# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:

# Copyright 2015-2016 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qutebrowser.  If not, see <http://www.gnu.org/licenses/>.

"""Base class for a QtWebKit/QtWebEngine web inspector."""

import base64
import binascii

from PyQt5.QtWidgets import QWidget

from qutebrowser.utils import log, objreg
from qutebrowser.misc import miscwidgets
from qutebrowser.config import config


def create(parent=None):
    """Get a WebKitInspector/WebEngineInspector.

    Args:
        parent: The Qt parent to set.
    """
    # Importing modules here so we don't depend on QtWebEngine without the
    # argument and to avoid circular imports.
    if objreg.get('args').backend == 'webengine':
        from qutebrowser.browser.webengine import webengineinspector
        return webengineinspector.WebEngineInspector(parent)
    else:
        from qutebrowser.browser.webkit import webkitinspector
        return webkitinspector.WebKitInspector(parent)


class WebInspectorError(Exception):

    """Raised when the inspector could not be initialized."""

    pass


class AbstractWebInspector(QWidget):

    """A customized WebInspector which stores its geometry."""

    def __init__(self, parent=None):
        super().__init__(parent)
        self._widget = None
        self._layout = miscwidgets.WrapperLayout(self)
        self._load_state_geometry()

    def _set_widget(self, widget):
        self._widget = widget
        self._layout.wrap(self, widget)

    def _load_state_geometry(self):
        """Load the geometry from the state file."""
        state_config = objreg.get('state-config')
        try:
            data = state_config['geometry']['inspector']
            geom = base64.b64decode(data, validate=True)
        except KeyError:
            # First start
            pass
        except binascii.Error:
            log.misc.exception("Error while reading geometry")
        else:
            log.init.debug("Loading geometry from {}".format(geom))
            ok = self.restoreGeometry(geom)
            if not ok:
                log.init.warning("Error while loading geometry.")

    def closeEvent(self, e):
        """Save the geometry when closed."""
        state_config = objreg.get('state-config')
        data = bytes(self.saveGeometry())
        geom = base64.b64encode(data).decode('ASCII')
        state_config['geometry']['inspector'] = geom
        super().closeEvent(e)

    def _check_developer_extras(self):
        """Check if developer-extras are enabled."""
        if not config.get('general', 'developer-extras'):
            raise WebInspectorError(
                "Please enable developer-extras before using the "
                "webinspector!")

    def inspect(self, page):
        """Inspect the given QWeb(Engine)Page."""
        raise NotImplementedError

    def toggle(self, page):
        if self._widget.isVisible():
            self.hide()
        else:
            self.inspect(page)
