    oStreamer.writeDouble(iValue);
    return kResultOk;
  }
};

class Int32ParamSerializer : public IParamSerializer<int32>
{
public:
  tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const override
  {
    return IBStreamHelper::readInt32(iStreamer, oValue);
  }
 
  tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const override
  {
    oStreamer.writeInt32(iValue);
    return kResultOk;
  }
};

class Int64ParamSerializer : public IParamSerializer<int64>
{
public:
  tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const override
  {
    return IBStreamHelper::readInt64(iStreamer, oValue);
  }
 
  tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const override
  {
    oStreamer.writeInt64(iValue);
    return kResultOk;
  }
};

class BooleanParamSerializer : public IParamSerializer<bool>, public IDiscreteConverter<bool>
{
public:
  explicit BooleanParamSerializer(std::string iFalseString = "Off",
                                  std::string iTrueString = "On") :
    fFalseString{std::move(iFalseString)},
    fTrueString{std::move(iTrueString)}
  {}
 
  tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const override
  {
    return IBStreamHelper::readBool(iStreamer, oValue);
  }
 
  tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const override
  {
    oStreamer.writeBool(iValue);
    return kResultOk;
  }
 
  void writeToStream(ParamType const &iValue, std::ostream &oStream) const override
  {
    oStream << (iValue ? fTrueString : fFalseString);
  }
 
  int32 getStepCount() const override { return 1; }
 
  tresult convertFromDiscreteValue(int32 iDiscreteValue, bool &oValue) const override
  {
    oValue = iDiscreteValue != 0;
    return kResultOk;
  }
 
  tresult convertToDiscreteValue(const bool &iValue, int32 &oDiscreteValue) const override
  {
    oDiscreteValue = iValue ? 1 : 0;
    return kResultOk;
  }
 
protected:
  std::string fFalseString;
  std::string fTrueString;
};
 

template<int size = 128>
class CStringParamSerializer : public IParamSerializer<char[size]>
{
public:
  using ParamType = char[size];
 
  // readFromStream
  tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const override
  {
    if(iStreamer.readRaw(static_cast<void*>(oValue), size) == size)
    {
      oValue[size - 1] = 0; // making sure it is null terminated
      return kResultOk;
    }
    else
      return kResultFalse;
  }
 
  // writeToStream - IBStreamer
  tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const override
  {
    if(oStreamer.writeRaw(static_cast<void const *>(iValue), size) == size)
      return kResultOk;
    else
      return kResultFalse;
  }
 
  // writeToStream - std::ostream
  void writeToStream(ParamType const &iValue, std::ostream &oStream) const override
  {
    std::string_view sv(iValue, size);
    auto pos = sv.find('\0');
    if(pos != std::string_view::npos)
    {
      oStream << sv.substr(0, pos);
    }
    else
    {
      oStream << sv;
      DLOG_F(WARNING, "%.*s not properly null terminated!", static_cast<int>(size), iValue);
    }
  }
};

template<typename T, class Compare = std::less<T>>
class DiscreteTypeParamSerializer : public IParamSerializer<T>, public IDiscreteConverter<T>
{
public:
  using TMap = std::map<T, std::pair<std::string, int32>, Compare>;

  using TList = std::vector<T>;

  using ConstructorType = std::initializer_list<std::pair<const T, std::string>> const &;
 
  using ParamType = T;
 
  // DiscreteTypeParamSerializer
  DiscreteTypeParamSerializer(ConstructorType iInitList)
  {
#ifndef NDEBUG
    // by definition, a discrete parameter has a step count > 0
    auto stepCount = static_cast<int32>(iInitList.size() - 1);
    DCHECK_F(stepCount > 0);
#endif
 
    int32 i = 0;
    for(auto &pair : iInitList)
    {
      fMap[pair.first] = std::make_pair(pair.second, i);
      fList.emplace_back(pair.first);
      i++;
    }
 
    // sanity check... if not the same size it means that 2 entries in the list were the same!
    DCHECK_F(fList.size() == fMap.size());
  }
 
  // getStepCount
  int32 getStepCount() const override { return static_cast<int32>(fMap.size() - 1); }
 
  // convertFromDiscreteValue
  tresult convertFromDiscreteValue(int32 iDiscreteValue, ParamType &oValue) const override
  {
    if(iDiscreteValue < 0 || iDiscreteValue > getStepCount())
      return kResultFalse;
    oValue = fList[iDiscreteValue];
    return kResultOk;
  }
 
  // convertToDiscreteValue
  tresult convertToDiscreteValue(ParamType const &iValue, int32 &oDiscreteValue) const override
  {
    auto iter = fMap.find(iValue);
    if(iter != fMap.cend())
    {
      oDiscreteValue = std::get<1>(iter->second);
      return kResultOk;
    }
    else
    {
      DLOG_F(WARNING, "could not convertToDiscreteValue...");
      return kResultFalse;
    }
  }
 
  // readFromStream
  tresult readFromStream(IBStreamer &iStreamer, ParamType &oValue) const override
  {
    int32 discreteValue;
    if(IBStreamHelper::readInt32(iStreamer, discreteValue) == kResultOk)
    {
      return convertFromDiscreteValue(discreteValue, oValue);
    }
    return kResultFalse;
  }
 
  // writeToStream
  tresult writeToStream(const ParamType &iValue, IBStreamer &oStreamer) const override
  {
    int32 discreteValue;
    if(convertToDiscreteValue(iValue, discreteValue) == kResultOk)
    {
      if(oStreamer.writeInt32(discreteValue))
        return kResultOk;
    }
 
    return kResultFalse;
  }
 
  // writeToStream
  void writeToStream(ParamType const &iValue, std::ostream &oStream) const override
  {
    auto iter = fMap.find(iValue);
    if(iter != fMap.cend())
    {
      oStream << std::get<0>(iter->second);
    }
  }
 
private:
  TMap fMap{};
  TList fList{};
};
 
}