# Copyright 2016, Tresys Technology, LLC
#
# This file is part of SETools.
#
# SETools is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation, either version 2.1 of
# the License, or (at your option) any later version.
#
# SETools 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with SETools.  If not, see
# <http://www.gnu.org/licenses/>.
#

import logging

from PyQt5.QtCore import Qt, QSortFilterProxyModel, QStringListModel, QThread
from PyQt5.QtGui import QPalette, QTextCursor
from PyQt5.QtWidgets import QCompleter, QHeaderView, QMessageBox, QProgressDialog, QScrollArea
from setools import RoleQuery

from ..logtosignal import LogHandlerToSignal
from ..models import SEToolsListModel, invert_list_selection
from ..rolemodel import RoleTableModel, role_detail
from ..widget import SEToolsWidget
from .queryupdater import QueryResultsUpdater


class RoleQueryTab(SEToolsWidget, QScrollArea):

    """Role browser and query tab."""

    def __init__(self, parent, policy, perm_map):
        super(RoleQueryTab, self).__init__(parent)
        self.log = logging.getLogger(__name__)
        self.policy = policy
        self.query = RoleQuery(policy)
        self.setupUi()

    def __del__(self):
        self.thread.quit()
        self.thread.wait(5000)
        logging.getLogger("setools.rolequery").removeHandler(self.handler)

    def setupUi(self):
        self.load_ui("rolequery.ui")

        # populate role list
        self.role_model = SEToolsListModel(self)
        self.role_model.item_list = sorted(r for r in self.policy.roles())
        self.roles.setModel(self.role_model)

        # populate type list
        self.type_model = SEToolsListModel(self)
        self.type_model.item_list = sorted(self.policy.types())
        self.types.setModel(self.type_model)

        # set up results
        self.table_results_model = RoleTableModel(self)
        self.sort_proxy = QSortFilterProxyModel(self)
        self.sort_proxy.setSourceModel(self.table_results_model)
        self.table_results.setModel(self.sort_proxy)
        self.table_results.sortByColumn(0, Qt.AscendingOrder)

        # setup indications of errors on level/range
        self.orig_palette = self.name.palette()
        self.error_palette = self.name.palette()
        self.error_palette.setColor(QPalette.Base, Qt.red)
        self.clear_name_error()

        # set up processing thread
        self.thread = QThread()
        self.worker = QueryResultsUpdater(self.query, self.table_results_model)
        self.worker.moveToThread(self.thread)
        self.worker.raw_line.connect(self.raw_results.appendPlainText)
        self.worker.finished.connect(self.update_complete)
        self.worker.finished.connect(self.thread.quit)
        self.thread.started.connect(self.worker.update)

        # create a "busy, please wait" dialog
        self.busy = QProgressDialog(self)
        self.busy.setModal(True)
        self.busy.setRange(0, 0)
        self.busy.setMinimumDuration(0)
        self.busy.canceled.connect(self.thread.requestInterruption)
        self.busy.reset()

        # update busy dialog from query INFO logs
        self.handler = LogHandlerToSignal()
        self.handler.message.connect(self.busy.setLabelText)
        logging.getLogger("setools.rolequery").addHandler(self.handler)

        # Ensure settings are consistent with the initial .ui state
        self.notes.setHidden(not self.notes_expander.isChecked())

        # connect signals
        self.roles.doubleClicked.connect(self.get_detail)
        self.roles.get_detail.triggered.connect(self.get_detail)
        self.name.textEdited.connect(self.clear_name_error)
        self.name.editingFinished.connect(self.set_name)
        self.name_regex.toggled.connect(self.set_name_regex)
        self.types.selectionModel().selectionChanged.connect(self.set_types)
        self.invert_types.clicked.connect(self.invert_type_selection)
        self.buttonBox.clicked.connect(self.run)

    #
    # User browser
    #
    def get_detail(self):
        # .ui is set for single item selection.
        index = self.roles.selectedIndexes()[0]
        item = self.role_model.data(index, Qt.UserRole)

        self.log.debug("Generating detail window for {0}".format(item))
        role_detail(self, item)

    #
    # Name criteria
    #
    def clear_name_error(self):
        self.name.setToolTip("Match the role name.")
        self.name.setPalette(self.orig_palette)

    def set_name(self):
        try:
            self.query.name = self.name.text()
        except Exception as ex:
            self.log.error("Role name error: {0}".format(ex))
            self.name.setToolTip("Error: " + str(ex))
            self.name.setPalette(self.error_palette)

    def set_name_regex(self, state):
        self.log.debug("Setting name_regex {0}".format(state))
        self.query.name_regex = state
        self.clear_name_error()
        self.set_name()

    #
    # Type criteria
    #
    def set_types(self):
        selected_types = []
        for index in self.types.selectionModel().selectedIndexes():
            selected_types.append(self.type_model.data(index, Qt.UserRole))

        self.query.types = selected_types

    def invert_type_selection(self):
        invert_list_selection(self.types.selectionModel())

    #
    # Results runner
    #

    def run(self, button):
        # right now there is only one button.
        self.query.types_equal = self.types_equal.isChecked()

        # start processing
        self.busy.setLabelText("Processing query...")
        self.busy.show()
        self.raw_results.clear()
        self.thread.start()

    def update_complete(self, count):
        self.log.info("{0} role(s) found.".format(count))

        # update sizes/location of result displays
        if not self.busy.wasCanceled():
            self.busy.setLabelText("Resizing the result table's columns; GUI may be unresponsive")
            self.busy.repaint()
            self.table_results.resizeColumnsToContents()
            # If the types column width is too long, pull back
            # to a reasonable size
            header = self.table_results.horizontalHeader()
            if header.sectionSize(1) > 400:
                header.resizeSection(1, 400)

        if not self.busy.wasCanceled():
            self.busy.setLabelText("Resizing the result table's rows; GUI may be unresponsive")
            self.busy.repaint()
            self.table_results.resizeRowsToContents()

        if not self.busy.wasCanceled():
            self.busy.setLabelText("Moving the raw result to top; GUI may be unresponsive")
            self.busy.repaint()
            self.raw_results.moveCursor(QTextCursor.Start)

        self.busy.reset()