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

# Copyright 2017-2021 Ryan Roden-Corrent (rcorre) <ryan@rcorre.net>
#
# 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 <https://www.gnu.org/licenses/>.

"""Completion category that uses a list of tuples as a data source."""

import re
from typing import Iterable, Tuple

from PyQt5.QtCore import QSortFilterProxyModel, QRegularExpression
from PyQt5.QtGui import QStandardItem, QStandardItemModel
from PyQt5.QtWidgets import QWidget

from qutebrowser.completion.models import util
from qutebrowser.utils import qtutils, log


class ListCategory(QSortFilterProxyModel):

    """Expose a list of items as a category for the CompletionModel."""

    def __init__(self,
                 name: str,
                 items: Iterable[Tuple[str, ...]],
                 sort: bool = True,
                 delete_func: util.DeleteFuncType = None,
                 parent: QWidget = None):
        super().__init__(parent)
        self.name = name
        self.srcmodel = QStandardItemModel(parent=self)
        self._pattern = ''
        # ListCategory filters all columns
        self.columns_to_filter = [0, 1, 2]
        self.setFilterKeyColumn(-1)
        for item in items:
            self.srcmodel.appendRow([QStandardItem(x) for x in item])
        self.setSourceModel(self.srcmodel)
        self.delete_func = delete_func
        self._sort = sort

    def set_pattern(self, val):
        """Setter for pattern.

        Args:
            val: The value to set.
        """
        if len(val) > 5000:  # avoid crash on huge search terms (#5973)
            log.completion.warning(f"Trimming {len(val)}-char pattern to 5000")
            val = val[:5000]
        self._pattern = val
        val = re.sub(r' +', r' ', val)  # See #1919
        val = re.escape(val)
        val = val.replace(r'\ ', '.*')
        rx = QRegularExpression(val, QRegularExpression.CaseInsensitiveOption)
        qtutils.ensure_valid(rx)
        self.setFilterRegularExpression(rx)
        self.invalidate()
        sortcol = 0
        self.sort(sortcol)

    def lessThan(self, lindex, rindex):
        """Custom sorting implementation.

        Prefers all items which start with self._pattern. Other than that, uses
        normal Python string sorting.

        Args:
            lindex: The QModelIndex of the left item (*left* < right)
            rindex: The QModelIndex of the right item (left < *right*)

        Return:
            True if left < right, else False
        """
        qtutils.ensure_valid(lindex)
        qtutils.ensure_valid(rindex)

        left = self.srcmodel.data(lindex)
        right = self.srcmodel.data(rindex)

        if left is None or right is None:  # pragma: no cover
            log.completion.warning("Got unexpected None value, "
                                   "left={!r} right={!r} "
                                   "lindex={!r} rindex={!r}"
                                   .format(left, right, lindex, rindex))
            return False

        leftstart = left.startswith(self._pattern)
        rightstart = right.startswith(self._pattern)

        if leftstart and not rightstart:
            return True
        elif rightstart and not leftstart:
            return False
        elif self._sort:
            return left < right
        else:
            return False