Refactor json utility to wxdata, add ReadJsonString function

wxdata/source/scwx/util/json.cpp

@@ -0,0 +1,199 @@
+#include <scwx/util/json.hpp>
+#include <scwx/util/logger.hpp>
+
+#include <fstream>
+
+#include <boost/json.hpp>
+#include <fmt/ranges.h>
+
+namespace scwx::util::json
+{
+
+static const std::string logPrefix_ = "scwx::util::json";
+static const auto        logger_    = scwx::util::Logger::Create(logPrefix_);
+
+/* Adapted from:
+ * https://www.boost.org/doc/libs/1_77_0/libs/json/doc/html/json/examples.html#json.examples.pretty
+ *
+ * Copyright (c) 2019, 2020 Vinnie Falco
+ * Copyright (c) 2020 Krystian Stasiowski
+ * Distributed under the Boost Software License, Version 1.0. (See
+ * http://www.boost.org/LICENSE_1_0.txt)
+ */
+static void PrettyPrintJson(std::ostream&             os,
+                            boost::json::value const& jv,
+                            std::string*              indent = nullptr);
+
+boost::json::value ReadJsonFile(const std::string& path)
+{
+   boost::json::value json;
+
+   std::ifstream ifs {path};
+   json = ReadJsonStream(ifs);
+
+   return json;
+}
+
+boost::json::value ReadJsonStream(std::istream& is)
+{
+   std::string line;
+
+   boost::json::stream_parser p;
+   boost::system::error_code  ec;
+
+   while (std::getline(is, line))
+   {
+      p.write(line, ec);
+      if (ec)
+      {
+         logger_->warn("{}", ec.message());
+         return nullptr;
+      }
+   }
+
+   p.finish(ec);
+   if (ec)
+   {
+      logger_->warn("{}", ec.message());
+      return nullptr;
+   }
+
+   return p.release();
+}
+
+boost::json::value ReadJsonString(std::string_view sv)
+{
+   boost::json::stream_parser p;
+   boost::system::error_code  ec;
+
+   p.write(sv, ec);
+   if (ec)
+   {
+      logger_->warn("{}", ec.message());
+      return nullptr;
+   }
+
+   p.finish(ec);
+   if (ec)
+   {
+      logger_->warn("{}", ec.message());
+      return nullptr;
+   }
+
+   return p.release();
+}
+
+void WriteJsonFile(const std::string&        path,
+                   const boost::json::value& json,
+                   bool                      prettyPrint)
+{
+   std::ofstream ofs {path};
+
+   if (!ofs.is_open())
+   {
+      logger_->warn("Cannot write JSON file: \"{}\"", path);
+   }
+   else
+   {
+      if (prettyPrint)
+      {
+         PrettyPrintJson(ofs, json);
+      }
+      else
+      {
+         ofs << json;
+      }
+      ofs.close();
+   }
+}
+
+static void PrettyPrintJson(std::ostream&             os,
+                            boost::json::value const& jv,
+                            std::string*              indent)
+{
+   std::string indent_;
+   if (!indent)
+      indent = &indent_;
+   switch (jv.kind())
+   {
+   case boost::json::kind::object:
+   {
+      os << "{\n";
+      indent->append(4, ' ');
+      auto const& obj = jv.get_object();
+      if (!obj.empty())
+      {
+         auto it = obj.begin();
+         for (;;)
+         {
+            os << *indent << boost::json::serialize(it->key()) << " : ";
+            PrettyPrintJson(os, it->value(), indent);
+            if (++it == obj.end())
+               break;
+            os << ",\n";
+         }
+      }
+      os << "\n";
+      indent->resize(indent->size() - 4);
+      os << *indent << "}";
+      break;
+   }
+
+   case boost::json::kind::array:
+   {
+      os << "[\n";
+      indent->append(4, ' ');
+      auto const& arr = jv.get_array();
+      if (!arr.empty())
+      {
+         auto it = arr.begin();
+         for (;;)
+         {
+            os << *indent;
+            PrettyPrintJson(os, *it, indent);
+            if (++it == arr.end())
+               break;
+            os << ",\n";
+         }
+      }
+      os << "\n";
+      indent->resize(indent->size() - 4);
+      os << *indent << "]";
+      break;
+   }
+
+   case boost::json::kind::string:
+   {
+      os << boost::json::serialize(jv.get_string());
+      break;
+   }
+
+   case boost::json::kind::uint64:
+      os << jv.get_uint64();
+      break;
+
+   case boost::json::kind::int64:
+      os << jv.get_int64();
+      break;
+
+   case boost::json::kind::double_:
+      os << jv.get_double();
+      break;
+
+   case boost::json::kind::bool_:
+      if (jv.get_bool())
+         os << "true";
+      else
+         os << "false";
+      break;
+
+   case boost::json::kind::null:
+      os << "null";
+      break;
+   }
+
+   if (indent->empty())
+      os << "\n";
+}
+
+} // namespace scwx::util::json