import { IExchangeConnector } from '../connectors/types.js';
import logger from '../utils/logger.js';
import { config } from '../config/index.js';
import { SymbolMapper } from '../utils/symbolMapper.js';
import { healthTracker } from './healthTracker.js';
import * as runtimeOrderRepository from './runtimeOrderRepository.js';

const normalizeThrown = (value: unknown): Error => {
    if (value instanceof Error) return value;
    if (value && typeof value === 'object') return new Error(JSON.stringify(value));
    return new Error(String(value ?? 'Unknown error'));
};

export interface OrderSyncOrderRecord {
    id?: string;
    order_id?: string;
    symbol: string;
    status?: string;
    qty?: number | string;
    price?: number | string;
    action?: string;
    trade_id?: string;
    user_id?: string;
    profile_id?: string;
    filled_at?: string;
    updated_at?: string;
    created_at?: string;
}

export interface OrderStatusSyncEvent {
    orderId: string;
    symbol: string;
    previousStatus: string;
    status: string;
    action?: string;
    tradeId?: string;
    userId?: string;
    profileId?: string;
    filledAt?: Date;
    fillPrice?: number;
    fillQty?: number;
    quarantined?: boolean;
}

export interface OrderStatusSyncScopeOptions {
    userId?: string;
    includeOrphanUserOrders?: boolean;
    profileNullOnly?: boolean;
}

/**
 * OrderStatusSyncService
 * 
 * Periodically checks for orders stuck in 'pending_new' status and updates them
 * by querying the exchange for the actual order status.
 * 
 * This prevents stale data in the database when orders are filled but the status
 * update fails or is missed.
 */
export class OrderStatusSyncService {
    private static readonly UUID_PATTERN = /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
    private interval: NodeJS.Timeout | null = null;
    private isRunning = false;
    private lastStats = {
        updated: 0,
        failed: 0,
        notFound: 0,
        quarantined: 0,
        lastRunAt: 0
    };
    private missingExchangeDetections = new Map<string, { count: number; lastSeenAt: number }>();
    private static warnedCapabilities = new Set<string>();

    constructor(
        private exchange: IExchangeConnector,
        private syncIntervalMs: number = config.ORDER_SYNC_INTERVAL_MS,
        private profileId?: string,
        private onStatusChange?: (event: OrderStatusSyncEvent) => Promise<void> | void,
        private scopeOptions: OrderStatusSyncScopeOptions = {}
    ) { }

    /**
     * Start the background sync service
     */
    public start() {
        if (this.interval) {
            logger.warn('[OrderSync] Service already running');
            return;
        }

        const scopeParts: string[] = [];
        if (this.profileId) scopeParts.push(`profile=${this.profileId}`);
        if (this.scopeOptions.userId) scopeParts.push(`user=${this.scopeOptions.userId}`);
        if (this.scopeOptions.profileNullOnly) scopeParts.push('profile=null');
        if (this.scopeOptions.includeOrphanUserOrders) scopeParts.push('include-orphans=true');
        const scopeLabel = scopeParts.length > 0 ? scopeParts.join(',') : 'global';
        const cadenceLabel = this.syncIntervalMs >= 60_000
            ? `${(this.syncIntervalMs / 60_000).toFixed(this.syncIntervalMs % 60_000 === 0 ? 0 : 1)} minute(s)`
            : `${Math.max(1, Math.round(this.syncIntervalMs / 1000))} second(s)`;
        logger.info(`[OrderSync] Starting order status sync (${scopeLabel}, every ${cadenceLabel})...`);

        // Run immediately on start
        this.syncStaleOrders();

        // Then run periodically
        this.interval = setInterval(() => {
            this.syncStaleOrders();
        }, this.syncIntervalMs);
    }

    /**
     * Stop the background sync service
     */
    public stop() {
        if (this.interval) {
            clearInterval(this.interval);
            this.interval = null;
            logger.info('[OrderSync] Service stopped');
        }
    }

    /**
     * Main sync logic: Query DB for stale orders and update their status
     */
    private async syncStaleOrders() {
        if (this.isRunning) {
            logger.debug('[OrderSync] Previous sync still running, skipping...');
            return;
        }

        this.isRunning = true;

        try {
            const staleOrders = await this.getStaleOrders();
            const recentClosedOrders = await this.getRecentClosedOrders();
            const candidateOrders = new Map<string, OrderSyncOrderRecord>();
            for (const row of [...(staleOrders || []), ...(recentClosedOrders || [])]) {
                const key = String(row.order_id || row.id || '').trim();
                if (!key) continue;
                if (!candidateOrders.has(key)) {
                    candidateOrders.set(key, row);
                }
            }

            if (candidateOrders.size === 0) {
                logger.debug('[OrderSync] No stale or recent-closed orders found');
                return;
            }

            logger.info(`[OrderSync] Found ${staleOrders.length} stale + ${recentClosedOrders.length} recent-closed orders to check${this.profileId ? ` (profile=${this.profileId})` : ''}`);

            let updated = 0;
            let failed = 0;
            let notFound = 0;
            let quarantined = 0;

            for (const order of candidateOrders.values()) {
                try {
                    const result = await this.syncOrderStatus(order);
                    if (result === 'quarantined') {
                        quarantined++;
                    } else {
                        updated++;
                    }
                } catch (error: any) {
                    if (error.message?.includes('not found')) {
                        notFound++;
                    } else {
                        failed++;
                    }
                }
            }

            this.lastStats = {
                updated,
                failed,
                notFound,
                quarantined,
                lastRunAt: Date.now()
            };
            logger.info(`[OrderSync] Sync complete: ${updated} updated, ${notFound} not found on exchange, ${quarantined} quarantined, ${failed} failed${this.profileId ? ` (profile=${this.profileId})` : ''}`);

        } catch (error: any) {
            logger.error(`[OrderSync] Sync error: ${error.message}`);
        } finally {
            healthTracker.recordOrderSyncLoop();
            this.isRunning = false;
        }
    }

    /**
     * Get orders from DB that are stuck in pending_new status
     */
    private async getStaleOrders(): Promise<OrderSyncOrderRecord[]> {
        try {
            const staleOrders = await runtimeOrderRepository.getStaleOrders(config.STALE_ORDER_THRESHOLD_MINUTES, {
                profileId: this.profileId,
                userId: this.scopeOptions.userId,
                includeOrphanUserOrders: this.scopeOptions.includeOrphanUserOrders,
                profileNullOnly: this.scopeOptions.profileNullOnly
            });
            return staleOrders;
        } catch (error: any) {
            logger.error(`[OrderSync] Error fetching stale orders: ${error.message}`);
            return [];
        }
    }

    private async getRecentClosedOrders(): Promise<OrderSyncOrderRecord[]> {
        const profileId = String(this.profileId || '').trim();
        if (!profileId || !OrderStatusSyncService.UUID_PATTERN.test(profileId)) return [];
        try {
            const rows = await runtimeOrderRepository.getRecentlyClosedOrdersForProfile(
                profileId,
                config.ORDER_SYNC_RECENT_CLOSED_LOOKBACK_MINUTES
            );
            return rows || [];
        } catch (error: any) {
            logger.error(`[OrderSync] Error fetching recent closed orders: ${error.message}`);
            return [];
        }
    }

    /**
     * Check a single order's status on the exchange and update DB
     */
    private async emitStatusChange(event: OrderStatusSyncEvent): Promise<void> {
        if (!this.onStatusChange) return;
        try {
            await this.onStatusChange(event);
        } catch (error: any) {
            logger.error(`[OrderSync] onStatusChange callback failed for ${event.orderId}: ${error.message}`);
        }
    }

    private isMissingOrderError(error: any): boolean {
        const message = String(error?.message || error || '').toLowerCase();
        const details = String(error?.details || '').toLowerCase();
        const code = String(error?.code || error?.status || error?.statusCode || '').toLowerCase();

        const corpus = `${message} ${details} ${code}`;
        return (
            corpus.includes('not found')
            || corpus.includes('404')
            || corpus.includes('unknown order')
            || corpus.includes('does not exist')
            || corpus.includes('no such order')
        );
    }

    private async syncOrderStatus(order: OrderSyncOrderRecord): Promise<'updated' | 'quarantined'> {
        const orderId = order.order_id || order.id;

        if (!orderId) {
            logger.warn('[OrderSync] Order missing ID, skipping');
            return 'updated';
        }

        try {
            // Check if exchange supports getOrder
            if (!this.exchange.getOrder) {
                if (!OrderStatusSyncService.warnedCapabilities.has('getOrder')) {
                    OrderStatusSyncService.warnedCapabilities.add('getOrder');
                    logger.warn('[OrderSync] Exchange does not support getOrder. Background sync will be limited.');
                }
                return 'updated'; // Don't mark as unknown if we can't check
            }

            // Query exchange for order status
            let exchangeOrder: any = null;
            let missingFromExchange = false;
            try {
                // Ensure symbol is mapped to exchange format (e.g. BTC/USDT -> BTC/USD for Alpaca)
                const tradeSymbol = SymbolMapper.toTradeSymbol(order.symbol, config.EXECUTION_PROVIDER);
                exchangeOrder = await this.exchange.getOrder(orderId, tradeSymbol);
            } catch (error: any) {
                if (this.isMissingOrderError(error)) {
                    missingFromExchange = true;
                    logger.warn(`[OrderSync] Order ${orderId} not found on exchange (exception path): ${error.message}`);
                } else {
                    // Transient exchange failure: keep existing status and retry later.
                    logger.debug(`[OrderSync] Could not fetch order ${orderId} from exchange: ${error.message}`);
                    return 'updated';
                }
            }

            if (!exchangeOrder) {
                missingFromExchange = true;
            }

            if (!missingFromExchange) {
                this.missingExchangeDetections.delete(orderId);
            }

            if (missingFromExchange) {
                const normalizedCurrentStatus = String(order.status || '').toLowerCase();
                const alreadyClosed = ['filled', 'partially_filled', 'partially-filled', 'canceled', 'expired', 'rejected', 'unknown']
                    .includes(normalizedCurrentStatus);
                if (alreadyClosed) {
                    this.missingExchangeDetections.delete(orderId);
                    logger.debug(`[OrderSync] Closed order ${orderId} missing from exchange; preserving DB state (${normalizedCurrentStatus}).`);
                    return 'updated';
                }

                const createdAt = order.created_at ? new Date(order.created_at).getTime() : Date.now();
                const orderAge = Date.now() - createdAt;
                const ageHours = orderAge / (1000 * 60 * 60);
                const ageMinutes = orderAge / (1000 * 60);
                const graceMinutes = Math.max(0, Number(config.ORDER_SYNC_MISSING_GRACE_MINUTES || 0));
                const minConfirmations = Math.max(1, Math.floor(Number(config.ORDER_SYNC_MISSING_CONFIRMATION_COUNT || 1)));
                if (ageMinutes < graceMinutes) {
                    logger.debug(`[OrderSync] Order ${orderId} missing on exchange but within grace window (${ageMinutes.toFixed(1)}m < ${graceMinutes}m).`);
                    return 'updated';
                }
                const detection = this.missingExchangeDetections.get(orderId) || { count: 0, lastSeenAt: 0 };
                const nextDetection = {
                    count: detection.count + 1,
                    lastSeenAt: Date.now()
                };
                this.missingExchangeDetections.set(orderId, nextDetection);
                if (nextDetection.count < minConfirmations) {
                    logger.warn(`[OrderSync] Order ${orderId} missing from exchange (confirmation ${nextDetection.count}/${minConfirmations}). Deferring state mutation.`);
                    return 'updated';
                }
                const normalizedAction = String(order.action || '').toUpperCase();
                const normalizedSide = String((order as any).side || '').toUpperCase();

                // If lifecycle is already closed, mark stale order canceled so dashboard
                // does not keep ghost active rows. Applies to EXIT and legacy rows without action.
                if (order.trade_id) {
                    const isLifecycleClosed = await runtimeOrderRepository.isTradeLifecycleClosed(
                        order.trade_id,
                        order.profile_id,
                        order.symbol
                    );

                    if (isLifecycleClosed) {
                        logger.warn(`[OrderSync] Order ${orderId} (${order.symbol}) not found on exchange, but lifecycle ${order.trade_id} is closed. Marking as canceled.`);
                        await runtimeOrderRepository.updateOrderStatus(orderId, 'canceled');
                        this.missingExchangeDetections.delete(orderId);
                        await this.emitStatusChange({
                            orderId,
                            symbol: order.symbol,
                            previousStatus: (order.status || '').toLowerCase(),
                            status: 'canceled',
                            action: order.action,
                            tradeId: order.trade_id,
                            userId: order.user_id,
                            profileId: order.profile_id
                        });
                        return 'updated';
                    }
                }

                // Legacy safety: older EXIT-like orders may be missing trade_id.
                // For dedicated profiles, resolve by profile+symbol virtual lifecycle state.
                const isExitLikeWithoutTradeId = !order.trade_id
                    && !!order.profile_id
                    && (normalizedAction === 'EXIT' || (!normalizedAction && normalizedSide === 'SELL'));
                if (isExitLikeWithoutTradeId) {
                    try {
                        const virtualPosition = await runtimeOrderRepository.getVirtualOpenPosition(order.profile_id!, order.symbol);
                        if (!virtualPosition) {
                            logger.warn(`[OrderSync] Legacy EXIT-like order ${orderId} (${order.symbol}) has no open virtual lifecycle. Marking as canceled.`);
                            await runtimeOrderRepository.updateOrderStatus(orderId, 'canceled');
                            this.missingExchangeDetections.delete(orderId);
                            await this.emitStatusChange({
                                orderId,
                                symbol: order.symbol,
                                previousStatus: (order.status || '').toLowerCase(),
                                status: 'canceled',
                                action: order.action,
                                tradeId: order.trade_id,
                                userId: order.user_id,
                                profileId: order.profile_id
                            });
                            return 'updated';
                        }
                    } catch (virtualErr: any) {
                        logger.warn(`[OrderSync] Failed virtual lifecycle check for legacy order ${orderId}: ${virtualErr.message}`);
                    }
                }

                // If order is older than 24 hours and not found, mark as expired to clean up UI
                if (ageHours > 24) {
                    logger.error(`[OrderSync][QUARANTINE] Order ${orderId} not found and >24h old. Marking as UNKNOWN for manual review.`);
                    await runtimeOrderRepository.updateOrderStatus(orderId, 'unknown');
                    this.missingExchangeDetections.delete(orderId);
                    await this.emitStatusChange({
                        orderId,
                        symbol: order.symbol,
                        previousStatus: (order.status || '').toLowerCase(),
                        status: 'unknown',
                        action: order.action,
                        tradeId: order.trade_id,
                        userId: order.user_id,
                        profileId: order.profile_id,
                        quarantined: true
                    });
                    return 'quarantined';
                } else {
                    logger.debug(`[OrderSync] Order ${orderId} (${order.symbol}) not found on exchange (age: ${ageHours.toFixed(1)}h) - keeping existing status`);
                }
                return 'updated';
            }

            const exchangeStatus = String(exchangeOrder.status || '').toLowerCase();
            const fillPriceRaw = exchangeOrder.filled_avg_price;
            const fillPrice = fillPriceRaw !== undefined ? Number(fillPriceRaw) : undefined;
            const fillQtyRaw = exchangeOrder.filled_qty ?? exchangeOrder.filledQty ?? exchangeOrder.filled_quantity;
            const fillQty = fillQtyRaw !== undefined ? Number(fillQtyRaw) : undefined;
            const dbQty = Number(order.qty ?? 0);
            const dbPrice = Number(order.price ?? 0);
            const fillLike = exchangeStatus === 'filled' || exchangeStatus === 'partially_filled';
            const qtyDrift = fillLike
                && Number.isFinite(fillQty)
                && (fillQty as number) > 0
                && (!Number.isFinite(dbQty) || dbQty <= 0 || Math.abs((fillQty as number) - dbQty) / Math.max(Math.abs(fillQty as number), Math.abs(dbQty), 1e-9) > 1e-6);
            const priceDrift = fillLike
                && Number.isFinite(fillPrice)
                && (fillPrice as number) > 0
                && (!Number.isFinite(dbPrice) || dbPrice <= 0 || Math.abs((fillPrice as number) - dbPrice) / Math.max(Math.abs(fillPrice as number), Math.abs(dbPrice), 1e-9) > 5e-4);
            const fillDataDrift = qtyDrift || priceDrift;
            const exchangeFilledAt = fillLike
                ? (() => {
                    const rawFilledAt = String(exchangeOrder.filled_at || '').trim();
                    if (!rawFilledAt) return new Date();
                    const parsed = Date.parse(rawFilledAt);
                    return Number.isFinite(parsed) && parsed > 0 ? new Date(parsed) : new Date();
                })()
                : undefined;

            // Update DB if status changed
            if (exchangeStatus && exchangeStatus !== order.status?.toLowerCase()) {
                logger.info(`[OrderSync] Updating order ${orderId} (${order.symbol}): ${order.status} → ${exchangeStatus}`);

                await runtimeOrderRepository.updateOrderStatus(
                    orderId,
                    exchangeStatus,
                    exchangeFilledAt,
                    Number.isFinite(fillPrice) ? fillPrice : undefined,
                    Number.isFinite(fillQty) ? fillQty : undefined
                );
                await this.emitStatusChange({
                    orderId,
                    symbol: order.symbol,
                    previousStatus: (order.status || '').toLowerCase(),
                    status: exchangeStatus,
                    action: order.action,
                    tradeId: order.trade_id,
                    userId: order.user_id,
                    profileId: order.profile_id,
                    filledAt: exchangeFilledAt,
                    fillPrice: Number.isFinite(fillPrice) ? fillPrice : undefined,
                    fillQty: Number.isFinite(fillQty) ? fillQty : undefined
                });
                this.missingExchangeDetections.delete(orderId);
            } else if (fillDataDrift) {
                logger.info(`[OrderSync] Refreshing fill data for ${orderId} (${order.symbol}): qty ${order.qty} -> ${fillQty}, price ${order.price} -> ${fillPrice}`);
                await runtimeOrderRepository.updateOrderStatus(
                    orderId,
                    exchangeStatus || String(order.status || 'filled'),
                    exchangeFilledAt,
                    Number.isFinite(fillPrice) ? fillPrice : undefined,
                    Number.isFinite(fillQty) ? fillQty : undefined
                );
                await this.emitStatusChange({
                    orderId,
                    symbol: order.symbol,
                    previousStatus: (order.status || '').toLowerCase(),
                    status: exchangeStatus || (order.status || '').toLowerCase(),
                    action: order.action,
                    tradeId: order.trade_id,
                    userId: order.user_id,
                    profileId: order.profile_id,
                    filledAt: exchangeFilledAt,
                    fillPrice: Number.isFinite(fillPrice) ? fillPrice : undefined,
                    fillQty: Number.isFinite(fillQty) ? fillQty : undefined
                });
                this.missingExchangeDetections.delete(orderId);
            } else {
                logger.debug(`[OrderSync] Order ${orderId} status unchanged: ${exchangeStatus}`);
                this.missingExchangeDetections.delete(orderId);
            }

            return 'updated';

        } catch (error: any) {
            logger.error(`[OrderSync] Failed to sync order ${orderId}: ${error.message}`);
            throw normalizeThrown(error);
        }
    }

    /**
     * Manually trigger a sync (useful for testing or on-demand sync)
     */
    public async triggerSync(): Promise<void> {
        logger.info('[OrderSync] Manual sync triggered');
        await this.syncStaleOrders();
    }

    public getLastStats() {
        return this.lastStats;
    }
}