"""``/processing-log`` (admin) — filterable Operations log view.

Path is kebab-case per CONTRACT.md §9. Filters are camelCase queries:
- ``bookId`` (not ``book_id``)
- ``stage``
- ``status`` — one of ``success | failed | in_flight``
- ``since`` — ISO timestamp lower bound on ``started_at``
- ``limit`` (default 100, max 500)

Admin-only because the log surfaces error messages from every book the
user has ingested — sensitive enough to keep behind ``require_admin``.
"""

from __future__ import annotations

from fastapi import APIRouter, Depends, Query

from src.api.deps import require_admin
from src.api.dto.processing_log import ProcessingLogEntryDTO, ProcessingOutcomeEnum
from src.lib.auth.models import User
from src.lib.processing.models import StageRun
from src.lib.processing.repo import query

router = APIRouter(tags=["processing-log"])


_STATUS_TO_OUTCOME: dict[ProcessingOutcomeEnum, str] = {
    ProcessingOutcomeEnum.success: "success",
    ProcessingOutcomeEnum.failed: "failed",
    ProcessingOutcomeEnum.in_flight: "in-flight",
}


def _to_dto(run: StageRun) -> ProcessingLogEntryDTO:
    if run.success == 1:
        outcome = ProcessingOutcomeEnum.success
    elif run.success == 0:
        outcome = ProcessingOutcomeEnum.failed
    else:
        outcome = ProcessingOutcomeEnum.in_flight
    return ProcessingLogEntryDTO(
        id=run.id,
        book_id=run.book_id,
        stage=run.stage,
        started_at=run.started_at,
        finished_at=run.finished_at,
        outcome=outcome,
        pages_done=run.pages_done,
        engine=run.engine,
        provider=run.provider,
        backend=run.backend,
        where=run.where,
        error=run.error,
        duration_ms=run.duration_ms,
    )


@router.get("/processing-log", response_model=list[ProcessingLogEntryDTO])
def list_processing_log(
    _: User = Depends(require_admin),
    book_id: str | None = Query(default=None, alias="bookId"),
    stage: str | None = Query(default=None),
    status: ProcessingOutcomeEnum | None = Query(default=None),
    since: str | None = Query(
        default=None,
        description="ISO timestamp lower bound on started_at; applied client-side",
    ),
    limit: int = Query(default=100, ge=1, le=500),
) -> list[ProcessingLogEntryDTO]:
    """Filterable list — newest first.

    The repo's :func:`query` does book/stage/outcome filtering in SQL;
    the ``since`` filter applies in Python since the repo signature
    doesn't expose it (a Stage 3 router shouldn't grow the lib's
    signature for one filter; if the FE wants this pushed down later we
    revisit).
    """
    outcome_str = _STATUS_TO_OUTCOME[status] if status is not None else None
    runs = query(
        book_id=book_id,
        stage=stage,
        outcome=outcome_str,
        limit=limit if since is None else max(limit * 2, 500),
    )
    if since:
        runs = [r for r in runs if r.started_at >= since]
    return [_to_dto(r) for r in runs[:limit]]