#
# Copyright © 2009- The Spyder Development Team
# Licensed under the terms of the MIT License

"""
Compatibility functions
"""

from collections.abc import Callable
import sys

from .QtWidgets import QFileDialog


TEXT_TYPES = (str,)


def is_text_string(obj):
    """Return True if `obj` is a text string, False if it is anything else,
    like binary data."""
    return isinstance(obj, str)


def to_text_string(obj, encoding=None):
    """Convert `obj` to (unicode) text string"""
    if encoding is None:
        return str(obj)
    elif isinstance(obj, str):
        # In case this function is not used properly, this could happen
        return obj
    else:
        return str(obj, encoding)


# =============================================================================
# QVariant conversion utilities
# =============================================================================
PYQT_API_1 = False
def to_qvariant(obj=None):  # analysis:ignore
    """Convert Python object to QVariant
    This is a transitional function from PyQt API#1 (QVariant exist)
    to PyQt API#2 and Pyside (QVariant does not exist)"""
    return obj

def from_qvariant(qobj=None, pytype=None):  # analysis:ignore
    """Convert QVariant object to Python object
    This is a transitional function from PyQt API #1 (QVariant exist)
    to PyQt API #2 and Pyside (QVariant does not exist)"""
    return qobj


# =============================================================================
# Wrappers around QFileDialog static methods
# =============================================================================
def getexistingdirectory(parent=None, caption='', basedir='',
                         options=QFileDialog.ShowDirsOnly):
    """Wrapper around QtGui.QFileDialog.getExistingDirectory static method
    Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
    # Calling QFileDialog static method
    if sys.platform == "win32":
        # On Windows platforms: redirect standard outputs
        _temp1, _temp2 = sys.stdout, sys.stderr
        sys.stdout, sys.stderr = None, None
    try:
        result = QFileDialog.getExistingDirectory(parent, caption, basedir,
                                                  options)
    finally:
        if sys.platform == "win32":
            # On Windows platforms: restore standard outputs
            sys.stdout, sys.stderr = _temp1, _temp2
    if not is_text_string(result):
        # PyQt API #1
        result = to_text_string(result)
    return result


def _qfiledialog_wrapper(attr, parent=None, caption='', basedir='',
                         filters='', selectedfilter='', options=None):
    if options is None:
        options = QFileDialog.Options(0)

    func = getattr(QFileDialog, attr)

    # Calling QFileDialog static method
    if sys.platform == "win32":
        # On Windows platforms: redirect standard outputs
        _temp1, _temp2 = sys.stdout, sys.stderr
        sys.stdout, sys.stderr = None, None
    result = func(parent, caption, basedir, filters, selectedfilter, options)
    if sys.platform == "win32":
        # On Windows platforms: restore standard outputs
        sys.stdout, sys.stderr = _temp1, _temp2

    output, selectedfilter = result

    # Always returns the tuple (output, selectedfilter)
    return output, selectedfilter


def getopenfilename(parent=None, caption='', basedir='', filters='',
                    selectedfilter='', options=None):
    """Wrapper around QtGui.QFileDialog.getOpenFileName static method
    Returns a tuple (filename, selectedfilter) -- when dialog box is canceled,
    returns a tuple of empty strings
    Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
    return _qfiledialog_wrapper('getOpenFileName', parent=parent,
                                caption=caption, basedir=basedir,
                                filters=filters, selectedfilter=selectedfilter,
                                options=options)


def getopenfilenames(parent=None, caption='', basedir='', filters='',
                     selectedfilter='', options=None):
    """Wrapper around QtGui.QFileDialog.getOpenFileNames static method
    Returns a tuple (filenames, selectedfilter) -- when dialog box is canceled,
    returns a tuple (empty list, empty string)
    Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
    return _qfiledialog_wrapper('getOpenFileNames', parent=parent,
                                caption=caption, basedir=basedir,
                                filters=filters, selectedfilter=selectedfilter,
                                options=options)


def getsavefilename(parent=None, caption='', basedir='', filters='',
                    selectedfilter='', options=None):
    """Wrapper around QtGui.QFileDialog.getSaveFileName static method
    Returns a tuple (filename, selectedfilter) -- when dialog box is canceled,
    returns a tuple of empty strings
    Compatible with PyQt >=v4.4 (API #1 and #2) and PySide >=v1.0"""
    return _qfiledialog_wrapper('getSaveFileName', parent=parent,
                                caption=caption, basedir=basedir,
                                filters=filters, selectedfilter=selectedfilter,
                                options=options)
