from __future__ import annotations

from datetime import datetime
from math import ceil, log10
from typing import Optional, Tuple, Dict, Any, Callable

from poezio import poopt
from poezio.theming import dump_tuple, get_theme
from poezio.ui.funcs import truncate_nick
from poezio.user import User


class BaseMessage:
    """Base class for all ui-related messages"""
    __slots__ = ('txt', 'time', 'identifier')

    txt: str
    identifier: str
    time: datetime

    def __init__(self, txt: str, identifier: str = '', time: Optional[datetime] = None):
        self.txt = txt
        self.identifier = identifier
        if time is not None:
            self.time = time
        else:
            self.time = datetime.now()

    def compute_offset(self, with_timestamps: bool, nick_size: int) -> int:
        """Compute the offset of the message"""
        theme = get_theme()
        return theme.SHORT_TIME_FORMAT_LENGTH + 1


class EndOfArchive(BaseMessage):
    """Marker added to a buffer when we reach the end of a MAM archive"""


class InfoMessage(BaseMessage):
    """Information message"""
    def __init__(self, txt: str, identifier: str = '', time: Optional[datetime] = None):
        txt = ('\x19%s}' % dump_tuple(get_theme().COLOR_INFORMATION_TEXT)) + txt
        super().__init__(txt=txt, identifier=identifier, time=time)


class UIMessage(BaseMessage):
    """Message displayed through poezio UI"""
    __slots__ = ('level', 'color')
    level: str
    color: Optional[Tuple]

    def __init__(self, txt: str, level: str):
        BaseMessage.__init__(self, txt=txt)
        self.level = level.capitalize()
        colors = get_theme().INFO_COLORS
        self.color = colors.get(level.lower(), colors.get('default', None))

    def compute_offset(self, with_timestamps: bool, nick_size: int) -> int:
        """Compute the x-position at which the message should be printed"""
        offset = 0
        theme = get_theme()
        if with_timestamps:
            offset += 1 + theme.SHORT_TIME_FORMAT_LENGTH
        level = self.level
        if not level:  # not a message, nothing to do afterwards
            return offset
        level = truncate_nick(level, nick_size) or ''
        offset += poopt.wcswidth(level)
        offset += 2
        return offset


class LoggableTrait:
    """Trait for classes of messages that should go through the logger"""
    pass


class PersistentInfoMessage(InfoMessage, LoggableTrait):
    """Information message thatt will be logged"""
    pass


class MucOwnLeaveMessage(InfoMessage, LoggableTrait):
    """Status message displayed on our room leave/kick/ban"""


class MucOwnJoinMessage(InfoMessage, LoggableTrait):
    """Status message displayed on our room join"""


class XMLLog(BaseMessage):
    """XML Log message"""
    __slots__ = ('incoming')
    incoming: bool

    def __init__(
            self,
            txt: str,
            incoming: bool,
    ):
        BaseMessage.__init__(
            self,
            txt=txt,
        )
        self.incoming = incoming

    def compute_offset(self, with_timestamps: bool, nick_size: int) -> int:
        offset = 0
        theme = get_theme()
        if with_timestamps:
            offset += 1 + theme.SHORT_TIME_FORMAT_LENGTH
        if self.incoming:
            nick = theme.CHAR_XML_IN
        else:
            nick = theme.CHAR_XML_OUT
        nick = truncate_nick(nick, nick_size) or ''
        offset += 1 + len(nick)
        return offset


class StatusMessage(BaseMessage):
    """A dynamically formatted status message"""
    __slots__ = ('format_string', 'format_args')
    format_string: str
    format_args: Dict[str, Callable[[], Any]]

    def __init__(self, format_string: str, format_args: dict):
        BaseMessage.__init__(
            self,
            txt='',
        )
        self.format_string = format_string
        self.format_args = format_args
        self.rebuild()

    def rebuild(self):
        real_args = {}
        for key, func in self.format_args.items():
            real_args[key] = func()
        self.txt = self.format_string.format(**real_args)


class Message(BaseMessage, LoggableTrait):
    __slots__ = ('nick_color', 'nickname', 'user', 'delayed', 'history',
                 'highlight', 'me', 'old_message', 'revisions',
                 'jid', 'ack')
    nick_color: Optional[Tuple]
    nickname: Optional[str]
    user: Optional[User]
    delayed: bool
    history: bool
    highlight: bool
    me: bool
    old_message: Optional[Message]
    revisions: int
    jid: Optional[str]
    ack: int

    def __init__(self,
                 txt: str,
                 nickname: Optional[str],
                 time: Optional[datetime] = None,
                 nick_color: Optional[Tuple] = None,
                 delayed: bool = False,
                 history: bool = False,
                 user: Optional[User] = None,
                 identifier: Optional[str] = '',
                 highlight: bool = False,
                 old_message: Optional[Message] = None,
                 revisions: int = 0,
                 jid: Optional[str] = None,
                 ack: int = 0) -> None:
        """
        Create a new Message object with parameters, check for /me messages,
        and delayed messages
        """
        BaseMessage.__init__(
            self,
            txt=txt.replace('\t', '    ') + '\x19o',
            identifier=identifier or '',
            time=time,
        )
        if txt.startswith('/me '):
            me = True
            txt = '\x19%s}%s\x19o' % (dump_tuple(get_theme().COLOR_ME_MESSAGE),
                                      txt[4:])
        else:
            me = False
        self.txt = txt
        self.delayed = delayed or history
        self.history = history
        self.nickname = nickname
        self.nick_color = nick_color
        self.user = user
        self.highlight = highlight
        self.me = me
        self.old_message = old_message
        self.revisions = revisions
        self.jid = jid
        self.ack = ack

    def _other_elems(self) -> str:
        "Helper for the repr_message function"
        acc = []
        fields = list(self.__slots__)
        fields.remove('old_message')
        for field in fields:
            acc.append('%s=%s' % (field, repr(getattr(self, field))))
        return 'Message(%s, %s' % (', '.join(acc), 'old_message=')

    def __repr__(self) -> str:
        """
        repr() for the Message class, for debug purposes, since the default
        repr() is recursive, so it can stack overflow given too many revisions
        of a message
        """
        init = self._other_elems()
        acc = [init]
        next_message = self.old_message
        rev = 1
        while next_message is not None:
            acc.append(next_message._other_elems())
            next_message = next_message.old_message
            rev += 1
        acc.append('None')
        while rev:
            acc.append(')')
            rev -= 1
        return ''.join(acc)

    def compute_offset(self, with_timestamps: bool, nick_size: int) -> int:
        """Compute the x-position at which the message should be printed"""
        offset = 0
        theme = get_theme()
        if with_timestamps:
            if self.history:
                offset += 1 + theme.LONG_TIME_FORMAT_LENGTH
            else:
                offset += 1 + theme.SHORT_TIME_FORMAT_LENGTH

        if not self.nickname:  # not a message, nothing to do afterwards
            return offset

        nick = truncate_nick(self.nickname, nick_size) or ''
        offset += poopt.wcswidth(nick)
        if self.ack:
            theme = get_theme()
            if self.ack > 0:
                offset += poopt.wcswidth(theme.CHAR_ACK_RECEIVED) + 1
            else:
                offset += poopt.wcswidth(theme.CHAR_NACK) + 1
        if self.me:
            offset += 3
        else:
            offset += 2
        if self.revisions:
            offset += ceil(log10(self.revisions + 1))
        return offset