from __future__ import annotations

from yuxi.utils.logging_config import logger


class ChannelRuntime:
    def __init__(self):
        self._joined_channels: set[str] = set()
        self._channel_members: dict[str, set[str]] = {}
        self._channel_modes: dict[str, str] = {}
        self._channel_topics: dict[str, str] = {}

    @property
    def joined_channels(self) -> set[str]:
        return self._joined_channels

    def add_channel(self, channel: str) -> None:
        self._joined_channels.add(channel)
        if channel not in self._channel_members:
            self._channel_members[channel] = set()

    def remove_channel(self, channel: str) -> None:
        self._joined_channels.discard(channel)

    def handle_names(self, channel: str, names_str: str) -> None:
        members = {name.lstrip("@+") for name in names_str.split() if name}
        self._channel_members[channel] = members
        logger.debug(f"IRC NAMES {channel}: {len(members)} members")

    def handle_join(self, channel: str, nick: str) -> None:
        if channel in self._channel_members:
            self._channel_members[channel].add(nick)
        logger.debug(f"IRC JOIN: {nick} -> {channel}")

    def handle_part(self, channel: str, nick: str) -> None:
        if channel in self._channel_members:
            self._channel_members[channel].discard(nick)
        logger.debug(f"IRC PART: {nick} <- {channel}")

    def handle_kick(self, channel: str, nick: str) -> None:
        if channel in self._channel_members:
            self._channel_members[channel].discard(nick)
        logger.debug(f"IRC KICK: {nick} from {channel}")

    def handle_quit(self, nick: str) -> None:
        for channel in self._channel_members:
            self._channel_members[channel].discard(nick)
        logger.debug(f"IRC QUIT: {nick}")

    def handle_nick_change(self, old_nick: str, new_nick: str) -> None:
        for channel in self._channel_members:
            members = self._channel_members[channel]
            if old_nick in members:
                members.discard(old_nick)
                members.add(new_nick)
        logger.debug(f"IRC NICK: {old_nick} -> {new_nick}")

    def get_members(self, channel: str) -> set[str]:
        return self._channel_members.get(channel, set())

    def handle_mode(self, channel: str, modes: str) -> None:
        channel_lower = channel.lower()
        current = self._channel_modes.get(channel_lower, "")
        self._channel_modes[channel_lower] = _merge_modes(current, modes)
        logger.debug(f"IRC MODE {channel}: {modes} -> {self._channel_modes[channel_lower]}")

    def set_topic(self, channel: str, topic: str) -> None:
        self._channel_topics[channel.lower()] = topic

    def get_topic(self, channel: str) -> str | None:
        return self._channel_topics.get(channel.lower())

    def get_modes(self, channel: str) -> str:
        return self._channel_modes.get(channel.lower(), "")


def _merge_modes(current: str, incoming: str) -> str:
    if not current:
        return incoming
    if not incoming:
        return current
    adding = True
    mode_set: set[str] = set()

    for char in current:
        if char in "+-":
            continue
        mode_set.add(char)

    for char in incoming:
        if char == "+":
            adding = True
        elif char == "-":
            adding = False
        elif adding:
            mode_set.add(char)
        else:
            mode_set.discard(char)

    sorted_modes = sorted(mode_set)
    return "+" + "".join(sorted_modes)