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#pragma once
#include "jansson_handle.hpp"
#include "base/exception.hpp"
#include "base/string_utils.hpp"
#include <cstdint>
#include <memory>
#include <string>
#include <vector>
#include "3party/jansson/src/jansson.h"
namespace my
{
struct JSONDecRef
{
void operator()(json_t * root) const { json_decref(root); }
};
using JSONPtr = std::unique_ptr<json_t, JSONDecRef>;
inline JSONPtr NewJSONObject() { return JSONPtr(json_object()); }
inline JSONPtr NewJSONArray() { return JSONPtr(json_array()); }
inline JSONPtr NewJSONString(std::string const & s) { return JSONPtr(json_string(s.c_str())); }
inline JSONPtr NewJSONInt(json_int_t value) { return JSONPtr(json_integer(value)); }
inline JSONPtr NewJSONReal(double value) { return JSONPtr(json_real(value)); }
inline JSONPtr NewJSONBool(bool value) { return JSONPtr(value ? json_true() : json_false()); }
inline JSONPtr NewJSONNull() { return JSONPtr(json_null()); }
class Json
{
JsonHandle m_handle;
public:
DECLARE_EXCEPTION(Exception, RootException);
Json() = default;
explicit Json(std::string const & s) { ParseFrom(s); }
explicit Json(char const * s) { ParseFrom(s); }
void ParseFrom(std::string const & s) { ParseFrom(s.c_str()); }
void ParseFrom(char const * s)
{
json_error_t jsonError;
m_handle.AttachNew(json_loads(s, 0, &jsonError));
if (!m_handle)
MYTHROW(Exception, (jsonError.line, jsonError.text));
}
json_t * get() const { return m_handle.get(); }
};
json_t * GetJSONObligatoryField(json_t * root, std::string const & field);
json_t * GetJSONOptionalField(json_t * root, std::string const & field);
bool JSONIsNull(json_t * root);
} // namespace my
inline void FromJSON(json_t * root, json_t *& value) { value = root; }
void FromJSON(json_t * root, double & result);
void FromJSON(json_t * root, bool & result);
template <typename T,
typename std::enable_if<std::is_integral<T>::value, void>::type* = nullptr>
void FromJSON(json_t * root, T & result)
{
if (!json_is_number(root))
MYTHROW(my::Json::Exception, ("Object must contain a json number."));
result = static_cast<T>(json_integer_value(root));
}
template <typename T>
void FromJSONObject(json_t * root, std::string const & field, T & result)
{
auto * json = my::GetJSONObligatoryField(root, field);
try
{
FromJSON(json, result);
}
catch (my::Json::Exception const & e)
{
MYTHROW(my::Json::Exception, ("An error occured while parsing field", field, e.Msg()));
}
}
template <typename T>
void FromJSONObjectOptionalField(json_t * root, std::string const & field, T & result)
{
auto * json = my::GetJSONOptionalField(root, field);
if (!json)
{
result = T{};
return;
}
FromJSON(json, result);
}
template <typename T,
typename std::enable_if<std::is_integral<T>::value, void>::type* = nullptr>
inline my::JSONPtr ToJSON(T value) { return my::NewJSONInt(value); }
inline my::JSONPtr ToJSON(double value) { return my::NewJSONReal(value); }
inline my::JSONPtr ToJSON(bool value) { return my::NewJSONBool(value); }
template <typename T>
void ToJSONObject(json_t & root, std::string const & field, T const & value)
{
json_object_set_new(&root, field.c_str(), ToJSON(value).release());
}
template <typename T>
void FromJSONObject(json_t * root, std::string const & field, std::vector<T> & result)
{
auto * arr = my::GetJSONObligatoryField(root, field);
if (!json_is_array(arr))
MYTHROW(my::Json::Exception, ("The field", field, "must contain a json array."));
size_t sz = json_array_size(arr);
result.resize(sz);
for (size_t i = 0; i < sz; ++i)
FromJSON(json_array_get(arr, i), result[i]);
}
// The function tries to parse array of values from a value
// corresponding to |field| in a json object corresponding to |root|.
// Returns true when the value is non-null and array is successfully
// parsed. Returns false when there is no such |field| in the |root|
// or the value is null. Also, the method may throw an exception in
// case of json parsing errors.
template <typename T>
bool FromJSONObjectOptional(json_t * root, std::string const & field, std::vector<T> & result)
{
auto * arr = my::GetJSONOptionalField(root, field);
if (!arr || my::JSONIsNull(arr))
{
result.clear();
return false;
}
if (!json_is_array(arr))
MYTHROW(my::Json::Exception, ("The field", field, "must contain a json array."));
size_t const sz = json_array_size(arr);
result.resize(sz);
for (size_t i = 0; i < sz; ++i)
FromJSON(json_array_get(arr, i), result[i]);
return true;
}
template <typename T>
void ToJSONObject(json_t & root, std::string const & field, std::vector<T> const & values)
{
auto arr = my::NewJSONArray();
for (auto const & value : values)
json_array_append_new(arr.get(), ToJSON(value).release());
json_object_set_new(&root, field.c_str(), arr.release());
}
template <typename T>
void FromJSONObjectOptionalField(json_t * root, std::string const & field, std::vector<T> & result)
{
json_t * arr = my::GetJSONOptionalField(root, field);
if (!arr)
{
result.clear();
return;
}
if (!json_is_array(arr))
MYTHROW(my::Json::Exception, ("The field", field, "must contain a json array."));
size_t sz = json_array_size(arr);
result.resize(sz);
for (size_t i = 0; i < sz; ++i)
FromJSON(json_array_get(arr, i), result[i]);
}
bool CheckJsonArray(json_t const * data);
struct JSONFreeDeleter
{
void operator()(char * buffer) const { free(buffer); }
};
namespace std
{
void FromJSON(json_t * root, std::string & result);
inline my::JSONPtr ToJSON(std::string const & s) { return my::NewJSONString(s); }
} // namespace std
namespace strings
{
void FromJSON(json_t * root, UniString & result);
my::JSONPtr ToJSON(UniString const & s);
} // namespace strings
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