"""Dashboard service: KPIs and activity feed."""

from __future__ import annotations

from datetime import UTC, datetime
from decimal import Decimal

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.activity import Activity
from app.models.deal import Deal, DealStage
from app.services._base import OrgScopedQuery


async def get_kpis(db: AsyncSession, *, org_id: int) -> dict[str, object]:
    """Compute headline KPIs for the org's dashboard."""
    scoped = OrgScopedQuery(Deal, db, org_id=org_id)
    open_stages = (DealStage.lead, DealStage.qualified, DealStage.proposal, DealStage.negotiation)

    all_deals = await scoped.list(skip=0, limit=10_000, order_by=Deal.id)
    open_deals = [d for d in all_deals if d.stage in open_stages]
    open_deals_count = len(open_deals)

    pipeline_value = float(sum((d.value for d in open_deals), Decimal("0")))

    now = datetime.now(UTC)
    # SQLite returns naive datetimes; strip tz for comparison
    month_start = now.replace(tzinfo=None, day=1, hour=0, minute=0, second=0, microsecond=0)
    won_this_month = [
        d for d in all_deals if d.stage == DealStage.won and d.created_at >= month_start
    ]
    won_count = len(won_this_month)

    won_total = sum(1 for d in all_deals if d.stage == DealStage.won)
    lost_total = sum(1 for d in all_deals if d.stage == DealStage.lost)
    if won_total + lost_total == 0:
        conversion_rate = 0.0
    else:
        conversion_rate = round((won_total / (won_total + lost_total)) * 100, 2)

    return {
        "open_deals_count": open_deals_count,
        "pipeline_value": pipeline_value,
        "won_this_month": won_count,
        "conversion_rate": conversion_rate,
    }


async def get_activity_feed(db: AsyncSession, *, org_id: int, limit: int = 20) -> list[Activity]:
    """Return the most recent activities, ordered by created_at desc."""
    result = await db.execute(
        select(Activity)
        .where(Activity.org_id == org_id, Activity.deleted_at.is_(None))
        .order_by(Activity.created_at.desc())
        .limit(limit)
    )
    return list(result.scalars().all())


__all__ = ["get_activity_feed", "get_kpis"]