// Token market check: price, change, volume and liquidity from DexScreener. Zero dependencies.
import { pathToFileURL } from "node:url";

const API = "https://api.dexscreener.com";
const num = (v) => (Number.isFinite(Number(v)) && v !== null && v !== undefined ? Number(v) : null);

export async function tokenMarket(chain, address) {
  if (!chain || !address) throw new Error("Usage: token.mjs <chain> <tokenAddress>");
  if (!/^[a-z0-9-]+$/i.test(chain) || !/^[A-Za-z0-9]+$/.test(address)) throw new Error("Invalid chain or address");
  const res = await fetch(`${API}/tokens/v1/${chain}/${address}`, { headers: { accept: "application/json" } });
  if (!res.ok) throw new Error(`DexScreener answered ${res.status}`);
  const pairs = (await res.json()) ?? [];
  const mine = (Array.isArray(pairs) ? pairs : []).filter(
    (p) => p?.baseToken?.address?.toLowerCase() === address.toLowerCase(),
  );
  const list = mine.length ? mine : Array.isArray(pairs) ? pairs : [];
  if (!list.length) throw new Error(`No trading pairs found for ${address} on ${chain}`);
  const best = list.reduce((a, b) => ((num(b.liquidity?.usd) ?? 0) > (num(a.liquidity?.usd) ?? 0) ? b : a));
  return {
    source: "dexscreener",
    fetchedAt: new Date().toISOString(),
    chainId: best.chainId,
    address: best.baseToken.address,
    symbol: best.baseToken.symbol,
    name: best.baseToken.name,
    priceUsd: num(best.priceUsd),
    change: {
      m5: num(best.priceChange?.m5),
      h1: num(best.priceChange?.h1),
      h6: num(best.priceChange?.h6),
      h24: num(best.priceChange?.h24),
    },
    volume24hUsd: num(best.volume?.h24),
    txns24h: { buys: num(best.txns?.h24?.buys), sells: num(best.txns?.h24?.sells) },
    liquidityUsd: num(best.liquidity?.usd),
    marketCapUsd: num(best.marketCap),
    fdvUsd: num(best.fdv),
    pairCount: list.length,
    bestPair: {
      dexId: best.dexId,
      pairAddress: best.pairAddress,
      quoteSymbol: best.quoteToken?.symbol ?? null,
      url: best.url,
      createdAt: best.pairCreatedAt ? new Date(best.pairCreatedAt).toISOString() : null,
    },
  };
}

if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
  tokenMarket(process.argv[2], process.argv[3])
    .then((r) => console.log(JSON.stringify(r, null, 2)))
    .catch((e) => {
      console.log(JSON.stringify({ error: String(e?.message ?? e) }));
      process.exit(1);
    });
}