from fastapi import APIRouter, Depends, Query
from sqlalchemy import and_, or_, select
from sqlalchemy.ext.asyncio import AsyncSession

from ..cursors import decode, decode_datetime, encode
from ..db import get_session
from ..models import NotificationOutbox
from ..schemas import NotificationOutboxItem, OutboxPage

router = APIRouter()


@router.get("/notifiers/outbox", response_model=OutboxPage)
async def list_outbox(
    state: str | None = Query(default=None),
    cursor: str | None = Query(default=None, max_length=512),
    limit: int = Query(default=100, ge=1, le=500),
    session: AsyncSession = Depends(get_session),
) -> OutboxPage:
    stmt = select(NotificationOutbox).order_by(
        NotificationOutbox.created_at.desc(), NotificationOutbox.id.desc()
    )
    if state is not None:
        stmt = stmt.where(NotificationOutbox.state == state)
    if cursor is not None:
        ts_str, last_id = decode(cursor, 2)
        ts = decode_datetime(ts_str)
        stmt = stmt.where(
            or_(
                NotificationOutbox.created_at < ts,
                and_(
                    NotificationOutbox.created_at == ts,
                    NotificationOutbox.id < last_id,
                ),
            )
        )
    rows = (await session.execute(stmt.limit(limit + 1))).scalars().all()
    next_cursor = None
    if len(rows) > limit:
        rows = rows[:limit]
        next_cursor = encode(rows[-1].created_at.isoformat(), rows[-1].id)
    return OutboxPage(
        items=[
            NotificationOutboxItem(
                id=str(r.id),
                notifier=r.notifier,
                state=r.state,
                incident_id=str(r.incident_id),
                event_type=r.event_type,
                attempts=r.attempts,
                next_attempt_at=r.next_attempt_at,
                last_error=r.last_error,
                updated_at=r.updated_at,
            )
            for r in rows
        ],
        next_cursor=next_cursor,
    )