/* -*- mode: C; c-basic-offset: 2 -*-
 *
 * Pycairo - Python bindings for cairo
 *
 * Copyright © 2017 Christoph Reiter
 *
 * This library is free software; you can redistribute it and/or
 * modify it either under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation
 * (the "LGPL") or, at your option, under the terms of the Mozilla
 * Public License Version 1.1 (the "MPL"). If you do not alter this
 * notice, a recipient may use your version of this file under either
 * the MPL or the LGPL.
 *
 * You should have received a copy of the LGPL along with this library
 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * You should have received a copy of the MPL along with this library
 * in the file COPYING-MPL-1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
 * the specific language governing rights and limitations.
 */

#define PY_SSIZE_T_CLEAN
#include <Python.h>

#include "private.h"


/* Returns 1 if the object has the correct file type for a filesystem path.
 * Parsing it with Pycairo_fspath_converter() might still fail.
 */
int
Pycairo_is_fspath (PyObject *obj) {
#if PY_MAJOR_VERSION < 3
    return (PyString_Check (obj) || PyUnicode_Check (obj));
#elif PY_MAJOR_VERSION >= 3 && PY_MINOR_VERSION >= 6 && !defined(PYPY_VERSION)
    /* PyOS_FSPath() is missing in PyPy:
     * https://bitbucket.org/pypy/pypy/issues/2961 */
    PyObject *real = PyOS_FSPath (obj);
    if (real == NULL) {
        PyErr_Clear ();
        return 0;
    } else {
        Py_DECREF (real);
        return 1;
    }
#else
    return (PyBytes_Check (obj) || PyUnicode_Check (obj));
#endif
}

/* Converts a Python object to a cairo path. The result needs to be freed with
 * PyMem_Free().
 */
int
Pycairo_fspath_converter (PyObject *obj, char** result) {
    char *internal, *buf;
    PyObject *bytes;

#if defined(MS_WINDOWS) && PY_MAJOR_VERSION < 3
    PyObject *uni, *other;

    if (PyString_Check (obj)) {
        uni = PyString_AsDecodedObject (
            obj, Py_FileSystemDefaultEncoding, "strict");
        if (uni == NULL)
            return 0;
    } else if (PyUnicode_Check (obj)) {
        uni = obj;
        Py_INCREF (uni);
    } else {
        PyErr_SetString (PyExc_TypeError, "paths must be str/unicode");
        return 0;
    }

    if (cairo_version() >= CAIRO_VERSION_ENCODE(1, 15, 10)) {
        bytes = PyUnicode_AsEncodedString (uni, "utf-8", "strict");
        Py_DECREF (uni);
        if (bytes == NULL) {
            return 0;
        }

        if (PyString_AsStringAndSize (bytes, &internal, NULL) == -1) {
            Py_DECREF (bytes);
            return 0;
        }
    } else {
        bytes = PyUnicode_AsMBCSString (uni);
        if (bytes == NULL) {
            Py_DECREF (uni);
            return 0;
        }

        if (PyString_AsStringAndSize (bytes, &internal, NULL) == -1) {
            Py_DECREF (uni);
            Py_DECREF (bytes);
            return 0;
        }

        /* PyUnicode_AsMBCSString doesn't do error handling, so we have to
         * decode and compare again */
        other = PyUnicode_DecodeMBCS (
            internal, PyString_Size (bytes), "strict");
        if (other == NULL) {
            Py_DECREF (uni);
            Py_DECREF (bytes);
            return 0;
        }

        if (PyUnicode_Compare (uni, other) != 0) {
            Py_DECREF (uni);
            Py_DECREF (bytes);
            Py_DECREF (other);
            PyErr_SetString (
                PyExc_ValueError, "only ANSI paths supported on Windows");
            return 0;
        }

        Py_DECREF (other);
        Py_DECREF (uni);
    }
#elif defined(MS_WINDOWS) && PY_MAJOR_VERSION >= 3
    PyObject *uni;

    if (PyUnicode_FSDecoder (obj, &uni) == 0)
        return 0;

    if (cairo_version() >= CAIRO_VERSION_ENCODE(1, 15, 10)) {
        bytes = PyUnicode_AsEncodedString (uni, "utf-8", "strict");
    } else {
        bytes = PyUnicode_AsMBCSString (uni);
    }

    Py_DECREF (uni);
    if (bytes == NULL)
        return 0;

    if (PyBytes_AsStringAndSize (bytes, &internal, NULL) == -1) {
        Py_DECREF (bytes);
        return 0;
    }
#elif !defined(MS_WINDOWS) && PY_MAJOR_VERSION < 3
    if (PyUnicode_Check (obj)) {
        bytes = PyUnicode_AsEncodedString (
            obj, Py_FileSystemDefaultEncoding, "strict");
        if (bytes == 0)
            return 0;
    } else if (PyString_Check (obj)) {
        bytes = obj;
        Py_INCREF (bytes);
    } else {
        PyErr_SetString (PyExc_TypeError, "paths must be str/unicode");
        return 0;
    }

    if (PyString_AsStringAndSize (bytes, &internal, NULL) == -1) {
        Py_DECREF (bytes);
        return 0;
    }
#elif !defined(MS_WINDOWS) && PY_MAJOR_VERSION >= 3
    if (PyUnicode_FSConverter (obj, &bytes) == 0)
        return 0;

    if (PyBytes_AsStringAndSize (bytes, &internal, NULL) == -1) {
        Py_DECREF (bytes);
        return 0;
    }
#else
#error "unsupported"
#endif

    buf = PyMem_Malloc (strlen (internal) + 1);
    if (buf == NULL) {
        Py_DECREF (bytes);
        PyErr_NoMemory ();
        return 0;
    }
    strcpy (buf, internal);
    Py_DECREF (bytes);
    *result = buf;
    return 1;
}

/* Verifies that the object has a callable write() method.
 * Gives a borrowed reference.
 */
int
Pycairo_writer_converter (PyObject *obj, PyObject** file) {
    PyObject *attr;

    attr = PyObject_GetAttrString (obj, "write");
    if (attr == NULL)
        return 0;

    if (!PyCallable_Check (attr)) {
        Py_DECREF (attr);
        PyErr_SetString (
            PyExc_TypeError, "'write' attribute not callable");
        return 0;
    }

    Py_DECREF (attr);
    *file = obj;
    return 1;
}

int
Pycairo_reader_converter (PyObject *obj, PyObject** file) {
    PyObject *attr;

    attr = PyObject_GetAttrString (obj, "read");
    if (attr == NULL)
        return 0;

    if (!PyCallable_Check (attr)) {
        Py_DECREF (attr);
        PyErr_SetString (
            PyExc_TypeError, "'read' attribute not callable");
        return 0;
    }

    Py_DECREF (attr);
    *file = obj;
    return 1;
}

int
Pycairo_fspath_none_converter (PyObject *obj, char** result) {
    if (obj == Py_None) {
        *result = NULL;
        return 1;
    }

    return Pycairo_fspath_converter (obj, result);
}

PyObject*
Pycairo_richcompare (void* a, void *b, int op)
{
    PyObject *res;

    switch (op) {
        case Py_EQ:
            res = (a == b) ? Py_True : Py_False;
            break;
      case Py_NE:
            res = (a != b) ? Py_True : Py_False;
            break;
      case Py_LT:
            res = (a < b) ? Py_True : Py_False;
            break;
      case Py_LE:
            res = (a <= b) ? Py_True : Py_False;
            break;
      case Py_GT:
            res = (a > b) ? Py_True : Py_False;
            break;
      case Py_GE:
            res = (a >= b) ? Py_True : Py_False;
            break;
      default:
            res = Py_NotImplemented;
            break;
    }

    Py_INCREF (res);
    return res;
}

/* NULL on error */
static PyObject *
_conv_pyobject_to_pylong (PyObject *pyobj) {
#if PY_MAJOR_VERSION < 3
    if (PyInt_Check (pyobj)) {
        return PyNumber_Long (pyobj);
    } else if (!PyLong_Check (pyobj)) {
        PyErr_SetString (PyExc_TypeError, "not of type int or long");
        return NULL;
    }
    Py_INCREF (pyobj);
    return pyobj;
#else
    if (!PyLong_Check (pyobj)) {
        PyErr_SetString (PyExc_TypeError, "not of type int");
        return NULL;
    }
    Py_INCREF (pyobj);
    return pyobj;
#endif
}

/* -1 on error */
int
_conv_pyobject_to_ulong (PyObject *pyobj, unsigned long *result) {
    unsigned long temp;
    PyObject *pylong;

    pylong = _conv_pyobject_to_pylong (pyobj);
    if (pylong == NULL)
        return -1;

    temp = PyLong_AsUnsignedLong (pylong);
    if (PyErr_Occurred ())
        return -1;

    *result = temp;
    return 0;
}