import { DatabaseSync } from 'node:sqlite';
import { randomUUID } from 'node:crypto';
import { mkdir, chmod } from 'node:fs/promises';
import { join } from 'node:path';
import { NETWORK, CONSENSUS, nftTransferMessage, testnetOwnerOf, transactionCardIds,
  type TestnetSnapshot, type NftTransfer } from '../../shared/testnet.ts';
import { ADDITIONAL_MARKET_FEE, marketCommandSchema, marketMessage, type MarketCommand, type MarketListing,
  type MarketOrder, type MarketInfo, type MarketActivity } from '../../shared/market.ts';
import { CHAIN_ID, transactionId, transferSchema, verifySignature } from '../testnet/consensus.ts';
import { mockQuote, paymentMode } from './payments.ts';

type Chain = { snapshot(): TestnetSnapshot; summary?(): { tip: string; revision: number }; submitTransfer(raw: unknown): Promise<string> };
type Config = { feeBps: number; confirmations: number; usdCentsPerXmr: number };
export function marketConfig(env: NodeJS.ProcessEnv = process.env): Config {
  paymentMode(env);
  const integer = (name: string, fallback: number, min: number, max: number) => {
    const text = env[name] ?? String(fallback);
    if (!/^\d+$/.test(text)) throw new Error(`Invalid ${name}`);
    const n = Number(text);
    if (!Number.isSafeInteger(n) || n < min || n > max) throw new Error(`Invalid ${name}`);
    return n;
  };
  return { feeBps: integer('WIKIDECK_MARKET_FEE_BPS', 250, 0, 5000),
    confirmations: integer('WIKIDECK_MARKET_CONFIRMATIONS', 10, 2, 1000),
    usdCentsPerXmr: integer('WIKIDECK_MOCK_USD_CENTS_PER_XMR', 15000, 1, 100_000_000) };
}
const PAYMENT_WINDOW = 30 * 60_000;
const DELIVERY_WINDOW = 48 * 60 * 60_000;

/** Node-local marketplace, NOT consensus escrow. Its SQLite journal is backed up with the ledger. */
export class Market {
  private queue: Promise<unknown> = Promise.resolve();
  private queued = 0;
  private reconciled: { tip: string; revision: number; at: number } | undefined;
  private readonly db: DatabaseSync;
  private readonly chain: Chain;
  readonly config: Config;
  readonly id: string;
  private readonly now: () => number;
  private constructor(db: DatabaseSync, chain: Chain, config: Config, id: string, now: () => number) {
    this.db = db; this.chain = chain; this.config = config; this.id = id; this.now = now;
  }

  static async open(directory: string, chain: Chain, config = marketConfig(), now = Date.now): Promise<Market> {
    const folder = join(directory, NETWORK.includes('mainnet') ? 'mainnet' : 'testnet');
    await mkdir(folder, { recursive: true, mode: 0o700 });
    const file = join(folder, 'market.sqlite');
    const db = new DatabaseSync(file);
    try {
      db.exec(`PRAGMA journal_mode=WAL; PRAGMA synchronous=FULL; PRAGMA busy_timeout=5000;
        CREATE TABLE IF NOT EXISTS market_meta(key TEXT PRIMARY KEY, value TEXT NOT NULL);
        CREATE TABLE IF NOT EXISTS listings(id TEXT PRIMARY KEY, card TEXT NOT NULL, status TEXT NOT NULL, data TEXT NOT NULL);
        CREATE UNIQUE INDEX IF NOT EXISTS one_active_listing ON listings(card) WHERE status IN ('open','reserved');
        CREATE TABLE IF NOT EXISTS orders(id TEXT PRIMARY KEY, data TEXT NOT NULL);
        CREATE TABLE IF NOT EXISTS receipts(id TEXT PRIMARY KEY, digest TEXT NOT NULL, expires INTEGER NOT NULL, data TEXT NOT NULL);`);
      db.exec(`CREATE INDEX IF NOT EXISTS listings_by_status ON listings(status);
        CREATE INDEX IF NOT EXISTS listings_by_seller ON listings(json_extract(data,'$.seller'));
        CREATE INDEX IF NOT EXISTS orders_by_seller ON orders(json_extract(data,'$.seller'));
        CREATE INDEX IF NOT EXISTS orders_by_buyer ON orders(json_extract(data,'$.buyer'));`);
      const meta = db.prepare('SELECT value FROM market_meta WHERE key=?').get('identity') as { value: string } | undefined;
      let id: string;
      if (meta) {
        const identity = JSON.parse(meta.value);
        if (identity.network !== NETWORK || identity.chainId !== CHAIN_ID || identity.version !== 1 ||
            typeof identity.id !== 'string') throw new Error('Marketplace network/schema mismatch');
        id = identity.id;
      } else {
        id = randomUUID();
        db.prepare('INSERT INTO market_meta VALUES(?,?)').run('identity', JSON.stringify({ version: 1, network: NETWORK, chainId: CHAIN_ID, id }));
      }
      if (process.platform !== 'win32') await chmod(file, 0o600);
      return new Market(db, chain, config, id, now);
    } catch (error) { db.close(); throw error; }
  }
  close() { this.db.close(); }
  diagnostics() {
    const states=this.db.prepare("SELECT json_extract(data,'$.status') AS status,COUNT(*) AS count FROM orders GROUP BY json_extract(data,'$.status')").all();
    return { queued:this.queued,lastReconciledAt:this.reconciled?.at??null,orderStates:states };
  }
  info(): MarketInfo {
    return { network: NETWORK, chainId: CHAIN_ID, marketId: this.id, paymentMode: 'mock', feeBps: this.config.feeBps,
      additionalFee: { ...ADDITIONAL_MARKET_FEE },
      deliveryConfirmations: this.config.confirmations, mockUsdPerXmr: (this.config.usdCentsPerXmr / 100).toFixed(2), serverTime: this.now() };
  }
  private rows<T>(table: 'listings' | 'orders'): T[] {
    return (this.db.prepare(`SELECT data FROM ${table} ORDER BY rowid DESC LIMIT 10000`).all() as { data: string }[])
      .map(row => JSON.parse(row.data) as T);
  }
  private listing(id: string): MarketListing {
    const row = this.db.prepare('SELECT data FROM listings WHERE id=?').get(id) as { data: string } | undefined;
    if (!row) throw new Error('Listing not found');
    return JSON.parse(row.data);
  }
  private order(id: string): MarketOrder {
    const row = this.db.prepare('SELECT data FROM orders WHERE id=?').get(id) as { data: string } | undefined;
    if (!row) throw new Error('Order not found');
    return JSON.parse(row.data);
  }
  private saveListing(l: MarketListing) {
    this.db.prepare('INSERT INTO listings VALUES(?,?,?,?) ON CONFLICT(id) DO UPDATE SET status=excluded.status,data=excluded.data WHERE listings.data<>excluded.data')
      .run(l.id, l.cardHash, l.status, JSON.stringify(l));
  }
  private saveOrder(o: MarketOrder) {
    this.db.prepare('INSERT INTO orders VALUES(?,?) ON CONFLICT(id) DO UPDATE SET data=excluded.data WHERE orders.data<>excluded.data').run(o.id, JSON.stringify(o));
  }
  private atomic<T>(fn: () => T): T {
    this.db.exec('BEGIN IMMEDIATE');
    try { const result = fn(); this.db.exec('COMMIT'); return result; }
    catch (error) { this.db.exec('ROLLBACK'); throw error; }
  }
  private card(snapshot: TestnetSnapshot, hash: string, owner: string, sequence: number): boolean {
    const block = snapshot.blocks.find(b => b.tokenId === hash);
    return !!block && testnetOwnerOf(snapshot, hash) === owner &&
      snapshot.transfers.filter(tx => transactionCardIds(tx).includes(hash)).length === sequence &&
      snapshot.blocks.length + 1 - block.height >= CONSENSUS.coinbaseMaturity;
  }
  private deliveryId(order: MarketOrder): string {
    // Identity excludes signature bytes. Recognize exact sale delivery through ANY submission route,
    // including peer gossip or a direct /api/transfer, even before the market records delivery intent.
    return transactionId({ network: NETWORK, chainId: CHAIN_ID, cardHash: order.cardHash,
      from: order.seller, to: order.buyer, sequence: order.sequence, publicKey: '', signature: '' });
  }
  /** Reconcile from canonical transaction identity, never from a mempool acknowledgement. */
  private reconcile() {
    const s = this.chain.snapshot(), now = this.now();
    const deliveries = new Map<string, TestnetSnapshot['blocks'][number]>();
    for (const b of s.blocks) for (const tx of b.transactions) deliveries.set(transactionId(tx), b);
    const pendingIds = new Set(s.pendingTransfers.map(transactionId));
    this.atomic(() => {
      for (const o of this.rows<MarketOrder>('orders')) {
        const l = this.listing(o.listingId);
        if (o.status === 'refunded' || o.status === 'expired') continue;
        const deliveryId = this.deliveryId(o);
        const delivery = deliveries.get(deliveryId);
        const confirmations = delivery ? s.blocks.length - delivery.height + 1 : 0;
        o.deliveryConfirmations = confirmations;
        if (o.status === 'complete' || o.status === 'review') {
          if (!delivery || confirmations < o.requiredConfirmations) {
            o.status = 'review'; o.payout = 'review';
            if (o.additionalFee) o.additionalFee.payout = 'review';
          }
          this.saveOrder(o); continue; // Never automatically pay a second time after a reorganization.
        }
        if (delivery && o.status === 'awaiting-payment') {
          // A gift/direct delivery is not evidence that payment was received. Never pay an unpaid order.
          o.status = 'review'; o.payout = 'review';
          if (o.additionalFee) o.additionalFee.payout = 'review';
        } else if (delivery) {
          o.transferId = deliveryId;
          o.status = 'delivery-pending';
          if (confirmations >= o.requiredConfirmations) {
            o.status = 'complete'; o.payout = 'mock-paid'; l.status = 'sold';
            if (o.additionalFee) o.additionalFee.payout = 'mock-paid';
          }
        } else if (o.status === 'awaiting-payment' && now >= o.payBy) {
          o.status = 'expired'; l.status = l.kind === 'fixed' ? 'open' : 'expired';
        } else if (o.status !== 'awaiting-payment') {
          const pending = pendingIds.has(deliveryId);
          const conflict = s.pendingTransfers.some(tx => transactionCardIds(tx).includes(o.cardHash) && transactionId(tx) !== deliveryId);
          if (!this.card(s, o.cardHash, o.seller, o.sequence) || conflict || (now >= o.deliverBy && !pending)) o.status = 'refund-required';
          else if (o.status === 'delivery-pending' && !pending) o.status = 'paid';
        }
        this.saveOrder(o); this.saveListing(l);
      }
      for (const l of this.rows<MarketListing>('listings')) {
        if (l.status !== 'open') continue;
        if (l.additionalFee?.bps !== ADDITIONAL_MARKET_FEE.bps || l.additionalFee?.address !== ADDITIONAL_MARKET_FEE.address ||
          !this.card(s, l.cardHash, l.seller, l.sequence) || s.pendingTransfers.some(tx => transactionCardIds(tx).includes(l.cardHash))) l.status = 'invalid';
        else if (l.kind === 'auction' && now >= l.endsAt! + PAYMENT_WINDOW) l.status = 'expired';
        else if (l.kind === 'auction' && now >= l.endsAt! && !l.highestBid) l.status = 'expired';
        this.saveListing(l);
      }
      this.db.prepare('DELETE FROM receipts WHERE expires < ?').run(now - 86400_000);
    });
    const summary = this.chain.summary?.();
    if (summary) this.reconciled = { ...summary, at: now };
  }
  browse(offset = 0): { listings: MarketListing[]; next: number | null; info: MarketInfo } {
    if (!Number.isSafeInteger(offset) || offset < 0 || offset > 10000) throw new Error('Invalid marketplace page');
    // Reconciliation must not interleave with delivery submission while its chain await is outstanding.
    const summary = this.chain.summary?.();
    const last = this.reconciled;
    if (!this.queued && (!summary || !last || summary.tip !== last.tip || summary.revision !== last.revision || this.now() - last.at >= 1000)) this.reconcile();
    const rows = this.db.prepare("SELECT data FROM listings WHERE status IN ('open','reserved') ORDER BY rowid DESC LIMIT 25 OFFSET ?")
      .all(offset) as { data: string }[];
    return { listings: rows.slice(0,24).map(r=>JSON.parse(r.data)), next: rows.length>24?offset+24:null, info: this.info() };
  }
  execute(raw: unknown): Promise<MarketActivity | MarketListing | MarketOrder> {
    const cmd = marketCommandSchema.parse(raw);
    if (this.queued >= 64) return Promise.reject(new Error('Marketplace busy; retry shortly'));
    this.queued++;
    const result = this.queue.then(async () => {
      try { return await this.run(cmd); }
      finally { this.queued--; }
    });
    this.queue = result.catch(() => undefined);
    return result;
  }
  private async run(c: MarketCommand): Promise<MarketActivity | MarketListing | MarketOrder> {
    const now = this.now();
    if (c.chainId !== CHAIN_ID || c.marketId !== this.id || c.expiresAt < now || c.expiresAt > now + 5 * 60_000 ||
        !verifySignature(c.publicKey, c.actor, marketMessage(c), c.signature)) throw new Error('Invalid or expired marketplace signature');
    const key = `${c.actor}:${c.nonce}`, digest = marketMessage(c);
    const old = this.db.prepare('SELECT digest,data FROM receipts WHERE id=?').get(key) as { digest: string; data: string } | undefined;
    if (old) {
      if (old.digest !== digest) throw new Error('Nonce already used for different terms');
      return JSON.parse(old.data);
    }
    const a = c.action;
    const summary = this.chain.summary?.(), last = this.reconciled;
    if (a.type !== 'activity' || !summary || !last || summary.tip !== last.tip || summary.revision !== last.revision ||
      this.now() - last.at >= 1000) this.reconcile();
    if (a.type === 'activity') return {
      orders: (this.db.prepare("SELECT data FROM orders WHERE json_extract(data,'$.seller')=? OR json_extract(data,'$.buyer')=? ORDER BY rowid DESC")
        .all(c.actor,c.actor) as { data: string }[]).map(r=>JSON.parse(r.data)),
      listings: (this.db.prepare("SELECT data FROM listings WHERE json_extract(data,'$.seller')=? ORDER BY rowid DESC")
        .all(c.actor) as { data: string }[]).map(r=>JSON.parse(r.data)) };
    if (a.type === 'deliver') {
      const o = this.order(a.orderId), tx = transferSchema.parse(a.transfer);
      if (o.seller !== c.actor || !['paid', 'delivery-pending'].includes(o.status)) throw new Error('Only the paid order seller can deliver');
      if (tx.cardHash !== o.cardHash || tx.sequence !== o.sequence || tx.from !== o.seller || tx.to !== o.buyer ||
          !verifySignature(tx.publicKey, tx.from, nftTransferMessage(tx), tx.signature)) throw new Error('Delivery does not match this sale');
      // Persist intent before the ledger await. A crash/restart reconciles by deterministic tx ID.
      o.transfer = tx; o.transferId = transactionId(tx); o.status = 'delivery-pending'; this.saveOrder(o);
      await this.chain.submitTransfer(tx);
      return this.receipt(key, digest, c.expiresAt, o);
    }
    return this.atomic(() => {
      const result = this.mutate(c);
      return this.receipt(key, digest, c.expiresAt, result);
    });
  }
  private receipt<T>(key: string, digest: string, expires: number, value: T): T {
    this.db.prepare('INSERT INTO receipts VALUES(?,?,?,?)').run(key, digest, expires, JSON.stringify(value));
    return value;
  }
  private mutate(c: MarketCommand): MarketListing | MarketOrder {
    const a = c.action, now = this.now(), s = this.chain.snapshot();
    if (a.type === 'list') {
      if (a.feeBps !== this.config.feeBps) throw new Error('Market fee changed; review and sign again');
      if (!this.card(s, a.cardHash, c.actor, a.sequence) || s.pendingTransfers.some(tx => transactionCardIds(tx).includes(a.cardHash))) throw new Error('Card is missing, stale, immature, or already pending');
      if (a.kind === 'fixed' ? a.endsAt !== null : a.endsAt === null || a.endsAt < now + 60_000 || a.endsAt > now + 30 * 86400_000) throw new Error('Auction duration must be 1 minute to 30 days; fixed listings have no end');
      if (this.rows<MarketListing>('listings').filter(l => l.seller === c.actor && ['open','reserved'].includes(l.status)).length >= 100) throw new Error('Limit: 100 active listings per seller');
      if ((this.db.prepare('SELECT COUNT(*) AS n FROM listings').get() as { n: number }).n >= 10000) throw new Error('Marketplace journal limit reached; operator archival required');
      if (this.db.prepare("SELECT 1 FROM listings WHERE card=? AND status IN ('open','reserved')").get(a.cardHash)) throw new Error('Card already listed');
      const mint = s.blocks.find(b => b.tokenId === a.cardHash)!;
      const l: MarketListing = { id: randomUUID(), cardHash: a.cardHash, sequence: a.sequence, seller: c.actor,
        title: mint.article.title, image: mint.article.image!, kind: a.kind, priceCents: a.priceCents,
        feeBps: a.feeBps, additionalFee: { ...ADDITIONAL_MARKET_FEE },
        createdAt: now, endsAt: a.endsAt, status: 'open', highestBid: null };
      this.saveListing(l); return l;
    }
    if (a.type === 'bid' || a.type === 'buy' || a.type === 'cancel') {
      const l = this.listing(a.listingId);
      if (l.status !== 'open') throw new Error('Listing is no longer available');
      if (a.type === 'cancel') {
        if (l.seller !== c.actor || l.highestBid) throw new Error('Only the seller can cancel, and auctions with bids cannot be cancelled');
        l.status = 'cancelled'; this.saveListing(l); return l;
      }
      if (l.seller === c.actor) throw new Error('Cannot buy or bid on your own card');
      if (a.type === 'bid') {
        if (l.kind !== 'auction' || now >= l.endsAt!) throw new Error('Auction is not accepting bids');
        const minimum = l.highestBid ? l.highestBid.priceCents + 1 : l.priceCents;
        if (a.priceCents < minimum) throw new Error('Bid must meet the start price and exceed the current bid by at least $0.01');
        l.highestBid = { bidder: c.actor, priceCents: a.priceCents }; this.saveListing(l); return l;
      }
      const price = l.kind === 'fixed' ? l.priceCents : l.highestBid?.priceCents;
      if (l.kind === 'auction' && (now < l.endsAt! || now >= l.endsAt! + PAYMENT_WINDOW || l.highestBid?.bidder !== c.actor)) throw new Error('Only the auction winner can check out within 30 minutes of closing');
      if (price !== a.priceCents || l.feeBps !== a.feeBps) throw new Error('Sale terms changed; review and sign again');
      if (!this.card(s, l.cardHash, l.seller, l.sequence) || s.pendingTransfers.some(tx => transactionCardIds(tx).includes(l.cardHash))) throw new Error('Card is no longer available');
      if ((this.db.prepare('SELECT COUNT(*) AS n FROM orders').get() as { n: number }).n >= 10000) throw new Error('Marketplace order limit reached; operator archival required');
      const payBy = l.kind === 'auction' ? l.endsAt! + PAYMENT_WINDOW : now + PAYMENT_WINDOW;
      const o: MarketOrder = { id: randomUUID(), listingId: l.id, seller: l.seller, buyer: c.actor,
        cardHash: l.cardHash, sequence: l.sequence, priceCents: price!, feeBps: l.feeBps, createdAt: now, payBy,
        deliverBy: payBy + DELIVERY_WINDOW, status: 'awaiting-payment',
        ...mockQuote(price!, l.feeBps, this.config.usdCentsPerXmr), payout: 'not-started', deliveryConfirmations: 0,
        requiredConfirmations: this.config.confirmations };
      l.status = 'reserved'; this.saveListing(l); this.saveOrder(o); return o;
    }
    if (a.type === 'mock-pay' || a.type === 'refund') {
      const o = this.order(a.orderId);
      if (o.buyer !== c.actor) throw new Error('Only the order buyer can perform this action');
      if (a.type === 'mock-pay') {
        if (o.status !== 'awaiting-payment' || now >= o.payBy) throw new Error('Invoice is not payable');
        if (!this.card(s, o.cardHash, o.seller, o.sequence) || s.pendingTransfers.some(tx => transactionCardIds(tx).includes(o.cardHash))) throw new Error('Seller card changed; do not pay');
        o.status = 'paid'; o.deliverBy = now + DELIVERY_WINDOW;
      } else {
        if (o.status !== 'refund-required' || s.pendingTransfers.some(tx => transactionCardIds(tx).includes(o.cardHash)) ||
          s.blocks.some(b => b.transactions.some(tx => transactionId(tx) === this.deliveryId(o)))) throw new Error('Refund requires failed delivery and no pending/canonical sale transfer');
        o.status = 'refunded'; const l = this.listing(o.listingId); l.status = 'cancelled'; this.saveListing(l);
      }
      this.saveOrder(o); return o;
    }
    throw new Error('Unsupported market action');
  }
}