"""DTOs for ``/processing-log`` (admin-only GET).

One row per (book, stage) attempt; the table drives the Operations
"Processing log" page. Status is normalised to a typed enum on the wire
even though the DB stores it as 1/0/NULL — the FE codegen produces a
proper union over the three outcomes.
"""

from __future__ import annotations

from enum import Enum

from .common import ApiModel


class ProcessingOutcomeEnum(str, Enum):
    """How the most recent (book, stage) attempt resolved.

    ``in_flight`` rows are runs that started but haven't finished — a
    crashed/killed subprocess shows up here until the reconciler marks
    it failed (BACKEND_BUILD.md §5.5).
    """

    success = "success"
    failed = "failed"
    in_flight = "in_flight"


class ProcessingLogEntryDTO(ApiModel):
    """One row of ``processing_log``.

    ``where`` is server-formatted (e.g. ``"bge-m3 (local / FlagEmbedding-cuda)"``)
    so the FE doesn't have to know how engine + provider + backend
    compose. Mirrors :func:`src.lib.processing.models.StageRun.where`.
    """

    id: int
    book_id: str
    stage: str
    started_at: str
    finished_at: str | None = None
    outcome: ProcessingOutcomeEnum
    pages_done: int | None = None
    engine: str | None = None
    provider: str | None = None
    backend: str | None = None
    where: str
    error: str | None = None
    duration_ms: int | None = None