"""Macro indicators API.

  GET /api/macro/snapshot
      Latest macro snapshot (today's row, or the most recent available).

  GET /api/macro/history?days=30
      Time series of every indicator over the last N days. Used by the
      sparklines on the BTC page macro panel.
"""
from __future__ import annotations

from datetime import datetime, timedelta, timezone
from typing import Optional

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

from app.database import get_db
from app.models import MacroSnapshot

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


def _row_to_dict(r: MacroSnapshot) -> dict:
    """Snapshot row → JSON-friendly dict, in the canonical indicator order
    the frontend lists them in.

    Order rule (see UI mock-up in BtcPageClient MacroPanel):
        1. AHR999
        2. Altcoin Season Index
        3. Fear & Greed
        4. BTC Dominance
        5. ETH/BTC Ratio
        6. Stablecoin Total Supply
        7. ETF Net Flow (1d)
        8. BTC Open Interest
    """
    return {
        "date":        r.snapshot_date.isoformat() if r.snapshot_date else None,
        "captured_at": r.captured_at.replace(tzinfo=timezone.utc).isoformat() if r.captured_at else None,
        "indicators": {
            "ahr999":                r.ahr999,
            "altcoin_season_index":  r.altcoin_season_index,
            "fear_greed":            r.fear_greed,
            "fear_greed_label":      r.fear_greed_label,
            "btc_dominance_pct":     r.btc_dominance_pct,
            "eth_btc_ratio":         r.eth_btc_ratio,
            "stablecoin_supply_usd": r.stablecoin_supply_usd,
            "etf_flow_net_usd_1d":   r.etf_flow_net_usd_1d,
            "btc_open_interest_usd": r.btc_open_interest_usd,
        },
        "composite_score": r.composite_score,
        "regime_label":    r.regime_label,
    }


@router.get("/snapshot")
async def get_snapshot(db: AsyncSession = Depends(get_db)) -> dict:
    """Latest macro snapshot. May be null if poll hasn't run yet."""
    row = (await db.execute(
        select(MacroSnapshot).order_by(MacroSnapshot.snapshot_date.desc()).limit(1)
    )).scalar_one_or_none()
    if not row:
        return {"ok": False, "error": "no snapshots yet — poll has not run"}
    return {"ok": True, **_row_to_dict(row)}


@router.get("/history")
async def get_history(
    days: int = Query(default=30, ge=1, le=365),
    db: AsyncSession = Depends(get_db),
) -> dict:
    """Time series across the last N days — for the panel sparklines."""
    cutoff = (datetime.now(timezone.utc) - timedelta(days=days)).date()
    rows = (await db.execute(
        select(MacroSnapshot)
        .where(MacroSnapshot.snapshot_date >= cutoff)
        .order_by(MacroSnapshot.snapshot_date.asc())
    )).scalars().all()
    return {
        "ok": True,
        "days": days,
        "count": len(rows),
        "items": [_row_to_dict(r) for r in rows],
    }