from sqlalchemy import create_engine
from sqlalchemy import Column, Integer, String, Sequence, UniqueConstraint, PrimaryKeyConstraint
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from contextlib import contextmanager
Base = declarative_base()

class User(Base):
    __tablename__ = 'users'
    user_id = Column(Integer, primary_key=True)
    access = Column(Integer)

    def __repr__(self):
        return "<User(user_id='{user_id}', access='{access}')>".format(user_id=self.user_id, access=self.access)


class Tag(Base):
    __tablename__ = 'tags'
    service = Column(String(15), nullable=False)
    tag = Column(String(50),nullable=False)
    last_check = Column(Integer)
    missing_times = Column(Integer)
    __table_args__ = (PrimaryKeyConstraint('service', 'tag', name='tag_pkey'),)
    def __repr__(self):
        return "<Tag(tag='{tag}', last_check='{last_check}, missing_times='{missing_times}')>".format(tag=self.tag,
                                                                                                      last_check=self.last_check,
                                                                                                      missing_times=self.missing_times)


class Setting(Base):
    __tablename__ = 'settings'
    setting = Column(String(30), primary_key=True)
    value = Column(String(30), nullable=False)

    def __repr__(self):
        return "<Setting(setting='{setting}', value='{value}')>".format(setting=self.setting, value=self.value)


class QueueItem(Base):
    __tablename__ = 'queue'
    id = Column(Integer, Sequence('queue_id_seq'), primary_key=True)
    sender = Column(Integer, nullable=False)
    service = Column(String(15), nullable=False)
    post_id = Column(String(15), nullable=False)
    pic_name = Column(String(30))
    authors = Column(String(300))
    chars = Column(String)
    copyright = Column(String)
    __table_args__ = (UniqueConstraint('service', 'post_id', name='queue_service_post_id_key'),)

    def __repr__(self):
        return "<QueueItem(id='{id}', sender='{sender}', service='{service}', post_id='{post_id}', pic_name='{pic_name}', authors='{authors}', chars='{chars}', copyright='{copyright}')>".format(
            id=self.id, sender=self.sender, service=self.service, post_id=self.post_id, pic_name=self.pic_name,
            authors=self.authors, chars=self.chars, copyright=self.copyright)


class HistoryItem(Base):
    __tablename__ = 'history'
    service = Column(String(15), nullable=False)
    post_id = Column(String(15), nullable=False)
    wall_id = Column(Integer)
    __table_args__ = (PrimaryKeyConstraint('service', 'post_id', name='history_pkey'),)

    def __repr__(self):
        return "<Setting(service='{service}', post_id='{post_id}', wall_id='{wall_id}')>".format(service=self.service,
                                                                                                 post_id=self.post_id,
                                                                                                 wall_id=self.wall_id)


# logging.basicConfig()
# logging.getLogger('sqlalchemy.engine').setLevel(logging.INFO)
conn_string = "postgresql://{user}:{password}@{host}:{port}/{db}".format(user=DB_USER, password=DB_PASSWORD,
                                                                         host=DB_HOST,
                                                                         port=DB_PORT, db=DB_NAME)
engine = create_engine(conn_string)
Base.metadata.create_all(engine)
Session = sessionmaker(bind=engine)

@contextmanager
def session_scope():
    """Provide a transactional scope around a series of operations."""

    session = Session()
    try:
        yield session
        session.commit()
    except:
        session.rollback()
        raise
    finally:
        session.close()