1 files changed, 272 insertions, 0 deletions
diff --git a/libraries/logic/Json.cpp b/libraries/logic/Json.cpp
new file mode 100644
index 00000000..f2cbc8a3
--- /dev/null
+++ b/libraries/logic/Json.cpp
@@ -0,0 +1,272 @@
+// Licensed under the Apache-2.0 license. See README.md for details.
+
+#include "Json.h"
+
+#include <QFile>
+
+#include "FileSystem.h"
+#include <math.h>
+
+namespace Json
+{
+void write(const QJsonDocument &doc, const QString &filename)
+{
+	FS::write(filename, doc.toJson());
+}
+void write(const QJsonObject &object, const QString &filename)
+{
+	write(QJsonDocument(object), filename);
+}
+void write(const QJsonArray &array, const QString &filename)
+{
+	write(QJsonDocument(array), filename);
+}
+
+QByteArray toBinary(const QJsonObject &obj)
+{
+	return QJsonDocument(obj).toBinaryData();
+}
+QByteArray toBinary(const QJsonArray &array)
+{
+	return QJsonDocument(array).toBinaryData();
+}
+QByteArray toText(const QJsonObject &obj)
+{
+	return QJsonDocument(obj).toJson(QJsonDocument::Compact);
+}
+QByteArray toText(const QJsonArray &array)
+{
+	return QJsonDocument(array).toJson(QJsonDocument::Compact);
+}
+
+static bool isBinaryJson(const QByteArray &data)
+{
+	decltype(QJsonDocument::BinaryFormatTag) tag = QJsonDocument::BinaryFormatTag;
+	return memcmp(data.constData(), &tag, sizeof(QJsonDocument::BinaryFormatTag)) == 0;
+}
+QJsonDocument requireDocument(const QByteArray &data, const QString &what)
+{
+	if (isBinaryJson(data))
+	{
+		QJsonDocument doc = QJsonDocument::fromBinaryData(data);
+		if (doc.isNull())
+		{
+			throw JsonException(what + ": Invalid JSON (binary JSON detected)");
+		}
+		return doc;
+	}
+	else
+	{
+		QJsonParseError error;
+		QJsonDocument doc = QJsonDocument::fromJson(data, &error);
+		if (error.error != QJsonParseError::NoError)
+		{
+			throw JsonException(what + ": Error parsing JSON: " + error.errorString());
+		}
+		return doc;
+	}
+}
+QJsonDocument requireDocument(const QString &filename, const QString &what)
+{
+	return requireDocument(FS::read(filename), what);
+}
+QJsonObject requireObject(const QJsonDocument &doc, const QString &what)
+{
+	if (!doc.isObject())
+	{
+		throw JsonException(what + " is not an object");
+	}
+	return doc.object();
+}
+QJsonArray requireArray(const QJsonDocument &doc, const QString &what)
+{
+	if (!doc.isArray())
+	{
+		throw JsonException(what + " is not an array");
+	}
+	return doc.array();
+}
+
+void writeString(QJsonObject &to, const QString &key, const QString &value)
+{
+	if (!value.isEmpty())
+	{
+		to.insert(key, value);
+	}
+}
+
+void writeStringList(QJsonObject &to, const QString &key, const QStringList &values)
+{
+	if (!values.isEmpty())
+	{
+		QJsonArray array;
+		for(auto value: values)
+		{
+			array.append(value);
+		}
+		to.insert(key, array);
+	}
+}
+
+template<>
+QJsonValue toJson<QUrl>(const QUrl &url)
+{
+	return QJsonValue(url.toString(QUrl::FullyEncoded));
+}
+template<>
+QJsonValue toJson<QByteArray>(const QByteArray &data)
+{
+	return QJsonValue(QString::fromLatin1(data.toHex()));
+}
+template<>
+QJsonValue toJson<QDateTime>(const QDateTime &datetime)
+{
+	return QJsonValue(datetime.toString(Qt::ISODate));
+}
+template<>
+QJsonValue toJson<QDir>(const QDir &dir)
+{
+	return QDir::current().relativeFilePath(dir.absolutePath());
+}
+template<>
+QJsonValue toJson<QUuid>(const QUuid &uuid)
+{
+	return uuid.toString();
+}
+template<>
+QJsonValue toJson<QVariant>(const QVariant &variant)
+{
+	return QJsonValue::fromVariant(variant);
+}
+
+
+template<> QByteArray requireIsType<QByteArray>(const QJsonValue &value, const QString &what)
+{
+	const QString string = ensureIsType<QString>(value, what);
+	// ensure that the string can be safely cast to Latin1
+	if (string != QString::fromLatin1(string.toLatin1()))
+	{
+		throw JsonException(what + " is not encodable as Latin1");
+	}
+	return QByteArray::fromHex(string.toLatin1());
+}
+
+template<> QJsonArray requireIsType<QJsonArray>(const QJsonValue &value, const QString &what)
+{
+	if (!value.isArray())
+	{
+		throw JsonException(what + " is not an array");
+	}
+	return value.toArray();
+}
+
+
+template<> QString requireIsType<QString>(const QJsonValue &value, const QString &what)
+{
+	if (!value.isString())
+	{
+		throw JsonException(what + " is not a string");
+	}
+	return value.toString();
+}
+
+template<> bool requireIsType<bool>(const QJsonValue &value, const QString &what)
+{
+	if (!value.isBool())
+	{
+		throw JsonException(what + " is not a bool");
+	}
+	return value.toBool();
+}
+
+template<> double requireIsType<double>(const QJsonValue &value, const QString &what)
+{
+	if (!value.isDouble())
+	{
+		throw JsonException(what + " is not a double");
+	}
+	return value.toDouble();
+}
+
+template<> int requireIsType<int>(const QJsonValue &value, const QString &what)
+{
+	const double doubl = requireIsType<double>(value, what);
+	if (fmod(doubl, 1) != 0)
+	{
+		throw JsonException(what + " is not an integer");
+	}
+	return int(doubl);
+}
+
+template<> QDateTime requireIsType<QDateTime>(const QJsonValue &value, const QString &what)
+{
+	const QString string = requireIsType<QString>(value, what);
+	const QDateTime datetime = QDateTime::fromString(string, Qt::ISODate);
+	if (!datetime.isValid())
+	{
+		throw JsonException(what + " is not a ISO formatted date/time value");
+	}
+	return datetime;
+}
+
+template<> QUrl requireIsType<QUrl>(const QJsonValue &value, const QString &what)
+{
+	const QString string = ensureIsType<QString>(value, what);
+	if (string.isEmpty())
+	{
+		return QUrl();
+	}
+	const QUrl url = QUrl(string, QUrl::StrictMode);
+	if (!url.isValid())
+	{
+		throw JsonException(what + " is not a correctly formatted URL");
+	}
+	return url;
+}
+
+template<> QDir requireIsType<QDir>(const QJsonValue &value, const QString &what)
+{
+	const QString string = requireIsType<QString>(value, what);
+	// FIXME: does not handle invalid characters!
+	return QDir::current().absoluteFilePath(string);
+}
+
+template<> QUuid requireIsType<QUuid>(const QJsonValue &value, const QString &what)
+{
+	const QString string = requireIsType<QString>(value, what);
+	const QUuid uuid = QUuid(string);
+	if (uuid.toString() != string) // converts back => valid
+	{
+		throw JsonException(what + " is not a valid UUID");
+	}
+	return uuid;
+}
+
+template<> QJsonObject requireIsType<QJsonObject>(const QJsonValue &value, const QString &what)
+{
+	if (!value.isObject())
+	{
+		throw JsonException(what + " is not an object");
+	}
+	return value.toObject();
+}
+
+template<> QVariant requireIsType<QVariant>(const QJsonValue &value, const QString &what)
+{
+	if (value.isNull() || value.isUndefined())
+	{
+		throw JsonException(what + " is null or undefined");
+	}
+	return value.toVariant();
+}
+
+template<> QJsonValue requireIsType<QJsonValue>(const QJsonValue &value, const QString &what)
+{
+	if (value.isNull() || value.isUndefined())
+	{
+		throw JsonException(what + " is null or undefined");
+	}
+	return value;
+}
+
+}