import crypto from 'crypto';

const BASE = 'https://web3.okx.com';

// Signature rule (all aggregator endpoints are GET):
//   GET  → body = "", requestPath includes query string (e.g., "/api/v6/dex/aggregator/quote?chainIndex=1&...")
//   POST → body = JSON string of request body, requestPath is path only (not used in this skill)
async function okxFetch(method: 'GET' | 'POST', path: string, body?: object) {
  const timestamp = new Date().toISOString();
  const bodyStr = body ? JSON.stringify(body) : '';
  const sign = crypto
    .createHmac('sha256', process.env.OKX_SECRET_KEY!)
    .update(timestamp + method + path + bodyStr)
    .digest('base64');
  const headers: Record<string, string> = {
    'OK-ACCESS-KEY': process.env.OKX_API_KEY!,
    'OK-ACCESS-SIGN': sign,
    'OK-ACCESS-PASSPHRASE': process.env.OKX_PASSPHRASE!,
    'OK-ACCESS-TIMESTAMP': timestamp,
    'Content-Type': 'application/json',
  };
  const res = await fetch(`${BASE}${path}`, {
    method,
    headers,
    ...(body && { body: bodyStr }),
  });
  if (res.status === 429) throw { code: 'RATE_LIMITED', msg: 'Rate limited — retry with backoff', retryable: true };
  if (res.status >= 500) throw { code: `HTTP_${res.status}`, msg: 'Server error', retryable: true };
  const json = await res.json();
  if (json.code !== '0') throw { code: json.code, msg: json.msg || 'API error', retryable: false };
  return json.data;
}

// 1. Quote — sell 100 USDC for ETH
const params = new URLSearchParams({
  chainIndex: '1', fromTokenAddress: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48', // USDC
  toTokenAddress: '0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',   // native ETH
  amount: '100000000', swapMode: 'exactIn', // 100 USDC (6 decimals)
});
const quote = await okxFetch('GET', `/api/v6/dex/aggregator/quote?${params}`);
console.log(`Expected: ${quote[0].toTokenAmount} ETH (minimal units)`);

// 2. Approve — ERC-20 tokens need approval before swap (skip for native ETH)
const approveParams = new URLSearchParams({
  chainIndex: '1', tokenContractAddress: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48',
  approveAmount: '100000000',
});
const approve = await okxFetch('GET', `/api/v6/dex/aggregator/approve-transaction?${approveParams}`);
// → build tx: { to: tokenContractAddress, data: approve[0].data }, sign & send
// approve[0].dexContractAddress is the spender (already encoded in calldata), NOT the tx target

// 3. Swap
const swapParams = new URLSearchParams({
  chainIndex: '1', fromTokenAddress: '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48',
  toTokenAddress: '0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee',
  amount: '100000000', slippagePercent: '1',
  userWalletAddress: '0xYourWallet', swapMode: 'exactIn',
});
const swap = await okxFetch('GET', `/api/v6/dex/aggregator/swap?${swapParams}`);
// → sign & send swap[0].tx { from, to, data, value, gas }

const params = new URLSearchParams({
  chainIndex: '501', fromTokenAddress: '11111111111111111111111111111111', // native SOL
  toTokenAddress: 'DezXAZ8z7PnrnRJjz3wXBoRgixCa6xjnB7YaB1pPB263', // BONK
  amount: '1000000000', slippagePercent: '1', userWalletAddress: 'YourSolanaWallet',
});
const result = await okxFetch('GET', `/api/v6/dex/aggregator/swap-instruction?${params}`);
// → result[0].instructionLists: assemble into VersionedTransaction, sign & send

1. okx-dex-token    /market/token/search?search=BONK&chains=501              → get BONK tokenContractAddress
       ↓ tokenContractAddress
2. okx-wallet-portfolio  /balance/all-token-balances-by-address                    → verify SOL balance >= 1
       ↓ sufficient balance confirmed
3. okx-dex-swap     /aggregator/quote                                         → get quote (show expected output, gas, price impact)
       ↓ user confirms
4. okx-dex-swap     /aggregator/swap-instruction                              → get serialized instruction (Solana)
5. User signs & sends tx (or use `okx-onchain-gateway` to broadcast via OKX nodes)

1. okx-dex-token    /market/token/search?search=USDC&chains=1                → get USDC address
2. okx-wallet-portfolio  /balance/token-balances-by-address                        → verify USDC balance >= 100
3. okx-dex-swap     /aggregator/quote                                         → get quote
       ↓ check isHoneyPot, taxRate, priceImpactPercent
4. okx-dex-swap     /aggregator/approve-transaction                           → get ERC-20 approval calldata
5. User signs & sends approval tx
6. okx-dex-swap     /aggregator/swap                                          → get swap calldata
7. User signs & sends swap tx (or use `okx-onchain-gateway` to broadcast via OKX nodes)

1. okx-dex-swap     /aggregator/quote                                         → get quote with route info
2. Display to user: expected output, gas, price impact, route
3. If price impact > 5% → warn user
4. If isHoneyPot = true → block trade, warn user
5. User confirms → proceed to approve (if EVM) → swap

1. GET /aggregator/quote               -> Get price and route
2. GET /aggregator/approve-transaction  -> Get approval calldata (if needed)
3. User signs & sends approval tx
4. GET /aggregator/swap                 -> Get swap calldata
5. User signs & sends swap tx

1. GET /aggregator/quote               -> Get price and route
2. GET /aggregator/swap-instruction     -> Get serialized instruction
3. User signs & sends tx

1. GET /api/v6/dex/aggregator/quote?chainIndex=1&fromTokenAddress=0xa0b8...&toTokenAddress=0xeeee...&amount=100000000&swapMode=exactIn
-> Display:
  Expected output: 0.031 ETH
  Gas fee: ~$2.50
  Price impact: 0.05%
  Route: USDC -> WETH -> ETH (Uniswap V3)

2. User confirms

3. GET /api/v6/dex/aggregator/approve-transaction?chainIndex=1&tokenContractAddress=0xa0b8...&approveAmount=100000000
-> Returns approval calldata and spender address
-> Build tx: { to: "0xa0b8..." (token contract), data: response.data } — sign & send

4. GET /api/v6/dex/aggregator/swap?chainIndex=1&...&slippagePercent=1&userWalletAddress=0x...
-> Returns tx: { from, to, data, gas, gasPrice, value, minReceiveAmount }
-> User signs and broadcasts

GET /api/v6/dex/aggregator/get-liquidity?chainIndex=1
-> Display: Uniswap V2, Uniswap V3, SushiSwap, Curve, Balancer, ... (80+ sources)