Restructure rule classes.

Classes under "rulesets" have been moved to "rules", and split up into
futher subdirectories matching their library. As a result we can now
better separate the python bindings, so that things that belongs to the
simulation are separeted from things that belongs to the ai.

rules/python/PythonClass.cpp

@@ -0,0 +1,111 @@
+// Cyphesis Online RPG Server and AI Engine
+// Copyright (C) 2011 Alistair Riddoch
+//
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software Foundation,
+// Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+
+#include <Python.h>
+
+#include "PythonClass.h"
+
+#include "Python_Script_Utils.h"
+
+#include "common/log.h"
+#include "common/compose.hpp"
+
+/// \brief ScriptKit constructor
+/// 
+/// @param package name of the script package scripts are to be created from
+/// @param type name of the type instanced to create scripts
+PythonClass::PythonClass(const std::string & package,
+                         const std::string & type) :
+    m_package(package),
+    m_type(type),
+    m_module(nullptr)
+{
+}
+
+PythonClass::~PythonClass() = default;
+
+int PythonClass::load()
+{
+    auto module= Get_PyModule(m_package);
+    if (module.isNull()) {
+        return -1;
+    }
+    m_module = module;
+    return getClass(m_module);
+}
+
+/// \brief Retrieve the pythonclass object from the module which has
+/// already been loaded.
+int PythonClass::getClass(const Py::Module& module)
+{
+    auto new_class = Get_PyClass(module, m_package, m_type);
+    if (new_class.isNull()) {
+        // If this is a new class, leave it as zero and fail and this
+        // should be discarded by <*>RuleHandler
+        // If this is an existing class, leave it as the old value, but
+        // fail the update. This should signal back to the client.
+        return -1;
+    }
+    if (!new_class.isCallable()) {
+        log(ERROR, String::compose("Python class \"%1.%2\" is not callable.",
+                                   m_package, m_type));
+        return -1;
+    }
+//    if (!PyType_IsSubtype((PyTypeObject*)new_class.type().ptr, m_base)) {
+//        log(ERROR, String::compose("Python class \"%1.%2\" does not inherit "
+//                                   "from a core server type \"%3\".",
+//                                   m_package, m_type, m_base->tp_name));
+//        return -1;
+//    }
+    m_class = Py::Callable(new_class);
+
+    return 0;
+}
+
+int PythonClass::refresh()
+{
+    log(NOTICE, String::compose("Refreshing Python module \"%1.%2\".", m_package, m_type));
+    if (m_module.isNull()) {
+        log(ERROR, String::compose("Abort refresh of non loaded module \"%1.%2\".", m_package, m_type));
+        return -1;
+    }
+    Py::Module new_module(PyImport_ReloadModule(m_module.ptr()));
+    if (new_module.isNull()) {
+        log(ERROR, String::compose("Error reloading python module \"%1\"",
+                                   m_package));
+        PyErr_Clear();
+        return -1;
+    }
+    int ret = getClass(new_module);
+    if (ret != 0) {
+        log(ERROR, String::compose(R"(Error finding python class "%1" in "%2")",
+                                   m_type, m_package));
+        return -1;
+        // After reloading, but failing to get the class, I think the old class
+        // should still work, but is no longer bound to the name. It won't
+        // be collected at least until we release the reference we hold
+        // in m_class
+    }
+    if (m_module != new_module) {
+        log(WARNING, String::compose("Python module \"%1.%2\" has changed "
+                                     "its pointer on reload",
+                                     m_package, m_type));
+        m_module = new_module;
+    }
+    return 0;
+}