from sqlalchemy import create_engine, Column, Integer, String, DateTime, ForeignKey, BigInteger, JSON
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
import datetime

Base = declarative_base()

class User(Base):
    __tablename__ = "users"
    id = Column(Integer, primary_key=True, index=True)
    email = Column(String, unique=True, index=True)
    created_at = Column(DateTime, default=datetime.datetime.utcnow)
    accounts = relationship("Account", back_populates="user")
    files = relationship("File", back_populates="user")

class Account(Base):
    __tablename__ = "accounts"
    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"))
    google_email = Column(String, unique=True, index=True)
    credentials = Column(JSON)
    drive_space_total = Column(BigInteger)
    drive_space_used = Column(BigInteger)
    drive_space_reserved = Column(BigInteger, default=1073741824)  # 1GB reserved
    user = relationship("User", back_populates="accounts")
    file_parts = relationship("FilePart", back_populates="account")

class File(Base):
    __tablename__ = "files"
    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"))
    filename = Column(String)
    original_size = Column(BigInteger)
    sha256 = Column(String)
    upload_time = Column(DateTime, default=datetime.datetime.utcnow)
    download_token = Column(String, unique=True, index=True)
    user = relationship("User", back_populates="files")
    parts = relationship("FilePart", back_populates="file")

class FilePart(Base):
    __tablename__ = "file_parts"
    id = Column(Integer, primary_key=True, index=True)
    file_id = Column(Integer, ForeignKey("files.id"))
    part_index = Column(Integer)
    size = Column(BigInteger)
    account_id = Column(Integer, ForeignKey("accounts.id"))
    drive_file_id = Column(String)
    sha256 = Column(String)
    file = relationship("File", back_populates="parts")
    account = relationship("Account", back_populates="file_parts")