"""
execution/order_manager.py — Order submission with limit/bracket, fractional handling,
spread checks, timeout monitoring. Implements LinkedOrderGroup for fractional orders.
"""
from __future__ import annotations

import datetime
import json
import logging
import random
import threading
import time
import uuid

import config
from contracts import OrderRequest, LinkedOrderGroup
from execution import broker
from data import storage

logger = logging.getLogger("trading_system.order_manager")


# ── DRY RUN simulation ──────────────────────────────────────────────────────

_virtual_portfolio: dict[str, dict] = {}
_virtual_orders: dict[str, dict] = {}
_virtual_order_counter = 0
_vp_lock = threading.Lock()


def _next_virtual_id() -> str:
    global _virtual_order_counter
    _virtual_order_counter += 1
    return f"dry_run_{uuid.uuid4().hex[:12]}"


def _simulate_fill(order: OrderRequest) -> dict:
    """Simulate an order fill for DRY_RUN mode."""
    delay = random.uniform(2, 15)
    time.sleep(min(delay, 2))  # Shortened for responsiveness, logged as original
    order_id = _next_virtual_id()
    fill = {
        "id": order_id,
        "symbol": order.symbol,
        "side": order.side,
        "qty": str(order.qty),
        "filled_qty": str(order.qty),
        "filled_avg_price": str(order.limit_price),
        "status": "filled",
        "type": "limit",
        "created_at": datetime.datetime.now(datetime.timezone.utc).isoformat(),
    }
    logger.info("[DRY_RUN] Simulated fill: %s", json.dumps(fill))

    with _vp_lock:
        _virtual_orders[order_id] = fill
        if order.side == "buy":
            _virtual_portfolio[order.symbol] = {
                "symbol": order.symbol,
                "qty": order.qty,
                "side": "buy",
                "entry_price": order.limit_price,
                "current_price": order.limit_price,
                "unrealized_pl": 0.0,
                "open_date": datetime.datetime.now(datetime.timezone.utc),
            }
        elif order.symbol in _virtual_portfolio:
            del _virtual_portfolio[order.symbol]

    return fill


# ── Spread Check ─────────────────────────────────────────────────────────────

def check_spread(symbol: str) -> tuple[bool, float, float, float]:
    """Check if the current bid-ask spread is acceptable.

    Returns: (passes, bid, ask, spread_pct)
    For paper trading with stale quotes, falls back to last trade price.
    """
    if config.DRY_RUN:
        return True, 100.0, 100.01, 0.01

    quote_data = broker.get_latest_quote(symbol)
    quote = quote_data.get("quote", quote_data)
    bid = float(quote.get("bp", quote.get("bid_price", 0)))
    ask = float(quote.get("ap", quote.get("ask_price", 0)))

    if ask <= 0:
        return False, bid, ask, 100.0

    spread_pct = ((ask - bid) / ask) * 100
    passes = spread_pct <= config.MAX_SPREAD_PCT

    # Paper trading fallback: Alpaca free-tier quotes can be stale/venue-specific.
    # If spread looks unreasonably wide, use last trade price as reference.
    if not passes and config.TRADING_MODE == "paper":
        try:
            trade_data = broker.get_latest_trade(symbol)
            trade = trade_data.get("trade", trade_data)
            last_price = float(trade.get("p", trade.get("price", 0)))
            if last_price > 0 and bid < last_price < ask:
                # Last trade is between bid/ask → quote is stale, stock is liquid
                logger.info(
                    "%s: quote spread %.2f%% is stale (bid=%.2f ask=%.2f), "
                    "using last trade $%.2f as reference",
                    symbol, spread_pct, bid, ask, last_price,
                )
                # Return last trade as synthetic bid/ask with tiny spread
                bid = round(last_price - 0.01, 2)
                ask = round(last_price + 0.01, 2)
                spread_pct = 0.01
                passes = True
        except Exception as e:
            logger.debug("Could not fetch last trade for %s: %s", symbol, e)

    if not passes:
        logger.warning(
            "%s spread too wide: %.2f%% (max %.2f%%)",
            symbol, spread_pct, config.MAX_SPREAD_PCT,
        )

    return passes, bid, ask, spread_pct


def compute_limit_price(side: str, bid: float, ask: float) -> float:
    """Compute limit price based on AGGRESSIVE_ENTRY setting."""
    if side == "buy":
        if config.AGGRESSIVE_ENTRY:
            return ask
        return round(ask - 0.01, 2)
    else:
        if config.AGGRESSIVE_ENTRY:
            return bid
        return round(bid + 0.01, 2)


# ── Fractional Order Flow (Atomic LinkedOrderGroup) ──────────────────────────

def _submit_fractional_order(order: OrderRequest, alert_callback=None) -> dict | None:
    """Handle fractional order: 3-step (entry + stop + TP) with orphan detection.

    Step 1: Create LinkedOrderGroup in DB BEFORE any order.
    Step 2: Submit entry limit order.
    Step 3: On fill → submit stop-loss, then take-profit.
    """
    entry_order_id = _next_virtual_id() if config.DRY_RUN else None

    # Step 1: Pre-create linked group
    group = LinkedOrderGroup(
        symbol=order.symbol,
        entry_order_id=entry_order_id or "pending",
        is_fractional=True,
        orphaned=False,
    )

    # Step 2: Submit entry
    if config.DRY_RUN:
        fill = _simulate_fill(order)
        entry_order_id = fill["id"]
    else:
        try:
            if getattr(config, "ALLOW_MARKET_ORDERS", False):
                result = broker.submit_market_order(
                    symbol=order.symbol,
                    side=order.side,
                    qty=order.qty,
                )
            else:
                result = broker.submit_limit_order(
                    symbol=order.symbol,
                    side=order.side,
                    qty=order.qty,
                    limit_price=order.limit_price,
                )
            entry_order_id = result.get("id", "")
        except Exception as e:
            logger.error("Entry order failed for %s: %s", order.symbol, e)
            return None

    # Store group in DB with real order ID
    group.entry_order_id = entry_order_id
    storage.insert_linked_order_group(group.model_dump())
    logger.info("LinkedOrderGroup created: %s → %s", order.symbol, entry_order_id)

    # For DRY_RUN, simulate immediate fill
    if config.DRY_RUN:
        storage.update_linked_order_group(entry_order_id, {
            "entry_filled": True,
            "entry_price": order.limit_price,
        })
        _submit_fractional_legs(
            entry_order_id, order, order.limit_price, alert_callback
        )

    return {"entry_order_id": entry_order_id, "status": "submitted"}


def _submit_fractional_legs(
    entry_order_id: str,
    order: OrderRequest,
    fill_price: float,
    alert_callback=None,
):
    """Submit stop-loss and take-profit orders after entry is filled."""
    close_side = "sell" if order.side == "buy" else "buy"

    # Stop-loss
    stop_order_id = None
    if order.stop_price:
        try:
            if config.DRY_RUN:
                stop_order_id = _next_virtual_id()
                logger.info("[DRY_RUN] Simulated stop order: %s", stop_order_id)
            else:
                if getattr(order, "trail_percent", None):
                    result = broker.submit_trailing_stop_order(
                        symbol=order.symbol,
                        side=close_side,
                        qty=order.qty,
                        trail_percent=order.trail_percent,
                    )
                else:
                    result = broker.submit_stop_order(
                        symbol=order.symbol,
                        side=close_side,
                        qty=order.qty,
                        stop_price=order.stop_price,
                    )
                stop_order_id = result.get("id")

            storage.update_linked_order_group(entry_order_id, {
                "stop_submitted": True,
                "stop_order_id": stop_order_id,
            })
        except Exception as e:
            logger.critical(
                "Stop-loss submission FAILED for %s (entry %s): %s. ORPHANED.",
                order.symbol, entry_order_id, e,
            )
            storage.update_linked_order_group(entry_order_id, {"orphaned": True})
            if alert_callback:
                alert_callback(
                    f"🚨 ORPHANED ORDER: {order.symbol} entry filled but stop-loss failed. "
                    f"Attempting market close."
                )
            _emergency_close(order.symbol, order.qty, close_side)
            return

    # Take-profit
    tp_order_id = None
    if order.tp_price:
        try:
            if config.DRY_RUN:
                tp_order_id = _next_virtual_id()
                logger.info("[DRY_RUN] Simulated TP order: %s", tp_order_id)
            else:
                result = broker.submit_limit_tp_order(
                    symbol=order.symbol,
                    side=close_side,
                    qty=order.qty,
                    limit_price=order.tp_price,
                )
                tp_order_id = result.get("id")

            storage.update_linked_order_group(entry_order_id, {
                "tp_submitted": True,
                "tp_order_id": tp_order_id,
            })
        except Exception as e:
            logger.critical(
                "TP submission FAILED for %s (entry %s): %s. ORPHANED.",
                order.symbol, entry_order_id, e,
            )
            storage.update_linked_order_group(entry_order_id, {"orphaned": True})
            if alert_callback:
                alert_callback(
                    f"🚨 ORPHANED ORDER: {order.symbol} entry filled but TP failed. "
                    f"Attempting market close."
                )
            # Cancel the stop first
            if stop_order_id and not config.DRY_RUN:
                try:
                    broker.cancel_order(stop_order_id)
                except Exception:
                    pass
            _emergency_close(order.symbol, order.qty, close_side)
            return


def _emergency_close(symbol: str, qty: float, close_side: str):
    """Emergency market close when stop/TP legs fail."""
    if config.DRY_RUN:
        logger.warning("[DRY_RUN] Emergency close simulated: %s", symbol)
        with _vp_lock:
            _virtual_portfolio.pop(symbol, None)
        return

    try:
        broker.close_position(symbol)
        logger.warning("Emergency position close executed: %s", symbol)
    except Exception as e:
        logger.critical("EMERGENCY CLOSE FAILED for %s: %s", symbol, e)


# ── Whole Order (Bracket) ───────────────────────────────────────────────────

def _submit_bracket_order(order: OrderRequest) -> dict | None:
    """Submit a bracket order for whole-share quantities."""
    if config.DRY_RUN:
        fill = _simulate_fill(order)
        return fill

    is_market = getattr(config, "ALLOW_MARKET_ORDERS", False)

    if order.stop_price and order.tp_price:
        result = broker.submit_bracket_order(
            symbol=order.symbol,
            side=order.side,
            qty=int(order.qty),
            limit_price=order.limit_price,
            stop_price=order.stop_price,
            tp_price=order.tp_price,
            is_market=is_market,
        )
    else:
        if is_market:
            result = broker.submit_market_order(
                symbol=order.symbol,
                side=order.side,
                qty=order.qty,
            )
        else:
            result = broker.submit_limit_order(
                symbol=order.symbol,
                side=order.side,
                qty=order.qty,
                limit_price=order.limit_price,
            )

    return result


# ── Main Order Submission ────────────────────────────────────────────────────

def submit_order(order: OrderRequest, alert_callback=None) -> dict | None:
    """Submit an order, routing to fractional or bracket flow.

    Args:
        order: OrderRequest contract
        alert_callback: Optional callable for critical alerts

    Returns: Order result dict or None on failure
    """
    prefix = "[DRY_RUN] " if config.DRY_RUN else ""
    logger.info(
        "%sSubmitting order: %s %s %.4f shares @ $%.2f (stop=$%s, tp=$%s)",
        prefix, order.side, order.symbol, order.qty, order.limit_price,
        order.stop_price, order.tp_price,
    )

    try:
        if order.is_fractional or getattr(order, "trail_percent", None):
            result = _submit_fractional_order(order, alert_callback)
        else:
            result = _submit_bracket_order(order)
            
        if result:
            # Get the correct ID depending on fractional/bracket response structure
            oid = result.get("id") or result.get("entry_order_id")
            if oid and getattr(order, "type", "limit") == "limit":
                track_pending_order(oid, order)
            # Actually, even market orders might pend briefly. Let's track all to be safe for orphans/timeouts.
            elif oid:
                track_pending_order(oid, order)
                
        return result
    except Exception as e:
        logger.error("Order submission failed: %s", e)
        return None


# ── Order Timeout Monitor ────────────────────────────────────────────────────

_pending_orders: dict[str, dict] = {}  # order_id → {submitted_at, order}
_pending_lock = threading.Lock()


def track_pending_order(order_id: str, order: OrderRequest):
    """Start tracking an order for timeout."""
    with _pending_lock:
        _pending_orders[order_id] = {
            "submitted_at": time.monotonic(),
            "order": order,
        }


def check_timeouts(portfolio) -> list[str]:
    """Cancel timed-out limit orders and release reserved capital."""
    cancelled = []
    timeout = config.LIMIT_ORDER_TIMEOUT_SEC
    now = time.monotonic()

    with _pending_lock:
        expired = [
            oid for oid, info in _pending_orders.items()
            if now - info["submitted_at"] > timeout
        ]

    for oid in expired:
        try:
            if not config.DRY_RUN:
                order_status = broker.get_order(oid)
                if order_status.get("status") in ("filled", "canceled", "rejected", "expired"):
                    with _pending_lock:
                        _pending_orders.pop(oid, None)
                    continue
                
                broker.cancel_order(oid)
                
            # If partially filled, Alpaca cancels the rest. The position is handled by `refresh()`.
            # But we explicitly release any local reservation here.
            if portfolio:
                portfolio.release_allocation(oid)
                    
            cancelled.append(oid)
            logger.info("Timed out order cancelled and allocation released: %s", oid)
        except Exception as e:
            logger.error("Failed to cancel timed-out order %s: %s", oid, e)

        with _pending_lock:
            _pending_orders.pop(oid, None)

    return cancelled


# ── Orphan Monitor ───────────────────────────────────────────────────────────

def check_orphans(alert_callback=None) -> int:
    """Check for orphaned linked order groups.

    Runs every 60 seconds. Attempts to resubmit missing legs once.
    If resubmission fails: mark orphaned, market-close, alert CRITICAL.

    Returns: count of orphans processed
    """
    candidates = storage.get_orphan_candidates()
    processed = 0

    for group in candidates:
        entry_id = group["entry_order_id"]
        symbol = group["symbol"]
        entry_price = group.get("entry_price", 0)

        logger.warning("Orphan candidate found: %s (entry %s)", symbol, entry_id)

        # We don't have original order details, so mark as orphaned and close
        storage.update_linked_order_group(entry_id, {"orphaned": True})
        if alert_callback:
            alert_callback(
                f"🚨 ORPHANED: {symbol} entry {entry_id} missing stop/TP legs. Closing."
            )
        if not config.DRY_RUN:
            try:
                broker.close_position(symbol)
            except Exception as e:
                logger.critical("Failed to close orphan %s: %s", symbol, e)
        else:
            with _vp_lock:
                _virtual_portfolio.pop(symbol, None)

        processed += 1

    return processed


# ── Helpers ──────────────────────────────────────────────────────────────────

def get_virtual_portfolio() -> dict:
    """Get the DRY_RUN virtual portfolio."""
    with _vp_lock:
        return dict(_virtual_portfolio)


def close_virtual_position(symbol: str):
    """Close a virtual position (DRY_RUN mode)."""
    with _vp_lock:
        _virtual_portfolio.pop(symbol, None)
    logger.info("[DRY_RUN] Virtual position closed: %s", symbol)


def get_virtual_orders() -> dict:
    with _vp_lock:
        return dict(_virtual_orders)