from sqlalchemy import Column, Integer, String, ForeignKey, DateTime, Boolean, Text
from sqlalchemy.sql import func
from sqlalchemy.orm import relationship

from app.database import Base

class Chat(Base):
    __tablename__ = "chats"

    id = Column(Integer, primary_key=True, index=True)
    employee_id = Column(Integer, ForeignKey("users.id"), nullable=False, unique=True)
    admin_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    # Отношения
    employee = relationship("User", foreign_keys=[employee_id], back_populates="employee_chats")
    admin = relationship("User", foreign_keys=[admin_id], back_populates="admin_chats")
    messages = relationship("Message", back_populates="chat", cascade="all, delete-orphan")

class Message(Base):
    __tablename__ = "messages"

    id = Column(Integer, primary_key=True, index=True)
    chat_id = Column(Integer, ForeignKey("chats.id", ondelete="CASCADE"), nullable=False)
    sender_id = Column(Integer, ForeignKey("users.id"), nullable=False)
    content = Column(Text, nullable=False)
    is_read = Column(Boolean, default=False)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    # Отношения
    chat = relationship("Chat", back_populates="messages")
    sender = relationship("User", back_populates="sent_messages")
    files = relationship("ChatFile", back_populates="message", cascade="all, delete-orphan")

class ChatFile(Base):
    __tablename__ = "chat_files"

    id = Column(Integer, primary_key=True, index=True)
    message_id = Column(Integer, ForeignKey("messages.id", ondelete="CASCADE"), nullable=False)
    file_name = Column(String(255), nullable=False)
    file_path = Column(String(255), nullable=False)
    file_size = Column(Integer, nullable=False)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    # Отношения
    message = relationship("Message", back_populates="files")