backend/app/db/models.py

"""Database models."""

from datetime import datetime, timezone
from typing import Optional
from uuid import UUID, uuid4

from sqlalchemy import JSON, Text, Integer, Float, String, DateTime, Boolean
from sqlalchemy.dialects.postgresql import UUID as PGUUID
from sqlalchemy.orm import Mapped, mapped_column

from app.db.database import Base


def utcnow() -> datetime:
    """Get current UTC datetime."""
    return datetime.now(timezone.utc)


class Generation(Base):
    """Music generation record."""

    __tablename__ = "generations"

    id: Mapped[UUID] = mapped_column(
        PGUUID(as_uuid=True),
        primary_key=True,
        default=uuid4,
    )
    prompt: Mapped[str] = mapped_column(Text, nullable=False)
    lyrics: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    style: Mapped[Optional[str]] = mapped_column(String(100), nullable=True)
    duration: Mapped[int] = mapped_column(Integer, default=30)
    
    # Generation status
    status: Mapped[str] = mapped_column(
        String(20),
        default="pending",
        nullable=False,
    )  # pending, processing, completed, failed
    
    # File paths
    audio_path: Mapped[Optional[str]] = mapped_column(String(500), nullable=True)
    instrumental_path: Mapped[Optional[str]] = mapped_column(
        String(500), nullable=True
    )
    vocal_path: Mapped[Optional[str]] = mapped_column(String(500), nullable=True)
    
    # Metadata
    generation_metadata: Mapped[Optional[dict]] = mapped_column(JSON, nullable=True)
    
    # Timestamps
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=utcnow,
        nullable=False,
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=utcnow,
        onupdate=utcnow,
        nullable=False,
    )
    completed_at: Mapped[Optional[datetime]] = mapped_column(
        DateTime(timezone=True),
        nullable=True,
    )
    
    # Error handling
    error_message: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    
    # Processing metrics
    processing_time_seconds: Mapped[Optional[float]] = mapped_column(
        Float, nullable=True
    )


class User(Base):
    """User model (for future authentication)."""

    __tablename__ = "users"

    id: Mapped[UUID] = mapped_column(
        PGUUID(as_uuid=True),
        primary_key=True,
        default=uuid4,
    )
    email: Mapped[str] = mapped_column(String(255), unique=True, nullable=False)
    username: Mapped[str] = mapped_column(String(100), unique=True, nullable=False)
    hashed_password: Mapped[str] = mapped_column(String(255), nullable=False)
    is_active: Mapped[bool] = mapped_column(Boolean, default=True)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=utcnow,
    )