import os
from sqlalchemy import Column, String, Integer, Boolean, ForeignKey
from sqlalchemy.orm import relationship, declarative_base, sessionmaker

from sqlalchemy import create_engine

Base = declarative_base()
basedir = os.path.abspath(os.path.dirname(__file__))

engine = create_engine('sqlite:///' + os.path.join(basedir, 'db/db.sqlite'))
Base.metadata.create_all(engine)

Session = sessionmaker(bind=engine)
session = Session()


class Permission:
    USE_COMMANDS = 1     # Пользоваться обычными командами.
    SEND_LINKS = 2      # Может отправлять ссылки без удаления.
    MODIFY_QUOTES = 4    # Может добавлять и удалять цитаты.
    MODERATE = 8
    ADMIN = 16       # Может банить юзеров и удалять сообщения.


class Quote(Base):
    __tablename__ = "quotes"
    id = Column(Integer, primary_key=True)
    chat_id = Column(Integer, ForeignKey('chats.chat_id'))
    text = Column(String)

    def __repr__(self):
        return f"Quote({self.text=}, {self.chat_id=})"


class Chat(Base):
    __tablename__ = "chats"
    id = Column(Integer, primary_key=True)
    chat_id = Column(Integer, unique=True)
    title = Column(String)

    # Settings
    quotes = relationship('Quote', backref='chat', cascade='all, delete')
    antispam = Column(Boolean)
    report = Column(Boolean)
    reminder = Column(Boolean)
    hidden = Column(Boolean)

    def __repr__(self):
        return f'Chat({self.chat_id=}, {self.title=})'


class User(Base):
    __tablename__ = "users"
    id = Column(Integer, primary_key=True)
    tg_id = Column(Integer, unique=True)
    first_name = Column(String)
    last_name = Column(String)
    username = Column(String)
    permissions = Column(Integer)

    def __repr__(self):
        return f'User({self.first_name} {self.last_name} {self.username})'

class Role(Base):
    __tablename__ = 'roles'
    id = Column(Integer, primary_key=True)
    name = Column(String(64), unique=True)
    default = Column(Boolean, default=False, index=True)
    permissions = Column(Integer)
    users = relationship('User', backref='role', lazy='dynamic')

    def add_permission(self, perm):
        if not self.has_permission(perm):
            self.permissions += perm

    def remove_permission(self, perm):
        if self.has_permission(perm):
            self.permissions -= perm

    def reset_permissions(self):
        self.permissions = 0

    def has_permission(self, perm):
        return self.permissions & perm == perm


    @staticmethod
    def insert_roles():
        roles = {
            "User": [Permission.USE_COMMANDS],
            "Moderator": [Permission.USE_COMMANDS, Permission.SEND_LINKS,
                          Permission.MODIFY_QUOTES, Permission.MODERATE],
            "Administrator": [Permission.USE_COMMANDS, Permission.SEND_LINKS,
                              Permission.MODIFY_QUOTES, Permission.MODERATE,
                              Permission.ADMIN],
        }
        default_role = 'User'
        for r in roles:
            role = Role.query.filter_by(name=r).first()
            if role is None:
                role = Role(name=r)
            role.reset_permissions()
            for perm in roles[r]:
                role.add_permission(perm)
            role.default = (role.name == default_role)
            session.add(role)
        session.commit()