/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt for Python.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef BASEWRAPPER_P_H
#define BASEWRAPPER_P_H

#include "sbkpython.h"
#include "basewrapper.h"

#include <unordered_map>
#include <set>
#include <string>
#include <vector>

struct SbkObject;
struct SbkObjectType;
struct SbkConverter;

namespace Shiboken
{
/**
    * This mapping associates a method and argument of an wrapper object with the wrapper of
    * said argument when it needs the binding to help manage its reference count.
    */
typedef std::unordered_multimap<std::string, PyObject *> RefCountMap;

/// Linked list of SbkBaseWrapper pointers
typedef std::set<SbkObject*> ChildrenList;

/// Structure used to store information about object parent and children.
struct ParentInfo
{
    /// Default ctor.
    ParentInfo() : parent(0), hasWrapperRef(false) {}
    /// Pointer to parent object.
    SbkObject* parent;
    /// List of object children.
    ChildrenList children;
    /// has internal ref
    bool hasWrapperRef;
};

} // namespace Shiboken

extern "C"
{

/**
 * \internal
 * Private data for SbkBaseWrapper
 */
struct SbkObjectPrivate
{
    /// Pointer to the C++ class.
    void** cptr;
    /// True when Python is responsible for freeing the used memory.
    unsigned int hasOwnership : 1;
    /// This is true when the C++ class of the wrapped object has a virtual destructor AND was created by Python.
    unsigned int containsCppWrapper : 1;
    /// Marked as false when the object is lost to C++ and the binding can not know if it was deleted or not.
    unsigned int validCppObject : 1;
    /// Marked as true when the object constructor was called
    unsigned int cppObjectCreated : 1;
    /// Information about the object parents and children, may be null.
    Shiboken::ParentInfo* parentInfo;
    /// Manage reference count of objects that are referred to but not owned from.
    Shiboken::RefCountMap* referredObjects;

    ~SbkObjectPrivate()
    {
        delete parentInfo;
        parentInfo = 0;
        delete referredObjects;
        referredObjects = 0;
    }
};

// TODO-CONVERTERS: to be deprecated/removed
/// The type behaviour was not defined yet
#define BEHAVIOUR_UNDEFINED 0
/// The type is a value type
#define BEHAVIOUR_VALUETYPE 1
/// The type is an object type
#define BEHAVIOUR_OBJECTTYPE 2

struct SbkObjectTypePrivate
{
    SbkConverter* converter;
    int* mi_offsets;
    MultipleInheritanceInitFunction mi_init;

    /// Special cast function, null if this class doesn't have multiple inheritance.
    SpecialCastFunction mi_specialcast;
    TypeDiscoveryFuncV2 type_discovery;
    /// Pointer to a function responsible for deletion of the C++ instance calling the proper destructor.
    ObjectDestructor cpp_dtor;
    /// True if this type holds two or more C++ instances, e.g.: a Python class which inherits from two C++ classes.
    int is_multicpp : 1;
    /// True if this type was defined by the user.
    int is_user_type : 1;
    /// Tells is the type is a value type or an object-type, see BEHAVIOUR_* constants.
    // TODO-CONVERTERS: to be deprecated/removed
    int type_behaviour : 2;
    int delete_in_main_thread : 1;
    /// C++ name
    char* original_name;
    /// Type user data
    void* user_data;
    DeleteUserDataFunc d_func;
    void (*subtype_init)(SbkObjectType*, PyObject*, PyObject*);
};


} // extern "C"

namespace Shiboken
{

/**
 * \internal
 * Data required to invoke a C++ destructor
 */
struct DestructorEntry
{
    ObjectDestructor destructor;
    void *cppInstance;
};

/**
 * Utility function used to transform a PyObject that implements sequence protocol into a std::list.
 **/
std::vector<SbkObject *> splitPyObject(PyObject* pyObj);

/**
*   Visitor class used by walkOnClassHierarchy function.
*/
class HierarchyVisitor
{
public:
    HierarchyVisitor(const HierarchyVisitor &) = delete;
    HierarchyVisitor(HierarchyVisitor &&) = delete;
    HierarchyVisitor &operator=(const HierarchyVisitor &) = delete;
    HierarchyVisitor &operator=(HierarchyVisitor &&) = delete;

    HierarchyVisitor();
    virtual ~HierarchyVisitor();

    virtual bool visit(SbkObjectType *node) = 0; // return true to terminate
};

class BaseCountVisitor : public HierarchyVisitor
{
public:
    bool visit(SbkObjectType *) override;

    int count() const { return m_count; }

private:
    int m_count = 0;
};

class BaseAccumulatorVisitor : public HierarchyVisitor
{
public:
    typedef std::vector<SbkObjectType *> Result;

    bool visit(SbkObjectType *node) override;

    Result bases() const { return m_bases; }

private:
    Result m_bases;
};

class GetIndexVisitor : public HierarchyVisitor
{
public:
    explicit GetIndexVisitor(PyTypeObject* desiredType) : m_desiredType(desiredType) {}

    bool visit(SbkObjectType *node) override;

    int index() const { return m_index; }

private:
    int m_index = -1;
    PyTypeObject *m_desiredType;
};

/// Collect destructors and C++ instances of each C++ object held by a Python
/// object
class DtorAccumulatorVisitor : public HierarchyVisitor
{
public:
    explicit DtorAccumulatorVisitor(SbkObject *pyObj) : m_pyObject(pyObj) {}

    bool visit(SbkObjectType *node) override;

    using DestructorEntries = std::vector<DestructorEntry>;

    const DestructorEntries &entries() const { return m_entries; }

private:
    DestructorEntries m_entries;
    SbkObject *m_pyObject;
};

/// \internal Internal function used to walk on classes inheritance trees.
/**
*   Walk on class hierarchy using a DFS algorithm.
*   For each pure Shiboken type found, HiearchyVisitor::visit is called and the algorithm consider
*   all children of this type as visited.
*/
bool walkThroughClassHierarchy(PyTypeObject *currentType, HierarchyVisitor *visitor);

inline int getTypeIndexOnHierarchy(PyTypeObject* baseType, PyTypeObject* desiredType)
{
    GetIndexVisitor visitor(desiredType);
    walkThroughClassHierarchy(baseType, &visitor);
    return visitor.index();
}

inline int getNumberOfCppBaseClasses(PyTypeObject* baseType)
{
    BaseCountVisitor visitor;
    walkThroughClassHierarchy(baseType, &visitor);
    return visitor.count();
}

inline std::vector<SbkObjectType *> getCppBaseClasses(PyTypeObject* baseType)
{
    BaseAccumulatorVisitor visitor;
    walkThroughClassHierarchy(baseType, &visitor);
    return visitor.bases();
}

namespace Object
{
/**
*   Decrements the reference counters of every object referred by self.
*   \param self    the wrapper instance that keeps references to other objects.
*/
void clearReferences(SbkObject* self);

/**
 * Destroy internal data
 **/
void deallocData(SbkObject* self, bool doCleanup);

} // namespace Object

} // namespace Shiboken

#endif