// modules/data/bitcoin.js — Blockstream block height polling
// Writes to S: lastKnownBlockHeight, _starPulseIntensity (legacy)
// Writes to state: blockHeight, lastBlockHeight, newBlockDetected, starPulseIntensity
import { S } from '../state.js';
import { state } from '../core/state.js';

const BITCOIN_REFRESH_MS = 60 * 1000;

export async function fetchBlockHeight() {
  try {
    const res = await fetch('https://blockstream.info/api/blocks/tip/height');
    if (!res.ok) return null;
    const height = parseInt(await res.text(), 10);
    if (isNaN(height)) return null;

    const prev = S.lastKnownBlockHeight;
    const isNew = prev !== null && height > prev;
    S.lastKnownBlockHeight = height;
    if (isNew) S._starPulseIntensity = 1.0;

    state.blockHeight = height;
    state.lastBlockHeight = prev || 0;
    state.newBlockDetected = isNew;
    if (isNew) state.starPulseIntensity = 1.0;

    return { height, isNewBlock: isNew };
  } catch {
    return null;
  }
}

export { BITCOIN_REFRESH_MS };