from datetime import datetime

from sqlalchemy import Boolean, Column, DateTime, ForeignKey, Integer, String, Text, create_engine
from sqlalchemy.orm import declarative_base, relationship, sessionmaker

try:
    from .config import Config
except ImportError:
    from config import Config


DATABASE_URL = Config.SQLALCHEMY_DATABASE_URI
connect_args = {"check_same_thread": False} if DATABASE_URL.startswith("sqlite") else {}

engine = create_engine(DATABASE_URL, connect_args=connect_args)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()


class User(Base):
    __tablename__ = "user"

    id = Column(Integer, primary_key=True, index=True)
    username = Column(String(150), unique=True, nullable=False, index=True)
    password = Column(String(200), nullable=False)

    chats = relationship("Chat", back_populates="user", cascade="all, delete-orphan")


class Chat(Base):
    __tablename__ = "chat"

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("user.id"), nullable=False)

    title = Column(String(200), default="New Chat")
    mode = Column(String(20), default="normal")

    is_pinned = Column(Boolean, default=False)
    is_archived = Column(Boolean, default=False)

    created_at = Column(DateTime, default=datetime.utcnow)

    user = relationship("User", back_populates="chats")
    messages = relationship("Message", back_populates="chat", cascade="all, delete-orphan")
    files = relationship("UploadedFile", back_populates="chat", cascade="all, delete-orphan")


class Message(Base):
    __tablename__ = "message"

    id = Column(Integer, primary_key=True, index=True)
    chat_id = Column(Integer, ForeignKey("chat.id"), nullable=False, index=True)

    role = Column(String(50), nullable=False)
    content = Column(Text, nullable=False)
    timestamp = Column(DateTime, default=datetime.utcnow)

    chat = relationship("Chat", back_populates="messages")


class UploadedFile(Base):
    __tablename__ = "uploaded_file"

    id = Column(Integer, primary_key=True, index=True)
    chat_id = Column(Integer, ForeignKey("chat.id"), nullable=False, index=True)

    filename = Column(String(200), nullable=False)
    filepath = Column(String(300), nullable=False)
    uploaded_at = Column(DateTime, default=datetime.utcnow)

    chat = relationship("Chat", back_populates="files")


def init_db():
    Base.metadata.create_all(bind=engine)