# -*- coding: utf-8 -*-
#
# Copyright © 2009-2011 Pierre Raybaut
# Licensed under the terms of the MIT License
# (see spyderlib/__init__.py for details)

"""Qt utilities"""

import os, re
import os.path as osp

from spyderlib.qt.QtGui import (QAction, QStyle, QWidget, QIcon, QApplication,
                                QLabel, QVBoxLayout, QHBoxLayout, QLineEdit,
                                QKeyEvent, QMenu, QKeySequence, QToolButton)
from spyderlib.qt.QtCore import (SIGNAL, QObject, Qt, QLocale, QTranslator,
                                 QLibraryInfo)
from spyderlib.qt.compat import to_qvariant, from_qvariant

# Local import
from spyderlib.config import get_icon
from spyderlib.utils import programs

# Note: How to redirect a signal from widget *a* to widget *b
* ?
# ----
# It has to be done manually:
#  * typing 'SIGNAL("clicked()")' works
#  * typing 'signalstr = "clicked()"; SIGNAL(signalstr)' won't work
# Here is an example of how to do it:
# (self.listwidget is widget *a* and sel
f is widget *b*)
#    self.connect(self.listwidget, SIGNAL('option_changed'),
#                 lambda *args: self.emit(SIGNAL('option_changed'), *args))


def qapplication(translate=True):
    """Return QApplication instance
    Creates it if it doesn't already exist"""
    app = QApplication.instance()
    if not app:
        # Set Application name for Gnome 3
        # https://groups.google.com/forum/#!topic/pyside/24qxvwfrRDs
        app = QApplication(['Spyder'])
    if translate:
        install_translator(app)
    return app

def file_uri(fname):
    """Select the right file uri scheme according to the operating system"""
    if os.name == 'nt':
        # Local file
        if re.search(r'^[a-zA-Z]:', fname):
            return 'file:///' + fname
        # UNC based path
        else:
            return 'file://' + fname
    else:
        return 'file://' + fname

QT_TRANSLATOR = None
def install_translator(qapp):
    """Install Qt translator to the QApplication instance"""
    global QT_TRANSLATOR
    if QT_TRANSLATOR is None:
        qt_translator = QTranslator()
        if qt_translator.load("qt_"+QLocale.system().name(),
                      QLibraryInfo.location(QLibraryInfo.TranslationsPath)):
            QT_TRANSLATOR = qt_translator # Keep reference alive
    if QT_TRANSLATOR is not None:
        qapp.installTranslator(QT_TRANSLATOR)


def keybinding(attr):
    """Return keybinding"""
    ks = getattr(QKeySequence, attr)
    return from_qvariant(QKeySequence.keyBindings(ks)[0], str)


def _process_mime_path(path, extlist):
    if path.startswith(r"file://"):
        if os.name == 'nt':
            # On Windows platforms, a local path reads: file:///c:/...
            # and a UNC based path reads like: file://server/share
            if path.startswith(r"file:///"): # this is a local path
                path=path[8:]
            else: # this is a unc path
                path = path[5:]
        else:
            path = path[7:]
    if osp.exists(path):
        if extlist is None or osp.splitext(path)[1] in extlist:
            return path


def mimedata2url(source, extlist=None):
    """
    Extract url list from MIME data
    extlist: for example ('.py', '.pyw')
    """
    pathlist = []
    if source.hasUrls():
        for url in source.urls():
            path = _process_mime_path(unicode(url.toString()), extlist)
            if path is not None:
                pathlist.append(path)
    elif source.hasText():
        for rawpath in unicode(source.text()).splitlines():
            path = _process_mime_path(rawpath, extlist)
            if path is not None:
                pathlist.append(path)
    if pathlist:
        return pathlist


def keyevent2tuple(event):
    """Convert QKeyEvent instance into a tuple"""
    return (event.type(), event.key(), event.modifiers(), event.text(),
            event.isAutoRepeat(), event.count())

    
def tuple2keyevent(past_event):
    """Convert tuple into a QKeyEvent instance"""
    return QKeyEvent(*past_event)


def restore_keyevent(event):
    if isinstance(event, tuple):
        _, key, modifiers, text, _, _ = event
        event = tuple2keyevent(event)
    else:
        text = event.text()
        modifiers = event.modifiers()
        key = event.key()
    ctrl = modifiers & Qt.ControlModifier
    shift = modifiers & Qt.ShiftModifier
    return event, text, key, ctrl, shift


def create_toolbutton(parent, text=None, shortcut=None, icon=None, tip=None,
                      toggled=None, triggered=None,
                      autoraise=True, text_beside_icon=False):
    """Create a QToolButton"""
    button = QToolButton(parent)
    if text is not None:
        button.setText(text)
    if icon is not None:
        if isinstance(icon, (str, unicode)):
            icon = get_icon(icon)
        button.setIcon(icon)
    if text is not None or tip is not None:
        button.setToolTip(text if tip is None else tip)
    if text_beside_icon:
        button.setToolButtonStyle(Qt.ToolButtonTextBesideIcon)
    button.setAutoRaise(autoraise)
    if triggered is not None:
        QObject.connect(button, SIGNAL('clicked()'), triggered)
    if toggled is not None:
        QObject.connect(button, SIGNAL("toggled(bool)"), toggled)
        button.setCheckable(True)
    if shortcut is not None:
        button.setShortcut(shortcut)
    return button


def action2button(action, autoraise=True, text_beside_icon=False, parent=None):
    """Create a QToolButton directly from a QAction object"""
    if parent is None:
        parent = action.parent()
    button = QToolButton(parent)
    button.setDefaultAction(action)
    button.setAutoRaise(autoraise)
    if text_beside_icon:
        button.setToolButtonStyle(Qt.ToolButtonTextBesideIcon)
    return button


def toggle_actions(actions, enable):
    """Enable/disable actions"""
    if actions is not None:
        for action in actions:
            if action is not None:
                action.setEnabled(enable)


def create_action(parent, text, shortcut=None, icon=None, tip=None,
                  toggled=None, triggered=None, data=None,
                  context=Qt.WindowShortcut):
    """Create a QAction"""
    action = QAction(text, parent)
    if triggered is not None:
        parent.connect(action, SIGNAL("triggered()"), triggered)
    if toggled is not None:
        parent.connect(action, SIGNAL("toggled(bool)"), toggled)
        action.setCheckable(True)
    if icon is not None:
        if isinstance(icon, (str, unicode)):
            icon = get_icon(icon)
        action.setIcon( icon )
    if shortcut is not None:
        action.setShortcut(shortcut)
    if tip is not None:
        action.setToolTip(tip)
        action.setStatusTip(tip)
    if data is not None:
        action.setData(to_qvariant(data))
    #TODO: Hard-code all shortcuts and choose context=Qt.WidgetShortcut
    # (this will avoid calling shortcuts from another dockwidget
    #  since the context thing doesn't work quite well with these widgets)
    action.setShortcutContext(context)
    return action


def add_actions(target, actions, insert_before=None):
    """Add actions to a menu"""
    previous_action = None
    target_actions = list(target.actions())
    if target_actions:
        previous_action = target_actions[-1]
        if previous_action.isSeparator():
            previous_action = None
    for action in actions:
        if (action is None) and (previous_action is not None):
            if insert_before is None:
                target.addSeparator()
            else:
                target.insertSeparator(insert_before)
        elif isinstance(action, QMenu):
            if insert_before is None:
                target.addMenu(action)
            else:
                target.insertMenu(insert_before, action)
        elif isinstance(action, QAction):
            if insert_before is None:
                target.addAction(action)
            el