#!/usr/bin/env node
// Igneum devnet observer. Connects to a node's wRPC JSON endpoint, subscribes to new blocks and
// writes what it sees to Neon so /api/live and /live can show it.
//
//   node tools/observer/observer.mjs
//
// Environment (every value has a default):
//   IGNEUM_RPC    wRPC JSON url of the node        default ws://127.0.0.1:28610 (igneum-devnet wRPC JSON port)
//   DATABASE_URL  Neon connection string           default: read from ~/.config/igneum/env
//   LIVE_RETAIN_HOURS  hours of blocks to keep     default 24
//   LIVE_TABLE_PREFIX  prefix for every table name  default '' (a test observer can write fintest_live_* instead)
//   IGNEUM_EVM_RPC     execution-layer JSON-RPC (http) of a node on the proving build, for the shard plans and proof
//                      records   default http://127.0.0.1:26800 (the Mac app's node; the observer node has no EVM listener yet)
//
// Tables (created on start if missing): live_blocks, live_state, live_events, live_checkpoints, live_certificates,
// live_proofs. See README.md.
// Proving v0 (4 Oct 2026, spec 7.7): every chain block's shard plan is read over the EVM RPC (igneum_getShardPlan) as
// the block joins the selected chain, one live_proofs row per shard (planned); the proof records of the chain blocks
// of the last 10 minutes are polled in rotation (igneum_getProofRecords, 80 blocks per 2 s tick, four calls in flight) and move a shard to
// proving (a record in the pool), verified (the SP1 proof verified, or the record carried and checked) or paid (a
// carrying block paid it). live_state.proving carries the activation state and the 10-minute counts. A node without
// the proving RPCs (method not found) gives proving = {supported: false}; the observer rechecks every 5 minutes.
// Finality v2: subscribes to FinalityLock notifications and polls getFinalityCheckpoints and getFinalityWeights
// every 2 s; writes the checkpoints table and emits "checkpoint N locked (xx% of weight)" events.
// Light client (site/api/checkpoint.mjs, site/verify/): every certificate a block carries is stored with the voter
// table the node reports and the header chain from the previous locked checkpoint, so a browser can verify it.
// Explorer (5 October 2026, docs/plans/explorer.md): every block row also carries what /explorer, /block/<hash> and
// /address/<addr> show: the EVM transaction count and hashes, the miner's EVM payout address (the coinbase's IGNA
// tag, else the vote key hash's low 20 bytes as consensus/core/src/evm.rs falls back to), the number of proof records
// carried (the IGNP section), the subsidy the payload declares and the outputs paid, the header fields, the mergeset
// and the certificate indices, all read from the blockAdded notification itself: no extra RPC per block. The chain
// block number comes with the shard plan the proving feed already fetches. live_state.rpc_load counts this
// process's RPC calls per minute (wRPC and EVM) so the load of a change can be measured; live_state.supply_check is
// the hourly comparison of the coinbase sums with the emission rule (site/lib/emission.mjs, spec 2.5).
// Zero dependencies: Node 22 WebSocket and fetch, Neon's HTTP SQL endpoint.
//
// Ingest path (4 Oct 2026, after the observer fell 80 min behind under machine load 200 to 300): notifications
// only enqueue; a drain loop turns them into rows; the block flush, the colour marking (mergesets, from the
// notification's verbose data with getBlock only on a cache miss, four at a time) and the certificate work each run
// on their own timer and never wait on one another. live_state carries observer_lag_s (now minus the newest stored
// block's header time) and queue_depth. Per-minute counts are bucketed by the block's own timestamp, so a catch-up
// fills past minutes instead of painting a spike. If no blockAdded arrives for 60 s while the node's block_count
// advances, the observer resubscribes; after two failed attempts it exits 2 so tools/observer/run.sh restarts it.

import { readFileSync } from 'node:fs';
import { homedir } from 'node:os';
import { blockSubsidy } from '../../site/lib/emission.mjs';
import { keccak256 } from '../../site/lib/eth.mjs';
import { makeRunner as makeDetector, optsFromEnv as detectorOpts } from './detector.mjs'; // Counter ASIC 3.0 item 4a: the share-pattern detector
import { vendorShareTick } from './vendor-share.mjs'; // Counter ASIC 3.0 item 7: hash rate by vendor

const RPC = process.env.IGNEUM_RPC || 'ws://127.0.0.1:28610';
const RETAIN_HOURS = Number(process.env.LIVE_RETAIN_HOURS || 24);
const T = (process.env.LIVE_TABLE_PREFIX || '').replace(/[^a-z0-9_]/gi, '');
const TB = `${T}live_blocks`, TS = `${T}live_state`, TE = `${T}live_events`, TC = `${T}live_checkpoints`, TX = `${T}live_certificates`, TP = `${T}live_proofs`;
const EVM = process.env.IGNEUM_EVM_RPC || 'http://127.0.0.1:26800';
const STATE_EVERY_MS = 2000;
const FLUSH_EVERY_MS = 500;
const PRUNE_EVERY_MS = 60_000;
const QUIET_AFTER_MS = 5 * 60_000;
const DIFFICULTY_STEP = 0.05;
const STARTED_AT = new Date();

// ---------- Neon ----------
function databaseUrl() {
  if (process.env.DATABASE_URL) return process.env.DATABASE_URL;
  let env = '';
  try { env = readFileSync(`${homedir()}/.config/igneum/env`, 'utf8'); } catch { }
  const m = /^DATABASE_URL=(.*)$/m.exec(env);
  if (!m) { console.error('DATABASE_URL is not set and ~/.config/igneum/env has none'); process.exit(1); }
  return m[1].trim().replace(/^['"]|['"]$/g, '');
}
const DB_URL = databaseUrl();
const DB_HOST = new URL(DB_URL).hostname.replace('-pooler', '');

async function sql(query, params = []) {
  const r = await fetch(`https://${DB_HOST}/sql`, {
    method: 'POST',
    headers: { 'Neon-Connection-String': DB_URL, 'Content-Type': 'application/json' },
    body: JSON.stringify({ query, params }),
  });
  const j = await r.json();
  if (!r.ok) throw new Error(j.message || JSON.stringify(j));
  return j.rows || [];
}

async function setupSchema() {
  const stmts = [
    `CREATE TABLE IF NOT EXISTS ${TB} (
       hash text PRIMARY KEY,
       blue_score bigint NOT NULL,
       daa_score bigint NOT NULL,
       timestamp_ms bigint NOT NULL,
       parents int NOT NULL,
       parent_hashes text[] NOT NULL DEFAULT '{}',
       is_chain_block boolean NOT NULL DEFAULT false,
       vote_key_hash text,
       miner_address text,
       engine text,
       received_at timestamptz NOT NULL DEFAULT now())`,
    `CREATE INDEX IF NOT EXISTS ${TB}_received_at ON ${TB} (received_at)`,
    `CREATE INDEX IF NOT EXISTS ${TB}_timestamp_ms ON ${TB} (timestamp_ms)`,
    `CREATE INDEX IF NOT EXISTS ${TB}_vote_key_received ON ${TB} (vote_key_hash, received_at)`,
    // GHOSTDAG colour (4 Oct 2026, additive): pending until a chain block merges it, then blue (paid) or red (excluded)
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS color text NOT NULL DEFAULT 'pending'`,
    // Explorer (5 Oct 2026, additive): what the block pages show, from the notification; number from the shard plan
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS tx_count int`,
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS evm_miner text`,
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS proof_records int`,
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS subsidy_sompi bigint`,
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS paid_sompi bigint`,
    // wei-scale amounts on the Igneum 2.0 chain (8 Oct 2026): widen both in place, a no-op once numeric
    `ALTER TABLE ${TB} ALTER COLUMN subsidy_sompi TYPE numeric(40,0)`,
    `ALTER TABLE ${TB} ALTER COLUMN paid_sompi TYPE numeric(40,0)`,
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS selected_parent text`,
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS number bigint`,
    `ALTER TABLE ${TB} ADD COLUMN IF NOT EXISTS detail jsonb`,
    `CREATE INDEX IF NOT EXISTS ${TB}_evm_miner_received ON ${TB} (evm_miner, received_at)`,
    `CREATE INDEX IF NOT EXISTS ${TB}_miner_address_received ON ${TB} (miner_address, received_at)`,
    `CREATE INDEX IF NOT EXISTS ${TB}_number ON ${TB} (number)`,
    `CREATE TABLE IF NOT EXISTS ${TS} (
       id int PRIMARY KEY DEFAULT 1 CHECK (id = 1),
       block_count bigint, header_count bigint, blue_score bigint, difficulty double precision,
       hashes_per_second_estimate bigint, peers int, mempool int,
       node_version text, network text,
       blocks_60s int, blocks_per_minute jsonb,
       observer_started_at timestamptz, updated_at timestamptz)`,
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS finality jsonb`,
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS observer_lag_s double precision`,
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS queue_depth int`,
    // Proving v0 (4 Oct 2026, additive): {supported, active, activation_daa, tip_daa, blocks_fully_proven_10m, ...}
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS proving jsonb`,
    // Explorer: this process's RPC calls per minute, and the hourly coinbase-versus-rule comparison
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS rpc_load jsonb`,
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS supply_check jsonb`,
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS detector jsonb`,
    // Vendor share (Counter ASIC 3.0 item 7, tools/observer/vendor-share.mjs): hash rate by vendor, fleet-reported and chain-attributed
    `ALTER TABLE ${TS} ADD COLUMN IF NOT EXISTS vendor_share jsonb`,
    // One row per planned shard of a chain block (spec 7.7 item 8): the plan as the block joins the chain, then the
    // record's progress. prover is the first 8 hex characters of the record's vote key hash (never the full key, R4.6.2).
    `CREATE TABLE IF NOT EXISTS ${TP} (
       block_hash text NOT NULL,
       shard int NOT NULL,
       shards int NOT NULL,
       block_number bigint,
       block_daa bigint,
       block_ts bigint,
       pgas bigint,
       state text NOT NULL DEFAULT 'planned',
       prover text,
       verified boolean,
       carried_by text,
       carrier_number bigint,
       carrier_daa bigint,
       lag_daa int,
       payout_wei text,
       received_at timestamptz NOT NULL DEFAULT now(),
       updated_at timestamptz NOT NULL DEFAULT now(),
       PRIMARY KEY (block_hash, shard))`,
    `CREATE INDEX IF NOT EXISTS ${TP}_received_at ON ${TP} (received_at)`,
    `CREATE TABLE IF NOT EXISTS ${TE} (
       id bigserial PRIMARY KEY,
       ts timestamptz NOT NULL DEFAULT now(),
       kind text NOT NULL,
       text text NOT NULL)`,
    `CREATE INDEX IF NOT EXISTS ${TE}_ts ON ${TE} (ts)`,
    `CREATE TABLE IF NOT EXISTS ${TC} (
       index bigint PRIMARY KEY,
       hash text NOT NULL,
       blue_score bigint NOT NULL,
       daa_score bigint NOT NULL,
       state text NOT NULL,
       signed_weight bigint NOT NULL DEFAULT 0,
       active_weight bigint NOT NULL DEFAULT 0,
       total_weight bigint NOT NULL DEFAULT 0,
       fraction_active double precision NOT NULL DEFAULT 0,
       fraction_total double precision NOT NULL DEFAULT 0,
       votes_seen int NOT NULL DEFAULT 0,
       voters int NOT NULL DEFAULT 0,
       aggregators text[] NOT NULL DEFAULT '{}',
       locked_at timestamptz,
       first_seen_at timestamptz NOT NULL DEFAULT now(),
       updated_at timestamptz NOT NULL DEFAULT now())`,
    `CREATE INDEX IF NOT EXISTS ${TC}_state ON ${TC} (state, index)`,
    // One row per certified checkpoint: the certificate bytes as carried in a block, the voter table (canonical
    // order: above dust, not stripped, sorted by key hash) with public keys, and the selected-chain headers from
    // the previous locked checkpoint to this one, raw as the node's RPC gives them.
    `CREATE TABLE IF NOT EXISTS ${TX} (
       index bigint PRIMARY KEY,
       hash text NOT NULL,
       blue_score bigint,
       daa_score bigint,
       chain_id text NOT NULL,
       voter_count int NOT NULL,
       bitmap_hex text NOT NULL,
       signature_hex text NOT NULL,
       aggregator text NOT NULL,
       aggregator_proof_hex text NOT NULL,
       certificate_hex text NOT NULL,
       carrier text NOT NULL,
       voters jsonb NOT NULL,
       voters_index bigint NOT NULL,
       total_weight bigint NOT NULL,
       active_weight double precision NOT NULL,
       prev_index bigint,
       prev_hash text,
       headers jsonb NOT NULL,
       headers_complete boolean NOT NULL DEFAULT false,
       created_at timestamptz NOT NULL DEFAULT now())`,
  ];
  for (const s of stmts) await sql(s);
}

// ---------- Address decoding (crypto/addresses/src/bech32.rs, ported) ----------
const CHARSET = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';
function polymod(values) {
  let c = 1n;
  for (const d of values) {
    const c0 = c >> 35n;
    c = ((c & 0x07ffffffffn) << 5n) ^ BigInt(d);
    if (c0 & 0x01n) c ^= 0x98f2bc8e61n;
    if (c0 & 0x02n) c ^= 0x79b76d99e2n;
    if (c0 & 0x04n) c ^= 0xf33e5fb3c4n;
    if (c0 & 0x08n) c ^= 0xae2eabe2a8n;
    if (c0 & 0x10n) c ^= 0x1e4f43e470n;
  }
  return c ^ 1n;
}
function conv8to5(bytes) {
  const out = []; let buff = 0, bits = 0;
  for (const b of bytes) {
    buff = ((buff << 8) | b) & 0xffff; bits += 8;
    while (bits >= 5) { bits -= 5; out.push((buff >> bits) & 31); buff &= (1 << bits) - 1; }
  }
  if (bits > 0) out.push((buff << (5 - bits)) & 31);
  return out;
}
export function encodeAddress(prefix, version, payload) {
  const five = conv8to5([version, ...payload]);
  const pre = [...prefix].map(ch => ch.charCodeAt(0) & 0x1f);
  const sum = polymod([...pre, 0, ...five, 0, 0, 0, 0, 0, 0, 0, 0]);
  const sumBytes = []; for (let i = 4; i >= 0; i--) sumBytes.push(Number((sum >> BigInt(i * 8)) & 0xffn));
  return `${prefix}:${[...five, ...conv8to5(sumBytes)].map(v => CHARSET[v]).join('')}`;
}
function scriptToAddress(prefix, script) {
  if (script.length === 34 && script[0] === 0x20 && script[33] === 0xac) return encodeAddress(prefix, 0, script.slice(1, 33));
  if (script.length === 35 && script[0] === 0x21 && script[34] === 0xab) return encodeAddress(prefix, 1, script.slice(1, 34));
  if (script.length === 35 && script[0] === 0xaa && script[1] === 0x20 && script[34] === 0x87) return encodeAddress(prefix, 8, script.slice(2, 34));
  return null;
}
function payloadBytes(p) {
  if (Array.isArray(p)) return Uint8Array.from(p);
  if (typeof p === 'string') return Uint8Array.from(Buffer.from(p, 'hex'));
  return new Uint8Array();
}
// Coinbase payload: blue score u64 LE, subsidy u64 LE, script version u16 LE, script length u8, script, extra data.
function minerFromCoinbase(block, prefix) {
  const tx = block.transactions && block.transactions[0];
  if (!tx) return { address: null, extra: null };
  const b = payloadBytes(tx.payload);
  if (b.length < 19) return { address: null, extra: null };
  const len = b[18];
  const script = b.slice(19, 19 + len);
  const extra = b.slice(19 + len);
  // The node prefixes the extra data with its own version tag ("2.1.0/"). Anything after that is the
  // miner's tag (engine or label). The node exposes no engine name over RPC, so this is null on devnet v0.
  // Finality v2: the miner's key reveal (IGNK ...) and the node's finality section (... IGNF) are binary; only the
  // text before the reveal is the miner's tag.
  let text = Buffer.from(extra).toString('latin1');
  const reveal = text.indexOf('IGNK');
  if (reveal >= 0) text = text.slice(0, reveal);
  text = text.replace(/[^\x20-\x7e]/g, '').replace(/^\d+\.\d+\.\d+(-[\w.]+)?\//, '').trim();
  return { address: scriptToAddress(prefix, script), extra: text ? text.slice(0, 64) : null };
}

// ---------- RPC client ----------
class Rpc {
  constructor(url) { this.url = url; this.id = 0; this.pending = new Map(); this.onNotification = () => { }; this.ws = null; this.open = false; }
  connect() {
    return new Promise((resolve) => {
      const ws = new WebSocket(this.url); this.ws = ws;
      ws.onopen = () => { this.open = true; log('rpc connected', this.url); resolve(true); };
      ws.onmessage = (e) => {
        // A header nonce is a full u64; JSON.parse would round it above 2^53, so it is kept as a string
        let m; try { m = JSON.parse(String(e.data).replace(/"nonce":(\d+)/g, '"nonce":"$1"')); } catch { return; }
        if (m.id !== undefined && m.id !== null && this.pending.has(m.id)) {
          const p = this.pending.get(m.id); this.pending.delete(m.id);
          m.error ? p.reject(new Error(m.error.message || JSON.stringify(m.error))) : p.resolve(m.params);
        } else if (m.method) this.onNotification(m.method, m.params);
      };
      ws.onerror = () => { };
      ws.onclose = () => {
        const wasOpen = this.open; this.open = false;
        for (const p of this.pending.values()) p.reject(new Error('rpc closed'));
        this.pending.clear();
        if (wasOpen) log('rpc closed'); else resolve(false);
        this.onClose && this.onClose();
      };
    });
  }
  call(method, params = {}) {
    rpcLoad.wrpc++;
    return new Promise((resolve, reject) => {
      if (!this.open) return reject(new Error('rpc not connected'));
      const id = ++this.id; this.pending.set(id, { resolve, reject });
      this.ws.send(JSON.stringify({ id, method, params }));
      setTimeout(() => { if (this.pending.has(id)) { this.pending.delete(id); reject(new Error(`${method} timed out`)); } }, 10_000);
    });
  }
}

// ---------- Observer ----------
const log = (...a) => console.log(new Date().toISOString(), ...a);
const short = h => (h || '').slice(0, 8);

// RPC load (5 Oct 2026): calls this process makes, counted per wall-clock minute, the last five minutes kept. Logged
// once a minute and written to live_state.rpc_load, so a change to the observer can be measured against the rule
// in docs/plans/explorer.md (the explorer must stay under 2x of the load before it).
const rpcLoad = { wrpc: 0, evm: 0, minutes: [], minuteStart: Date.now() };
function rollRpcLoad(now) {
  if (now - rpcLoad.minuteStart < 60_000) return;
  const secs = (now - rpcLoad.minuteStart) / 1000;
  const m = { at: new Date(rpcLoad.minuteStart).toISOString(), wrpc: Math.round(rpcLoad.wrpc * 60 / secs), evm: Math.round(rpcLoad.evm * 60 / secs) };
  rpcLoad.minutes.push(m); if (rpcLoad.minutes.length > 5) rpcLoad.minutes.shift();
  log(`rpc load: wrpc ${m.wrpc}/min, evm ${m.evm}/min`);
  rpcLoad.wrpc = 0; rpcLoad.evm = 0; rpcLoad.minuteStart = now;
}
function rpcLoadState() {
  const ms = rpcLoad.minutes; if (!ms.length) return null;
  const avg = k => Math.round(ms.reduce((a, m) => a + m[k], 0) / ms.length);
  return { wrpc_per_min: ms[ms.length - 1].wrpc, evm_per_min: ms[ms.length - 1].evm, wrpc_per_min_5m: avg('wrpc'), evm_per_min_5m: avg('evm'), minutes: ms.length, evm_rpc: EVM };
}

// Explorer detail of a block, all from the notification (header, coinbase, verbose data, EVM transactions).
// Coinbase payload: blue score u64 LE, subsidy u64 LE (the full E(daa) of this block, coinbase.rs), script version
// u16 LE, script length u8, script, extra data. Extra data: the node's version tag, the miner's tag, the key reveal
// (IGNK, finality.rs), the payout address (IGNA || 40 hex, evm.rs), the proof-record section (records || len_le32 ||
// IGNP, proving.rs, 274 bytes each) and the finality section (items || len_le32 || IGNF).
const PROOF_RECORD_LEN = 274;
function coinbaseDetail(block, prefix) {
  const tx = block.transactions && block.transactions[0];
  if (!tx) return null;
  const b = payloadBytes(tx.payload);
  if (b.length < 19) return null;
  const dv = new DataView(b.buffer, b.byteOffset, b.byteLength);
  const subsidy = dv.getBigUint64(8, true);
  const extra = b.subarray(19 + b[18]);
  const text = Buffer.from(extra).toString('latin1');
  const a = text.indexOf('IGNA');
  const evmMiner = a >= 0 && /^[0-9a-f]{40}$/.test(text.slice(a + 4, a + 44)) ? '0x' + text.slice(a + 4, a + 44) : null;
  // proof records: strip the finality section, then read the IGNP trailer
  let body = extra; let n = body.length;
  if (n >= 8 && String.fromCharCode(...body.subarray(n - 4)) === 'IGNF') { const len = new DataView(body.buffer, body.byteOffset, n).getUint32(n - 8, true); if (len + 8 <= n) body = body.subarray(0, n - 8 - len); }
  n = body.length; let records = 0;
  if (n >= 8 && String.fromCharCode(...body.subarray(n - 4)) === 'IGNP') { const len = new DataView(body.buffer, body.byteOffset, n).getUint32(n - 8, true); if (len + 8 <= n) records = Math.floor(len / PROOF_RECORD_LEN); }
  const outputs = (tx.outputs || []).map(o => {
    const spk = typeof o.scriptPublicKey === 'string' ? o.scriptPublicKey : (o.scriptPublicKey && o.scriptPublicKey.script) || '';
    const script = Uint8Array.from(Buffer.from(String(spk).slice(4), 'hex')); // 2-byte version prefix, then the script
    const addr = (o.verboseData && o.verboseData.scriptPublicKeyAddress) || scriptToAddress(prefix, script);
    const pool = !addr && script.length > 2 && script[0] === 0x6a; // OP_RETURN "igneum-proving-pool-v0": the pool output burns on the UTXO side
    return { address: addr, value: String(o.value), pool };
  });
  const paid = outputs.reduce((t, o) => t + BigInt(o.value), 0n);
  return { id: tx.verboseData && tx.verboseData.transactionId, subsidy: subsidy.toString(), paid: paid.toString(), outputs, evm_miner: evmMiner, records, reveal: text.includes('IGNK') };
}
// EVM transactions ride in the block as raw bytes (RpcBlock.evm_transactions, Vec<Vec<u8>>): the hash is keccak-256 of
// the envelope. Decoding fields from the RLP is left to the execution layer (/api/explorer reads them from the EVM RPC
// when one is configured); here the count and the hashes are enough for the table and the block page.
function evmTxs(block) {
  const list = block.evmTransactions || [];
  return list.map(t => {
    const raw = typeof t === 'string' ? Buffer.from(t.replace(/^0x/, ''), 'hex') : Array.isArray(t) ? Buffer.from(t) : null;
    if (!raw) return { hash: null, size: null };
    return { hash: '0x' + Buffer.from(keccak256(raw)).toString('hex'), size: raw.length };
  });
}
function blockDetail(block, prefix) {
  const h = block.header, vd = block.verboseData || {};
  const cb = coinbaseDetail(block, prefix);
  const txs = evmTxs(block);
  const certs = certificatesIn(block).map(c => c.index);
  const vk = h.voteKeyHash || null;
  const evmMiner = (cb && cb.evm_miner) || (vk ? '0x' + vk.slice(24, 64) : null); // evm.rs miner_evm_address: bytes 12..32 of the vote key hash
  return {
    row: {
      tx_count: txs.length, evm_miner: evmMiner, proof_records: cb ? cb.records : 0,
      subsidy_sompi: cb ? cb.subsidy : null, paid_sompi: cb ? cb.paid : null, selected_parent: vd.selectedParentHash || null,
    },
    detail: {
      version: h.version, bits: h.bits, nonce: String(h.nonce), blue_work: h.blueWork, hash_merkle_root: h.hashMerkleRoot,
      accepted_id_merkle_root: h.acceptedIdMerkleRoot, utxo_commitment: h.utxoCommitment, pruning_point: h.pruningPoint,
      difficulty: vd.difficulty ?? null, parents_by_level: Array.isArray(h.parentsByLevel) ? h.parentsByLevel.length : null,
      mergeset: { blues: vd.mergeSetBluesHashes || [], reds: vd.mergeSetRedsHashes || [] },
      coinbase: cb, txs, certificates: certs,
    },
  };
}

const pendingBlocks = [];          // rows waiting for the next flush
const pendingChain = { add: new Set(), remove: new Set() };
const pendingMerge = new Map();     // chain block hash -> { blues, reds } from its verbose data, or null to fetch with getBlock
const pendingUnmerge = new Set();   // chain blocks removed by a reorg: their mergeset goes back to pending
const mergesets = new Map();        // block hash -> { blues, reds } from the notification's verbose data (bounded cache)
const MERGESET_CACHE = 4000;
const inbox = [];                   // raw notifications, drained off the socket path
let draining = false;
let newestStoredTs = 0;             // header timestamp of the newest block written to the table
let lastBlockAt = 0;                // wall clock of the last blockAdded notification
let blockCountAtLastBlock = 0;      // the node's block_count when a block last arrived
let lastDagBlockCount = 0;
let lastResubscribeAt = 0;
let resubscribeAttempts = 0;
let flushBusy = false;
const miners = new Map();          // vote_key_hash -> { lastSeen ms, quiet bool }
const minuteCounts = new Map();    // minute epoch -> count (last 60 minutes)
const recentArrivals = [];         // ms timestamps of arrivals in the last 60 s
const workSamples = [];            // { t: ms, w: BigInt blue work } of the heaviest header seen, last 10 min
let lastDifficultyEvent = null;

// Fallback hash-rate estimate when the node refuses estimateNetworkHashesPerSecond (it needs a 1,000-block
// window): blue work added per second over the last 10 minutes, the same quantity the node measures.
function noteWork(now, blueWorkHex) {
  if (!blueWorkHex) return;
  let w; try { w = BigInt('0x' + blueWorkHex); } catch { return; }
  const last = workSamples[workSamples.length - 1];
  if (last && w <= last.w) return;
  workSamples.push({ t: now, w });
  while (workSamples.length && workSamples[0].t < now - 10 * 60_000) workSamples.shift();
}
function localHashesPerSecond() {
  if (workSamples.length < 2) return null;
  const a = workSamples[0], b = workSamples[workSamples.length - 1];
  const secs = (b.t - a.t) / 1000;
  if (secs < 20) return null;
  return Number((b.w - a.w) / BigInt(Math.round(secs)));
}
let knownPeers = null;             // Set of peer ids from the previous tick
let network = 'igneum-devnet';
let addressPrefix = 'igneumdev';
let nodeVersion = null;
let sinkHash = null;

async function recordEvent(kind, text) {
  log('event', kind, text);
  try { await sql(`INSERT INTO ${TE} (kind, text) VALUES ($1, $2)`, [kind, text]); } catch (e) { log('event write failed', e.message); }
}

// Counts are bucketed by the block's own header timestamp, never by when the observer processed it: a catch-up
// after a stall fills in the past minutes instead of painting a spike into the minute it happened to run.
function noteArrival(now, ts) {
  recentArrivals.push(ts);
  const minute = Math.floor(ts / 60_000) * 60_000;
  minuteCounts.set(minute, (minuteCounts.get(minute) || 0) + 1);
  if (minuteCounts.size > 70) for (const k of minuteCounts.keys()) if (k < now - 61 * 60_000) minuteCounts.delete(k);
}
function blocks60s(now) {
  if (recentArrivals.length > 2000) { const keep = recentArrivals.filter(t => t > now - 120_000); recentArrivals.length = 0; recentArrivals.push(...keep); }
  let n = 0; for (const t of recentArrivals) if (t > now - 60_000) n++;
  return n;
}
function blocksPerMinute(now) {
  const out = []; const start = Math.floor(now / 60_000) * 60_000 - 59 * 60_000;
  for (let m = start; m <= now; m += 60_000) out.push([m, minuteCounts.get(m) || 0]);
  return out;
}

function onBlock(block) {
  const h = block.header; if (!h || !h.hash) return;
  const now = Date.now();
  const parents = (h.parentsByLevel && h.parentsByLevel[0]) || [];
  const miner = minerFromCoinbase(block, addressPrefix);
  for (const cert of certificatesIn(block)) pendingCerts.push({ cert, carrier: h.hash });
  const vk = h.voteKeyHash || null;
  const vd = block.verboseData;
  if (vd && Array.isArray(vd.mergeSetBluesHashes)) {
    const ms = { blues: vd.mergeSetBluesHashes, reds: vd.mergeSetRedsHashes || [] };
    mergesets.set(h.hash, ms);
    if (mergesets.size > MERGESET_CACHE) mergesets.delete(mergesets.keys().next().value);
    if (vd.isChainBlock) pendingMerge.set(h.hash, ms);
  }
  if (vd && vd.isChainBlock) queuePlan(h.hash);
  lastBlockAt = now; blockCountAtLastBlock = lastDagBlockCount; resubscribeAttempts = 0;
  let ex = null; try { ex = blockDetail(block, addressPrefix); } catch (e) { log('block detail failed', short(h.hash), e.message); }
  pendingBlocks.push({
    hash: h.hash, blue_score: h.blueScore, daa_score: h.daaScore, timestamp_ms: h.timestamp,
    parents: parents.length, parent_hashes: parents,
    is_chain_block: !!(block.verboseData && block.verboseData.isChainBlock),
    vote_key_hash: vk, miner_address: miner.address, engine: miner.extra,
    tx_count: ex ? ex.row.tx_count : null, evm_miner: ex ? ex.row.evm_miner : null, proof_records: ex ? ex.row.proof_records : null,
    subsidy_sompi: ex ? ex.row.subsidy_sompi : null, paid_sompi: ex ? ex.row.paid_sompi : null, selected_parent: ex ? ex.row.selected_parent : null,
    detail: ex ? JSON.stringify(ex.detail) : null,
  });
  noteArrival(now, Number(h.timestamp) || now);
  noteWork(now, h.blueWork);
  if (vk) {
    const m = miners.get(vk);
    if (!m) { miners.set(vk, { lastSeen: now, quiet: false }); recordEvent('miner_seen', `New miner ${short(vk)} seen${miner.address ? ` (${miner.address.slice(0, 24)}...)` : ''}`); }
    else { if (m.quiet) { m.quiet = false; recordEvent('miner_back', `Miner ${short(vk)} is back after a quiet spell`); } m.lastSeen = now; }
  }
}

function pgArray(list) { return `{${list.map(s => `"${String(s).replace(/["\\]/g, '')}"`).join(',')}}`; }

async function flushBlocks() {
  if (!pendingBlocks.length) return;
  const rows = pendingBlocks.splice(0, 200);
  const cols = ['hash', 'blue_score', 'daa_score', 'timestamp_ms', 'parents', 'parent_hashes', 'is_chain_block', 'vote_key_hash', 'miner_address', 'engine',
    'tx_count', 'evm_miner', 'proof_records', 'subsidy_sompi', 'paid_sompi', 'selected_parent', 'detail'];
  // numeric, not bigint: the Igneum 2.0 chain reports the subsidy and the paid amount in wei (9.52 IGN = 9522644482386090276, past int64; 8 Oct 2026)
  const cast = { parent_hashes: '::text[]', detail: '::jsonb', subsidy_sompi: '::numeric', paid_sompi: '::numeric' };
  const params = []; const values = [];
  for (const r of rows) {
    const ph = [];
    for (const c of cols) { params.push(c === 'parent_hashes' ? pgArray(r[c]) : r[c]); ph.push(`$${params.length}${cast[c] || ''}`); }
    values.push(`(${ph.join(',')})`);
  }
  try {
    await sql(`INSERT INTO ${TB} (${cols.join(',')}) VALUES ${values.join(',')} ON CONFLICT (hash) DO NOTHING`, params);
    for (const r of rows) if (Number(r.timestamp_ms) > newestStoredTs) newestStoredTs = Number(r.timestamp_ms);
  } catch (e) { log('block insert failed', e.message); if (pendingBlocks.length < 5000) pendingBlocks.unshift(...rows); return; }
  if (pendingBlocks.length) await flushBlocks();
}

// Colour: every chain block's mergeset is blue (in the selected chain's past, paid) or red (excluded). Blocks no chain
// block has merged yet stay pending. A reorg puts the removed chain blocks' mergesets back to pending first.
async function mergesetOf(rpc, hash) {
  const c = mergesets.get(hash); if (c) return c;
  const b = (await rpc.call('getBlock', { hash, includeTransactions: false })).block;
  const vd = (b && b.verboseData) || {};
  return { blues: vd.mergeSetBluesHashes || [], reds: vd.mergeSetRedsHashes || [] };
}
// Up to four RPC lookups in flight; the cache answers nearly all of them, so this is normally no RPC at all
async function mergesetsOf(rpc, hashes, onFail) {
  const out = new Map();
  for (let i = 0; i < hashes.length; i += 4) {
    await Promise.all(hashes.slice(i, i + 4).map(async h => { try { out.set(h, await mergesetOf(rpc, h)); } catch (e) { onFail(h, e); } }));
  }
  return out;
}
let colorsBusy = false;
async function flushColors(rpc) {
  if (colorsBusy || (!pendingMerge.size && !pendingUnmerge.size)) return;
  colorsBusy = true;
  try {
    if (pendingUnmerge.size) {
      const hs = [...pendingUnmerge].slice(0, 50); const back = [];
      const got = await mergesetsOf(rpc, hs, (h, e) => log('unmerge fetch failed', h.slice(0, 8), e.message));
      for (const h of hs) { pendingUnmerge.delete(h); const m = got.get(h); if (m) back.push(...m.blues, ...m.reds); }
      if (back.length) await sql(`UPDATE ${TB} SET color = 'pending' WHERE hash = ANY($1::text[]) AND color <> 'pending'`, [pgArray(back)]);
    }
    const blues = [], reds = [], need = [];
    const batch = [...pendingMerge].slice(0, 200);
    for (const [h, m] of batch) { if (m) { blues.push(...m.blues); reds.push(...m.reds); } else need.push(h); pendingMerge.delete(h); }
    if (need.length) { const got = await mergesetsOf(rpc, need, (h, e) => log('mergeset fetch failed', h.slice(0, 8), e.message)); for (const m of got.values()) { blues.push(...m.blues); reds.push(...m.reds); } }
    if (blues.length) await sql(`UPDATE ${TB} SET color = 'blue' WHERE hash = ANY($1::text[]) AND color <> 'blue'`, [pgArray(blues)]);
    if (reds.length) await sql(`UPDATE ${TB} SET color = 'red' WHERE hash = ANY($1::text[]) AND color <> 'red'`, [pgArray(reds)]);
  } catch (e) { log('color update failed', e.message); }
  colorsBusy = false;
}

async function flushChain() {
  if (pendingChain.add.size) { const a = [...pendingChain.add]; pendingChain.add.clear(); try { await sql(`UPDATE ${TB} SET is_chain_block = true WHERE hash = ANY($1::text[]) AND NOT is_chain_block`, [pgArray(a)]); } catch (e) { log('chain update failed', e.message); } }
  if (pendingChain.remove.size) { const r = [...pendingChain.remove]; pendingChain.remove.clear(); try { await sql(`UPDATE ${TB} SET is_chain_block = false WHERE hash = ANY($1::text[]) AND is_chain_block`, [pgArray(r)]); } catch (e) { log('chain update failed', e.message); } }
}

async function tick(rpc) {
  try { await tickInner(rpc); rpc.noteTick && rpc.noteTick(true); } catch (e) { rpc.noteTick && rpc.noteTick(false); }
}
async function tickInner(rpc) {
  const now = Date.now();
  rollRpcLoad(now);
  let dag, info, peersRes, hps;
  try {
    [dag, info, peersRes, hps] = await Promise.all([
      rpc.call('getBlockDagInfo', {}),
      rpc.call('getInfo', {}),
      rpc.call('getConnectedPeerInfo', {}),
      rpc.call('estimateNetworkHashesPerSecond', { windowSize: 1000, startHash: null }).catch(() => null),
    ]);
  } catch (e) { log('tick failed', e.message); throw e; }
  if (dag.network) network = String(dag.network).startsWith('igneum') ? dag.network : `igneum-${dag.network}`;
  nodeVersion = info.serverVersion || nodeVersion;
  if (dag.sink && dag.sink !== sinkHash) { sinkHash = dag.sink; pendingChain.add.add(dag.sink); }
  lastDagBlockCount = Number(dag.blockCount) || 0;

  // self-check: the node keeps adding blocks but none reach us, so the subscription is dead; resubscribe, then give up
  if (lastBlockAt && now - lastBlockAt > 60_000 && lastDagBlockCount > blockCountAtLastBlock && now - lastResubscribeAt > 60_000) {
    lastResubscribeAt = now; resubscribeAttempts++;
    const msg = `no blockAdded for ${Math.round((now - lastBlockAt) / 1000)} s while the node's block_count rose ${blockCountAtLastBlock} -> ${lastDagBlockCount}`;
    if (resubscribeAttempts > 2) { log(msg + '; resubscribed twice without effect, exiting for a restart'); await recordEvent('observer', 'Observer lost the block feed; restarting'); process.exit(2); }
    log(msg + `; resubscribing (attempt ${resubscribeAttempts})`);
    try { await rpc.call('subscribe', { BlockAdded: {} }); await rpc.call('subscribe', { VirtualChainChanged: { include_accepted_transaction_ids: false } }); }
    catch (e) { log('resubscribe failed', e.message); resubscribeAttempts++; }
  }
  const lagS = newestStoredTs ? Math.max(0, (now - newestStoredTs) / 1000) : null;
  const queueDepth = inbox.length + pendingBlocks.length + pendingMerge.size;

  // peers joined or left
  const peers = peersRes.peerInfo || [];
  const ids = new Map(peers.map(p => [p.id, `${p.address && p.address.ip}:${p.address && p.address.port}`]));
  if (knownPeers) {
    // never an address in a public event (review round 4, R4.6.2): the count is the information
    for (const [id] of ids) if (!knownPeers.has(id)) recordEvent('peer_joined', `Peer joined (${ids.size} peers)`);
    for (const [id] of knownPeers) if (!ids.has(id)) recordEvent('peer_left', `Peer left (${ids.size} peers)`);
  }
  knownPeers = ids;

  // difficulty step over 5%
  const diff = Number(dag.difficulty) || 0;
  if (lastDifficultyEvent === null) lastDifficultyEvent = diff;
  else if (lastDifficultyEvent > 0 && Math.abs(diff - lastDifficultyEvent) / lastDifficultyEvent > DIFFICULTY_STEP) {
    const pct = ((diff - lastDifficultyEvent) / lastDifficultyEvent * 100).toFixed(1);
    recordEvent('difficulty', `Difficulty ${diff > lastDifficultyEvent ? 'up' : 'down'} ${Math.abs(pct)}% to ${diff.toLocaleString('en-GB', { maximumFractionDigits: 0 })}`);
    lastDifficultyEvent = diff;
  }

  // miners gone quiet
  for (const [vk, m] of miners) if (!m.quiet && now - m.lastSeen > QUIET_AFTER_MS) { m.quiet = true; recordEvent('miner_quiet', `Miner ${short(vk)} has gone quiet (no block for 5 min)`); }

  // finality v2: checkpoints and weights (a node from before the finality layer answers with an error; then null)
  const finality = await finalityTick(rpc);
  // proving v0: activation state and the 10-minute counts (a node without the RPCs gives {supported: false})
  await provingTick();
  const proving = await provingState();

  try {
    await sql(`INSERT INTO ${TS} (id, block_count, header_count, blue_score, difficulty, hashes_per_second_estimate, peers, mempool,
                 node_version, network, blocks_60s, blocks_per_minute, observer_started_at, updated_at, finality, observer_lag_s, queue_depth, proving, rpc_load, supply_check)
               VALUES (1, $1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11::jsonb, $12, now(), $13::jsonb, $14, $15, $16::jsonb, $17::jsonb, $18::jsonb)
               ON CONFLICT (id) DO UPDATE SET block_count = EXCLUDED.block_count, header_count = EXCLUDED.header_count, blue_score = EXCLUDED.blue_score,
                 difficulty = EXCLUDED.difficulty, hashes_per_second_estimate = EXCLUDED.hashes_per_second_estimate, peers = EXCLUDED.peers,
                 mempool = EXCLUDED.mempool, node_version = EXCLUDED.node_version, network = EXCLUDED.network, blocks_60s = EXCLUDED.blocks_60s,
                 blocks_per_minute = EXCLUDED.blocks_per_minute, observer_started_at = EXCLUDED.observer_started_at, updated_at = now(),
                 finality = EXCLUDED.finality, observer_lag_s = EXCLUDED.observer_lag_s, queue_depth = EXCLUDED.queue_depth, proving = EXCLUDED.proving,
                 rpc_load = EXCLUDED.rpc_load, supply_check = EXCLUDED.supply_check`,
      [dag.blockCount, dag.headerCount, (await rpc.call('getSinkBlueScore', {}).catch(() => ({}))).blueScore ?? null, diff,
        hps ? hps.networkHashesPerSecond : localHashesPerSecond(), peers.length, info.mempoolSize ?? 0,
        nodeVersion, network, blocks60s(now), JSON.stringify(blocksPerMinute(now)), STARTED_AT.toISOString(),
        finality ? JSON.stringify(finality) : null, lagS === null ? null : Math.round(lagS * 10) / 10, queueDepth, JSON.stringify(proving),
        JSON.stringify(rpcLoadState()), lastSupplyCheck ? JSON.stringify(lastSupplyCheck) : null]);
  } catch (e) { log('state write failed', e.message); }
}

// ---------- Finality v2 (spec 03) ----------
const checkpointStates = new Map();   // index -> last state written; set BEFORE any await, so the two lock paths never both record
const checkpointDetailed = new Set();  // indices written with votesSeen (the FinalityLock notification carries none; the poll fills it in once)
let finalitySupported = null;         // null = unknown, false = the node has no finality RPC
let lastWeightsAt = 0;
let lastWeights = null;

function pct(x) { return (Number(x) * 100).toFixed(1); }

async function recordLock(cp) {
  // The lockEvent text the site shows: "checkpoint N locked (xx% of weight)"
  const votes = cp.votesSeen !== undefined ? `${cp.votesSeen} votes of ${cp.voters} voters` : `${cp.voters} voters`;
  recordEvent('checkpoint_locked', `checkpoint ${cp.index} locked (${pct(cp.fractionTotal)}% of weight, ${pct(cp.fractionActive)}% of active, ${votes}) at block ${short(cp.hash)}`);
}

async function upsertCheckpoint(cp) {
  const locked = cp.state === 'locked';
  try {
    await sql(`INSERT INTO ${TC} (index, hash, blue_score, daa_score, state, signed_weight, active_weight, total_weight, fraction_active, fraction_total,
                 votes_seen, voters, aggregators, locked_at, updated_at)
               VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13::text[], $14, now())
               ON CONFLICT (index) DO UPDATE SET hash = EXCLUDED.hash, blue_score = EXCLUDED.blue_score, daa_score = EXCLUDED.daa_score, state = EXCLUDED.state,
                 signed_weight = EXCLUDED.signed_weight, active_weight = EXCLUDED.active_weight, total_weight = EXCLUDED.total_weight,
                 fraction_active = EXCLUDED.fraction_active, fraction_total = EXCLUDED.fraction_total, votes_seen = EXCLUDED.votes_seen, voters = EXCLUDED.voters,
                 aggregators = EXCLUDED.aggregators, locked_at = COALESCE(${TC}.locked_at, EXCLUDED.locked_at), updated_at = now()`,
      // The FinalityLock notification carries no votesSeen; the 2-s poll fills it in
      [cp.index, cp.hash, cp.blueScore, cp.daaScore, cp.state, cp.signedWeight, cp.activeWeight, cp.totalWeight, cp.fractionActive, cp.fractionTotal,
        cp.votesSeen ?? 0, cp.voters ?? 0, pgArray(cp.aggregators || []), locked ? new Date().toISOString() : null]);
  } catch (e) { log('checkpoint write failed', e.message); }
}

async function finalityTick(rpc) {
  if (finalitySupported === false) return null;
  let cps;
  try { cps = await rpc.call('getFinalityCheckpoints', { last: 60 }); }
  catch (e) {
    if (finalitySupported === null) { log('node has no finality RPC (pre-v2 node):', e.message); finalitySupported = false; }
    return null;
  }
  finalitySupported = true;
  lastCheckpointsReport = cps;
  if (!certBackfillDone) backfillCertificate(rpc, cps).catch(e => log('certificate backfill failed', e.message));
  for (const cp of cps.checkpoints || []) {
    const prev = checkpointStates.get(cp.index);
    const changed = prev !== cp.state || prev === undefined;
    const detail = cp.votesSeen !== undefined && !checkpointDetailed.has(cp.index);
    if (changed || detail) {
      // claim the transition before the first await: the FinalityLock notification handler checks this map synchronously,
      // and until 4 October 2026 both paths recorded the same lock (two "locked" events 30 ms apart on the live feed)
      checkpointStates.set(cp.index, cp.state);
      if (cp.votesSeen !== undefined) checkpointDetailed.add(cp.index);
      await upsertCheckpoint(cp);
      if (changed && cp.state === 'locked' && prev !== 'locked') {
        // a lock recorded over a known earlier state is a revisit (4 October 2026, 20:15:59: index 1319, locked 14 min
        // before, was recorded again right after a restart; this line says what the seed held for it)
        if (prev !== undefined) log(`checkpoint ${cp.index}: locked after a seeded or earlier state '${prev}'`);
        await recordLock(cp);
      }
    } else if (cp.state !== 'locked' && (cp.index % 1 === 0)) {
      // vote counts move while a checkpoint is open: refresh it
      await upsertCheckpoint(cp);
    }
  }
  for (const k of checkpointStates.keys()) if (k + 500 < Number(cps.nextIndex)) checkpointStates.delete(k);
  for (const k of checkpointDetailed) if (k + 500 < Number(cps.nextIndex)) checkpointDetailed.delete(k);
  const now = Date.now();
  if (now - lastWeightsAt > 10_000) {
    lastWeightsAt = now;
    try {
      const w = await rpc.call('getFinalityWeights', {});
      lastWeights = {
        checkpoint_index: w.checkpointIndex, checkpoint_hash: w.checkpointHash, daa_score: w.daaScore,
        total_weight: w.totalWeight, active_weight: w.activeWeight, voters: w.voters,
        keys: (w.keys || []).slice(0, 64).map(k => ({ id: short(k.keyHash), blocks: k.blocks, voter: k.voter, participation: k.participation, stripped_until_daa: k.strippedUntilDaa, revealed: !!k.pubkey })),
      };
    } catch (e) { if (!String(e.message).includes('no checkpoint')) log('getFinalityWeights failed', e.message); }
  }
  const locked = (cps.checkpoints || []).filter(c => c.state === 'locked');
  const newest = locked.length ? locked[locked.length - 1] : null;
  return {
    params: cps.params, chain_id: cps.chainId, next_index: cps.nextIndex, finality_active: cps.finalityActive,
    latest_locked_index: cps.latestLockedIndex, latest_locked_hash: cps.latestLockedHash,
    latest_locked_blue_score: newest ? newest.blueScore : null,
    weights: lastWeights,
  };
}

// ---------- Finality v2 certificates (spec 03 C3): what the light client verifies ----------
// A block's coinbase extra data ends with the node's finality section `items || len_le32 || "IGNF"`; items are
// tagged 1 vote (280 bytes), 2 certificate, 3 evidence (560 bytes). A certificate is `index_le64 || checkpoint(32)
// || voter_count_le32 || bitmap_len_le32 || bitmap || signature(96) || aggregator(32) || proof(96)`
// (vendor/igneum-node/consensus/core/src/finality.rs, Certificate::write). Bit p of the bitmap (byte p/8, bit
// p%8) is position p of the canonical voter list at the checkpoint.
const pendingCerts = [];            // { cert, carrier } seen in blocks, waiting for the next flush
const storedCerts = new Map();      // index -> checkpoint hash already in the table
let lastCheckpointsReport = null;   // the last getFinalityCheckpoints answer: chain id and the locked list
let certBackfillDone = false;
let certsBusy = false;
const MAX_CHAIN_HEADERS = 200;
const ZERO_HASH = '0'.repeat(64);
const hexOf = u8 => Buffer.from(u8).toString('hex');

function certificatesIn(block) {
  const tx = block.transactions && block.transactions[0];
  if (!tx) return [];
  const p = payloadBytes(tx.payload);
  if (p.length < 19) return [];
  const extra = p.subarray(19 + p[18]);
  const n = extra.length;
  if (n < 8 || String.fromCharCode(...extra.subarray(n - 4)) !== 'IGNF') return [];
  const len = new DataView(extra.buffer, extra.byteOffset, n).getUint32(n - 8, true);
  if (len + 8 > n) return [];
  const body = extra.subarray(n - 8 - len, n - 8);
  const out = []; let o = 0;
  while (o < body.length) {
    const tag = body[o];
    if (tag === 1) o += 1 + 280;
    else if (tag === 3) o += 1 + 560;
    else if (tag === 2) { const c = parseCertificate(body, o + 1); if (!c) break; out.push(c); o += 1 + c.length; }
    else break;
  }
  return out;
}
function parseCertificate(b, s) {
  if (b.length < s + 48) return null;
  const dv = new DataView(b.buffer, b.byteOffset, b.byteLength);
  const voterCount = dv.getUint32(s + 40, true);
  const bl = dv.getUint32(s + 44, true);
  const end = s + 48 + bl + 96 + 32 + 96;
  if (bl > 1 << 20 || b.length < end) return null;
  return {
    index: Number(dv.getBigUint64(s, true)), checkpoint: hexOf(b.subarray(s + 8, s + 40)), voterCount,
    bitmap: hexOf(b.subarray(s + 48, s + 48 + bl)), signature: hexOf(b.subarray(s + 48 + bl, s + 144 + bl)),
    aggregator: hexOf(b.subarray(s + 144 + bl, s + 176 + bl)), aggregatorProof: hexOf(b.subarray(s + 176 + bl, end)),
    bytes: hexOf(b.subarray(s, end)), length: end - s,
  };
}

// Stores a certificate with everything a verifier needs: the voter table and the header chain back to the previous
// locked checkpoint. The node reports the voter table at its latest determined checkpoint; captured as the lock
// lands (the next determination is 30 blue score away) it is the table at this checkpoint, and `voters_index`
// records which checkpoint it was read at either way.
async function completeCertificate(rpc, cert, carrier) {
  if (storedCerts.get(cert.index) === cert.checkpoint) return;
  const report = lastCheckpointsReport || await rpc.call('getFinalityCheckpoints', { last: 60 });
  const cp = (report.checkpoints || []).find(c => Number(c.index) === cert.index);
  if (cp && cp.hash !== cert.checkpoint) { log(`certificate at ${cert.index} is for ${short(cert.checkpoint)}, the node's checkpoint is ${short(cp.hash)}; not stored`); return; }
  const w = await rpc.call('getFinalityWeights', {});
  const voters = (w.keys || []).filter(k => k.voter)
    .sort((a, b) => (a.keyHash < b.keyHash ? -1 : a.keyHash > b.keyHash ? 1 : 0))
    .map(k => ({ pubkey: k.pubkey, weight: Number(k.blocks), participation: Number(k.participation) }));
  if (voters.length !== cert.voterCount) log(`certificate at ${cert.index} names ${cert.voterCount} voters, the node's table at checkpoint ${w.checkpointIndex} has ${voters.length}`);
  const prev = (report.checkpoints || []).filter(c => c.state === 'locked' && Number(c.index) < cert.index).sort((a, b) => Number(b.index) - Number(a.index))[0] || null;
  const headers = []; let hash = cert.checkpoint; let complete = false;
  while (headers.length < MAX_CHAIN_HEADERS) {
    const b = (await rpc.call('getBlock', { hash, includeTransactions: false })).block;
    headers.push(b.header);
    if (prev && hash === prev.hash) { complete = true; break; }
    hash = (b.verboseData && b.verboseData.selectedParentHash) || ZERO_HASH;
    if (hash === ZERO_HASH) { complete = !prev; break; }
  }
  headers.reverse();
  const top = headers[headers.length - 1];
  try {
    await sql(`INSERT INTO ${TX} (index, hash, blue_score, daa_score, chain_id, voter_count, bitmap_hex, signature_hex, aggregator, aggregator_proof_hex,
                 certificate_hex, carrier, voters, voters_index, total_weight, active_weight, prev_index, prev_hash, headers, headers_complete)
               VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13::jsonb, $14, $15, $16, $17, $18, $19::jsonb, $20)
               ON CONFLICT (index) DO NOTHING`,
      [cert.index, cert.checkpoint, Number(top.blueScore), Number(top.daaScore), report.chainId || network, cert.voterCount, cert.bitmap, cert.signature,
        cert.aggregator, cert.aggregatorProof, cert.bytes, carrier, JSON.stringify(voters), Number(w.checkpointIndex), Number(w.totalWeight), Number(w.activeWeight),
        prev ? Number(prev.index) : null, prev ? prev.hash : null, JSON.stringify(headers), complete]);
    storedCerts.set(cert.index, cert.checkpoint);
    log(`certificate ${cert.index} stored: ${voters.length} voters (table at checkpoint ${w.checkpointIndex}), ${headers.length} headers${complete ? '' : ' (chain incomplete)'}, carried by ${short(carrier)}`);
  } catch (e) { log('certificate write failed', e.message); }
}

async function flushCertificates(rpc) {
  if (certsBusy || !pendingCerts.length) return;
  certsBusy = true;
  try {
    while (pendingCerts.length) {
      const { cert, carrier } = pendingCerts.shift();
      try { await completeCertificate(rpc, cert, carrier); } catch (e) { log('certificate store failed', e.message); }
    }
  } finally { certsBusy = false; }
}

// On start: the newest locked checkpoint without a stored certificate is looked up in the blocks after it (a
// certificate is carried by the first templates after the lock). One pass, up to three pages of getBlocks.
async function backfillCertificate(rpc, report) {
  certBackfillDone = true;
  const newest = (report.checkpoints || []).filter(c => c.state === 'locked').sort((a, b) => Number(b.index) - Number(a.index))[0];
  if (!newest || storedCerts.get(Number(newest.index)) === newest.hash) return;
  let low = newest.hash; let seen = 0;
  for (let page = 0; page < 3; page++) {
    const blocks = (await rpc.call('getBlocks', { lowHash: low, includeBlocks: true, includeTransactions: true })).blocks || [];
    for (const b of blocks) {
      seen++;
      for (const c of certificatesIn(b)) if (c.index === Number(newest.index)) { await completeCertificate(rpc, c, b.header.hash); return; }
    }
    if (blocks.length < 2) break;
    low = blocks[blocks.length - 1].header.hash;
  }
  log(`no block within ${seen} of checkpoint ${newest.index} carries its certificate`);
}

// ---------- Proving v0 (spec 7.7): shard plans and proof records over the execution layer's JSON-RPC ----------
// The chain block hash is the same hash on both layers (the executor keys its segments by it), so every lookup is
// {blockHash}. The EVM node may trail the observer's node by a segment or two: a plan that is "not found" is retried
// with a growing delay, up to 30 attempts. A node without the RPCs answers -32601 once and the feed is marked
// unsupported (rechecked every 5 minutes, so an upgraded node is picked up without a restart).
// PROOF_WINDOW_MS: how long a planned block keeps being read for its records. 30 minutes (7 October 2026, was 10): the fleet's
// proofs land a median 258 s after the block and the tail runs past 10 minutes, and a block dropped from the open set never
// moves past 'proving' on the page. The open set at 0.45 blocks a second is about 800 blocks; the batch of 80 reads each one
// every 10 ticks.
const PLAN_BATCH = 24, RECORD_BATCH_ACTIVE = 80, RECORD_BATCH_INACTIVE = 10, PROOF_WINDOW_MS = 30 * 60_000;
// OBSERVER_CLAIMS: '1' reads open claims through igneum_getProofClaims; a method name reads them through that method; unset
// or '0' reads none (the records reply's own claims field is used whenever the node sends one, flag or not)
let CLAIMS_RPC = process.env.OBSERVER_CLAIMS === '1' ? 'igneum_getProofClaims' : /^[a-z_]+$/i.test(process.env.OBSERVER_CLAIMS || '') && process.env.OBSERVER_CLAIMS !== '0' ? process.env.OBSERVER_CLAIMS : null;
const pendingPlans = new Map();   // chain block hash -> { tries, nextAt }
const openBlocks = new Map();     // chain block hash -> { number, daa, ts, shards: [state...], provers, polledAt, done }
const daaOfNumber = new Map();    // chain block number -> daa score, from the plans fetched (carriers are later chain blocks)
const provers = new Set();        // prover id8s seen this run (one event each)
let provingSupported = null;      // null unknown, false = no RPC, true
let provingRecheckAt = 0;
let provingStatus = null;         // the last igneum_getProvingStatus answer
let provingStatusAt = 0;          // when it was read (ms); live_state.proving.status_at, the API's status_age_s
let provingReason = null;         // why supported is false
let provingWasActive = null;
let plansBusy = false, recordsBusy = false, firstPaidSeen = false;
let lastProvingStats = null, lastProvingStatsAt = 0;
const hx = v => (v === null || v === undefined ? null : (typeof v === 'string' && v.startsWith('0x') ? parseInt(v, 16) : Number(v)));
const weiStr = v => { if (v === null || v === undefined) return null; try { return BigInt(v).toString(); } catch { return null; } };

async function evm(method, params = []) {
  rpcLoad.evm++;
  const r = await fetch(EVM, { method: 'POST', headers: { 'content-type': 'application/json' }, body: JSON.stringify({ jsonrpc: '2.0', id: 1, method, params }), signal: AbortSignal.timeout(8000) });
  const j = await r.json();
  if (j.error) { const e = new Error(`${method}: ${j.error.message}`); e.code = j.error.code; throw e; }
  return j.result;
}

function queuePlan(hash) { if (!openBlocks.has(hash) && !pendingPlans.has(hash)) pendingPlans.set(hash, { tries: 0, nextAt: 0 }); }
function dropPlan(hash) { pendingPlans.delete(hash); openBlocks.delete(hash); }

async function provingTick() {
  const now = Date.now();
  if (provingSupported === false && now < provingRecheckAt) return;
  try {
    const s = await evm('igneum_getProvingStatus');
    if (provingSupported !== true) log(`proving RPCs available at ${EVM} (activation ${s.activationDaa === null ? 'not set' : hx(s.activationDaa)}, verifier ${s.verifier})`);
    provingSupported = true; provingReason = null; provingStatus = s; provingStatusAt = Date.now();
    if (provingWasActive === false && s.active) recordEvent('proving', `Proving layer active: payouts start at DAA ${hx(s.activationDaa)}`);
    provingWasActive = !!s.active;
  } catch (e) {
    const absent = e.code === -32601;
    if (provingSupported !== false || !absent) log(absent ? `node at ${EVM} has no proving RPCs` : `proving status failed: ${e.message}`);
    provingSupported = false; provingStatus = null; provingReason = absent ? 'node without proving' : `evm rpc unreachable (${e.message.slice(0, 60)})`;
    provingRecheckAt = now + (absent ? 5 * 60_000 : 20_000);
  }
}

async function flushPlans() {
  if (plansBusy || provingSupported !== true || !pendingPlans.size) return;
  plansBusy = true;
  try {
    const now = Date.now();
    const due = [...pendingPlans].filter(([, p]) => p.nextAt <= now).slice(0, PLAN_BATCH).map(([h]) => h);
    const rows = [];
    for (let i = 0; i < due.length; i += 4) {
      await Promise.all(due.slice(i, i + 4).map(async h => {
        const p = pendingPlans.get(h); if (!p) return;
        try {
          const plan = await evm('igneum_getShardPlan', [{ blockHash: '0x' + h }]);
          pendingPlans.delete(h);
          const number = hx(plan.number), daa = hx(plan.daaScore);
          daaOfNumber.set(number, daa);
          const shards = (plan.shards || []).map(() => 'planned');
          openBlocks.set(h, { number, daa, ts: now, shards, provers: shards.map(() => null), polledAt: 0, done: false });
          (plan.shards || []).forEach((s, i) => rows.push({ hash: h, shard: i, shards: shards.length, number, daa, pgas: hx(s.pgas) }));
        } catch (e) {
          p.tries++;
          if (p.tries > 30 || !/not found/.test(e.message)) { pendingPlans.delete(h); if (!/not found/.test(e.message)) log('shard plan failed', h.slice(0, 8), e.message); }
          else p.nextAt = now + Math.min(30_000, 1000 * p.tries);
        }
      }));
    }
    if (rows.length) {
      const params = [], values = [];
      for (const r of rows) {
        params.push(r.hash, r.shard, r.shards, r.number, r.daa, r.pgas);
        const n = params.length;
        values.push(`($${n - 5},$${n - 4},$${n - 3},$${n - 2},$${n - 1},$${n})`);
      }
      // block_ts comes from the block table (the header time the page's axis uses), one update for the batch
      await sql(`INSERT INTO ${TP} (block_hash, shard, shards, block_number, block_daa, pgas) VALUES ${values.join(',')} ON CONFLICT (block_hash, shard) DO NOTHING`, params);
      await sql(`UPDATE ${TP} p SET block_ts = b.timestamp_ms FROM ${TB} b WHERE b.hash = p.block_hash AND p.block_ts IS NULL AND p.block_hash = ANY($1::text[])`, [pgArray([...new Set(rows.map(r => r.hash))])]).catch(() => { });
      // explorer: the chain block's number (the EVM block number), one update for the batch, no extra RPC
      const nums = [...new Map(rows.map(r => [r.hash, r.number]))];
      await sql(`UPDATE ${TB} b SET number = v.n::bigint FROM (SELECT unnest($1::text[]) AS h, unnest($2::text[]) AS n) v WHERE b.hash = v.h AND b.number IS NULL`, [pgArray(nums.map(x => x[0])), pgArray(nums.map(x => String(x[1])))]).catch(e => log('number update failed', e.message));
    }
  } catch (e) { log('plan flush failed', e.message); }
  finally { plansBusy = false; }
}

// Per shard: paid (a carrying segment paid it) > verified (the proof verified in the pool, or the record carried and
// checked by consensus, which is what happens before activation) > proving (a record in the pool) > planned.
function shardStates(block, r) {
  const n = block.shards.length, states = block.shards.map(() => 'planned'), out = states.map(() => ({ prover: null, verified: null, carrier: null, carrierNumber: null, payout: null }));
  // an open claim (a prover has taken the shard, no proof yet) reads 'proving' from the claim until the proof lands: the
  // records reply's own claims field when the node carries one, or the claims RPC behind OBSERVER_CLAIMS (7 October 2026)
  for (const c of r.claims || []) { const i = c.shard; if (i >= n || states[i] !== 'planned') continue; states[i] = 'proving'; out[i] = { ...out[i], prover: short(String(c.keyHash || c.prover || '').replace(/^0x/, '')) }; }
  for (const e of r.pool || []) { const i = e.shard; if (i >= n) continue; const rank = e.verified === true ? 2 : 1; if (rank > ['planned', 'proving', 'verified', 'paid'].indexOf(states[i])) { states[i] = rank === 2 ? 'verified' : 'proving'; out[i] = { ...out[i], prover: short(String(e.keyHash || '').replace(/^0x/, '')), verified: e.verified, carrier: e.includedIn ? String(e.includedIn).replace(/^0x/, '') : null }; } }
  for (const c of r.carried || []) { const i = c.shard; if (i >= n || !c.valid) continue; if (states[i] !== 'paid') { states[i] = 'verified'; out[i] = { ...out[i], prover: short(String(c.keyHash || '').replace(/^0x/, '')), carrier: String(c.carrier || '').replace(/^0x/, ''), carrierNumber: hx(c.carrierNumber) }; } }
  (r.paid || []).forEach((p, i) => { if (!p || i >= n) return; states[i] = 'paid'; out[i] = { ...out[i], prover: short(String(p.keyHash || '').replace(/^0x/, '')), carrierNumber: hx(p.carrierNumber), payout: weiStr(p.wei) }; });
  return { states, out };
}

async function pollRecords() {
  if (recordsBusy || provingSupported !== true) return;
  recordsBusy = true;
  try {
    const now = Date.now();
    for (const [h, b] of openBlocks) if (b.done || now - b.ts > PROOF_WINDOW_MS) openBlocks.delete(h);
    const active = !!(provingStatus && provingStatus.active);
    const batch = [...openBlocks].sort((a, b) => a[1].polledAt - b[1].polledAt).slice(0, active ? RECORD_BATCH_ACTIVE : RECORD_BATCH_INACTIVE);
    const updates = [];
    for (let i = 0; i < batch.length; i += 4) {
      await Promise.all(batch.slice(i, i + 4).map(async ([h, b]) => {
        b.polledAt = now;
        let r; try { r = await evm('igneum_getProofRecords', [{ blockHash: '0x' + h }]); } catch (e) { if (!/not found/.test(e.message)) log('proof records failed', h.slice(0, 8), e.message); return; }
        // the claims read, behind the flag until the node ships the RPC (main's ask of 7 October 2026 on the 0.3.20 line); a
        // method the node lacks turns the flag off for the run instead of logging on every block
        if (CLAIMS_RPC && !b.done && !(r && r.claims)) { try { const c = await evm(CLAIMS_RPC, [{ blockHash: '0x' + h }]); r = { ...(r || {}), claims: Array.isArray(c) ? c : (c && c.claims) || [] }; } catch (e) { if (/method not found|unknown method|not supported/i.test(e.message)) { log('claims RPC', CLAIMS_RPC, 'not on this node; claims off for the run'); CLAIMS_RPC = null; } else if (!/not found/.test(e.message)) log('proof claims failed', h.slice(0, 8), e.message); } }
        const { states, out } = shardStates(b, r);
        for (let s = 0; s < states.length; s++) {
          const key = `${states[s]}|${out[s].prover}|${out[s].carrierNumber}|${out[s].carrier}`;
          if (b.provers[s] === key) continue;
          b.provers[s] = key; b.shards[s] = states[s];
          let carrierDaa = out[s].carrierNumber !== null ? daaOfNumber.get(out[s].carrierNumber) ?? null : null;
          if (carrierDaa === null && out[s].carrierNumber !== null) { try { const p = await evm('igneum_getShardPlan', ['0x' + out[s].carrierNumber.toString(16)]); carrierDaa = hx(p.daaScore); daaOfNumber.set(out[s].carrierNumber, carrierDaa); } catch { } }
          updates.push({ hash: h, shard: s, state: states[s], prover: out[s].prover, verified: out[s].verified, carrier: out[s].carrier, carrierNumber: out[s].carrierNumber, carrierDaa, lag: carrierDaa !== null && b.daa !== null ? carrierDaa - b.daa : null, payout: out[s].payout });
          if (out[s].prover && !provers.has(out[s].prover)) { provers.add(out[s].prover); recordEvent('prover_seen', `Prover ${out[s].prover} seen (shard ${s} of block ${short(h)})`); }
          if (states[s] === 'paid' && !firstPaidSeen) { firstPaidSeen = true; recordEvent('proving', `First paid shard seen: block ${short(h)} shard ${s}, carried ${updates[updates.length - 1].lag ?? '?'} DAA later`); }
        }
        if (states.every(s => s === 'paid')) b.done = true;
      }));
    }
    for (const u of updates) {
      await sql(`UPDATE ${TP} SET state = $3, prover = $4, verified = $5, carried_by = $6, carrier_number = $7, carrier_daa = $8, lag_daa = $9, payout_wei = COALESCE($10, payout_wei), updated_at = now()
                  WHERE block_hash = $1 AND shard = $2`, [u.hash, u.shard, u.state, u.prover, u.verified, u.carrier, u.carrierNumber, u.carrierDaa, u.lag, u.payout]).catch(e => log('proof row update failed', e.message));
    }
  } catch (e) { log('records poll failed', e.message); }
  finally { recordsBusy = false; }
}

// live_state.proving: activation and the last 10 minutes (counts refreshed every 10 s; the status every tick)
async function provingState() {
  if (provingSupported !== true) return { supported: false, reason: provingReason || 'not checked yet', evm_rpc: EVM };
  const s = provingStatus, now = Date.now();
  if (now - lastProvingStatsAt > 10_000) {
    lastProvingStatsAt = now;
    try {
      const rows = await sql(`WITH w AS (SELECT * FROM ${TP} WHERE received_at > now() - interval '10 minutes')
        SELECT (SELECT count(DISTINCT block_hash) FROM w)::int AS blocks,
               (SELECT count(*) FROM (SELECT block_hash FROM w GROUP BY block_hash HAVING bool_and(state IN ('verified','paid'))) f)::int AS blocks_full,
               (SELECT count(*) FROM w WHERE state IN ('verified','paid'))::int AS shards_proven,
               (SELECT count(*) FROM w WHERE state = 'paid')::int AS shards_paid,
               (SELECT count(DISTINCT prover) FROM w WHERE prover IS NOT NULL AND state IN ('verified','paid'))::int AS provers,
               (SELECT percentile_cont(0.5) WITHIN GROUP (ORDER BY lag_daa) FROM w WHERE lag_daa IS NOT NULL)::float AS median_lag`);
      lastProvingStats = rows[0] || null;
    } catch (e) { log('proving stats failed', e.message); }
  }
  const st = lastProvingStats || {};
  return {
    supported: true, active: !!s.active, activation_daa: s.activationDaa === null ? null : hx(s.activationDaa), tip_daa: hx(s.tipDaa),
    verifier: s.verifier, pool: s.pool || null, paid_shards_total: s.paidShards ?? null, shard_budget_pgas: hx(s.shardBudget),
    blocks_10m: st.blocks ?? 0, blocks_fully_proven_10m: st.blocks_full ?? 0, shards_proven_10m: st.shards_proven ?? 0, shards_paid_10m: st.shards_paid ?? 0,
    // DAA score of the carrying chain block minus the proven block's; the devnet targets one DAA step per second
    median_proof_lag_s: st.median_lag === null || st.median_lag === undefined ? null : Math.round(st.median_lag * 10) / 10,
    provers_10m: st.provers ?? 0, open_blocks: openBlocks.size, pending_plans: pendingPlans.size, evm_rpc: EVM,
    // 8 October 2026: when the status above was read, so the API can call an old snapshot stale (site/lib/proving-health.mjs)
    status_at: provingStatusAt ? new Date(provingStatusAt).toISOString() : null,
  };
}

// ---------- Supply check (spec 2.5 against the chain) ----------
// Two comparisons over the newest stored blocks, once an hour and 20 s after start: (a) the subsidy each payload
// declares equals blockSubsidy(daa, 1) of site/lib/emission.mjs; (b) each block's outputs sum to the declared subsidy
// of every block it merges (utxo_validation.rs:176 pays a merged block what its own payload declares; blues and reds
// inside the DAA window alike). Written to live_state.supply_check; /api/supply shows it beside the rule's total.
const SUPPLY_CHECK_EVERY_MS = 60 * 60_000, SUPPLY_SAMPLE = 500;
const VENDOR_SHARE_EVERY_MS = 60_000;   // live_state.vendor_share, written by tools/observer/vendor-share.mjs
let lastSupplyCheck = null;
async function supplyCheck() {
  try {
    const rows = await sql(`SELECT hash, daa_score, subsidy_sompi, paid_sompi, detail->'mergeset' AS mergeset FROM ${TB}
                              WHERE subsidy_sompi IS NOT NULL ORDER BY received_at DESC LIMIT ${SUPPLY_SAMPLE}`);
    const byHash = new Map(rows.map(r => [r.hash, r]));
    let ruleOk = 0, ruleBad = 0, sumOk = 0, sumBad = 0, sumSkipped = 0; const examples = [];
    for (const r of rows) {
      const want = blockSubsidy(Number(r.daa_score), 1);
      if (BigInt(r.subsidy_sompi) === want) ruleOk++; else { ruleBad++; if (examples.length < 3) examples.push({ kind: 'rule', block: short(r.hash), daa: Number(r.daa_score), declared: String(r.subsidy_sompi), rule: want.toString() }); }
      const ms = r.mergeset || { blues: [], reds: [] };
      const merged = [...(ms.blues || []), ...(ms.reds || [])];
      if (!merged.length || merged.some(h => !byHash.has(h))) { sumSkipped++; continue; } // a merged block outside the sample: no verdict
      const expect = merged.reduce((t, h) => t + BigInt(byHash.get(h).subsidy_sompi), 0n);
      if (BigInt(r.paid_sompi) === expect) sumOk++; else { sumBad++; if (examples.length < 3) examples.push({ kind: 'sum', block: short(r.hash), paid: String(r.paid_sompi), expected: expect.toString(), merged: merged.length }); }
    }
    lastSupplyCheck = { checked_at: new Date().toISOString(), sampled: rows.length, rule_match: ruleOk, rule_mismatch: ruleBad, sum_match: sumOk, sum_mismatch: sumBad, sum_skipped: sumSkipped, examples, bps: 1 };
    log(`supply check: ${rows.length} blocks, payload subsidy = rule ${ruleOk}/${ruleOk + ruleBad}, outputs = merged subsidies ${sumOk}/${sumOk + sumBad} (${sumSkipped} without a verdict)`);
  } catch (e) { log('supply check failed', e.message); }
}

async function prune() {
  try {
    await sql(`DELETE FROM ${TB} WHERE received_at < now() - ($1 || ' hours')::interval`, [String(RETAIN_HOURS)]);
    await sql(`DELETE FROM ${TP} WHERE received_at < now() - ($1 || ' hours')::interval`, [String(RETAIN_HOURS)]);
    await sql(`DELETE FROM ${TE} WHERE ts < now() - interval '7 days'`);
    await sql(`DELETE FROM ${TC} WHERE updated_at < now() - interval '7 days'`);
  } catch (e) { log('prune failed', e.message); }
}

async function seedFromDb() {
  try {
    const rows = await sql(`SELECT vote_key_hash, max(received_at) AS last FROM ${TB} WHERE vote_key_hash IS NOT NULL AND received_at > now() - interval '1 day' GROUP BY 1`);
    for (const r of rows) miners.set(r.vote_key_hash, { lastSeen: new Date(r.last).getTime(), quiet: Date.now() - new Date(r.last).getTime() > QUIET_AFTER_MS });
    const mins = await sql(`SELECT (floor(timestamp_ms / 60000.0) * 60000)::bigint AS m, count(*)::int AS n FROM ${TB} WHERE timestamp_ms > (extract(epoch from now()) * 1000 - 61 * 60000) GROUP BY 1`);
    for (const r of mins) minuteCounts.set(Number(r.m), r.n);
    const recent = await sql(`SELECT timestamp_ms FROM ${TB} WHERE timestamp_ms > (extract(epoch from now()) * 1000 - 120000)`);
    for (const r of recent) recentArrivals.push(Number(r.timestamp_ms));
    const newest = await sql(`SELECT max(timestamp_ms)::bigint AS t FROM ${TB}`);
    if (newest.length && newest[0].t) newestStoredTs = Number(newest[0].t);
    const st = await sql(`SELECT difficulty FROM ${TS} WHERE id = 1`);
    const cps = await sql(`SELECT index, state FROM ${TC} WHERE updated_at > now() - interval '1 day'`);
    for (const r of cps) checkpointStates.set(Number(r.index), r.state);
    { const by = {}; for (const r of cps) by[r.state] = (by[r.state] || 0) + 1; log(`seeded ${cps.length} checkpoint states: ${Object.entries(by).map(([k, v]) => `${k} ${v}`).join(', ') || 'none'}`); }
    const certs = await sql(`SELECT index, hash FROM ${TX}`);
    for (const r of certs) storedCerts.set(Number(r.index), r.hash);
    // proving: keep polling the blocks of the last 10 minutes that are not fully paid, so a restart loses nothing
    const open = await sql(`SELECT block_hash, block_number, block_daa, extract(epoch from received_at) * 1000 AS ts, array_agg(state ORDER BY shard) AS states, array_agg(prover ORDER BY shard) AS provers
                              FROM ${TP} WHERE received_at > now() - interval '10 minutes' GROUP BY 1, 2, 3, 4`);
    for (const r of open) {
      daaOfNumber.set(Number(r.block_number), Number(r.block_daa));
      openBlocks.set(r.block_hash, { number: Number(r.block_number), daa: Number(r.block_daa), ts: Number(r.ts), shards: r.states, provers: r.states.map(() => null), polledAt: 0, done: r.states.every(s => s === 'paid') });
      for (const p of r.provers) if (p) provers.add(p);
    }
    if (open.some(r => r.states.some(s => s === 'paid'))) firstPaidSeen = true;
    if (st.length && st[0].difficulty) lastDifficultyEvent = Number(st[0].difficulty);
  } catch (e) { log('seed failed', e.message); }
}

async function main() {
  await setupSchema();
  await seedFromDb();
  log(`observer started, rpc ${RPC}, evm rpc ${EVM}, keeping ${RETAIN_HOURS} h of blocks, ${miners.size} miners known, ${openBlocks.size} blocks open for proofs`);
  const rpc = new Rpc(RPC);
  // The socket handler only enqueues; the drain loop does the work in bounded batches so the socket is always read
  rpc.onNotification = (method, params) => { inbox.push([method, params]); if (!draining) { draining = true; setImmediate(drain); } };
  function drain() {
    const batch = inbox.splice(0, 500);
    for (const [m, p] of batch) { try { handle(m, p); } catch (e) { log('notification failed', e.message); } }
    if (inbox.length) setImmediate(drain); else draining = false;
  }
  function handle(method, params) {
    const inner = params && (params.BlockAdded || params.VirtualChainChanged || params);
    if (method === 'blockAddedNotification' && inner && inner.block) onBlock(inner.block);
    else if (method === 'finalityLockNotification' && inner) {
      // The node's lockEvent: write the checkpoint and the event at once; the 2 s poll fills in the rest
      const cp = inner.FinalityLock || inner;
      if (cp.index !== undefined && checkpointStates.get(Number(cp.index)) !== 'locked') {
        checkpointStates.set(Number(cp.index), 'locked');
        upsertCheckpoint({ ...cp, state: 'locked', aggregators: [] });
        recordLock(cp);
      }
    }
    else if (method === 'virtualChainChangedNotification' && inner) {
      for (const h of inner.addedChainBlockHashes || []) { pendingChain.remove.delete(h); pendingChain.add.add(h); pendingUnmerge.delete(h); if (!pendingMerge.has(h)) pendingMerge.set(h, mergesets.get(h) || null); queuePlan(h); }
      for (const h of inner.removedChainBlockHashes || []) { pendingChain.add.delete(h); pendingChain.remove.add(h); pendingMerge.delete(h); pendingUnmerge.add(h); dropPlan(h); }
    }
  }
  let connected = false;
  const connect = async () => {
    while (!(await rpc.connect())) { log('rpc connect failed, retrying in 3 s'); await new Promise(r => setTimeout(r, 3000)); }
    try {
      const srv = await rpc.call('getServerInfo', {});
      nodeVersion = srv.serverVersion || null;
      const net = String(srv.networkId || 'devnet');
      network = net.startsWith('igneum') ? net : `igneum-${net}`;
      addressPrefix = network.includes('devnet') ? 'igneumdev' : network.includes('testnet') ? 'igneumtest' : network.includes('simnet') ? 'igneumsim' : 'igneum';
      await rpc.call('subscribe', { BlockAdded: {} });
      await rpc.call('subscribe', { VirtualChainChanged: { include_accepted_transaction_ids: false } });
      await rpc.call('subscribe', { FinalityLock: {} }).catch(e => log('FinalityLock subscription refused (pre-v2 node?):', e.message));
      log(`subscribed on ${network}, node ${nodeVersion}`);
      if (connected) recordEvent('observer', 'Observer reconnected to the node'); else recordEvent('observer', `Observer started against ${network}`);
      connected = true;
    } catch (e) { log('subscribe failed', e.message); }
  };
  rpc.onClose = () => { setTimeout(connect, 2000); };
  await connect();
  // Watchdog (5 October 2026): after the observer node was restarted for 0.3.9 the reporter logged "rpc not connected" for
  // an hour without reconnecting (the socket's close never resolved into a new connect). Ten failed ticks in a row force
  // the socket shut and a fresh connect; the live page must never go stale while the node answers.
  let failedTicks = 0;
  rpc.noteTick = (ok) => {
    failedTicks = ok ? 0 : failedTicks + 1;
    if (failedTicks === 10) {
      log('watchdog: 10 failed ticks, forcing a reconnect');
      failedTicks = 0;
      try { rpc.ws && rpc.ws.close(); } catch { }
      rpc.open = false;
      setTimeout(connect, 1000);
    }
  };

  setInterval(async () => { if (flushBusy) return; flushBusy = true; try { await flushBlocks(); await flushChain(); } finally { flushBusy = false; } }, FLUSH_EVERY_MS);
  setInterval(() => flushColors(rpc), FLUSH_EVERY_MS);
  setInterval(() => flushCertificates(rpc), FLUSH_EVERY_MS);
  setInterval(flushPlans, FLUSH_EVERY_MS);
  setInterval(pollRecords, STATE_EVERY_MS);
  setInterval(() => tick(rpc), STATE_EVERY_MS);
  setInterval(prune, PRUNE_EVERY_MS);
  setInterval(supplyCheck, SUPPLY_CHECK_EVERY_MS); setTimeout(supplyCheck, 20_000);
  // Detector (6 Oct 2026): once a minute, live_state.detector and live_events kind `detector`; tools/observer/detector.mjs
  const detector = makeDetector({ sql, TB, TS, recordEvent, log }, detectorOpts());
  setInterval(() => detector().catch(e => log('detector failed', e.message)), 60_000); setTimeout(() => detector().catch(e => log('detector failed', e.message)), 40_000);
  setInterval(() => vendorShareTick(sql, T, log), VENDOR_SHARE_EVERY_MS); setTimeout(() => vendorShareTick(sql, T, log), 30_000);
  tick(rpc); prune();
}

process.on('unhandledRejection', e => log('unhandled', e && e.message));
main().catch(e => { console.error(e); process.exit(1); });