"""Market data access layer with caching support."""

from __future__ import annotations

import asyncio
import logging
import math
from datetime import datetime, timezone
from typing import Any

from app.core.calculations import option_row_greeks
from app.services.cache import CacheService
from app.strategies.engine import StrategySelectionEngine

logger = logging.getLogger(__name__)

try:
    import yfinance as yf
except ImportError:  # pragma: no cover - optional dependency
    yf = None


class DataService:
    """Fetches portfolio and market data, using Redis when available."""

    def __init__(self, cache: CacheService, default_symbol: str = "GLD") -> None:
        self.cache = cache
        self.default_symbol = default_symbol

    async def get_portfolio(self, symbol: str | None = None) -> dict[str, Any]:
        ticker = (symbol or self.default_symbol).upper()
        cache_key = f"portfolio:{ticker}"

        cached = await self.cache.get_json(cache_key)
        if cached and isinstance(cached, dict):
            return cached

        quote = await self.get_quote(ticker)
        portfolio = {
            "symbol": ticker,
            "spot_price": quote["price"],
            "portfolio_value": round(quote["price"] * 1000, 2),
            "loan_amount": 600_000.0,
            "ltv_ratio": round(600_000.0 / max(quote["price"] * 1000, 1), 4),
            "updated_at": datetime.now(timezone.utc).isoformat(),
            "source": quote["source"],
        }
        await self.cache.set_json(cache_key, portfolio)
        return portfolio

    async def get_quote(self, symbol: str) -> dict[str, Any]:
        cache_key = f"quote:{symbol}"
        cached = await self.cache.get_json(cache_key)
        if cached and isinstance(cached, dict):
            return cached

        quote = await self._fetch_quote(symbol)
        await self.cache.set_json(cache_key, quote)
        return quote

    async def get_option_expirations(self, symbol: str | None = None) -> dict[str, Any]:
        ticker_symbol = (symbol or self.default_symbol).upper()
        cache_key = f"options:{ticker_symbol}:expirations"

        cached = await self.cache.get_json(cache_key)
        if cached and isinstance(cached, dict):
            return cached

        quote = await self.get_quote(ticker_symbol)
        if yf is None:
            payload = self._fallback_option_expirations(
                ticker_symbol,
                quote,
                source="fallback",
                error="yfinance is not installed",
            )
            await self.cache.set_json(cache_key, payload)
            return payload

        try:
            ticker = yf.Ticker(ticker_symbol)
            expirations = await asyncio.to_thread(lambda: list(ticker.options or []))
            if not expirations:
                payload = self._fallback_option_expirations(
                    ticker_symbol,
                    quote,
                    source="fallback",
                    error="No option expirations returned by yfinance",
                )
                await self.cache.set_json(cache_key, payload)
                return payload

            payload = {
                "symbol": ticker_symbol,
                "updated_at": datetime.now(timezone.utc).isoformat(),
                "expirations": expirations,
                "underlying_price": quote["price"],
                "source": "yfinance",
            }
            await self.cache.set_json(cache_key, payload)
            return payload
        except Exception as exc:  # pragma: no cover - network dependent
            logger.warning("Failed to fetch option expirations for %s from yfinance: %s", ticker_symbol, exc)
            payload = self._fallback_option_expirations(
                ticker_symbol,
                quote,
                source="fallback",
                error=str(exc),
            )
            await self.cache.set_json(cache_key, payload)
            return payload

    async def get_options_chain_for_expiry(self, symbol: str | None = None, expiry: str | None = None) -> dict[str, Any]:
        ticker_symbol = (symbol or self.default_symbol).upper()
        expirations_data = await self.get_option_expirations(ticker_symbol)
        expirations = list(expirations_data.get("expirations") or [])
        target_expiry = expiry or (expirations[0] if expirations else None)
        quote = await self.get_quote(ticker_symbol)

        if not target_expiry:
            return self._fallback_options_chain(
                ticker_symbol,
                quote,
                expirations=expirations,
                selected_expiry=None,
                source=expirations_data.get("source", quote.get("source", "fallback")),
                error=expirations_data.get("error"),
            )

        cache_key = f"options:{ticker_symbol}:{target_expiry}"
        cached = await self.cache.get_json(cache_key)
        if cached and isinstance(cached, dict):
            return cached

        if yf is None:
            payload = self._fallback_options_chain(
                ticker_symbol,
                quote,
                expirations=expirations,
                selected_expiry=target_expiry,
                source="fallback",
                error="yfinance is not installed",
            )
            await self.cache.set_json(cache_key, payload)
            return payload

        try:
            ticker = yf.Ticker(ticker_symbol)
            chain = await asyncio.to_thread(ticker.option_chain, target_expiry)
            calls = self._normalize_option_rows(chain.calls, ticker_symbol, target_expiry, "call", quote["price"])
            puts = self._normalize_option_rows(chain.puts, ticker_symbol, target_expiry, "put", quote["price"])

            if not calls and not puts:
                payload = self._fallback_options_chain(
                    ticker_symbol,
                    quote,
                    expirations=expirations,
                    selected_expiry=target_expiry,
                    source="fallback",
                    error="No option contracts returned by yfinance",
                )
                await self.cache.set_json(cache_key, payload)
                return payload

            payload = {
                "symbol": ticker_symbol,
                "selected_expiry": target_expiry,
                "updated_at": datetime.now(timezone.utc).isoformat(),
                "expirations": expirations,
                "calls": calls,
                "puts": puts,
                "rows": sorted(calls + puts, key=lambda row: (row["strike"], row["type"])),
                "underlying_price": quote["price"],
                "source": "yfinance",
            }
            await self.cache.set_json(cache_key, payload)
            return payload
        except Exception as exc:  # pragma: no cover - network dependent
            logger.warning("Failed to fetch options chain for %s %s from yfinance: %s", ticker_symbol, target_expiry, exc)
            payload = self._fallback_options_chain(
                ticker_symbol,
                quote,
                expirations=expirations,
                selected_expiry=target_expiry,
                source="fallback",
                error=str(exc),
            )
            await self.cache.set_json(cache_key, payload)
            return payload

    async def get_options_chain(self, symbol: str | None = None) -> dict[str, Any]:
        ticker_symbol = (symbol or self.default_symbol).upper()
        expirations_data = await self.get_option_expirations(ticker_symbol)
        expirations = list(expirations_data.get("expirations") or [])
        if not expirations:
            quote = await self.get_quote(ticker_symbol)
            return self._fallback_options_chain(
                ticker_symbol,
                quote,
                expirations=[],
                selected_expiry=None,
                source=expirations_data.get("source", quote.get("source", "fallback")),
                error=expirations_data.get("error"),
            )
        return await self.get_options_chain_for_expiry(ticker_symbol, expirations[0])

    async def get_strategies(self, symbol: str | None = None) -> dict[str, Any]:
        ticker = (symbol or self.default_symbol).upper()
        quote = await self.get_quote(ticker)
        engine = StrategySelectionEngine(spot_price=quote["price"] if ticker != "GLD" else 460.0)

        return {
            "symbol": ticker,
            "updated_at": datetime.now(timezone.utc).isoformat(),
            "paper_parameters": {
                "portfolio_value": engine.portfolio_value,
                "loan_amount": engine.loan_amount,
                "margin_call_threshold": engine.margin_call_threshold,
                "spot_price": engine.spot_price,
                "volatility": engine.volatility,
                "risk_free_rate": engine.risk_free_rate,
            },
            "strategies": engine.compare_all_strategies(),
            "recommendations": {
                profile: engine.recommend(profile)  # type: ignore[arg-type]
                for profile in ("conservative", "balanced", "cost_sensitive")
            },
            "sensitivity_analysis": engine.sensitivity_analysis(),
        }

    async def _fetch_quote(self, symbol: str) -> dict[str, Any]:
        if yf is None:
            return self._fallback_quote(symbol, source="fallback")

        try:
            ticker = yf.Ticker(symbol)
            history = await asyncio.to_thread(ticker.history, period="5d", interval="1d")
            if history.empty:
                return self._fallback_quote(symbol, source="fallback")

            closes = history["Close"]
            last = float(closes.iloc[-1])
            previous = float(closes.iloc[-2]) if len(closes) > 1 else last
            change = round(last - previous, 4)
            change_percent = round((change / previous) * 100, 4) if previous else 0.0
            return {
                "symbol": symbol,
                "price": round(last, 4),
                "change": change,
                "change_percent": change_percent,
                "updated_at": datetime.now(timezone.utc).isoformat(),
                "source": "yfinance",
            }
        except Exception as exc:  # pragma: no cover - network dependent
            logger.warning("Failed to fetch %s from yfinance: %s", symbol, exc)
            return self._fallback_quote(symbol, source="fallback")

    def _fallback_option_expirations(
        self,
        symbol: str,
        quote: dict[str, Any],
        *,
        source: str,
        error: str | None = None,
    ) -> dict[str, Any]:
        payload = {
            "symbol": symbol,
            "updated_at": datetime.now(timezone.utc).isoformat(),
            "expirations": [],
            "underlying_price": quote["price"],
            "source": source,
        }
        if error:
            payload["error"] = error
        return payload

    def _fallback_options_chain(
        self,
        symbol: str,
        quote: dict[str, Any],
        *,
        expirations: list[str],
        selected_expiry: str | None,
        source: str,
        error: str | None = None,
    ) -> dict[str, Any]:
        options_chain = {
            "symbol": symbol,
            "selected_expiry": selected_expiry,
            "updated_at": datetime.now(timezone.utc).isoformat(),
            "expirations": expirations,
            "calls": [],
            "puts": [],
            "rows": [],
            "underlying_price": quote["price"],
            "source": source,
        }
        if error:
            options_chain["error"] = error
        return options_chain

    def _normalize_option_rows(
        self,
        frame: Any,
        symbol: str,
        expiry: str,
        option_type: str,
        underlying_price: float,
    ) -> list[dict[str, Any]]:
        if frame is None or getattr(frame, "empty", True):
            return []

        rows: list[dict[str, Any]] = []
        for item in frame.to_dict(orient="records"):
            strike = self._safe_float(item.get("strike"))
            if strike <= 0:
                continue

            bid = self._safe_float(item.get("bid"))
            ask = self._safe_float(item.get("ask"))
            last_price = self._safe_float(item.get("lastPrice"))
            implied_volatility = self._safe_float(item.get("impliedVolatility"))
            contract_symbol = str(item.get("contractSymbol") or "").strip()

            row = {
                "contractSymbol": contract_symbol,
                "symbol": contract_symbol or f"{symbol} {expiry} {option_type.upper()} {strike:.2f}",
                "strike": strike,
                "bid": bid,
                "ask": ask,
                "premium": last_price or self._midpoint(bid, ask),
                "lastPrice": last_price,
                "impliedVolatility": implied_volatility,
                "expiry": expiry,
                "type": option_type,
                "openInterest": int(self._safe_float(item.get("openInterest"))),
                "volume": int(self._safe_float(item.get("volume"))),
            }
            row.update(option_row_greeks(row, underlying_price))
            rows.append(row)
        return rows

    @staticmethod
    def _safe_float(value: Any) -> float:
        try:
            result = float(value)
        except (TypeError, ValueError):
            return 0.0
        return 0.0 if math.isnan(result) else result

    @staticmethod
    def _midpoint(bid: float, ask: float) -> float:
        if bid > 0 and ask > 0:
            return round((bid + ask) / 2, 4)
        return max(bid, ask, 0.0)

    @staticmethod
    def _fallback_quote(symbol: str, source: str) -> dict[str, Any]:
        return {
            "symbol": symbol,
            "price": 215.0,
            "change": 0.0,
            "change_percent": 0.0,
            "updated_at": datetime.now(timezone.utc).isoformat(),
            "source": source,
        }