/****************************************************************************
**
** Copyright (C) 2019 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.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "sbkstring.h"
#include "sbkstaticstrings_p.h"
#include "autodecref.h"

#include <vector>

namespace Shiboken
{

namespace String
{

// PYSIDE-795: Redirecting PySequence to Iterable
bool checkIterable(PyObject *obj)
{
    return PyObject_HasAttr(obj, Shiboken::PyMagicName::iter());
}

bool checkType(PyTypeObject *type)
{
    return type == &PyUnicode_Type
#if PY_MAJOR_VERSION < 3
            || type == &PyString_Type
#endif
    ;
}

bool check(PyObject *obj)
{
    return obj == Py_None ||
#if PY_MAJOR_VERSION < 3
        PyString_Check(obj) ||
#endif
        PyUnicode_Check(obj);
}

bool checkChar(PyObject *pyobj)
{
    return check(pyobj) && (len(pyobj) == 1);
}

bool isConvertible(PyObject *obj)
{
    return check(obj);
}

PyObject *fromCString(const char *value)
{
#ifdef IS_PY3K
    return PyUnicode_FromString(value);
#else
    return PyBytes_FromString(value);
#endif
}

PyObject *fromCString(const char *value, int len)
{
#ifdef IS_PY3K
    return PyUnicode_FromStringAndSize(value, len);
#else
    return PyBytes_FromStringAndSize(value, len);
#endif
}

const char *toCString(PyObject *str, Py_ssize_t *len)
{
    if (str == Py_None)
        return nullptr;
    if (PyUnicode_Check(str)) {
        if (len) {
            // We need to encode the unicode string into utf8 to know the size of returned char *.
            Shiboken::AutoDecRef uniStr(PyUnicode_AsUTF8String(str));
            *len = PyBytes_GET_SIZE(uniStr.object());
        }
#ifdef IS_PY3K
        // Return unicode from str instead of uniStr, because the lifetime of the returned pointer
        // depends on the lifetime of str.
        return _PepUnicode_AsString(str);
#else
        str = PyUnicode_AsUTF8String(str);
        if (str == NULL) {
            return NULL;
        }
        return PyString_AsString(str);
#endif
    }
    if (PyBytes_Check(str)) {
        if (len)
            *len = PyBytes_GET_SIZE(str);
        return PyBytes_AS_STRING(str);
    }
    return nullptr;
}

bool concat(PyObject **val1, PyObject *val2)
{
    if (PyUnicode_Check(*val1) && PyUnicode_Check(val2)) {
        PyObject *result = PyUnicode_Concat(*val1, val2);
        Py_DECREF(*val1);
        *val1 = result;
        return true;
    }

    if (PyBytes_Check(*val1) && PyBytes_Check(val2)) {
        PyBytes_Concat(val1, val2);
        return true;
    }

#if PY_MAJOR_VERSION < 3
    if (PyString_Check(*val1) && PyString_Check(val2)) {
        PyString_Concat(val1, val2);
        return true;
    }
#endif
    return false;
}

PyObject *fromFormat(const char *format, ...)
{
    va_list argp;
    va_start(argp, format);
    PyObject *result = nullptr;
#ifdef IS_PY3K
    result = PyUnicode_FromFormatV(format, argp);
#else
    result = PyString_FromFormatV(format, argp);
#endif
    va_end(argp);
    return result;
}

PyObject *fromStringAndSize(const char *str, Py_ssize_t size)
{
#ifdef IS_PY3K
    return PyUnicode_FromStringAndSize(str, size);
#else
    return PyString_FromStringAndSize(str, size);
#endif
}

int compare(PyObject *val1, const char *val2)
{
    if (PyUnicode_Check(val1))
#ifdef IS_PY3K
       return PyUnicode_CompareWithASCIIString(val1, val2);
#else
    {
        PyObject *uVal2 = PyUnicode_FromString(val2);
        bool result = PyUnicode_Compare(val1, uVal2);
        Py_XDECREF(uVal2);
        return result;
    }
    if (PyString_Check(val1))
        return strcmp(PyString_AS_STRING(val1), val2);
#endif
    return 0;

}

Py_ssize_t len(PyObject *str)
{
    if (str == Py_None)
        return 0;

    if (PyUnicode_Check(str))
        return PepUnicode_GetLength(str);

    if (PyBytes_Check(str))
        return PyBytes_GET_SIZE(str);
    return 0;
}

///////////////////////////////////////////////////////////////////////
//
// Implementation of efficient Python strings
// ------------------------------------------
//
// Instead of repetitively executing
//
//     PyObject *attr = PyObject_GetAttrString(obj, "__name__");
//
// a helper of the form
//
// PyObject *name()
// {
//    static PyObject *const s = Shiboken::String::createStaticString("__name__");
//    return result;
// }
//
// can now be implemented, which registers the string into a static set avoiding
// repetitive string creation. The resulting code looks like:
//
//     PyObject *attr = PyObject_GetAttr(obj, name());
//
// Missing:
// There is no finalization for the string structures, yet.
// But this is a global fault in shiboken. We are missing a true
// finalization like in all other modules.

using StaticStrings = std::vector<PyObject *>;

static StaticStrings &staticStrings()
{
    static StaticStrings result;
    return result;
}

PyObject *createStaticString(const char *str)
{
#if PY_VERSION_HEX >= 0x03000000
    PyObject *result = PyUnicode_InternFromString(str);
#else
    PyObject *result = PyString_InternFromString(str);
#endif
    if (result == nullptr) {
        // This error is never checked, but also very unlikely. Report and exit.
        PyErr_Print();
        Py_FatalError("unexpected error in createStaticString()");
    }
    staticStrings().push_back(result);
    return result;
}

void finalizeStaticStrings() // Currently unused
{
    auto &list = staticStrings();
    for (auto s : list)
        Py_DECREF(s);
    list.clear();
}

} // namespace String
} // namespace Shiboken
