"""Domain models - SQLAlchemy entities."""
from sqlalchemy import Column, String, Integer, DateTime, ForeignKey, Text, Float, LargeBinary
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from datetime import datetime
import uuid

Base = declarative_base()


def generate_uuid():
    return str(uuid.uuid4())


class User(Base):
    __tablename__ = "users"
    
    id = Column(String, primary_key=True, default=generate_uuid)
    clerk_user_id = Column(String, unique=True, nullable=False, index=True)
    email = Column(String, nullable=False)
    org_id = Column(String, nullable=False, index=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    
    documents = relationship("Document", back_populates="user", cascade="all, delete-orphan")
    chats = relationship("Chat", back_populates="user", cascade="all, delete-orphan")


class Folder(Base):
    __tablename__ = "folders"
    
    id = Column(String, primary_key=True, default=generate_uuid)
    name = Column(String, nullable=False)
    org_id = Column(String, nullable=False, index=True)
    # parent_id = None means root-level folder
    parent_id = Column(String, ForeignKey("folders.id"), nullable=True, index=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    
    documents = relationship("Document", back_populates="folder")
    # Self-referential: children folders
    children = relationship("Folder", foreign_keys=[parent_id], lazy="select")


class Document(Base):
    __tablename__ = "documents"
    
    id = Column(String, primary_key=True, default=generate_uuid)
    name = Column(String, nullable=False)
    size = Column(Integer, nullable=False)
    storage_path = Column(String, nullable=False)
    file_content = Column(LargeBinary, nullable=True)
    chunks = Column(Integer, default=0)
    # Processing status: pending | processing | done | error
    status = Column(String, default="pending", nullable=False)
    error_message = Column(Text, nullable=True)
    folder_id = Column(String, ForeignKey("folders.id"), nullable=True)
    user_id = Column(String, ForeignKey("users.id"), nullable=False)
    org_id = Column(String, nullable=False, index=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    
    user = relationship("User", back_populates="documents")
    folder = relationship("Folder", back_populates="documents")


class Chat(Base):
    __tablename__ = "chats"
    
    id = Column(String, primary_key=True, default=generate_uuid)
    title = Column(String, nullable=False)
    user_id = Column(String, ForeignKey("users.id"), nullable=False)
    org_id = Column(String, nullable=False, index=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    
    user = relationship("User", back_populates="chats")
    messages = relationship("Message", back_populates="chat", cascade="all, delete-orphan")


class Message(Base):
    __tablename__ = "messages"
    
    id = Column(String, primary_key=True, default=generate_uuid)
    chat_id = Column(String, ForeignKey("chats.id"), nullable=False)
    role = Column(String, nullable=False)
    content = Column(Text, nullable=False)
    sources = Column(Text, nullable=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    
    chat = relationship("Chat", back_populates="messages")