Add initial oracle price engine

1 week ago · 508629be3f
1 changed files with 293 additions and 0 deletions
--- a/oracle/price_engine.js
+++ b/oracle/price_engine.js
@ -0,0 +1,293 @@
+const fs = require('fs');
+const path = require('path');
+
+const ORACLE_DIR = __dirname;
+const ASSETS_FILE = path.join(ORACLE_DIR, 'assets.json');
+const SOURCES_FILE = path.join(ORACLE_DIR, 'sources.json');
+const CACHE_FILE = path.join(ORACLE_DIR, 'price_cache.json');
+
+function readJson(filePath) {
+  try {
+    return JSON.parse(fs.readFileSync(filePath, 'utf8'));
+  } catch (err) {
+    throw new Error(`Failed to read JSON file ${filePath}: ${err.message}`);
+  }
+}
+
+function writeJson(filePath, data) {
+  const tmpFile = `${filePath}.tmp`;
+  fs.writeFileSync(tmpFile, JSON.stringify(data, null, 2) + '\n', 'utf8');
+  fs.renameSync(tmpFile, filePath);
+}
+
+function nowIso() {
+  return new Date().toISOString();
+}
+
+function ageSeconds(isoTime) {
+  if (!isoTime) return null;
+  const ts = new Date(isoTime).getTime();
+  if (Number.isNaN(ts)) return null;
+  return Math.max(0, Math.floor((Date.now() - ts) / 1000));
+}
+
+function getFreshnessStatus(age) {
+  if (age === null) return 'stale';
+  if (age <= 120) return 'fresh';
+  if (age <= 300) return 'degraded';
+  return 'stale';
+}
+
+function loadAssets() {
+  return readJson(ASSETS_FILE);
+}
+
+function loadSources() {
+  return readJson(SOURCES_FILE);
+}
+
+function loadCache() {
+  return readJson(CACHE_FILE);
+}
+
+function saveCache(cacheData) {
+  writeJson(CACHE_FILE, cacheData);
+}
+
+function listAssets() {
+  const assetsDoc = loadAssets();
+  const assets = assetsDoc.assets || {};
+
+  const out = Object.entries(assets)
+    .sort((a, b) => {
+      const pa = a[1].quote_priority ?? 9999;
+      const pb = b[1].quote_priority ?? 9999;
+      return pa - pb;
+    })
+    .map(([pairKey, asset]) => ({
+      pair_key: pairKey,
+      symbol: asset.symbol,
+      name: asset.name,
+      chain: asset.chain,
+      type: asset.type,
+      contract: asset.contract || null,
+      decimals: asset.decimals,
+      billing_enabled: !!asset.billing_enabled,
+      quote_priority: asset.quote_priority,
+      primary_source: asset.primary_source || null,
+      fallback_source: asset.fallback_source || null
+    }));
+
+  return {
+    assets: out
+  };
+}
+
+function getPrices() {
+  const cache = loadCache();
+  const assetsDoc = loadAssets();
+  const cacheAssets = cache.assets || {};
+  const assetDefs = assetsDoc.assets || {};
+
+  const resultAssets = {};
+
+  for (const [pairKey, assetDef] of Object.entries(assetDefs)) {
+    const cached = cacheAssets[pairKey] || {};
+    const age = ageSeconds(cached.updated_at);
+    const freshness = getFreshnessStatus(age);
+
+    resultAssets[pairKey] = {
+      pair_key: pairKey,
+      symbol: assetDef.symbol,
+      name: assetDef.name,
+      chain: assetDef.chain,
+      type: assetDef.type,
+      contract: assetDef.contract || null,
+      decimals: assetDef.decimals,
+      billing_enabled: !!assetDef.billing_enabled,
+      quote_priority: assetDef.quote_priority,
+      price_usd: cached.price_usd ?? null,
+      price_cad: cached.price_cad ?? null,
+      source: cached.source ?? null,
+      source_status: cached.source_status ?? null,
+      updated_at: cached.updated_at ?? null,
+      age_seconds: age,
+      freshness,
+      stale: freshness === 'stale'
+    };
+  }
+
+  const overallAges = Object.values(resultAssets)
+    .map(a => a.age_seconds)
+    .filter(a => a !== null);
+
+  let overallStatus = 'stale';
+  if (overallAges.length > 0) {
+    const maxAge = Math.max(...overallAges);
+    overallStatus = getFreshnessStatus(maxAge);
+  }
+
+  return {
+    version: cache.version || '0.1',
+    updated_at: cache.updated_at || null,
+    status: overallStatus,
+    assets: resultAssets
+  };
+}
+
+function roundAmount(value, decimals = 8) {
+  if (typeof value !== 'number' || !Number.isFinite(value)) return null;
+  return Number(value.toFixed(decimals));
+}
+
+function buildQuote({ fiat = 'CAD', amount }) {
+  const normalizedFiat = String(fiat || 'CAD').toUpperCase();
+  const numericAmount = Number(amount);
+
+  if (!Number.isFinite(numericAmount) || numericAmount <= 0) {
+    throw new Error('Invalid quote amount');
+  }
+
+  if (normalizedFiat !== 'CAD') {
+    throw new Error('Only CAD quotes are supported in v0.1');
+  }
+
+  const prices = getPrices();
+  const quoteTtlSeconds = 900;
+  const quotedAt = nowIso();
+  const expiresAt = new Date(Date.now() + quoteTtlSeconds * 1000).toISOString();
+
+  const quotes = Object.values(prices.assets)
+    .filter(asset => asset.billing_enabled)
+    .sort((a, b) => (a.quote_priority ?? 9999) - (b.quote_priority ?? 9999))
+    .map(asset => {
+      if (!asset.price_cad || asset.price_cad <= 0) {
+        return {
+          pair_key: asset.pair_key,
+          symbol: asset.symbol,
+          chain: asset.chain,
+          crypto_amount: null,
+          display_amount: null,
+          price_cad: asset.price_cad,
+          recommended: asset.quote_priority === 1,
+          available: false,
+          reason: 'missing_price'
+        };
+      }
+
+      const cryptoAmount = numericAmount / asset.price_cad;
+      const precision = asset.symbol === 'USDC' ? 6 : 8;
+
+      return {
+        pair_key: asset.pair_key,
+        symbol: asset.symbol,
+        chain: asset.chain,
+        crypto_amount: roundAmount(cryptoAmount, precision),
+        display_amount: roundAmount(cryptoAmount, precision)?.toFixed(precision) || null,
+        price_cad: asset.price_cad,
+        recommended: asset.quote_priority === 1,
+        available: !asset.stale,
+        reason: asset.stale ? 'stale_price' : null
+      };
+    });
+
+  return {
+    fiat: normalizedFiat,
+    amount: roundAmount(numericAmount, 2),
+    quoted_at: quotedAt,
+    expires_at: expiresAt,
+    ttl_seconds: quoteTtlSeconds,
+    source_status: prices.status,
+    quotes
+  };
+}
+
+function updateCachedPrice(pairKey, update) {
+  const assetsDoc = loadAssets();
+  const cache = loadCache();
+
+  if (!assetsDoc.assets || !assetsDoc.assets[pairKey]) {
+    throw new Error(`Unknown asset pair key: ${pairKey}`);
+  }
+
+  if (!cache.assets) {
+    cache.assets = {};
+  }
+
+  const assetDef = assetsDoc.assets[pairKey];
+  const existing = cache.assets[pairKey] || {};
+
+  cache.assets[pairKey] = {
+    symbol: assetDef.symbol,
+    chain: assetDef.chain,
+    price_usd: update.price_usd ?? existing.price_usd ?? null,
+    price_cad: update.price_cad ?? existing.price_cad ?? null,
+    source: update.source ?? existing.source ?? null,
+    source_status: update.source_status ?? existing.source_status ?? 'primary',
+    updated_at: update.updated_at ?? nowIso(),
+    age_seconds: 0,
+    stale: false
+  };
+
+  cache.updated_at = nowIso();
+  cache.status = 'fresh';
+
+  saveCache(cache);
+  return cache.assets[pairKey];
+}
+
+function getStatus() {
+  const sources = loadSources();
+  const prices = getPrices();
+
+  const sourceStatuses = Object.values(prices.assets).map(a => ({
+    pair_key: a.pair_key,
+    symbol: a.symbol,
+    chain: a.chain,
+    source: a.source,
+    source_status: a.source_status,
+    updated_at: a.updated_at,
+    age_seconds: a.age_seconds,
+    freshness: a.freshness
+  }));
+
+  return {
+    service: 'otb-oracle',
+    version: '0.1.0',
+    time_utc: nowIso(),
+    overall_status: prices.status,
+    configured_sources: Object.keys(sources.sources || {}),
+    assets: sourceStatuses
+  };
+}
+
+module.exports = {
+  loadAssets,
+  loadSources,
+  loadCache,
+  saveCache,
+  listAssets,
+  getPrices,
+  buildQuote,
+  updateCachedPrice,
+  getStatus
+};
+
+if (require.main === module) {
+  try {
+    console.log(JSON.stringify({
+      health: {
+        ok: true,
+        service: 'otb-oracle',
+        version: '0.1.0',
+        time_utc: nowIso(),
+        status: 'healthy'
+      },
+      assets: listAssets(),
+      prices: getPrices()
+    }, null, 2));
+  } catch (err) {
+    console.error(`price_engine.js failed: ${err.message}`);
+    process.exit(1);
+  }
+}