import enum
import json
import logging
import re
from dataclasses import dataclass
from pathlib import PurePath
from typing import List, Optional, Tuple

from PyQt6 import uic
from PyQt6.QtCore import (
    QDateTime,
    QLocale,
    QMimeData,
    QModelIndex,
    QPoint,
    Qt,
    QThread,
    QUrl,
)
from PyQt6.QtGui import QColor, QKeySequence, QShortcut
from PyQt6.QtWidgets import QApplication, QHeaderView, QMenu, QTreeView

from vorta.store.models import SettingsModel
from vorta.utils import get_asset, pretty_bytes, uses_dark_mode
from vorta.views.partials.treemodel import (
    FileSystemItem,
    FileTreeModel,
    FileTreeSortProxyModel,
    path_to_str,
    relative_path,
)
from vorta.views.utils import get_colored_icon

uifile = get_asset('UI/dialogs/archive/diff_result.ui')
DiffResultUI, DiffResultBase = uic.loadUiType(uifile)

logger = logging.getLogger(__name__)


class ParseThread(QThread):
    """A thread parsing diff results."""

    def __init__(self, fs_data: str, json_lines: bool, model: 'DiffTree', parent=None):
        """Init."""
        super().__init__(parent)
        self.model = model
        self.fs_data = fs_data
        self.json_lines = json_lines

    def run(self) -> None:
        """Do the work"""
        # Older version do not support json output
        if self.json_lines:
            # If fs_data is already a dict, then there was just a single json-line
            # and the default handler already parsed into json dict, otherwise
            # fs_data is a str, and needs to be split and parsed into json dicts
            if isinstance(self.fs_data, dict):
                lines = [self.fs_data]
            else:
                lines = [json.loads(line) for line in self.fs_data.split('\n') if line]

            parse_diff_json(lines, self.model)
        else:
            lines = [line for line in self.fs_data.split('\n') if line]
            parse_diff_lines(lines, self.model)


class DiffResultDialog(DiffResultBase, DiffResultUI):
    """Display the results of `borg diff`."""

    def __init__(self, archive_newer, archive_older, model: 'DiffTree'):
        """Init."""
        super().__init__()
        self.setupUi(self)

        self.model = model
        self.model.setParent(self)

        self.treeView: QTreeView
        self.treeView.setUniformRowHeights(True)  # Allows for scrolling optimizations.
        self.treeView.setAlternatingRowColors(True)
        self.treeView.setTextElideMode(Qt.TextElideMode.ElideMiddle)  # to better see name of paths

        # custom context menu
        self.treeView.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)
        self.treeView.customContextMenuRequested.connect(self.treeview_context_menu)

        # shortcuts
        shortcut_copy = QShortcut(QKeySequence.StandardKey.Copy, self.treeView)
        shortcut_copy.activated.connect(self.diff_item_copy)

        # add sort proxy model
        self.sortproxy = DiffSortProxyModel(self)
        self.sortproxy.setSourceModel(self.model)
        self.treeView.setModel(self.sortproxy)
        self.sortproxy.sorted.connect(self.slot_sorted)

        self.treeView.setSortingEnabled(True)

        # header
        header = self.treeView.header()
        header.setStretchLastSection(False)  # stretch only first section
        header.setSectionResizeMode(0, QHeaderView.ResizeMode.Stretch)
        header.setSectionResizeMode(1, QHeaderView.ResizeMode.ResizeToContents)
        header.setSectionResizeMode(2, QHeaderView.ResizeMode.ResizeToContents)

        # signals

        self.archiveNameLabel_1.setText(f'{archive_newer.name}')
        self.archiveNameLabel_2.setText(f'{archive_older.name}')

        self.comboBoxDisplayMode.currentIndexChanged.connect(self.change_display_mode)
        diff_result_display_mode = SettingsModel.get(key='diff_files_display_mode').str_value
        self.comboBoxDisplayMode.setCurrentIndex(int(diff_result_display_mode))
        self.bFoldersOnTop.toggled.connect(self.sortproxy.keepFoldersOnTop)
        self.bCollapseAll.clicked.connect(self.treeView.collapseAll)

        self.buttonBox.accepted.connect(self.accept)
        self.buttonBox.rejected.connect(self.reject)

        self.set_icons()

        # Connect to palette change
        self._palette_connection = QApplication.instance().paletteChanged.connect(lambda p: self.set_icons())
        self.destroyed.connect(self._on_destroyed)

    def set_icons(self):
        """Set or update the icons in the right color scheme."""
        self.bCollapseAll.setIcon(get_colored_icon('angle-up-solid'))
        self.bFoldersOnTop.setIcon(get_colored_icon('folder-on-top'))
        self.comboBoxDisplayMode.setItemIcon(0, get_colored_icon("view-list-tree"))
        self.comboBoxDisplayMode.setItemIcon(1, get_colored_icon("view-list-tree"))
        self.comboBoxDisplayMode.setItemIcon(2, get_colored_icon("view-list-details"))

    def _on_destroyed(self):
        try:
            QApplication.instance().paletteChanged.disconnect(self._palette_connection)
        except (TypeError, RuntimeError):
            pass

    def treeview_context_menu(self, pos: QPoint):
        """Display a context menu for `treeView`."""
        index = self.treeView.indexAt(pos)
        if not index.isValid():
            # popup only for items
            return

        menu = QMenu(self.treeView)

        menu.addAction(
            get_colored_icon('copy'),
            self.tr("Copy"),
            lambda: self.diff_item_copy(index),
        )

        if self.model.getMode() != self.model.DisplayMode.FLAT:
            menu.addSeparator()
            menu.addAction(
                get_colored_icon('angle-down-solid'),
                self.tr("Expand recursively"),
                lambda: self.treeView.expandRecursively(index),
            )

        menu.popup(self.treeView.viewport().mapToGlobal(pos))

    def diff_item_copy(self, index: QModelIndex = None):
        """
        Copy a diff item path to the clipboard.

        Copies the first selected item if no index is specified.
        """
        if index is None or (not index.isValid()):
            indexes = self.treeView.selectionModel().selectedRows()

            if not indexes:
                return

            index = indexes[0]

        index = self.sortproxy.mapToSource(index)
        item: DiffItem = index.internalPointer()
        path = PurePath('/', *item.path)

        data = QMimeData()
        data.setUrls([QUrl(path.as_uri())])
        data.setText(str(path))

        QApplication.clipboard().setMimeData(data)

    def change_display_mode(self, selection: int):
        """
        Change the display mode of the tree view

        The `selection` parameter specifies the index of the selected mode in
        `comboBoxDisplayMode`.

        """
        if selection == 0:
            mode = FileTreeModel.DisplayMode.TREE
            self.bCollapseAll.setEnabled(True)
        elif selection == 1:
            mode = FileTreeModel.DisplayMode.SIMPLIFIED_TREE
            self.bCollapseAll.setEnabled(True)
        elif selection == 2:
            mode = FileTreeModel.DisplayMode.FLAT
            self.bCollapseAll.setEnabled(False)
        else:
            raise Exception("Unknown item in comboBoxDisplayMode with index {}".format(selection))

        SettingsModel.update({SettingsModel.str_value: str(selection)}).where(
            SettingsModel.key == 'diff_files_display_mode'
        ).execute()

        self.model.setMode(mode)

    def slot_sorted(self, column, order):
        """React the tree view being sorted."""
        # reveal selection
        selectedRows = self.treeView.selectionModel().selectedRows()
        if selectedRows:
            self.treeView.scrollTo(selectedRows[0])


# ---- Output parsing --------------------------------------------------------


def parse_diff_json(diffs: List[dict], model: 'DiffTree'):
    """Parse the json output from `borg diff`."""
    items = []
    for item in diffs:
        path = PurePath(item['path'])
        file_type = FileType.FILE
        changed_size = 0
        size = 0
        change_type: ChangeType = None
        mode_change: Optional[Tuple[str, str]] = None
        owner_change: Optional[Tuple[str, str, str, str]] = None
        ctime_change: Optional[Tuple[QDateTime, QDateTime]] = None
        mtime_change: Optional[Tuple[QDateTime, QDateTime]] = None
        modified: Optional[Tuple[int, int]] = None

        # added link, removed link, changed link
        # modified (added, removed), added (size), removed (size)
        # added directory, removed directory
        # owner (old_user, new_user, old_group, new_group))
        # mode (old_mode, new_mode)
        # ctime (old_ctime, new_ctime)
        # mtime (old_mtime, new_mtime)
        for change in item['changes']:
            # if more than one type of change has happened for this file/dir/link, then report the most important
            # (higher priority)
            if {'type': 'modified'} == change:
                # modified, but can't compare ids -> no added, removed
                change_type = ChangeType.MODIFIED
            elif change['type'] == 'modified':
                # modified with added, removed
                change_type = ChangeType.MODIFIED
                size = change['added'] - change['removed']
                modified = (change['added'], change['removed'])
                changed_size = sum(modified)

            elif change['type'] == 'changed link':
                change_type = ChangeType.CHANGED_LINK
                file_type = FileType.LINK

            elif change['type'].startswith(('added', 'removed')):
                if 'directory' in change['type']:
                    file_type = FileType.DIRECTORY
                elif 'link' in change['type']:
                    file_type = FileType.LINK
                elif 'chrdev' in change['type']:
                    file_type = FileType.CHRDEV
                elif 'blkdev' in change['type']:
                    file_type = FileType.BLKDEV
                elif 'fifo' in change['type']:
                    file_type = FileType.FIFO
                # else default FileType.FILE

                size = change.get('size', 0)

                a_r = change['type'].split()[0]  # 'added' or 'removed'
                if a_r == 'added':
                    change_type = ChangeType.ADDED
                else:
                    change_type = ChangeType.REMOVED
                    size = -size

                changed_size = size

            elif change['type'] == 'mode':
                # mode change can occur along with previous changes
                change_type = ChangeType.MODIFIED
                mode_change = (change['old_mode'], change['new_mode'])

            elif change['type'] == 'owner':
                # owner change can occur along with previous changes
                change_type = ChangeType.MODIFIED

                owner_change = (
                    change['old_user'],
                    change['old_group'],
                    change['new_user'],
                    change['new_group'],
                )

            elif change['type'] == 'ctime':
                # ctime change can occur along with previous changes
                change_type = ChangeType.MODIFIED
                ctime_change = (
                    QDateTime.fromString(change['old_ctime'], Qt.DateFormat.ISODateWithMs),
                    QDateTime.fromString(change['new_ctime'], Qt.DateFormat.ISODateWithMs),
                )
            elif change['type'] == 'mtime':
                # mtime change can occur along with previous changes
                change_type = ChangeType.MODIFIED
                mtime_change = (
                    QDateTime.fromString(change['old_mtime'], Qt.DateFormat.ISODateWithMs),
                    QDateTime.fromString(change['new_mtime'], Qt.DateFormat.ISODateWithMs),
                )

            else:
                raise Exception('Unknown change type: {}'.format(change['type']))

        items.append(
            (
                path,
                DiffData(
                    file_type=file_type,
                    change_type=change_type,
                    changed_size=changed_size,
                    size=size,
                    mode_change=mode_change,
                    owner_change=owner_change,
                    ctime_change=ctime_change,
                    mtime_change=mtime_change,
                    modified=modified,
                ),
            )
        )

    model.addItems(items)


# re pattern
pattern_otypes = r'directory|link|fifo|chrdev|blkdev'
pattern_ar = r'(?P<a_r>added|removed) ((?P<ar_type>' + pattern_otypes + r')|\s+(?P<size>[\d.]+) (?P<size_unit>\w+))\s*'
pattern_cl = r'changed link\s*'
pattern_modified = r'\s*\+?(?P<added>[\d.]+) (?P<added_unit>\w+)\s*-?(?P<removed>[\d.]+) (?P<removed_unit>\w+)'
pattern_mode = r'\[(?P<old_mode>[\w-]{10}) -> (?P<new_mode>[\w-]{10})\]'
pattern_owner = r'\[(?P<old_user>[\w ]+):(?P<old_group>[\w ]+) -> (?P<new_user>[\w ]+):(?P<new_group>[\w ]+)\]'
pattern_path = r'(?P<path>.*)'
pattern_changed_file = (
    r'(({ar} )|((?P<cl>{cl} )|'
    + r'((?P<modified>{modified}\s+)?)(?P<owner>{owner}\s+)?(?P<mode>{mode}\s+)?))'
    + r'{path}'
).format(
    ar=pattern_ar,
    cl=pattern_cl,
    modified=pattern_modified,
    mode=pattern_mode,
    owner=pattern_owner,
    path=pattern_path,
)
re_changed_file = re.compile(pattern_changed_file)


def parse_diff_lines(lines: List[str], model: 'DiffTree'):
    """
    Parse non-json diff output from borg.

    ::

        [-rw-rw-r-- -> lrwxrwxrwx] home/theuser/Documents/testdir/file2
        [-rw-rw-r-- -> drwxr-xr-x] home/theuser/Documents/testdir/file3
            +32 B     -36 B [-r--rw---- -> -rwxrwx--x] home/theuser/Documents/testfile.txt
        [drwxrwxr-x -> lrwxrwxrwx] home/theuser/Documents/testlink
        added directory     home/theuser/Documents/newfolder
        removed         0 B home/theuser/Documents/testdir/file1
        added          20 B home/theuser/Documents/testdir/file4
        changed link        home/theuser/Documents/testlink
        changed link [theuser:dip -> theuser:theuser] home/theuser/Documents/testlink

    Notes
    -----
    This method can't handle changes of type `modified` that do not provide
    the amount of `added` and `removed` bytes.

    """
    items = []
    for line in lines:
        if not line:
            continue

        parsed_line = re_changed_file.fullmatch(line)

        if not parsed_line:
            raise Exception("Couldn't parse diff output `{}`".format(line))

        path = PurePath(parsed_line['path'])
        file_type = FileType.FILE
        size = 0
        changed_size = 0
        change_type: ChangeType = None
        mode_change: Optional[Tuple[str, str]] = None
        owner_change: Optional[Tuple[str, str, str, str]] = None
        modified: Optional[Tuple[int, int]] = None

        if parsed_line['a_r']:
            # added or removed
            if parsed_line['ar_type']:
                if parsed_line['ar_type'] == 'directory':
                    file_type = FileType.DIRECTORY
                elif parsed_line['ar_type'] == 'link':
                    file_type = FileType.LINK
                elif parsed_line['ar_type'] == 'chrdev':
                    file_type = FileType.CHRDEV
                elif parsed_line['ar_type'] == 'blkdev':
                    file_type = FileType.BLKDEV
                elif parsed_line['ar_type'] == 'fifo':
                    file_type = FileType.FIFO
                else:
                    raise ValueError(f"Unknown file type `{parsed_line['ar_type']}`")
            else:
                # normal file
                size = size_to_byte(parsed_line['size'], parsed_line['size_unit'])

            if parsed_line['a_r'] == 'added':
                change_type = ChangeType.ADDED
            elif parsed_line['a_r'] == 'removed':
                change_type = ChangeType.REMOVED
                size = -size

            changed_size = size
        else:
            change_type = ChangeType.MODIFIED

            if parsed_line['owner']:
                # owner changed
                owner_change = (
                    parsed_line['old_user'],
                    parsed_line['old_group'],
                    parsed_line['new_user'],
                    parsed_line['new_group'],
                )

            if parsed_line['cl']:
                # link changed
                # links can't have changed permissions
                change_type = ChangeType.CHANGED_LINK
                file_type = FileType.LINK
            else:
                # modified contents or mode
                if parsed_line['modified']:
                    modified = (
                        size_to_byte(parsed_line['added'], parsed_line['added_unit']),
                        size_to_byte(parsed_line['removed'], parsed_line['removed_unit']),
                    )

                    size = modified[0] - modified[1]
                    changed_size = sum(modified)

                if parsed_line['mode']:
                    mode_change = (parsed_line['old_mode'], parsed_line['new_mode'])

        # add change to items list
        items.append(
            (
                path,
                DiffData(
                    file_type=file_type,
                    change_type=change_type,
                    changed_size=changed_size,
                    size=size,
                    mode_change=mode_change,
                    owner_change=owner_change,
                    modified=modified,
                ),
            )
        )

    model.addItems(items)


def size_to_byte(significand: str, unit: str) -> int:
    """Convert a size with a unit identifier from borg into a number of bytes."""
    if unit == 'B':
        return int(significand)
    elif unit == 'kB' or unit == 'KB':
        return int(float(significand) * 10**3)
    elif unit == 'MB':
        return int(float(significand) * 10**6)
    elif unit == 'GB':
        return int(float(significand) * 10**9)
    elif unit == 'TB':
        return int(float(significand) * 10**12)
    else:
        # unknown identifier
        raise Exception("Unknown unit `{}`".format(unit))


# ---- Sorting ---------------------------------------------------------------


class DiffSortProxyModel(FileTreeSortProxyModel):
    """
    Sort a DiffTree model.
    """

    def choose_data(self, index: QModelIndex):
        """Choose the data of index used for comparison."""
        item: DiffItem = index.internalPointer()
        if item is None or item.data is None:
            return ""
        column = index.column()

        if column == 0:
            return self.extract_path(index)
        elif column == 1:
            # change type
            ct = item.data.change_type
            if ct == ChangeType.NONE:
                return ChangeType.MODIFIED
            return ct
        elif column == 2:
            return item.data.changed_size
        else:
            # size
            return item.data.size


# ---- DiffTree --------------------------------------------------------------


class ChangeType(enum.Enum):
    """
    The possible types of changes from `borg diff`.

    modified - file contents changed.
    added - the file was added.
    removed - the file was removed.
    added directory - the directory was added.
    removed directory - the directory was removed.
    added link - the symlink was added.
    removed link - the symlink was removed.
    changed link - the symlink target was changed.
    mode - the file/directory/link mode was changed.
            Note: this could indicate a change from a file/directory/link
                    type to a different type (file/directory/link),
                    such as - a file is deleted and replaced with
                    a directory of the same name.
    owner - user and/or group ownership changed.
    ctime - creation time changed.
    mtime - modification time changed.

    size:
        If type == `added` or `removed`,
        then size provides the size of the added or removed file.
    added:
        If type == `modified` and chunk ids can be compared,
        then added and removed indicate the amount of
        data `added` and `removed`. If chunk ids can not be compared,
        then added and removed properties are not provided and
        the only information available is that the file contents were modified.
    removed:
        See added property.
    old_mode:
        If type == `mode`, then old_mode and new_mode provide the mode
        and permissions changes.
    new_mode:
        See old_mode property.
    old_user:
        If type == `owner`, then old_user, new_user, old_group
        and new_group provide the user and group ownership changes.
    old_group:
        See old_user property.
    new_user:
        See old_user property.
    new_group:
        See old_user property.
    old_ctime:
        If type == `ctime`, then old_ctime and new_ctime provide creation time changes.
    new_ctime:
        See old_ctime property.
    old_mtime:
        If type == `mtime`, then old_mtime and new_mtime provide modification time changes.
    new_mtime:
        See old_mtime property.
    """

    NONE = 0  # no change
    MODIFIED = 2  # int for sorting
    ADDED = 1
    REMOVED = 3
    ADDED_DIR = ADDED
    REMOVED_DIR = REMOVED
    ADDED_LINK = ADDED
    REMOVED_LINK = REMOVED
    CHANGED_LINK = MODIFIED
    MODE = MODIFIED  # changed permissions
    OWNER = MODIFIED
    CTIME = MODIFIED
    MTIME = MODIFIED

    def short(self):
        """Get a short identifier for the change type."""
        if self == self.ADDED:
            return 'A'
        if self == self.REMOVED:
            return 'D'
        if self == self.MODIFIED:
            return 'M'
        return ''

    def __ge__(self, other):
        """Greater than or equal for enums."""
        if self.__class__ is other.__class__:
            return other >= self
        return NotImplemented

    def __gt__(self, other):
        """Greater than for enums."""
        if self.__class__ is other.__class__:
            return other < self
        return NotImplemented

    def __le__(self, other):
        """Lower than or equal for enums."""
        if self.__class__ is other.__class__:
            return self.value == other.value or self < other
        return NotImplemented

    def __lt__(self, other):
        """Lower than for enums."""
        if self.__class__ is other.__class__:
            return self.value < other.value
        return NotImplemented


class FileType(enum.Enum):
    """The possible file types of changed file."""

    FILE = enum.auto()
    DIRECTORY = enum.auto()
    LINK = enum.auto()
    CHRDEV = enum.auto()
    BLKDEV = enum.auto()
    FIFO = enum.auto()


@dataclass
class DiffData:
    """The data linked to a diff item."""

    file_type: FileType
    change_type: ChangeType
    changed_size: int  # total modified bits
    size: int  # size change (disk usage)
    mode_change: Optional[Tuple[str, str]] = None
    owner_change: Optional[Tuple[str, str, str, str]] = None
    ctime_change: Optional[Tuple[QDateTime, QDateTime]] = None
    mtime_change: Optional[Tuple[QDateTime, QDateTime]] = None
    modified: Optional[Tuple[int, int]] = None


DiffItem = FileSystemItem[DiffData]


class DiffTree(FileTreeModel[DiffData]):
    """The file tree model for diff results."""

    def _make_filesystemitem(self, path, data):
        return super()._make_filesystemitem(path, data)

    def _merge_data(self, item, data):
        if data:
            logger.debug('Overriding data for {}'.format(path_to_str(item.path)))
        return super()._merge_data(item, data)

    def _flat_filter(self, item):
        """
        Return whether an item is part of the flat model representation.

        The item's data might have not been set yet.
        """
        return item.data and item.data.change_type != ChangeType.NONE

    def _simplify_filter(self, item: DiffItem) -> bool:
        """
        Return whether an item may be merged in simplified mode.

        Allows simplification only for unchanged items.
        """
        for child in item.children:
            if child.data.change_type != ChangeType.NONE:
                return False

        if item.data.change_type == ChangeType.NONE:
            return True

        return False  # otherwise the change is not displayed

    def _process_child(self, child):
        """
        Process a new child.

        This can make some changes to the child's data like
        setting a default value if the child's data is None.
        This can also update the data of the parent.
        This must emit `dataChanged` if data is changed.

        Parameters
        ----------
        child : FileSystemItem
            The child that was added.
        """
        parent = child._parent

        if not child.data:
            child.data = DiffData(FileType.DIRECTORY, ChangeType.NONE, 0, 0)

        if child.data.size != 0 or child.data.changed_size != 0:
            # update size
            size = child.data.size
            changed_size = child.data.changed_size

            def add_size(parent):
                if parent is self.root:
                    return

                if parent.data is None:
                    raise Exception("Item {} without data".format(path_to_str(parent.path)))
                else:
                    parent.data.size += size
                    parent.data.changed_size += changed_size

                # update parent
                parent = parent._parent
                if parent:
                    add_size(parent)

            add_size(parent)

    def columnCount(self, parent: QModelIndex = QModelIndex()) -> int:
        """
        Returns the number of columns for the children of the given parent.

        This corresponds to the number of data (column) entries shown
        for each item in the tree view.

        Parameters
        ----------
        parent : QModelIndex, optional
            The index of the parent, by default QModelIndex()

        Returns
        -------
        int
            The number of rows.
        """
        # name, change_type, changed bytes, size balance
        return 4

    def headerData(
        self,
        section: int,
        orientation: Qt.Orientation,
        role: int = Qt.ItemDataRole.DisplayRole,
    ):
        """
        Get the data for the given role and section in the given header.

        The header is identified by its orientation.
        For horizontal headers, the section number corresponds to
        the column number. Similarly, for vertical headers,
        the section number corresponds to the row number.

        Parameters
        ----------
        section : int
            The row or column number.
        orientation : Qt.Orientation
            The orientation of the header.
        role : int, optional
            The data role, by default Qt.ItemDataRole.DisplayRole

        Returns
        -------Improve
        Any
            The data for the specified header section.
        """
        if orientation == Qt.Orientation.Horizontal and role == Qt.ItemDataRole.DisplayRole:
            if section == 0:
                return self.tr("Name")
            elif section == 1:
                return self.tr("Change")
            elif section == 2:
                return self.tr("Size")
            elif section == 3:
                return self.tr("Balance")

        return None

    def data(self, index: QModelIndex, role: int = Qt.ItemDataRole.DisplayRole):
        """
        Get the data for the given role and index.

        The indexes internal pointer references the corresponding
        `FileSystemItem`.

        Parameters
        ----------
        index : QModelIndex
            The index of the item.
        role : int, optional
            The data role, by default Qt.ItemDataRole.DisplayRole

        Returns
        -------
        Any
            The data, return None if no data is available for the role.
        """
        if not index.isValid():
            return None

        item: DiffItem = index.internalPointer()
        column = index.column()

        if role == Qt.ItemDataRole.DisplayRole:
            if column == 0:
                # name
                if self.mode == self.DisplayMode.FLAT:
                    return path_to_str(item.path)

                if self.mode == self.DisplayMode.SIMPLIFIED_TREE:
                    parent = index.parent()
                    if parent == QModelIndex():
                        return path_to_str(relative_path(self.root.path, item.path))

                    return path_to_str(relative_path(parent.internalPointer().path, item.path))

                # standard tree mode
                return item.subpath
            elif column == 1:
                # change type
                return item.data.change_type.short()
            elif column == 2:
                return pretty_bytes(item.data.changed_size)
            else:
                # size
                return pretty_bytes(item.data.size)

        if role == Qt.ItemDataRole.ForegroundRole:
            # colour
            if item.data.change_type == ChangeType.ADDED:
                return QColor(Qt.GlobalColor.green) if uses_dark_mode() else QColor(Qt.GlobalColor.darkGreen)
            if item.data.change_type == ChangeType.MODIFIED:
                return QColor(Qt.GlobalColor.yellow) if uses_dark_mode() else QColor(Qt.GlobalColor.darkYellow)
            if item.data.change_type == ChangeType.REMOVED:
                return QColor(Qt.GlobalColor.red) if uses_dark_mode() else QColor(Qt.GlobalColor.darkRed)
            return None  # no change

        if role == Qt.ItemDataRole.ToolTipRole:
            if column == 0:
                # name column -> display fullpath
                return path_to_str(item.path)

            # info/data tooltip -> no real size limitation
            tooltip_template = "{name}\n" + "\n" + "{filetype} {changetype}"

            modified_template = self.tr("Added {}, deleted {}")
            owner_template = "{: <10} -> {: >10}"
            time_template = "{}: {} -> {}"
            permission_template = "{} -> {}"

            # format
            if item.data.file_type == FileType.FILE:
                filetype = self.tr("File")
            elif item.data.file_type == FileType.DIRECTORY:
                filetype = self.tr("Directory")
            elif item.data.file_type == FileType.LINK:
                filetype = self.tr("Link")
            elif item.data.file_type == FileType.BLKDEV:
                filetype = self.tr("Block device file")
            elif item.data.file_type == FileType.CHRDEV:
                filetype = self.tr("Character device file")
            else:
                raise Exception("Unknown filetype {}".format(item.data.file_type))

            if item.data.change_type == ChangeType.NONE:
                changetype = self.tr("unchanged")
            elif item.data.change_type == ChangeType.MODIFIED:
                changetype = self.tr("modified")
            elif item.data.change_type == ChangeType.REMOVED:
                changetype = self.tr("removed")
            elif item.data.change_type == ChangeType.ADDED:
                changetype = self.tr("added")
            else:
                raise Exception("Unknown changetype {}".format(item.data.change_type))

            tooltip = tooltip_template.format(name=item.path[-1], filetype=filetype, changetype=changetype)
            if item.data.modified:
                tooltip += '\n'
                tooltip += modified_template.format(
                    pretty_bytes(item.data.modified[0]),
                    pretty_bytes(item.data.modified[1]),
                )

            if item.data.mode_change:
                tooltip += '\n'
                tooltip += permission_template.format(*item.data.mode_change)

            if item.data.owner_change:
                tooltip += '\n'
                tooltip += owner_template.format(
                    '{}:{}'.format(item.data.owner_change[0], item.data.owner_change[1]),
                    "{}:{}".format(item.data.owner_change[2], item.data.owner_change[3]),
                )

            if item.data.ctime_change:
                tooltip += '\n'
                tooltip += time_template.format(
                    "Creation Time",
                    QLocale.system().toString(item.data.ctime_change[0], QLocale.FormatType.ShortFormat),
                    QLocale.system().toString(item.data.ctime_change[1], QLocale.FormatType.ShortFormat),
                )

            if item.data.mtime_change:
                tooltip += '\n'
                tooltip += time_template.format(
                    "Modification Time",
                    QLocale.system().toString(item.data.mtime_change[0], QLocale.FormatType.ShortFormat),
                    QLocale.system().toString(item.data.mtime_change[1], QLocale.FormatType.ShortFormat),
                )

            return tooltip
