from datetime import datetime, timedelta, timezone

from sqlalchemy import func
from sqlalchemy.orm import Session

from ..models import Consumer, Event, ParseJob
from ..schemas import AnalyticsSummary, TimelinePoint, TopItem


def get_analytics_summary(db: Session) -> AnalyticsSummary:
    now = datetime.now(timezone.utc)
    day_ago = now - timedelta(days=1)

    total_events = db.query(func.count(Event.id)).scalar() or 0
    events_with_coords = (
        db.query(func.count(Event.id))
        .filter(Event.latitude.isnot(None), Event.longitude.isnot(None))
        .scalar()
        or 0
    )
    events_last_24h = (
        db.query(func.count(Event.id))
        .filter(Event.ingested_at >= day_ago)
        .scalar()
        or 0
    )
    total_consumers = db.query(func.count(Consumer.id)).scalar() or 0
    active_consumers = (
        db.query(func.count(Consumer.id))
        .filter(Consumer.is_active.is_(True))
        .scalar()
        or 0
    )
    total_jobs = db.query(func.count(ParseJob.id)).scalar() or 0
    pending_jobs = (
        db.query(func.count(ParseJob.id))
        .filter(ParseJob.status.in_(["queued", "running", "pending"]))
        .scalar()
        or 0
    )

    return AnalyticsSummary(
        total_events=total_events,
        events_with_coords=events_with_coords,
        events_last_24h=events_last_24h,
        total_consumers=total_consumers,
        active_consumers=active_consumers,
        total_jobs=total_jobs,
        pending_jobs=pending_jobs,
    )


def get_timeline(db: Session, days: int = 30) -> list[TimelinePoint]:
    since = datetime.now(timezone.utc) - timedelta(days=days)
    day_col = func.date_trunc("day", Event.ingested_at).label("day")

    rows = (
        db.query(day_col, func.count(Event.id).label("count"))
        .filter(Event.ingested_at >= since)
        .group_by(day_col)
        .order_by(day_col)
        .all()
    )

    return [
        TimelinePoint(date=row.day.date().isoformat(), count=row.count)
        for row in rows
    ]


def get_top_localities(db: Session, limit: int = 10) -> list[TopItem]:
    rows = (
        db.query(Event.locality, func.count(Event.id).label("count"))
        .filter(Event.locality != "", Event.locality.isnot(None))
        .group_by(Event.locality)
        .order_by(func.count(Event.id).desc())
        .limit(limit)
        .all()
    )
    return [TopItem(name=row.locality, count=row.count) for row in rows]


def get_top_regions(db: Session, limit: int = 10) -> list[TopItem]:
    rows = (
        db.query(Event.region, func.count(Event.id).label("count"))
        .filter(Event.region.isnot(None), Event.region != "")
        .group_by(Event.region)
        .order_by(func.count(Event.id).desc())
        .limit(limit)
        .all()
    )
    return [TopItem(name=row.region, count=row.count) for row in rows]