/**
 * Uniswap v3 LP endpoints — custodial (ETH). Пути /:chain/lp/*.
 * Безопасность: JWT-bind ETH-кошелька, Idempotency-Key, auditLogStrict, decrypt mnemonic в памяти.
 */

import { Request, Response } from 'express';
import { logger } from '../lib/logger';
import { WalletModel } from '../models/wallet.model';
import { UserModel } from '../models/user.model';
import { decryptMnemonic } from '../services/crypto.service';
import { auditLogStrict, completeAudit } from '../lib/audit-log';
import { claimIdempotency, saveIdempotencyResponse, extractIdempotencyKey } from '../lib/idempotency';
import { StakingError } from '../services/staking.service';
import {
  getPools,
  quoteAdd,
  executeAddLiquidity,
  executeRemoveLiquidity,
  readLpPositions,
} from '../services/uniswap-lp.service';

function getUserId(req: Request): string | null {
  return (req as any).auth?.userId || null;
}
function assertEth(req: Request, res: Response): boolean {
  if (String(req.params.chain).toUpperCase() !== 'ETH') {
    res.status(400).json({ success: false, error: 'Uniswap v3 LP supported on ETH only' });
    return false;
  }
  return true;
}
function validAmount(v: unknown): v is string {
  return typeof v === 'string' && /^\d+$/.test(v);
}

interface Ctx { auditId: string; mnemonic: string; wallet: { address: string }; idempKey: string | null; zero: () => void; }

async function beginMutation(req: Request, res: Response, userId: string, event: string, meta: Record<string, unknown>): Promise<Ctx | null> {
  const wallet = await WalletModel.findByUserAndChain(userId, 'ETH');
  if (!wallet) { res.status(403).json({ success: false, error: 'No ETH wallet for user — create wallet first' }); return null; }

  const idempKey = extractIdempotencyKey(req.headers['idempotency-key']);
  if (idempKey) {
    try {
      const claim = await claimIdempotency(userId, idempKey, req.body || {});
      if (!claim.fresh && claim.cached) { res.status(claim.cached.status).type('application/json').send(claim.cached.body); return null; }
    } catch (err: any) { res.status(409).json({ success: false, error: err.message }); return null; }
  }

  let auditId: string;
  try {
    auditId = await auditLogStrict({ event, userId, ip: req.ip || null, meta });
  } catch (auditErr: any) {
    logger.error(`Audit INSERT must succeed for ${event}: ${auditErr.message}`);
    res.status(503).json({ success: false, error: 'Audit service unavailable' });
    return null;
  }

  const blob = await UserModel.getEncryptedMnemonic(userId);
  if (!blob) { await completeAudit(auditId, 'failure', undefined, 'NO_MNEMONIC'); res.status(404).json({ success: false, error: 'Encrypted mnemonic not found' }); return null; }
  let mnemonic: string;
  try { mnemonic = decryptMnemonic(blob); } catch { await completeAudit(auditId, 'failure', undefined, 'DECRYPT_FAILED'); res.status(500).json({ success: false, error: 'Mnemonic decrypt failed' }); return null; }

  const ctx: Ctx = { auditId, mnemonic, wallet, idempKey, zero: () => { ctx.mnemonic = ''; } };
  return ctx;
}

async function finish(res: Response, userId: string, idempKey: string | null, auditId: string, data: unknown): Promise<void> {
  await completeAudit(auditId, 'success');
  const body = { success: true, data };
  if (idempKey) { try { await saveIdempotencyResponse(userId, idempKey, 200, JSON.stringify(body)); } catch { /* ignore */ } }
  res.status(200).json(body);
}
async function fail(res: Response, userId: string, idempKey: string | null, auditId: string, err: any, label: string): Promise<void> {
  const code = err instanceof StakingError ? err.httpStatus : 502;
  await completeAudit(auditId, 'failure', undefined, err?.code || err?.message?.slice(0, 80));
  logger.warn(`LP ${label} failed: ${err?.message}`);
  const body = { success: false, error: err?.message || `${label} failed`, code: err?.code };
  if (idempKey) { try { await saveIdempotencyResponse(userId, idempKey, code, JSON.stringify(body)); } catch { /* ignore */ } }
  res.status(code).json(body);
}

// ── GET /:chain/lp/pools ───────────────────────────────────────────────
export async function lpPools(req: Request, res: Response): Promise<void> {
  if (!getUserId(req)) { res.status(401).json({ success: false, error: 'auth required' }); return; }
  if (!assertEth(req, res)) return;
  try {
    res.json({ success: true, data: await getPools() });
  } catch (err: any) {
    res.status(502).json({ success: false, error: err?.message || 'pools read failed' });
  }
}

// ── POST /:chain/lp/quote ──────────────────────────────────────────────
export async function lpQuote(req: Request, res: Response): Promise<void> {
  if (!getUserId(req)) { res.status(401).json({ success: false, error: 'auth required' }); return; }
  if (!assertEth(req, res)) return;
  const userId = getUserId(req)!;
  const b = req.body || {};
  if (!b.pool || !validAmount(String(b.amount0Desired ?? '')) || !validAmount(String(b.amount1Desired ?? ''))) {
    res.status(400).json({ success: false, error: 'pool, amount0Desired, amount1Desired (integer strings) required' });
    return;
  }
  try {
    // Кошелёк опционален: если есть — добавим проверку баланса token0/token1/gas (read-only, без 403).
    const wallet = await WalletModel.findByUserAndChain(userId, 'ETH');
    const quote = await quoteAdd({
      poolAddress: String(b.pool),
      priceLower: Number(b.priceLower),
      priceUpper: Number(b.priceUpper),
      amount0Desired: String(b.amount0Desired),
      amount1Desired: String(b.amount1Desired),
      slippageBps: b.slippageBps !== undefined ? Number(b.slippageBps) : undefined,
      ownerAddress: wallet?.address,
      useNativeEth: b.useNativeEth === true || b.useNativeEth === 'true',
    });
    res.json({ success: true, data: quote });
  } catch (err: any) {
    const status = err instanceof StakingError ? err.httpStatus : 502;
    res.status(status).json({ success: false, error: err?.message || 'quote failed', code: err?.code });
  }
}

// ── POST /:chain/lp/add ────────────────────────────────────────────────
export async function lpAdd(req: Request, res: Response): Promise<void> {
  const userId = getUserId(req);
  if (!userId) { res.status(401).json({ success: false, error: 'auth required' }); return; }
  if (!assertEth(req, res)) return;
  const b = req.body || {};
  if (!b.pool || !validAmount(String(b.amount0Desired ?? '')) || !validAmount(String(b.amount1Desired ?? ''))) {
    res.status(400).json({ success: false, error: 'pool, amount0Desired, amount1Desired (integer strings) required' });
    return;
  }

  const ctx = await beginMutation(req, res, userId, 'lp.add', { pool: String(b.pool) });
  if (!ctx) return;
  const { auditId, mnemonic, wallet, idempKey } = ctx;
  try {
    const result = await executeAddLiquidity({
      mnemonic, expectedFromAddress: wallet.address,
      poolAddress: String(b.pool),
      priceLower: Number(b.priceLower),
      priceUpper: Number(b.priceUpper),
      amount0Desired: String(b.amount0Desired),
      amount1Desired: String(b.amount1Desired),
      slippageBps: b.slippageBps !== undefined ? Number(b.slippageBps) : undefined,
      useNativeEth: b.useNativeEth === true || b.useNativeEth === 'true',
    });
    await finish(res, userId, idempKey, auditId, result);
  } catch (err: any) {
    await fail(res, userId, idempKey, auditId, err, 'add');
  } finally {
    ctx.zero();
  }
}

// ── POST /:chain/lp/remove ─────────────────────────────────────────────
export async function lpRemove(req: Request, res: Response): Promise<void> {
  const userId = getUserId(req);
  if (!userId) { res.status(401).json({ success: false, error: 'auth required' }); return; }
  if (!assertEth(req, res)) return;
  const b = req.body || {};
  const tokenId = String(b.tokenId ?? '');
  const percent = Number(b.percent ?? 100);
  if (!/^\d+$/.test(tokenId)) {
    res.status(400).json({ success: false, error: 'tokenId (integer string) required' });
    return;
  }

  const ctx = await beginMutation(req, res, userId, 'lp.remove', { tokenId, percent });
  if (!ctx) return;
  const { auditId, mnemonic, wallet, idempKey } = ctx;
  try {
    const result = await executeRemoveLiquidity({ mnemonic, expectedFromAddress: wallet.address, tokenId, percent });
    await finish(res, userId, idempKey, auditId, result);
  } catch (err: any) {
    await fail(res, userId, idempKey, auditId, err, 'remove');
  } finally {
    ctx.zero();
  }
}

// ── GET /:chain/lp/positions ───────────────────────────────────────────
export async function lpPositions(req: Request, res: Response): Promise<void> {
  const userId = getUserId(req);
  if (!userId) { res.status(401).json({ success: false, error: 'auth required' }); return; }
  if (!assertEth(req, res)) return;
  const wallet = await WalletModel.findByUserAndChain(userId, 'ETH');
  if (!wallet) { res.status(403).json({ success: false, error: 'No ETH wallet for user — create wallet first' }); return; }
  try {
    res.json({ success: true, data: await readLpPositions(wallet.address) });
  } catch (err: any) {
    res.status(502).json({ success: false, error: err?.message || 'positions read failed' });
  }
}