# Standard library imports
from __future__ import annotations

from operator import attrgetter
from random import shuffle
from typing import cast, Optional
import datetime as dt
import re

# PyQt imports
from PyQt6.QtCore import (
    QAbstractTableModel,
    QModelIndex,
    QRegularExpression,
    QSortFilterProxyModel,
    Qt,
    QTimer,
    QVariant,
)
from PyQt6.QtGui import (
    QBrush,
    QColor,
    QFont,
)

# Third party imports
# import line_profiler
import obswebsocket  # type: ignore

# import snoop  # type: ignore

# App imports
from classes import (
    ApplicationError,
    Col,
    InsertRows,
    InsertTrack,
    MusicMusterSignals,
    TrackAndPlaylist,
)
from config import Config
from helpers import (
    ask_yes_no,
    file_is_unreadable,
    get_all_track_metadata,
    get_embedded_time,
    get_relative_date,
    ms_to_mmss,
)
from log import log, log_call
from playlistrow import PlaylistRow, TrackSequence
import ds


HEADER_NOTES_COLUMN = 1
scene_change_re = re.compile(r"SetScene=\[([^[\]]*)\]")


class PlaylistModel(QAbstractTableModel):
    """
    The Playlist Model

    Cache the database info in self.playlist_rows, a dictionary of
    PlaylistRow objects indexed by row_number.

    Update strategy: update the database and then refresh the
    row-indexed cached copy (self.playlist_rows). Do not edit
    self.playlist_rows directly because keeping it and the
    database in sync is uncessarily challenging.

    refresh_row() will populate one row of playlist_rows from the
    database

    refresh_data() will repopulate all of playlist_rows from the
    database.
    """

    def __init__(
        self,
        playlist_id: int,
        is_template: bool,
    ) -> None:
        super().__init__()

        self.playlist_id = playlist_id
        self.is_template = is_template
        self.track_sequence = TrackSequence()

        self.playlist_rows: dict[int, PlaylistRow] = {}
        self.selected_rows: list[PlaylistRow] = []
        self.signals = MusicMusterSignals()
        self.played_tracks_hidden = False

        # Connect signals
        self.signals.signal_add_track_to_header.connect(self.add_track_to_header)
        self.signals.signal_begin_insert_rows.connect(self.begin_insert_rows)
        self.signals.signal_end_insert_rows.connect(self.end_insert_rows)
        self.signals.signal_playlist_selected_rows.connect(self.set_selected_rows)
        self.signals.signal_set_next_row.connect(self.set_next_row)
        self.signals.signal_track_started.connect(self.track_started)

        # Populate self.playlist_rows
        for dto in ds.playlistrows_by_playlist(self.playlist_id):
            self.playlist_rows[dto.row_number] = PlaylistRow(dto)
        self.update_track_times()

    def __repr__(self) -> str:
        return (
            f"<PlaylistModel: playlist_id={self.playlist_id}, "
            f"is_template={self.is_template}, "
            f"{self.rowCount()} rows>"
        )

    def active_section_header(self) -> int:
        """
        Return the row number of the first header that has any of the following below it:
         - unplayed tracks
         - the currently being played track
         - the track marked as next to play
        """

        header_row = 0

        for row_number in range(len(self.playlist_rows)):
            if self.is_header_row(row_number):
                header_row = row_number
                continue
            if not self.is_played_row(row_number):
                break

            # Here means that row_number points to a played track. The
            # current track will be marked as played when we start
            # playing it. It's also possible that the track marked as
            # next has already been played. Check for either of those.

            for ts in [self.track_sequence.next, self.track_sequence.current]:
                if (
                    ts
                    and ts.row_number == row_number
                    and ts.playlist_id == self.playlist_id
                ):
                    # We've found the current or next track, so return
                    # the last-found header row
                    return header_row

        return header_row

    # @log_call
    def add_track_to_header(self, track_and_playlist: TrackAndPlaylist) -> None:
        """
        Handle signal_add_track_to_header
        """

        if track_and_playlist.playlist_id != self.playlist_id:
            return

        if not self.selected_rows:
            raise ApplicationError("Add track to header but no row selected")

        if len(self.selected_rows) > 1:
            self.signals.show_warning_signal.emit(
                "Add track to header", "Select one header to add track to"
            )
            return

        selected_row = self.selected_rows[0]
        if selected_row.path:
            self.signals.show_warning_signal.emit(
                "Add track to header", "Select header to add track to"
            )
            return

        selected_row.track_id = track_and_playlist.track_id

        # Update local copy
        self.refresh_row(selected_row.row_number)
        # Repaint row
        roles_to_invalidate = [
            Qt.ItemDataRole.BackgroundRole,
            Qt.ItemDataRole.DisplayRole,
            Qt.ItemDataRole.FontRole,
            Qt.ItemDataRole.ForegroundRole,
        ]
        # only invalidate required roles
        self.invalidate_row(selected_row.row_number, roles_to_invalidate)

        self.signals.resize_rows_signal.emit(self.playlist_id)

    def _background_role(self, row: int, column: int, plr: PlaylistRow) -> QBrush:
        """Return background setting"""

        # Handle entire row colouring
        # Header row
        if self.is_header_row(row):
            # Check for specific header colouring
            if plr.row_bg is None:
                plr.row_bg = ds.notecolours_get_colour(plr.note)
            if plr.row_bg:
                return QBrush(QColor(plr.row_bg))
            else:
                return QBrush(QColor(Config.COLOUR_NOTES_PLAYLIST))
        # Unreadable track file
        if file_is_unreadable(plr.path):
            return QBrush(QColor(Config.COLOUR_UNREADABLE))
        # Current track
        if (
            self.track_sequence.current
            and self.track_sequence.current.playlist_id == self.playlist_id
            and self.track_sequence.current.row_number == row
        ):
            return QBrush(QColor(Config.COLOUR_CURRENT_PLAYLIST))
        # Next track
        if (
            self.track_sequence.next
            and self.track_sequence.next.playlist_id == self.playlist_id
            and self.track_sequence.next.row_number == row
        ):
            return QBrush(QColor(Config.COLOUR_NEXT_PLAYLIST))

        # Individual cell colouring
        if column == Col.START_GAP.value:
            if plr.start_gap and plr.start_gap >= Config.START_GAP_WARNING_THRESHOLD:
                return QBrush(QColor(Config.COLOUR_LONG_START))
        if column == Col.BITRATE.value:
            if not plr.bitrate or plr.bitrate < Config.BITRATE_LOW_THRESHOLD:
                return QBrush(QColor(Config.COLOUR_BITRATE_LOW))
            elif plr.bitrate < Config.BITRATE_OK_THRESHOLD:
                return QBrush(QColor(Config.COLOUR_BITRATE_MEDIUM))
            else:
                return QBrush(QColor(Config.COLOUR_BITRATE_OK))
        if column == Col.NOTE.value:
            if plr.note:
                if plr.note_bg is None:
                    plr.row_bg = ds.notecolours_get_colour(plr.note)
                if plr.note_bg:
                    return QBrush(QColor(plr.note_bg))

        return QBrush()

    def columnCount(self, parent: QModelIndex = QModelIndex()) -> int:
        """Standard function for view"""

        return len(Col)

    # @log_call
    def track_started(self, play_track: TrackAndPlaylist) -> None:
        """
        Notification from musicmuster that the current track has just
        started playing

        Actions required:
        - sanity check
        - change OBS scene if needed
        - update Playdates in database
        - update PlaylistRows in database
        - update display
        - find next track
        - update track times
        """

        if play_track.playlist_id != self.playlist_id:
            # Not for us
            return

        track_id = play_track.track_id
        # Sanity check - 1
        if not track_id:
            raise ApplicationError("current_track_started() called with no track_id")

        # Sanity check - 2
        if self.track_sequence.current is None:
            raise ApplicationError("track_started callced with no current track")

        row_number = self.track_sequence.current.row_number
        playlist_dto = self.playlist_rows[row_number]

        # Sanity check - 3
        if playlist_dto.track_id != track_id:
            raise ApplicationError("track_id mismatch between playlist_rows and signal")

        # Check for OBS scene change
        self.obs_scene_change(row_number)

        # Update Playdates in database
        ds.playdates_update(track_id)

        # Mark track as played in playlist
        playlist_dto.played = True

        # Update colour and times for current row
        roles_to_invalidate = [Qt.ItemDataRole.DisplayRole]
        self.invalidate_row(row_number, roles_to_invalidate)

        # Update previous row in case we're hiding played rows
        if self.track_sequence.previous and self.track_sequence.previous.row_number:
            # only invalidate required roles
            self.invalidate_row(self.track_sequence.previous.row_number, roles_to_invalidate)

        # Update all other track times
        self.update_track_times()

        # Find next track
        next_row = self.find_next_row_to_play(row_number)
        if next_row:
            self.signals.signal_set_next_track.emit(self.playlist_rows[next_row])

    def find_next_row_to_play(self, from_row_number: int) -> int | None:
        """
        Find the next row to play in this playlist. Return row number or
        None if there's no next track.
        """

        next_row = None
        unplayed_rows = [
            a
            for a in self.get_unplayed_rows()
            if not self.is_header_row(a)
            and not file_is_unreadable(self.playlist_rows[a].path)
        ]
        if unplayed_rows:
            try:
                next_row = min([a for a in unplayed_rows if a > from_row_number])
            except ValueError:
                next_row = min(unplayed_rows)

        return next_row

    def data(
        self, index: QModelIndex, role: int = Qt.ItemDataRole.DisplayRole
    ) -> QVariant | QFont | QBrush | str | int:
        """Return data to view"""

        if (
            not index.isValid()
            or not (0 <= index.row() < len(self.playlist_rows))
            or role
            in [
                Qt.ItemDataRole.DecorationRole,
                Qt.ItemDataRole.StatusTipRole,
                Qt.ItemDataRole.WhatsThisRole,
                Qt.ItemDataRole.SizeHintRole,
                Qt.ItemDataRole.TextAlignmentRole,
                Qt.ItemDataRole.CheckStateRole,
                Qt.ItemDataRole.InitialSortOrderRole,
            ]
        ):
            return QVariant()

        row = index.row()
        column = index.column()
        # plr for playlist row data as it's used a lot
        plr = self.playlist_rows[row]

        # These are ordered in approximately the frequency with which
        # they are called
        if role == Qt.ItemDataRole.BackgroundRole:
            return self._background_role(row, column, plr)
        elif role == Qt.ItemDataRole.DisplayRole:
            return self._display_role(row, column, plr)
        elif role == Qt.ItemDataRole.EditRole:
            return self._edit_role(row, column, plr)
        elif role == Qt.ItemDataRole.FontRole:
            return self._font_role(row, column, plr)
        elif role == Qt.ItemDataRole.ForegroundRole:
            return self._foreground_role(row, column, plr)
        elif role == Qt.ItemDataRole.ToolTipRole:
            return self._tooltip_role(row, column, plr)

        return QVariant()

    # @log_call
    def delete_rows(self, row_numbers: list[int]) -> None:
        """
        Delete passed rows from model

        Need to delete them in contiguous groups wrapped in beginRemoveRows / endRemoveRows
        calls. To keep it simple, if inefficient, delete rows one by one.

        Delete from highest row back so that not yet deleted row numbers don't change.
        """

        for row_group in self._reversed_contiguous_row_groups(row_numbers):
            # Signal that rows will be removed
            super().beginRemoveRows(QModelIndex(), min(row_group), max(row_group))
            # Remove rows from data store
            ds.playlist_remove_rows(self.playlist_id, row_group)
            # Signal that data store has been updated
            super().endRemoveRows()

        self.refresh_data()
        self.track_sequence.update()
        self.update_track_times()

    def _display_role(self, row: int, column: int, plr: PlaylistRow) -> str:
        """
        Return text for display
        """

        header_row = self.is_header_row(row)

        # Set / reset column span
        if column == HEADER_NOTES_COLUMN:
            column_span = 1
            if header_row:
                column_span = self.columnCount() - 1
            self.signals.span_cells_signal.emit(
                self.playlist_id, row, HEADER_NOTES_COLUMN, 1, column_span
            )

        if header_row:
            if column == HEADER_NOTES_COLUMN:
                header_text = self.header_text(plr)
                if not header_text:
                    return Config.SECTION_HEADER
                else:
                    formatted_header = self.header_text(plr)
                    trimmed_header = self.remove_section_timer_markers(formatted_header)
                    return trimmed_header
            else:
                return ""

        if column == Col.START_TIME.value:
            start_time = plr.forecast_start_time
            if start_time:
                return start_time.strftime(Config.TRACK_TIME_FORMAT)
            return ""

        if column == Col.END_TIME.value:
            end_time = plr.forecast_end_time
            if end_time:
                return end_time.strftime(Config.TRACK_TIME_FORMAT)
            return ""

        if column == Col.INTRO.value:
            if plr.intro:
                return f"{plr.intro / 1000:{Config.INTRO_SECONDS_FORMAT}}"
            else:
                return ""

        dispatch_table: dict[int, str] = {
            Col.ARTIST.value: plr.artist,
            Col.BITRATE.value: str(plr.bitrate),
            Col.DURATION.value: ms_to_mmss(plr.duration),
            Col.LAST_PLAYED.value: get_relative_date(plr.lastplayed),
            Col.NOTE.value: plr.note,
            Col.START_GAP.value: str(plr.start_gap),
            Col.TITLE.value: plr.title,
        }
        if column in dispatch_table:
            return dispatch_table[column]

        return ""

    def _edit_role(self, row: int, column: int, plr: PlaylistRow) -> str | int:
        """
        Return value for editing
        """

        # If this is a header row and we're being asked for the
        # HEADER_NOTES_COLUMN, return the note value
        if self.is_header_row(row) and column == HEADER_NOTES_COLUMN:
            return plr.note

        if column == Col.INTRO.value:
            return plr.intro or 0
        if column == Col.TITLE.value:
            return plr.title
        if column == Col.ARTIST.value:
            return plr.artist
        if column == Col.NOTE.value:
            return plr.note

        return ""

    def _foreground_role(self, row: int, column: int, plr: PlaylistRow) -> QBrush:
        """Return header foreground colour or QBrush() if none"""

        plr.row_fg = ds.notecolours_get_colour(plr.note, foreground=True)
        if plr.row_fg:
            return QBrush(QColor(plr.row_fg))
        return QBrush()

    def flags(self, index: QModelIndex) -> Qt.ItemFlag:
        """
        Standard model flags
        """

        if not index.isValid():
            return Qt.ItemFlag.ItemIsDropEnabled

        default = (
            Qt.ItemFlag.ItemIsEnabled
            | Qt.ItemFlag.ItemIsSelectable
            | Qt.ItemFlag.ItemIsDragEnabled
        )
        if index.column() in [
            Col.TITLE.value,
            Col.ARTIST.value,
            Col.NOTE.value,
            Col.INTRO.value,
        ]:
            return default | Qt.ItemFlag.ItemIsEditable

        return default

    def _font_role(self, row: int, column: int, plr: PlaylistRow) -> QFont:
        """
        Return font
        """

        # Notes column is never bold
        if column == Col.NOTE.value:
            return QFont()

        boldfont = QFont()
        boldfont.setBold(not self.playlist_rows[row].played)

        return boldfont

    # @log_call
    def get_duplicate_rows(self) -> list[int]:
        """
        Return a list of duplicate rows. If track appears in rows 2, 3 and 4, return [3, 4]
        (ie, ignore the first, not-yet-duplicate, track).
        """

        found = []
        result = []

        for i in range(len(self.playlist_rows)):
            track_id = self.playlist_rows[i].track_id
            if track_id is None:
                continue
            if track_id in found:
                result.append(i)
            else:
                found.append(track_id)

        return result

    # @log_call
    def _get_new_row_number(self) -> int:
        """
        Get row number for new row.

        If any rows are selected, return the first such row number, else
        return row number to add to end of model.
        """

        if not self.selected_rows:
            return len(self.playlist_rows)

        return self.selected_rows[0].row_number

    def get_row_info(self, row_number: int) -> PlaylistRow:
        """
        Return info about passed row
        """

        return self.playlist_rows[row_number]

    # @log_call
    def get_row_track_id(self, row_number: int) -> Optional[int]:
        """
        Return id of track associated with row or None if no track associated
        """

        return self.playlist_rows[row_number].track_id

    def get_row_track_path(self, row_number: int) -> str:
        """
        Return path of track associated with row or empty string if no track associated
        """

        return self.playlist_rows[row_number].path

    def get_rows_duration(self, row_numbers: list[int]) -> int:
        """
        Return the total duration of the passed rows
        """

        duration = 0
        for row_number in row_numbers:
            duration += self.playlist_rows[row_number].duration

        return duration

    def get_unplayed_rows(self) -> list[int]:
        """
        Return a list of unplayed row numbers
        """

        result = [
            a.row_number
            for a in self.playlist_rows.values()
            if not a.played and a.track_id is not None
        ]
        return result

    def headerData(
        self,
        section: int,
        orientation: Qt.Orientation,
        role: int = Qt.ItemDataRole.DisplayRole,
    ) -> str | int | QFont | QVariant:
        """
        Return text for headers
        """

        display_dispatch_table = {
            Col.START_GAP.value: Config.HEADER_START_GAP,
            Col.INTRO.value: Config.HEADER_INTRO,
            Col.TITLE.value: Config.HEADER_TITLE,
            Col.ARTIST.value: Config.HEADER_ARTIST,
            Col.DURATION.value: Config.HEADER_DURATION,
            Col.START_TIME.value: Config.HEADER_START_TIME,
            Col.END_TIME.value: Config.HEADER_END_TIME,
            Col.LAST_PLAYED.value: Config.HEADER_LAST_PLAYED,
            Col.BITRATE.value: Config.HEADER_BITRATE,
            Col.NOTE.value: Config.HEADER_NOTE,
        }

        if role == Qt.ItemDataRole.DisplayRole:
            if orientation == Qt.Orientation.Horizontal:
                return display_dispatch_table[section]
            else:
                if Config.ROWS_FROM_ZERO:
                    return section
                else:
                    return section + 1

        elif role == Qt.ItemDataRole.FontRole:
            boldfont = QFont()
            boldfont.setBold(True)
            return boldfont

        return QVariant()

    def header_text(self, plr: PlaylistRow) -> str:
        """
        Process possible section timing directives embeded in header
        """

        if plr.note.endswith(Config.SECTION_STARTS):
            return self.start_of_timed_section_header(plr)

        elif plr.note.endswith("="):
            return self.section_subtotal_header(plr)

        elif plr.note == "-":
            # If the hyphen is the only thing on the line, echo the note
            # that started the section without the trailing "+".
            for row_number in range(plr.row_number - 1, -1, -1):
                row_rat = self.playlist_rows[row_number]
                if self.is_header_row(row_number):
                    if row_rat.note.endswith("-"):
                        # We didn't find a matching section start
                        break
                    if row_rat.note.endswith("+"):
                        return f"[End: {row_rat.note[:-1]}]"
            return "-"

        return plr.note

    def hide_played_tracks(self, hide: bool) -> None:
        """
        Set played tracks hidden according to 'hide'
        """

        self.played_tracks_hidden = hide
        for row_number in range(len(self.playlist_rows)):
            if self.is_played_row(row_number):
                # only invalidate required roles
                roles = [
                    Qt.ItemDataRole.DisplayRole,
                ]
                self.invalidate_row(row_number, roles)

    # @log_call
    def insert_row(self, track_id: Optional[int] = None, note: str = "",) -> None:
        """
        Insert a row.
        """

        new_row_number = self._get_new_row_number()

        super().beginInsertRows(QModelIndex(), new_row_number, new_row_number)

        _ = ds.playlist_insert_row(
            playlist_id=self.playlist_id,
            row_number=new_row_number,
            track_id=track_id,
            note=note,
        )
        # Need to refresh self.playlist_rows because row numbers will have
        # changed
        self.refresh_data()

        super().endInsertRows()

        self.signals.resize_rows_signal.emit(self.playlist_id)
        self.track_sequence.update()
        self.update_track_times()
        roles_to_invalidate = [
            Qt.ItemDataRole.BackgroundRole,
            Qt.ItemDataRole.DisplayRole,
            Qt.ItemDataRole.FontRole,
            Qt.ItemDataRole.ForegroundRole,
        ]
        self.invalidate_rows(
            list(range(new_row_number, len(self.playlist_rows))), roles_to_invalidate
        )

    # @log_call
    def invalidate_row(self, modified_row: int, roles: list[Qt.ItemDataRole]) -> None:
        """
        Signal to view to refresh invalidated row
        """

        self.dataChanged.emit(
            self.index(modified_row, 0),
            self.index(modified_row, self.columnCount() - 1),
            roles,
        )

    def invalidate_rows(
        self, modified_rows: list[int], roles: list[Qt.ItemDataRole]
    ) -> None:
        """
        Signal to view to refresh invlidated rows
        """

        for modified_row in modified_rows:
            # only invalidate required roles
            self.invalidate_row(modified_row, roles)

    def is_header_row(self, row_number: int) -> bool:
        """
        Return True if row is a header row, else False
        """

        if row_number in self.playlist_rows:
            return self.playlist_rows[row_number].path == ""
        return False

    # @log_call
    def is_played_row(self, row_number: int) -> bool:
        """
        Return True if row is an unplayed track row, else False
        """

        return self.playlist_rows[row_number].played

    def is_track_in_playlist(self, track_id: int) -> Optional[PlaylistRow]:
        """
        If this track_id is in the playlist, return the RowAndTrack object
        else return None
        """

        for row_number in range(len(self.playlist_rows)):
            if self.playlist_rows[row_number].track_id == track_id:
                return self.playlist_rows[row_number]

        return None

    def mark_unplayed(self, row_numbers: list[int]) -> None:
        """
        Mark row as unplayed
        """

        for row_number in row_numbers:
            self.playlist_rows[row_number].played = False
            self.refresh_row(row_number)

        self.update_track_times()
        # only invalidate required roles
        roles = [
            Qt.ItemDataRole.FontRole,
        ]
        self.invalidate_rows(row_numbers, roles)

    # @log_call
    def move_rows(self, from_rows: list[int], to_row_number: int) -> bool:
        """
        Move the playlist rows in from_rows to to_row. Return True if successful
        else False.
        """

        log.debug(f"move_rows({from_rows=}, {to_row_number=})")

        if not from_rows:
            log.debug("move_rows called with no from_rows")
            return False

        # Don't move current row
        if self.track_sequence.current:
            current_row = self.track_sequence.current.row_number
            if current_row in from_rows:
                log.debug(
                    "move_rows: Removing {current_row=} from {from_rows=}"
                )
                from_rows.remove(self.track_sequence.current.row_number)

        from_rows = sorted(set(from_rows))
        if (min(from_rows) < 0 or max(from_rows) >= self.rowCount()
                or to_row_number < 0 or to_row_number > self.rowCount()):
            log.debug("move_rows: invalid indexes")
            return False

        if to_row_number in from_rows:
            return False  # Destination within rows to be moved

        # Notify model going to change
        self.beginResetModel()
        # Update database
        ds.playlist_move_rows(from_rows, self.playlist_id, to_row_number)
        # Notify model changed
        self.endResetModel()

        # Update display
        self.refresh_data()
        self.track_sequence.update()
        self.update_track_times()
        # TODO: do we need this?
        # # only invalidate required roles
        # roles = [
        #     Qt.ItemDataRole.DisplayRole,
        # ]
        # self.invalidate_rows(list(row_map.keys()), roles)
        return True

    # @log_call
    def move_rows_between_playlists(
        self,
        from_rows: list[int],
        to_row_number: int,
        to_playlist_id: int,
    ) -> None:
        """
        Move the playlist rows given to to_row and below of to_playlist.
        """

        # Don't move current row
        if self.track_sequence.current:
            current_row = self.track_sequence.current.row_number
            if current_row in from_rows:
                log.debug(
                    "move_rows_between_playlists: Removing {current_row=} from {from_rows=}"
                )
                from_rows.remove(self.track_sequence.current.row_number)

        # Row removal must be wrapped in beginRemoveRows .. endRemoveRows
        # and the row range must be contiguous. Process the highest rows
        # first so the lower row numbers are unchanged

        row_groups = self._reversed_contiguous_row_groups(from_rows)

        # Handle the moves in row_group chunks

        for row_group in row_groups:
            # Prepare source model
            super().beginRemoveRows(QModelIndex(), min(row_group), max(row_group))
            # Prepare destination model
            insert_rows = InsertRows(to_playlist_id,
                                     to_row_number,
                                     to_row_number + len(row_group)
                                     )
            self.signals.signal_begin_insert_rows.emit(insert_rows)
            ds.playlist_move_rows(from_rows=row_group,
                                  from_playlist_id=self.playlist_id,
                                  to_row=to_row_number,
                                  to_playlist_id=to_playlist_id)
            self.signals.signal_end_insert_rows.emit(to_playlist_id)
            super().endRemoveRows()

        self.refresh_data()
        self.track_sequence.update()
        self.update_track_times()

    def begin_insert_rows(self, insert_rows: InsertRows) -> None:
        """
        Prepare model to insert rows
        """

        if insert_rows.playlist_id != self.playlist_id:
            return

        super().beginInsertRows(QModelIndex(), insert_rows.from_row, insert_rows.to_row)

    def end_insert_rows(self, playlist_id: int) -> None:
        """
        End insert rows
        """

        if playlist_id != self.playlist_id:
            return

        super().endInsertRows()
        self.refresh_data()

    # @log_call
    def move_track_add_note(
        self, new_row_number: int, existing_plr: PlaylistRow, note: str
    ) -> None:
        """
        Move existing_rat track to new_row_number and append note to any existing note
        """

        if note:
            playlist_row = self.playlist_rows[existing_plr.row_number]
            if playlist_row.note:
                playlist_row.note += "\n" + note
            else:
                playlist_row.note = note
            self.refresh_row(existing_plr.row_number)

        self.move_rows([existing_plr.row_number], new_row_number)
        self.signals.resize_rows_signal.emit(self.playlist_id)

    # @log_call
    def obs_scene_change(self, row_number: int) -> None:
        """
        Check this row and any preceding headers for OBS scene change command
        and execute any found
        """

        # Check any headers before this row
        idx = row_number - 1
        while self.is_header_row(idx):
            idx -= 1
        # Step through headers in row order and finish with this row
        for chkrow in range(idx + 1, row_number + 1):
            match_obj = scene_change_re.search(self.playlist_rows[chkrow].note)
            if match_obj:
                scene_name = match_obj.group(1)
                if scene_name:
                    ws = obswebsocket.obsws(
                        host=Config.OBS_HOST,
                        port=Config.OBS_PORT,
                        password=Config.OBS_PASSWORD,
                    )
                    try:
                        ws.connect()
                        ws.call(
                            obswebsocket.requests.SetCurrentProgramScene(
                                sceneName=scene_name
                            )
                        )
                        log.debug(f"{self}: OBS scene changed to '{scene_name}'")
                        continue
                    except obswebsocket.exceptions.ConnectionFailure:
                        log.warning(f"{self}: OBS connection refused")
                        return

    # @log_call
    def previous_track_ended(self) -> None:
        """
        Notification from musicmuster that the previous track has ended.

        Actions required:
        - sanity check
        - update display
        """

        # Sanity check
        if not self.track_sequence.previous:
            log.error(
                f"{self}: playlistmodel:previous_track_ended called with no current track"
            )
            return
        if self.track_sequence.previous.row_number is None:
            log.error(
                f"{self}: previous_track_ended called with no row number "
                f"({self.track_sequence.previous=})"
            )
            return

        # Update display
        # only invalidate required roles
        roles = [
            Qt.ItemDataRole.BackgroundRole,
        ]
        self.invalidate_row(self.track_sequence.previous.row_number, roles)

    def refresh_data(self) -> None:
        """
        Populate self.playlist_rows with playlist data
        """

        # Note where each playlist_id is by mapping each playlistrow_id
        # to its current row_number
        plrid_to_row: dict[int, int] = {}
        for oldrow in self.playlist_rows:
            plrdata = self.playlist_rows[oldrow]
            plrid_to_row[plrdata.playlistrow_id] = plrdata.row_number

        # build a new playlist_rows
        new_playlist_rows: dict[int, PlaylistRow] = {}
        for dto in ds.playlistrows_by_playlist(self.playlist_id):
            if dto.playlistrow_id not in plrid_to_row:
                new_playlist_rows[dto.row_number] = PlaylistRow(dto)
            else:
                new_playlist_row = self.playlist_rows[plrid_to_row[dto.playlistrow_id]]
                new_playlist_row.row_number = dto.row_number
                new_playlist_rows[dto.row_number] = new_playlist_row

        # Copy to self.playlist_rows
        self.playlist_rows = new_playlist_rows

    def refresh_row(self, row_number: int) -> None:
        """Populate dict for one row from database"""

        plrid = self.playlist_rows[row_number].playlistrow_id
        refreshed_row = ds.playlistrow_by_id(plrid)
        if not refreshed_row:
            raise ApplicationError(f"Failed to retrieve row {self.playlist_id=}, {row_number=}")

        self.playlist_rows[row_number] = PlaylistRow(refreshed_row)

    # @log_call
    def remove_track(self, row_number: int) -> None:
        """
        Remove track from row, retaining row as a header row
        """

        self.playlist_rows[row_number].track_id = None

        # only invalidate required roles
        roles = [
            Qt.ItemDataRole.DisplayRole,
        ]
        self.invalidate_row(row_number, roles)

    def rescan_track(self, row_number: int) -> None:
        """
        Rescan track at passed row number
        """

        track = self.playlist_rows[row_number]
        metadata = get_all_track_metadata(track.path)
        _ = ds.track_update(track.track_id, metadata)

        roles = [
            Qt.ItemDataRole.BackgroundRole,
            Qt.ItemDataRole.DisplayRole,
        ]
        # only invalidate required roles
        self.invalidate_row(row_number, roles)
        self.signals.resize_rows_signal.emit(self.playlist_id)

    # @log_call
    def reset_track_sequence_row_numbers(self) -> None:
        """
        Signal handler for when row ordering has changed.

        Example: row 4 is marked as next. Row 2 is deleted. The PlaylistRows table will
        be correctly updated with change of row number, but track_sequence.next will still
        contain row_number==4. This function fixes up the track_sequence row numbers by
        looking up the playlistrow_id and retrieving the row number from the database.
        """

        self.track_sequence.update()

        self.update_track_times()

    def remove_comments(self, row_numbers: list[int]) -> None:
        """
        Remove comments from passed rows
        """

        if not row_numbers:
            return

        # Safety check
        if not ask_yes_no(
            title="Remove comments",
            question=f"Remove comments from {len(row_numbers)} rows?",
        ):
            return

        ds.playlist_remove_comments(self.playlist_id, row_numbers)

        # only invalidate required roles
        roles = [
            Qt.ItemDataRole.BackgroundRole,
            Qt.ItemDataRole.DisplayRole,
            Qt.ItemDataRole.ForegroundRole,
        ]
        self.invalidate_rows(row_numbers, roles)

    # @log_call
    def _reversed_contiguous_row_groups(
        self, row_numbers: list[int]
    ) -> list[list[int]]:
        """
        Take the list of row numbers and split into groups of contiguous rows. Return as a list
        of lists with the highest row numbers first.

        Example:
            input [2, 3, 4, 5, 7, 9, 10, 13, 17, 20, 21]
            return: [[20, 21], [17], [13], [9, 10], [7], [2, 3, 4, 5]]
        """

        result: list[list[int]] = []
        temp: list[int] = []
        last_value = row_numbers[0] - 1
        row_numbers.sort()

        for idx in range(len(row_numbers)):
            if row_numbers[idx] != last_value + 1:
                result.append(temp)
                temp = []
            last_value = row_numbers[idx]
            temp.append(last_value)
        if temp:
            result.append(temp)
        result.reverse()

        return result

    def remove_section_timer_markers(self, header_text: str) -> str:
        """
        Remove characters used to mark section timings from
        passed header text.

        Remove text using to signal header colours if colour entry
        is so marked.

        Return header text witout markers
        """

        if header_text == "=":
            return ""
        while header_text.endswith(Config.SECTION_STARTS):
            header_text = header_text[0:-1]
        while header_text.endswith(Config.SECTION_ENDINGS):
            header_text = header_text[0:-1]

        # Parse passed header text and remove the first colour match string
        return ds.notecolours_remove_colour_substring(header_text)

    def rowCount(self, index: QModelIndex = QModelIndex()) -> int:
        """Standard function for view"""

        return len(self.playlist_rows)

    def section_subtotal_header(self, plr: PlaylistRow) -> str:
        """
        Process this row as subtotal within a timed section and
        return display text for this row
        """

        count: int = 0
        unplayed_count: int = 0
        duration: int = 0

        if plr.row_number == 0:
            # Meaningless to have a subtotal on row 0
            return Config.SUBTOTAL_ON_ROW_ZERO

        # Show subtotal
        for row_number in range(plr.row_number - 1, -1, -1):
            row_rat = self.playlist_rows[row_number]
            if self.is_header_row(row_number) or row_number == 0:
                if row_rat.note.endswith(Config.SECTION_STARTS) or row_number == 0:
                    # If we are playing this section, also
                    # calculate end time when all tracks are played.
                    end_time_str = ""
                    if (
                        self.track_sequence.current
                        and self.track_sequence.current.end_time
                        and (
                            row_number
                            < self.track_sequence.current.row_number
                            < plr.row_number
                        )
                    ):
                        section_end_time = (
                            self.track_sequence.current.end_time
                            + dt.timedelta(milliseconds=duration)
                        )
                        end_time_str = (
                            ", section end time "
                            + section_end_time.strftime(Config.TRACK_TIME_FORMAT)
                        )
                    clean_header = self.remove_section_timer_markers(plr.note)
                    if clean_header:
                        return (
                            f"{clean_header} ["
                            f"{unplayed_count}/{count} track{'s' if count > 1 else ''} "
                            f"({ms_to_mmss(duration)}) unplayed{end_time_str}]"
                        )
                    else:
                        return (
                            f"[{unplayed_count}/{count} track{'s' if count > 1 else ''} "
                            f"({ms_to_mmss(duration)}) unplayed{end_time_str}]"
                        )
                else:
                    continue
            else:
                count += 1
                if not row_rat.played:
                    unplayed_count += 1
                    duration += row_rat.duration

        # We should never get here
        raise ApplicationError("Error in section_subtotal_header()")

    def selection_is_sortable(self, row_numbers: list[int]) -> bool:
        """
        Return True if the selection is sortable. That means:
        - at least two rows selected
        - selected rows are contiguous
        - selected rows do not include any header rows
        """

        # at least two rows selected
        if len(row_numbers) < 2:
            return False

        # selected rows are contiguous
        if sorted(row_numbers) != list(range(min(row_numbers), max(row_numbers) + 1)):
            return False

        # selected rows do not include any header rows
        for row_number in row_numbers:
            if self.is_header_row(row_number):
                return False

        return True

    # @log_call
    def set_selected_rows(self, playlist_id: int, selected_row_numbers: list[int]) -> None:
        """
        Handle signal_playlist_selected_rows to keep track of which rows
        are selected in the view
        """

        if playlist_id != self.playlist_id:
            return

        self.selected_rows = [self.playlist_rows[a] for a in selected_row_numbers]

    # @log_call
    def set_next_row(self, playlist_id: int) -> None:
        """
        Handle signal_set_next_row
        """

        log.debug(f"{self}: set_next_row({playlist_id=})")
        if playlist_id != self.playlist_id:
            # Not for us
            return

        if len(self.selected_rows) == 0:
            # No row selected so clear next track
            if self.track_sequence.next is not None:
                self.track_sequence.set_next(None)
            return

        if len(self.selected_rows) > 1:
            self.signals.show_warning_signal.emit(
                "Too many rows selected", "Select one row for next row"
            )
            return

        plr = self.selected_rows[0]
        if plr.track_id is None:
            raise ApplicationError(f"set_next_row: no track_id ({plr=})")

        old_next_row: Optional[int] = None
        if self.track_sequence.next:
            old_next_row = self.track_sequence.next.row_number

        self.track_sequence.set_next(plr)

        roles = [
            Qt.ItemDataRole.BackgroundRole,
        ]
        if old_next_row is not None:
            # only invalidate required roles
            self.invalidate_row(old_next_row, roles)
        # only invalidate required roles
        self.invalidate_row(plr.row_number, roles)

        self.signals.next_track_changed_signal.emit()
        self.update_track_times()

    # @log_call
    def setData(
        self,
        index: QModelIndex,
        value: str | float,
        role: int = Qt.ItemDataRole.EditRole,
    ) -> bool:
        """
        Update model with edited data
        """

        if not index.isValid() or role != Qt.ItemDataRole.EditRole:
            return False

        row_number = index.row()
        column = index.column()
        plr = self.playlist_rows[row_number]

        if column == Col.TITLE.value:
            plr.title = str(value)
        elif column == Col.ARTIST.value:
            plr.artist = str(value)
        elif column == Col.INTRO.value:
            plr.intro = int(round(float(value), 1) * 1000)
        elif column == Col.NOTE.value:
            plr.note = str(value)
        else:
            raise ApplicationError(f"setData called with unexpected column ({column=})")

        self.refresh_row(row_number)
        self.dataChanged.emit(index, index, [Qt.ItemDataRole.DisplayRole, role])

        return True

    def sort_by_artist(self, row_numbers: list[int]) -> None:
        """
        Sort selected rows by artist
        """

        self.sort_by_attribute(row_numbers, "artist")

    def sort_by_attribute(self, row_numbers: list[int], attr_name: str) -> None:
        """
        Sort selected rows by passed attribute name where 'attribute' is a
        key in PlaylistRowData
        """

        # Create a subset of playlist_rows with the rows we are
        # interested in
        shortlist_rows = {k: self.playlist_rows[k] for k in row_numbers}
        sorted_list = [
            playlist_row.row_number
            for playlist_row in sorted(
                shortlist_rows.values(), key=attrgetter(attr_name)
            )
        ]
        self.move_rows(sorted_list, min(sorted_list))

    def sort_by_duration(self, row_numbers: list[int]) -> None:
        """
        Sort selected rows by duration
        """

        self.sort_by_attribute(row_numbers, "duration")

    def sort_by_lastplayed(self, row_numbers: list[int]) -> None:
        """
        Sort selected rows by lastplayed
        """

        self.sort_by_attribute(row_numbers, "lastplayed")

    def sort_randomly(self, row_numbers: list[int]) -> None:
        """
        Sort selected rows randomly
        """

        shuffle(row_numbers)
        self.move_rows(row_numbers, min(row_numbers))

    def sort_by_title(self, row_numbers: list[int]) -> None:
        """
        Sort selected rows by title
        """

        self.sort_by_attribute(row_numbers, "title")

    def start_of_timed_section_header(self, plr: PlaylistRow) -> str:
        """
        Process this row as the start of a timed section and
        return display text for this row
        """

        count: int = 0
        unplayed_count: int = 0
        duration: int = 0

        clean_header = self.remove_section_timer_markers(plr.note)

        for row_number in range(plr.row_number + 1, len(self.playlist_rows)):
            row_rat = self.playlist_rows[row_number]
            if self.is_header_row(row_number):
                if row_rat.note.endswith(Config.SECTION_ENDINGS):
                    return (
                        f"{clean_header} "
                        f"[{count} tracks, {ms_to_mmss(duration)} unplayed]"
                    )
                else:
                    continue
            else:
                count += 1
                if not row_rat.played:
                    unplayed_count += 1
                    duration += row_rat.duration
        return (
            f"{clean_header} "
            f"[{count} tracks, {ms_to_mmss(duration, none='none')} "
            "unplayed (to end of playlist)]"
        )

    def supportedDropActions(self) -> Qt.DropAction:
        return Qt.DropAction.MoveAction | Qt.DropAction.CopyAction

    def _tooltip_role(self, row: int, column: int, plr: PlaylistRow) -> str:
        """
        Return tooltip. Currently only used for last_played column.
        """

        if column != Col.LAST_PLAYED.value:
            return ""

        track_id = self.playlist_rows[row].track_id
        if not track_id:
            return ""

        return ds.playdates_get_last(track_id)

    # @log_call
    def update_or_insert(self, track_id: int, row_number: int) -> None:
        """
        If the passed track_id exists in this playlist, update the
        row(s), otherwise insert this track at row_number.
        """

        track_rows = [
            a.row_number for a in self.playlist_rows.values() if a.track_id == track_id
        ]
        if track_rows:
            for row in track_rows:
                self.refresh_row(row)
            # only invalidate required roles
            roles = [
                Qt.ItemDataRole.BackgroundRole,
                Qt.ItemDataRole.DisplayRole,
                Qt.ItemDataRole.FontRole,
                Qt.ItemDataRole.ForegroundRole,
            ]
            self.invalidate_rows(track_rows, roles)
        else:
            self.insert_row(track_id=track_id)

    # @log_call
    def update_track_times(self) -> None:
        """
        Update track start/end times in self.playlist_rows
        """

        next_start_time: Optional[dt.datetime] = None
        update_rows: list[int] = []
        row_count = len(self.playlist_rows)

        current_track_row = None
        next_track_row = None
        if (
            self.track_sequence.current
            and self.track_sequence.current.playlist_id == self.playlist_id
        ):
            current_track_row = self.track_sequence.current.row_number
            # Update current track details now so that they are available
            # when we deal with next track row which may be above current
            # track row.
            self.playlist_rows[current_track_row].set_forecast_start_time(
                update_rows, self.track_sequence.current.start_time
            )

        if self.track_sequence.next and self.track_sequence.next.playlist_id == self.playlist_id:
            next_track_row = self.track_sequence.next.row_number

        for row_number in range(row_count):
            plr = self.playlist_rows[row_number]

            # Don't update times for tracks that have been played, for
            # unreadable tracks or for the current track, handled above.
            if (
                plr.played
                or row_number == current_track_row
                or (plr.path and file_is_unreadable(plr.path))
            ):
                continue

            # Reset start time if timing in header
            if self.is_header_row(row_number):
                header_time = get_embedded_time(plr.note)
                if header_time:
                    next_start_time = header_time
                continue

            # Set start time for next row if we have a current track
            if (
                row_number == next_track_row
                and self.track_sequence.current
                and self.track_sequence.current.end_time
            ):
                next_start_time = plr.set_forecast_start_time(
                    update_rows, self.track_sequence.current.end_time
                )
                continue

            # If we're between the current and next row, zero out
            # times
            if (current_track_row or row_count) < row_number < (next_track_row or 0):
                plr.set_forecast_start_time(update_rows, None)
                continue

            # Set start/end
            plr.forecast_start_time = next_start_time

        # Update start/stop times of rows that have changed
        for updated_row in update_rows:
            self.dataChanged.emit(
                self.index(updated_row, Col.START_TIME.value),
                self.index(updated_row, Col.END_TIME.value),
            )


class PlaylistProxyModel(QSortFilterProxyModel):
    """
    For searching and filtering
    """

    def __init__(
        self,
    ) -> None:
        super().__init__()

        # Search all columns
        self.setFilterKeyColumn(-1)

        self.track_sequence = TrackSequence()

    def __repr__(self) -> str:
        return f"<PlaylistProxyModel: sourceModel={self.sourceModel()}>"

    def filterAcceptsRow(self, source_row: int, source_parent: QModelIndex) -> bool:
        """
        Subclass to filter by played status. Return True to show this row, False to hide it.
        """

        if Config.HIDE_PLAYED_MODE != Config.HIDE_PLAYED_MODE_TRACKS:
            return super().filterAcceptsRow(source_row, source_parent)

        if self.sourceModel().played_tracks_hidden:
            if self.sourceModel().is_played_row(source_row):
                # Don't hide current track
                if (
                    self.track_sequence.current
                    and self.track_sequence.current.playlist_id
                    == self.sourceModel().playlist_id
                    and self.track_sequence.current.row_number == source_row
                ):
                    return True

                # Don't hide next track
                if (
                    self.track_sequence.next
                    and self.track_sequence.next.playlist_id
                    == self.sourceModel().playlist_id
                    and self.track_sequence.next.row_number == source_row
                ):
                    return True

                # Handle previous track
                if self.track_sequence.previous:
                    if (
                        self.track_sequence.previous.playlist_id
                        != self.sourceModel().playlist_id
                        or self.track_sequence.previous.row_number != source_row
                    ):
                        # This row isn't our previous track: hide it
                        return False
                    if self.track_sequence.current and self.track_sequence.current.start_time:
                        # This row is our previous track. Don't hide it
                        # until HIDE_AFTER_PLAYING_OFFSET milliseconds
                        # after current track has started
                        if self.track_sequence.current.start_time and dt.datetime.now() > (
                            self.track_sequence.current.start_time
                            + dt.timedelta(
                                milliseconds=Config.HIDE_AFTER_PLAYING_OFFSET
                            )
                        ):
                            return False
                        else:
                            # Invalidate this row in
                            # HIDE_AFTER_PLAYING_OFFSET and a bit
                            # milliseconds so that it hides then. We add
                            # 100mS on so that the if clause above is
                            # true next time through.
                            # only invalidate required roles
                            roles = [
                                Qt.ItemDataRole.DisplayRole,
                            ]
                            QTimer.singleShot(
                                Config.HIDE_AFTER_PLAYING_OFFSET + 100,
                                lambda: self.sourceModel().invalidate_row(
                                    source_row, roles
                                ),
                            )
                            return True
                    # Next track not playing yet so don't hide previous
                    else:
                        return True

                # No previous track so hide this played track immediately
                return False

        return super().filterAcceptsRow(source_row, source_parent)

    def set_incremental_search(self, search_string: str) -> None:
        """
        Update search pattern
        """

        self.setFilterRegularExpression(
            QRegularExpression(
                search_string, QRegularExpression.PatternOption.CaseInsensitiveOption
            )
        )

    def sourceModel(self) -> PlaylistModel:
        """
        Override sourceModel to return correct type
        """

        return cast(PlaylistModel, super().sourceModel())