Extract library entity randomization logic to separate class

lib/callback/IGameRandomizer.h

@@ -0,0 +1,46 @@
+/*
+ * IGameRandomizer.h, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+#pragma once
+
+#include "../constants/EntityIdentifiers.h"
+
+VCMI_LIB_NAMESPACE_BEGIN
+
+enum class EArtifactClass;
+
+namespace vstd
+{
+	class RNG;
+}
+
+/// Provides source of random rolls for game entities
+/// Instance of this interface only exists on server
+class IGameRandomizer : boost::noncopyable
+{
+public:
+	virtual ~IGameRandomizer();
+
+	virtual ArtifactID rollArtifact() = 0;
+	virtual ArtifactID rollArtifact(EArtifactClass type) = 0;
+	virtual ArtifactID rollArtifact(std::set<ArtifactID> filtered) = 0;
+
+	virtual std::vector<ArtifactID> rollMarketArtifactSet() = 0;
+
+	virtual CreatureID rollCreature() = 0;
+	virtual CreatureID rollCreature(int tier) = 0;
+
+	virtual HeroTypeID rollHero(PlayerColor player, FactionID faction) = 0;
+
+	virtual std::string rollTownName(FactionID faction) = 0;
+
+	virtual vstd::RNG & getDefault() = 0;
+};
+
+VCMI_LIB_NAMESPACE_END