from datetime import datetime, timezone
from pathlib import Path
from typing import Any, Dict
import sys
import time

from fastapi import APIRouter

PROJECT_ROOT = Path(__file__).resolve().parents[1]
if str(PROJECT_ROOT) not in sys.path:
    sys.path.append(str(PROJECT_ROOT))

from indian_paper_trading_strategy.engine.data import fetch_live_price, get_price_snapshot

NIFTY = "NIFTYBEES.NS"
GOLD = "GOLDBEES.NS"

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

_LTP_CACHE: Dict[str, Any] = {
    "ts_epoch": 0.0,
    "data": None,
}

CACHE_TTL_SECONDS = 5
STALE_SECONDS = 60


@router.get("/ltp")
def get_ltp(allow_cache: bool = False):
    now_epoch = time.time()
    cached = _LTP_CACHE["data"]
    if cached is not None and (now_epoch - _LTP_CACHE["ts_epoch"]) < CACHE_TTL_SECONDS:
        return cached

    nifty_ltp = None
    gold_ltp = None
    try:
        nifty_ltp = fetch_live_price(NIFTY)
    except Exception:
        nifty_ltp = None
    try:
        gold_ltp = fetch_live_price(GOLD)
    except Exception:
        gold_ltp = None

    nifty_meta = get_price_snapshot(NIFTY) or {}
    gold_meta = get_price_snapshot(GOLD) or {}
    now = datetime.now(timezone.utc)

    def _is_stale(meta: Dict[str, Any], ltp: float | None) -> bool:
        if ltp is None:
            return True
        source = meta.get("source")
        ts = meta.get("ts")
        if source != "live":
            return True
        if isinstance(ts, datetime):
            return (now - ts).total_seconds() > STALE_SECONDS
        return False

    nifty_source = str(nifty_meta.get("source") or "").lower()
    gold_source = str(gold_meta.get("source") or "").lower()
    stale_map = {
        NIFTY: _is_stale(nifty_meta, nifty_ltp),
        GOLD: _is_stale(gold_meta, gold_ltp),
    }
    stale_any = stale_map[NIFTY] or stale_map[GOLD]
    if allow_cache and stale_any:
        cache_sources = {"cache", "cached", "history"}
        if nifty_source in cache_sources and gold_source in cache_sources:
            stale_map = {NIFTY: False, GOLD: False}
            stale_any = False

    payload = {
        "ts": now.isoformat(),
        "ltp": {
            NIFTY: float(nifty_ltp) if nifty_ltp is not None else None,
            GOLD: float(gold_ltp) if gold_ltp is not None else None,
        },
        "source": {
            NIFTY: nifty_meta.get("source"),
            GOLD: gold_meta.get("source"),
        },
        "stale": stale_map,
        "stale_any": stale_any,
    }

    _LTP_CACHE["ts_epoch"] = now_epoch
    _LTP_CACHE["data"] = payload
    return payload