import { createRequire } from "node:module";
createRequire(import.meta.url)("bn-eslint.js");
import type { Round } from "./abi.js";
import { config } from "./config.js";
import { account, clampBet, getCurrentEpoch, getMinBetAmount, getRound, betBull, betBear, getBufferSeconds, getBlockTimestamp } from "./contract.js";
import { decide, type Side } from "./strategy.js";
import { outcome } from "./strategy.js";

const POLL_MS = 15_000;
const fmtBnb = (w: bigint) => (Number(w) / 1e18).toFixed(4);
const fmtTime = () => new Date().toLocaleTimeString("en-GB", { hour12: false });

let lastBetEpoch: bigint | null = null;
let lastBetSide: Side = null;
let lastBetWon: boolean | null = null;
let roundsSinceBet = 0;

async function fetchHistory(currentEpoch: bigint, count: number): Promise<Round[]> {
  const out: Round[] = [];
  for (let i = 0; i < count; i++) {
    const e = currentEpoch - BigInt(i);
    if (e <= 0n) break;
    try {
      const r = await getRound(e);
      out.unshift(r);
    } catch {
      break;
    }
  }
  return out;
}

async function run(): Promise<void> {
  const minBet = await getMinBetAmount();
  const amount = clampBet(config.betAmountWei, minBet);
  const currentEpoch = await getCurrentEpoch();
  const history = await fetchHistory(currentEpoch, config.lookbackRounds + 5);

  if (lastBetEpoch !== null && lastBetEpoch < currentEpoch) {
    const prevRound = history.find((r) => r.epoch === lastBetEpoch);
    if (prevRound) {
      const o = outcome(prevRound);
      lastBetWon = o === "tie" ? null : o === (lastBetSide === "bull" ? "bull" : "bear");
      const result = o === "tie" ? "TIE" : lastBetWon ? "WON" : "LOST";
      console.log(`[${fmtTime()}] Last bet epoch ${lastBetEpoch} (${lastBetSide}): ${result}`);
    }
    roundsSinceBet = lastBetEpoch === currentEpoch - 1n ? 1 : Number(currentEpoch - lastBetEpoch - 1n) + 1;
  } else if (lastBetEpoch === currentEpoch) {
    roundsSinceBet = 0;
  }

  const { side, edge } = decide(history, lastBetSide, lastBetWon, roundsSinceBet);

  if (side === null) {
    console.log(`[${fmtTime()}] Epoch ${currentEpoch} | skip (edge ${edge.toFixed(2)} < min or no signal)`);
    return;
  }

  const currentRound = history[history.length - 1];
  const now = await getBlockTimestamp();
  const buffer = await getBufferSeconds();
  if (currentRound && now >= currentRound.lockTimestamp - buffer) {
    console.log(`[${fmtTime()}] Epoch ${currentEpoch} | skip (lock window, no new bets)`);
    return;
  }

  try {
    const txHash = side === "bull" ? await betBull(amount) : await betBear(amount);
    lastBetEpoch = currentEpoch;
    lastBetSide = side;
    lastBetWon = null;
    roundsSinceBet = 0;
    console.log(`[${fmtTime()}] BET PLACED: ${side.toUpperCase()} ${fmtBnb(amount)} BNB @ epoch ${currentEpoch} | tx ${txHash}`);
  } catch (e) {
    console.error(`[${fmtTime()}] Bet failed:`, e);
  }
}

async function loop(): Promise<void> {
  console.log("--- PancakeSwap Prediction Bot ---");
  console.log(`Wallet: ${account.address}`);
  console.log(`Contract: ${config.contract}`);
  console.log(`Poll every ${POLL_MS / 1000}s. Press Ctrl+C to stop.\n`);

  for (;;) {
    try {
      await run();
    } catch (e) {
      console.error(`[${fmtTime()}] Error:`, e);
    }
    await new Promise((r) => setTimeout(r, POLL_MS));
  }
}

loop();