value_to_json.hpp

#pragma once
#include <ossia/detail/fmt.hpp>
#include <ossia/detail/json.hpp>
#include <ossia/network/dataspace/color.hpp>
#include <ossia/network/dataspace/dataspace.hpp>
#include <ossia/network/value/value.hpp>
 
#include <oscpack/osc/OscTypes.h>
namespace ossia::oscquery::detail
{
 
// TODO base64 encode
struct value_to_json
{
  ossia::json_writer& writer;
  const ossia::unit_t& unit;
  void operator()(impulse) const { writer.Null(); }
  void operator()(int v) const { writer.Int(v); }
  void operator()(float v) const { writer.Double(v); }
  void operator()(bool v) const
  {
    writer.Null(); // the value is already encoded in the typetag
  }
  void operator()(char v) const { write_json(writer, v); }
  void operator()(const std::string& v) const
  {
    // TODO handle base 64
    // bool b = Base64::Encode(get<coppa::Generic>(val).buf, &out);
    writer.String(v);
  }
 
  template <std::size_t N>
  void operator()(const std::array<float, N>& t) const
  {
    if constexpr(N == 4)
    {
      if(unit == ossia::rgba8_u{})
      {
        auto r = (uint8_t)t[0];
        auto g = (uint8_t)t[1];
        auto b = (uint8_t)t[2];
        auto a = (uint8_t)t[3];
 
        writer.StartArray();
        writer.String(fmt::format("#{:02X}{:02X}{:02X}{:02X}", r, g, b, a));
        writer.EndArray();
        return;
      }
    }
 
    writer.StartArray();
    for(std::size_t i = 0; i < N; i++)
    {
      writer.Double(t[i]);
    }
    writer.EndArray();
  }
 
  void operator()(const std::vector<ossia::value>& vec) const
  {
    writer.StartArray();
    for(const auto& sub : vec)
    {
      sub.apply(*this);
    }
    writer.EndArray();
  }
 
  void operator()(const value_map_type& vec) const { }
  void operator()() const { throw std::runtime_error("value_to_json: no type"); }
};
 
static inline auto from_hex(char c)
{
  // taken from
  // https://stackoverflow.com/questions/34365746/whats-the-fastest-way-to-convert-hex-to-integer-in-c
  struct Table
  {
    long long tab[128];
    constexpr Table()
        : tab{}
    {
      tab[(int)'0'] = 0;
      tab[(int)'1'] = 1;
      tab[(int)'2'] = 2;
      tab[(int)'3'] = 3;
      tab[(int)'4'] = 4;
      tab[(int)'5'] = 5;
      tab[(int)'6'] = 6;
      tab[(int)'7'] = 7;
      tab[(int)'8'] = 8;
      tab[(int)'9'] = 9;
      tab[(int)'a'] = 10;
      tab[(int)'A'] = 10;
      tab[(int)'b'] = 11;
      tab[(int)'B'] = 11;
      tab[(int)'c'] = 12;
      tab[(int)'C'] = 12;
      tab[(int)'d'] = 13;
      tab[(int)'D'] = 13;
      tab[(int)'e'] = 14;
      tab[(int)'E'] = 14;
      tab[(int)'f'] = 15;
      tab[(int)'F'] = 15;
    }
 
    constexpr auto operator[](const std::size_t idx) const { return tab[idx]; }
  };
  static constexpr Table t;
  return t[c];
}
 
struct json_to_value
{
  const rapidjson::Value& val;
  std::string_view& typetags;
  int& typetag_cursor;
  const ossia::unit_t& unit;
  bool operator()(impulse) const
  {
    typetag_cursor++;
    return val.IsNull();
  }
 
  bool operator()(int32_t& res) const
  {
    typetag_cursor++;
 
    bool b = val.IsInt();
    if(b)
      res = val.GetInt();
    return b;
  }
 
  bool operator()(float& res) const
  {
    typetag_cursor++;
 
    bool b = val.IsNumber();
    if(b)
      res = (float)val.GetDouble();
    return b;
  }
 
  bool operator()(bool& res) const
  {
    bool b = false;
 
    switch(typetags[typetag_cursor])
    {
      case 'F':
        res = false;
        b = true;
        break;
      case 'T':
        res = true;
        b = true;
        break;
      default:
        b = val.IsBool();
        if(b)
          res = val.GetBool();
    }
    typetag_cursor++;
    return b;
  }
 
  bool operator()(char& res) const
  {
    typetag_cursor++;
 
    bool b = val.IsString() && val.GetStringLength() > 0;
    if(b)
      res = val.GetString()[0];
    return b;
  }
 
  bool operator()(std::string& res) const
  {
    typetag_cursor++;
    // TODO handle base 64
    // bool b = Base64::Encode(get<coppa::Generic>(val).buf, &out);
 
    bool b = val.IsString();
    if(b)
      res = std::string(val.GetString(), val.GetStringLength());
    return b;
  }
 
  template <std::size_t N>
  bool operator()(std::array<float, N>& res) const
  {
    if constexpr(N == 4)
    {
      if(typetags[typetag_cursor] == oscpack::TypeTagValues::RGBA_COLOR_TYPE_TAG)
      {
        typetag_cursor += 1;
        bool b = val.IsString();
        if(b)
        {
          std::string_view hex(val.GetString(), val.GetStringLength());
          if(hex.size() == 9) // "#00000000"
          {
            res[0] = (from_hex(hex[1]) * 16 + from_hex(hex[2]));
            res[1] = (from_hex(hex[3]) * 16 + from_hex(hex[4]));
            res[2] = (from_hex(hex[5]) * 16 + from_hex(hex[6]));
            res[3] = (from_hex(hex[7]) * 16 + from_hex(hex[8]));
            return true;
          }
        }
        return false;
      }
    }
 
    typetag_cursor += N;
    bool b = val.IsArray();
    if(b)
    {
      auto arr = val.GetArray();
      if(arr.Size() == N)
      {
        for(int i = 0; i < (int)N; i++)
        {
          if(arr[i].IsNumber())
          {
            res[i] = arr[i].GetDouble();
          }
          else
          {
            b = false;
            break;
          }
        }
      }
      else
      {
        b = false;
      }
    }
    return b;
  }
 
  bool
  handleVecElement(const rapidjson::Value& elt, std::vector<ossia::value>& res) const
  {
    if((int)typetags.size() > typetag_cursor)
    {
      switch(typetags[typetag_cursor])
      {
        case oscpack::TypeTagValues::INFINITUM_TYPE_TAG: {
          ossia::impulse i;
          if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
            return false;
 
          res.emplace_back(i);
          return true;
        }
        case oscpack::TypeTagValues::INT32_TYPE_TAG: {
          int32_t i{};
          if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
            return false;
 
          res.emplace_back(i);
          return true;
        }
        case oscpack::TypeTagValues::FLOAT_TYPE_TAG: {
          float i{};
          if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
            return false;
 
          res.emplace_back(i);
          return true;
        }
        case oscpack::TypeTagValues::CHAR_TYPE_TAG: {
          char i{};
          if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
            return false;
 
          res.emplace_back(i);
          return true;
        }
 
        case oscpack::TypeTagValues::TRUE_TYPE_TAG:
        case oscpack::TypeTagValues::FALSE_TYPE_TAG: {
          bool i{};
          if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
            return false;
 
          res.emplace_back(i);
          return true;
        }
 
        case oscpack::TypeTagValues::STRING_TYPE_TAG:
        case oscpack::TypeTagValues::SYMBOL_TYPE_TAG: {
          std::string i;
          if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
            return false;
 
          res.emplace_back(std::move(i));
          return true;
        }
 
        case oscpack::TypeTagValues::ARRAY_BEGIN_TYPE_TAG: {
          if(can_read("[ff]"))
          {
            ++typetag_cursor; // We skip the '['
            std::array<float, 2> i;
            if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
              return false;
 
            res.emplace_back(i);
            ++typetag_cursor; // We skip the ']'
          }
          else if(can_read("[fff]"))
          {
            ++typetag_cursor; // We skip the '['
            std::array<float, 3> i;
            if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
              return false;
 
            res.emplace_back(i);
            ++typetag_cursor; // We skip the ']'
          }
          else if(can_read("[ffff]"))
          {
            ++typetag_cursor; // We skip the '['
            std::array<float, 4> i;
            if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
              return false;
 
            res.emplace_back(i);
            ++typetag_cursor; // We skip the ']'
          }
          else
          {
            std::vector<ossia::value> i;
            ++typetag_cursor; // We skip the '['
            if(!json_to_value{elt, typetags, typetag_cursor, unit}(i))
              return false;
 
            ++typetag_cursor; // We skip the ']'
            res.emplace_back(std::move(i));
          }
          return true;
        }
        case oscpack::TypeTagValues::ARRAY_END_TYPE_TAG:
        default: {
          // We should never end up here
          return false;
        }
      }
    }
    else
    {
      return false;
    }
  }
 
  bool can_read(std::string_view sv) const noexcept
  {
    const auto res = typetags.find(sv);
    if(res == std::string_view::npos)
    {
      return false;
    }
    else
    {
      return int64_t(res) == typetag_cursor;
    }
  }
 
  bool operator()(std::vector<ossia::value>& res) const
  {
    // TODO read from the typetag
    bool b = val.IsArray();
    if(b)
    {
      auto arr = val.GetArray();
 
      for(const auto& elt : arr)
      {
        if(!handleVecElement(elt, res))
          return false;
      }
    }
    return b;
  }
 
  bool operator()(ossia::value_map_type& res) const { return false; }
  bool operator()() const { throw std::runtime_error("json_to_value: no type"); }
};
 
struct json_to_single_value
{
  const rapidjson::Value& val;
  std::string_view typetags;
 
  bool operator()(impulse) const { return val.IsNull(); }
 
  bool operator()(int32_t& res) const
  {
    bool b = val.IsInt();
    if(b)
      res = val.GetInt();
    return b;
  }
 
  bool operator()(float& res) const
  {
    bool b = val.IsNumber();
    if(b)
      res = (float)val.GetDouble();
    return b;
  }
 
  bool operator()(bool& res) const
  {
    bool b = false;
    if(typetags == "F")
    {
      res = false;
      b = true;
    }
    else if(typetags == "T")
    {
      res = true;
      b = true;
    }
    else
    {
      // weird case where the typetag is wrongly set
      // then we expect that the value is not null
      // This doesn't follow the OSCQuery specification
      bool b = val.IsBool();
      if(b)
        res = val.GetBool();
    }
    return b;
  }
 
  bool operator()(char& res) const
  {
    bool b = val.IsString() && val.GetStringLength() > 0;
    if(b)
      res = val.GetString()[0];
    return b;
  }
 
  bool operator()(std::string& res) const
  {
    // TODO handle base 64
    // bool b = Base64::Encode(get<coppa::Generic>(val).buf, &out);
 
    bool b = val.IsString();
    if(b)
      res = std::string(val.GetString(), val.GetStringLength());
    return b;
  }
 
  template <std::size_t N>
  bool operator()(std::array<float, N>& res) const
  {
    if constexpr(N == 4)
    {
      if(typetags[0] == oscpack::TypeTagValues::RGBA_COLOR_TYPE_TAG)
      {
        bool b = val.IsString();
        if(b)
        {
          std::string_view hex(val.GetString(), val.GetStringLength());
          if(hex.size() == 9) // "#00000000"
          {
            res[0] = (from_hex(hex[1]) * 16 + from_hex(hex[2]));
            res[1] = (from_hex(hex[3]) * 16 + from_hex(hex[4]));
            res[2] = (from_hex(hex[5]) * 16 + from_hex(hex[6]));
            res[3] = (from_hex(hex[7]) * 16 + from_hex(hex[8]));
            return true;
          }
        }
        return false;
      }
    }
 
    return false;
  }
 
  bool operator()(std::vector<ossia::value>& res) const { return false; }
  bool operator()(ossia::value_map_type& res) const { return false; }
 
  bool operator()() const { throw std::runtime_error("json_to_value: no type"); }
};
 
inline ossia::value ReadValue(const rapidjson::Value& val)
{
  switch(val.GetType())
  {
    case rapidjson::kNumberType: {
      if(val.IsInt())
        return val.GetInt();
      else if(val.IsUint())
        return (int)val.GetUint();
      // There is also int64 and uint64 but we'll get a better approximation
      // with double
      else
        return val.GetDouble();
    }
    case rapidjson::kFalseType:
      return false;
    case rapidjson::kTrueType:
      return true;
 
    case rapidjson::kArrayType: {
      std::vector<ossia::value> tpl;
      tpl.reserve(val.Size());
      for(auto& elt : val.GetArray())
      {
        tpl.push_back(ReadValue(elt));
      }
      return ossia::value{std::move(tpl)};
    }
 
    case rapidjson::kStringType:
      return get_string(val);
 
    case rapidjson::kObjectType:
    case rapidjson::kNullType:
    default:
      return ossia::impulse{};
  }
}
 
struct json_to_value_unchecked
{
  const rapidjson::Value& val;
  void operator()(impulse) const { }
 
  void operator()(int32_t& res) const
  {
    if(val.IsInt())
      res = val.GetInt();
  }
 
  void operator()(float& res) const
  {
    if(val.IsNumber())
      res = (float)val.GetDouble();
  }
 
  void operator()(bool& res) const
  {
    if(val.IsBool())
      res = val.GetBool();
  }
 
  void operator()(char& res) const
  {
    if(val.IsString() && val.GetStringLength() > 0)
      res = val.GetString()[0];
  }
 
  void operator()(std::string& res) const
  {
    // TODO handle base 64
    // bool b = Base64::Encode(get<coppa::Generic>(val).buf, &out);
 
    if(val.IsString())
      res = get_string(val);
  }
 
  template <std::size_t N>
  void operator()(std::array<float, N>& res) const
  {
    if(val.IsArray())
    {
      auto arr = val.GetArray();
      if(arr.Size() == N)
      {
        for(int i = 0; i < (int)N; i++)
        {
          res[i] = arr[i].GetDouble();
        }
      }
    }
  }
 
  void operator()(std::vector<ossia::value>& res) const
  {
    if(val.IsArray())
    {
      res.clear();
      auto arr = val.GetArray();
      for(const auto& elt : arr)
      {
        res.push_back(ReadValue(elt));
      }
    }
  }
 
  void operator()(value_map_type& res) const { }
 
  void operator()() const
  {
    throw std::runtime_error("json_to_value_unchecked: no type");
  }
};
}