from datetime import datetime
from typing import Any

from fastapi import APIRouter, Body, Depends, HTTPException, Query
from pydantic import BaseModel
from sqlalchemy import func, select
from sqlalchemy.orm import Session, joinedload

from app.auth.api_key import get_api_key_auth
from app.auth.jwt_auth import get_current_user
from app.config import get_settings
from app.database import get_db
from app.models import Event, Host
from app.schemas.list_models import EventDetail, EventListResponse, EventSummary
from app.services.ingest import ingest_event
from app.services.problems import maybe_create_problem
from app.services.schema_validate import validate_event_payload

router = APIRouter(prefix="/events", tags=["events"])


class IngestResponse(BaseModel):
    status: str
    event_id: str
    created: bool
    sac_event_url: str
    problem_id: int | None = None


@router.post("", status_code=202, response_model=IngestResponse)
def post_event(
    payload: dict[str, Any] = Body(...),
    db: Session = Depends(get_db),
    _api_key: str = Depends(get_api_key_auth),
) -> IngestResponse:
    errors = validate_event_payload(payload)
    if errors:
        raise HTTPException(status_code=422, detail={"schema_errors": errors[:20]})

    event, created = ingest_event(db, payload)
    problem = None
    if created:
        problem = maybe_create_problem(db, event)
    db.commit()

    settings = get_settings()
    base = settings.sac_public_url.rstrip("/")
    return IngestResponse(
        status="accepted",
        event_id=event.event_id,
        created=created,
        sac_event_url=f"{base}/api/v1/events/{event.id}",
        problem_id=problem.id if problem else None,
    )


def _parse_optional_dt(value: str | None) -> datetime | None:
    if not value:
        return None
    return datetime.fromisoformat(value.replace("Z", "+00:00"))


@router.get("", response_model=EventListResponse)
def list_events(
    page: int = Query(1, ge=1),
    page_size: int = Query(50, ge=1, le=200),
    severity: str | None = None,
    type: str | None = None,
    host_id: int | None = None,
    hostname: str | None = None,
    from_time: str | None = Query(None, alias="from"),
    to_time: str | None = Query(None, alias="to"),
    q: str | None = None,
    db: Session = Depends(get_db),
    _user: str = Depends(get_current_user),
) -> EventListResponse:
    stmt = select(Event).join(Host).options(joinedload(Event.host))
    count_stmt = select(func.count()).select_from(Event).join(Host)

    if severity:
        stmt = stmt.where(Event.severity == severity)
        count_stmt = count_stmt.where(Event.severity == severity)
    if type:
        stmt = stmt.where(Event.type == type)
        count_stmt = count_stmt.where(Event.type == type)
    if host_id is not None:
        stmt = stmt.where(Event.host_id == host_id)
        count_stmt = count_stmt.where(Event.host_id == host_id)
    if hostname:
        like = f"%{hostname}%"
        stmt = stmt.where(Host.hostname.ilike(like))
        count_stmt = count_stmt.where(Host.hostname.ilike(like))
    dt_from = _parse_optional_dt(from_time)
    dt_to = _parse_optional_dt(to_time)
    if dt_from:
        stmt = stmt.where(Event.occurred_at >= dt_from)
        count_stmt = count_stmt.where(Event.occurred_at >= dt_from)
    if dt_to:
        stmt = stmt.where(Event.occurred_at <= dt_to)
        count_stmt = count_stmt.where(Event.occurred_at <= dt_to)
    if q:
        like = f"%{q}%"
        stmt = stmt.where(Event.summary.ilike(like) | Event.title.ilike(like))
        count_stmt = count_stmt.where(Event.summary.ilike(like) | Event.title.ilike(like))

    total = db.scalar(count_stmt) or 0
    rows = db.scalars(
        stmt.order_by(Event.occurred_at.desc())
        .offset((page - 1) * page_size)
        .limit(page_size)
    ).all()

    items = [
        EventSummary(
            id=e.id,
            event_id=e.event_id,
            host_id=e.host_id,
            hostname=e.host.hostname,
            occurred_at=e.occurred_at,
            received_at=e.received_at,
            category=e.category,
            type=e.type,
            severity=e.severity,
            title=e.title,
            summary=e.summary,
        )
        for e in rows
    ]
    return EventListResponse(items=items, total=total, page=page, page_size=page_size)


@router.get("/{event_db_id}", response_model=EventDetail)
def get_event(
    event_db_id: int,
    db: Session = Depends(get_db),
    _user: str = Depends(get_current_user),
) -> EventDetail:
    event = db.scalar(
        select(Event).where(Event.id == event_db_id).options(joinedload(Event.host))
    )
    if event is None:
        raise HTTPException(status_code=404, detail="Event not found")
    return EventDetail(
        id=event.id,
        event_id=event.event_id,
        host_id=event.host_id,
        hostname=event.host.hostname,
        occurred_at=event.occurred_at,
        received_at=event.received_at,
        category=event.category,
        type=event.type,
        severity=event.severity,
        title=event.title,
        summary=event.summary,
        details=event.details,
        raw=event.raw,
        dedup_key=event.dedup_key,
        correlation_id=event.correlation_id,
        payload=event.payload,
    )