from datetime import datetime

from sqlalchemy import DateTime, ForeignKey, Integer, String, Text, func
from sqlalchemy.orm import Mapped, mapped_column

from app.db import Base

# queued -> downloading -> postprocessing -> completed -> deleted (by the user)
#                                          -> failed
# unknown: state could not be reconciled after a restart
ACTIVE_STATUSES = ("queued", "downloading", "postprocessing")
TERMINAL_STATUSES = ("completed", "failed", "deleted")


class DownloadJob(Base):
    __tablename__ = "download_jobs"

    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
    video_id: Mapped[int] = mapped_column(ForeignKey("videos.id"), nullable=False, index=True)
    status: Mapped[str] = mapped_column(String(20), nullable=False, default="queued")
    metube_job_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
    metube_filename: Mapped[str | None] = mapped_column(String, nullable=True)
    media_url: Mapped[str | None] = mapped_column(String, nullable=True)
    progress_percent: Mapped[int | None] = mapped_column(Integer, nullable=True)
    error_message: Mapped[str | None] = mapped_column(Text, nullable=True)
    requested_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
    started_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    completed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
    )