import functools
import re
from datetime import timedelta
from typing import Any, Callable, Iterable, List, Match, Optional, Tuple, Union, cast

from deepdiff import DeepDiff
from gi.repository import Gdk, GLib, Gtk

from ..adapters import AdapterManager, CacheMissError, Result, SongCacheStatus
from ..adapters.api_objects import Playlist, Song
from ..config import AppConfiguration

deep_diff_exclude_regexp = [
    re.compile(path)
    for path in [
        r"root\[\d+\]\.props",
        r"root\[\d+\]\.g_type_instance",
    ]
]


def format_song_duration(duration_secs: Union[int, timedelta, None]) -> str:
    """
    Formats the song duration as mins:seconds with the seconds being
    zero-padded if necessary.

    >>> format_song_duration(80)
    '1:20'
    >>> format_song_duration(62)
    '1:02'
    >>> format_song_duration(timedelta(seconds=68.2))
    '1:08'
    >>> format_song_duration(None)
    '-:--'
    """
    if isinstance(duration_secs, timedelta):
        duration_secs = round(duration_secs.total_seconds())
    if duration_secs is None:
        return "-:--"

    duration_secs = max(duration_secs, 0)

    return f"{duration_secs // 60}:{duration_secs % 60:02}"


def pluralize(string: str, number: int, pluralized_form: str | None = None) -> str:
    """
    Pluralize the given string given the count as a number.

    >>> pluralize('foo', 1)
    'foo'
    >>> pluralize('foo', 2)
    'foos'
    >>> pluralize('foo', 0)
    'foos'
    """
    if number != 1:
        return pluralized_form or f"{string}s"
    return string


def format_sequence_duration(duration: Optional[timedelta]) -> str:
    """
    Formats duration in English.

    >>> format_sequence_duration(timedelta(seconds=90))
    '1 minute, 30 seconds'
    >>> format_sequence_duration(timedelta(seconds=(60 * 60 + 120)))
    '1 hour, 2 minutes'
    >>> format_sequence_duration(None)
    '0 seconds'
    """
    duration_secs = round(duration.total_seconds()) if duration else 0
    duration_mins = (duration_secs // 60) % 60
    duration_hrs = duration_secs // 60 // 60
    duration_secs = duration_secs % 60

    format_components = []
    if duration_hrs > 0:
        hrs = "{} {}".format(duration_hrs, pluralize("hour", duration_hrs))
        format_components.append(hrs)

    if duration_mins > 0:
        mins = "{} {}".format(duration_mins, pluralize("minute", duration_mins))
        format_components.append(mins)

    # Show seconds if there are no hours.
    if duration_hrs == 0:
        secs = "{} {}".format(duration_secs, pluralize("second", duration_secs))
        format_components.append(secs)

    return ", ".join(format_components)


def dot_join(*items: Any) -> str:
    """
    Joins the given strings with a dot character. Filters out ``None`` values.

    >>> dot_join(None, "foo", "bar", None, "baz")
    'foo  •  bar  •  baz'
    """
    return "  •  ".join(map(str, filter(lambda x: x is not None, items)))


def get_cached_status_icons(song_ids: List[str]) -> List[str]:
    cache_icon = {
        SongCacheStatus.CACHED: "folder-download-symbolic",
        SongCacheStatus.PERMANENTLY_CACHED: "view-pin-symbolic",
        SongCacheStatus.DOWNLOADING: "emblem-synchronizing-symbolic",
    }
    return [
        cache_icon.get(cache_status, "")
        for cache_status in AdapterManager.get_cached_statuses(song_ids)
    ]


def _parse_diff_location(location: str) -> Tuple:
    """
    Parses a diff location as returned by deepdiff.

    >>> _parse_diff_location("root[22]")
    ('22',)
    >>> _parse_diff_location("root[22][4]")
    ('22', '4')
    >>> _parse_diff_location("root[22].foo")
    ('22', 'foo')
    """
    match = re.match(r"root\[(\d*)\](?:\[(\d*)\]|\.(.*))?", location)
    return tuple(g for g in cast(Match, match).groups() if g is not None)


def diff_song_store(store_to_edit: Any, new_store: Iterable[Any]):
    """
    Diffing song stores is nice, because we can easily make edits by modifying
    the underlying store.
    """
    old_store = [row[:] for row in store_to_edit]

    # Diff the lists to determine what needs to be changed.
    diff = DeepDiff(old_store, new_store)
    changed = diff.get("values_changed", {})
    added = diff.get("iterable_item_added", {})
    removed = diff.get("iterable_item_removed", {})

    for edit_location, diff in changed.items():
        idx, field = _parse_diff_location(edit_location)
        store_to_edit[int(idx)][int(field)] = diff["new_value"]

    for remove_location, _ in reversed(list(removed.items())):
        remove_at = int(_parse_diff_location(remove_location)[0])
        del store_to_edit[remove_at]

    for _, value in added.items():
        store_to_edit.append(value)


def diff_model_store(store_to_edit: Any, new_store: Iterable[Any]):
    """
    The diff here is that if there are any differences, then we refresh the
    entire list. This is because it is too hard to do editing.
    """
    old_store = store_to_edit[:]

    diff = DeepDiff(old_store, new_store, exclude_regex_paths=deep_diff_exclude_regexp)
    if diff == {}:
        return

    store_to_edit.splice(0, len(store_to_edit), new_store)


def show_song_popover(
    song_ids: List[str],
    x: int,
    y: int,
    relative_to: Any,
    offline_mode: bool,
    position: Gtk.PositionType = Gtk.PositionType.BOTTOM,
    on_download_state_change: Callable[[str], None] = lambda _: None,
    on_remove_downloads_click: Callable[[], Any] = lambda: None,
    on_playlist_state_change: Callable[[], None] = lambda: None,
    show_remove_from_playlist_button: bool = False,
    extra_menu_items: List[Tuple[Gtk.ModelButton, Any]] | None = None,
):
    def on_download_songs_click(_: Any):
        AdapterManager.batch_download_songs(
            song_ids,
            before_download=on_download_state_change,
            on_song_download_complete=on_download_state_change,
        )

    def do_on_remove_downloads_click(_: Any):
        AdapterManager.cancel_download_songs(song_ids)
        AdapterManager.batch_delete_cached_songs(
            song_ids,
            on_song_delete=on_download_state_change,
        )
        on_remove_downloads_click()

    def on_add_to_playlist_click(_: Any, playlist: Playlist):
        update_playlist_result = AdapterManager.update_playlist(
            playlist_id=playlist.id, append_song_ids=song_ids
        )
        update_playlist_result.add_done_callback(lambda _: on_playlist_state_change())

    popover = Gtk.PopoverMenu()
    vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)

    # Add all of the menu items to the popover.
    song_count = len(song_ids)

    play_next_button = Gtk.ModelButton(text="Play next", sensitive=False)
    add_to_queue_button = Gtk.ModelButton(text="Add to queue", sensitive=False)
    if not offline_mode:
        play_next_button.set_action_name("app.play-next")
        play_next_button.set_action_target_value(GLib.Variant("as", song_ids))
        add_to_queue_button.set_action_name("app.add-to-queue")
        add_to_queue_button.set_action_target_value(GLib.Variant("as", song_ids))

    go_to_album_button = Gtk.ModelButton(text="Go to album", sensitive=False)
    go_to_artist_button = Gtk.ModelButton(text="Go to artist", sensitive=False)
    browse_to_song = Gtk.ModelButton(
        text=f"Browse to {pluralize('song', song_count)}", sensitive=False
    )
    download_song_button = Gtk.ModelButton(
        text=f"Download {pluralize('song', song_count)}", sensitive=False
    )
    remove_download_button = Gtk.ModelButton(
        text=f"Remove {pluralize('download', song_count)}", sensitive=False
    )

    # Retrieve songs and set the buttons as sensitive later.
    def on_get_song_details_done(songs: List[Song]):
        song_cache_statuses = AdapterManager.get_cached_statuses([s.id for s in songs])
        if not offline_mode and any(
            status == SongCacheStatus.NOT_CACHED for status in song_cache_statuses
        ):
            download_song_button.set_sensitive(True)
        if any(
            status
            in (
                SongCacheStatus.CACHED,
                SongCacheStatus.PERMANENTLY_CACHED,
                SongCacheStatus.DOWNLOADING,
            )
            for status in song_cache_statuses
        ):
            remove_download_button.set_sensitive(True)
            play_next_button.set_action_target_value(GLib.Variant("as", song_ids))
            play_next_button.set_action_name("app.play-next")
            add_to_queue_button.set_action_target_value(GLib.Variant("as", song_ids))
            add_to_queue_button.set_action_name("app.add-to-queue")

        albums, artists, parents = set(), set(), set()
        for song in songs:
            parents.add(parent_id if (parent_id := song.parent_id) else None)

            if (al := song.album) and (id_ := al.id) and not id_.startswith("invalid:"):
                albums.add(id_)

            if (a := song.artist) and (id_ := a.id) and not id_.startswith("invalid:"):
                artists.add(id_)

        if len(albums) == 1 and list(albums)[0] is not None:
            go_to_album_button.set_action_target_value(GLib.Variant("s", list(albums)[0]))
            go_to_album_button.set_action_name("app.go-to-album")
        if len(artists) == 1 and list(artists)[0] is not None:
            go_to_artist_button.set_action_target_value(GLib.Variant("s", list(artists)[0]))
            go_to_artist_button.set_action_name("app.go-to-artist")
        if len(parents) == 1 and list(parents)[0] is not None:
            browse_to_song.set_action_target_value(GLib.Variant("s", list(parents)[0]))
            browse_to_song.set_action_name("app.browse-to")

    def batch_get_song_details() -> List[Song]:
        return [AdapterManager.get_song_details(song_id).result() for song_id in song_ids]

    get_song_details_result: Result[List[Song]] = Result(batch_get_song_details)
    get_song_details_result.add_done_callback(
        lambda f: GLib.idle_add(on_get_song_details_done, f.result())
    )

    menu_items = [
        play_next_button,
        add_to_queue_button,
        Gtk.Separator(orientation=Gtk.Orientation.HORIZONTAL),
        go_to_album_button,
        go_to_artist_button,
        browse_to_song,
        Gtk.Separator(orientation=Gtk.Orientation.HORIZONTAL),
        (download_song_button, on_download_songs_click),
        (remove_download_button, do_on_remove_downloads_click),
        Gtk.Separator(orientation=Gtk.Orientation.HORIZONTAL),
        Gtk.ModelButton(
            text=f"Add {pluralize('song', song_count)} to playlist",
            menu_name="add-to-playlist",
            name="menu-item-add-to-playlist",
            sensitive=not offline_mode,
        ),
        *(extra_menu_items or []),
    ]

    for item in menu_items:
        if type(item) == tuple:
            el, fn = item
            el.connect("clicked", fn)
            el.get_style_context().add_class("menu-button")
            vbox.pack_start(item[0], False, True, 0)
        else:
            item.get_style_context().add_class("menu-button")
            vbox.pack_start(item, False, True, 0)

    popover.add(vbox)

    # Create the "Add song(s) to playlist" sub-menu.
    playlists_vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)

    if not offline_mode:
        # Back button
        playlists_vbox.add(Gtk.ModelButton(inverted=True, centered=True, menu_name="main"))

        # Loading indicator
        loading_indicator = Gtk.Spinner(name="menu-item-spinner")
        loading_indicator.start()
        playlists_vbox.add(loading_indicator)

        # Create a future to make the actual playlist buttons
        def on_get_playlists_done(f: Result[List[Playlist]]):
            playlists_vbox.remove(loading_indicator)

            for playlist in f.result():
                button = Gtk.ModelButton(text=playlist.name)
                button.get_style_context().add_class("menu-button")
                button.connect("clicked", on_add_to_playlist_click, playlist)
                button.show()
                playlists_vbox.pack_start(button, False, True, 0)

        playlists_result = AdapterManager.get_playlists()
        playlists_result.add_done_callback(on_get_playlists_done)

    popover.add(playlists_vbox)
    popover.child_set_property(playlists_vbox, "submenu", "add-to-playlist")

    # Positioning of the popover.
    rect = Gdk.Rectangle()
    rect.x, rect.y, rect.width, rect.height = x, y, 1, 1
    popover.set_pointing_to(rect)
    popover.set_position(position)
    popover.set_relative_to(relative_to)

    popover.popup()
    popover.show_all()


def async_callback(
    future_fn: Callable[..., Result],
    before_download: Callable[[Any], None] | None = None,
    on_failure: Callable[[Any, Exception], None] | None = None,
) -> Callable[[Callable], Callable]:
    """
    Defines the ``async_callback`` decorator.

    When a function is annotated with this decorator, the function becomes the done
    callback for the given result-generating lambda function. The annotated function
    will be called with the result of the Result generated by said lambda function.

    :param future_fn: a function which generates an :class:`AdapterManager.Result`.
    """

    def decorator(callback_fn: Callable) -> Callable:
        @functools.wraps(callback_fn)
        def wrapper(
            self: Any,
            *args,
            app_config: AppConfiguration | None = None,
            force: bool = False,
            order_token: int | None = None,
            **kwargs,
        ):
            def on_before_download():
                if before_download:
                    GLib.idle_add(before_download, self)

            def future_callback(is_immediate: bool, f: Result):
                try:
                    result = f.result()
                    is_partial = False
                except CacheMissError as e:
                    result = e.partial_data
                    if result is None:
                        if on_failure:
                            GLib.idle_add(on_failure, self, e)
                        return

                    is_partial = True
                except Exception as e:
                    if on_failure:
                        GLib.idle_add(on_failure, self, e)
                    return

                fn = functools.partial(
                    callback_fn,
                    self,
                    result,
                    app_config=app_config,
                    force=force,
                    order_token=order_token,
                    is_partial=is_partial,
                )

                if is_immediate:
                    # The data is available now, no need to wait for the future to
                    # finish, and no need to incur the overhead of adding to the GLib
                    # event queue.
                    fn()
                else:
                    # We don't have the data yet, meaning that it is a future, and we
                    # have to idle add so that we don't seg fault GTK.
                    GLib.idle_add(fn)

            result: Result = future_fn(
                *args,
                before_download=on_before_download,
                force=force,
                **kwargs,
            )
            result.add_done_callback(functools.partial(future_callback, result.data_is_available))

        return wrapper

    return decorator
