data_nexus/app/models.py

from sqlalchemy import Column, Integer, String, Text, ForeignKey, DateTime, BigInteger
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func
from ulid import ULID
from app.database import Base


def generate_ulid() -> str:
    """Generate a new ULID string."""
    return str(ULID())


class Project(Base):
    __tablename__ = "projects"

    id = Column(String(26), primary_key=True, default=generate_ulid)
    project_name = Column(String(100), unique=True, nullable=False, index=True)
    description = Column(Text, nullable=True)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    versions = relationship("DataVersion", back_populates="project")


class DataVersion(Base):
    __tablename__ = "data_versions"

    id = Column(String(26), primary_key=True, default=generate_ulid)
    project_id = Column(String(26), ForeignKey("projects.id"))
    stage = Column(String(50), nullable=False)
    commit_id = Column(String(64), nullable=False)
    author = Column(String(50))
    manifest_snapshot = Column(Text)
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    project = relationship("Project", back_populates="versions")
    files = relationship("DataFile", back_populates="version")


class DataFile(Base):
    __tablename__ = "data_files"

    id = Column(Integer, primary_key=True, index=True, autoincrement=True)
    version_id = Column(String(26), ForeignKey("data_versions.id"))
    relative_path = Column(String(255))
    storage_path = Column(String(500))
    file_size = Column(BigInteger)
    file_type = Column(String(20))
    file_sha = Column(String(64), index=True)  # Git Blob SHA for deduplication
    created_at = Column(DateTime(timezone=True), server_default=func.now())

    version = relationship("DataVersion", back_populates="files")