server.mjs

import http from "node:http";
import fs from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const publicDir = path.join(__dirname, "public");
const seedPath = path.join(__dirname, "data", "seed-data.json");
const cachePath = path.join(__dirname, "data", "dashboard-cache.json");
const breadthHistoryPath = path.join(__dirname, "data", "breadth-history.json");
const port = Number(process.env.PORT || 4173);
const host = process.env.HOST || (process.env.SPACE_ID ? "0.0.0.0" : "127.0.0.1");
const seedOnly = process.env.GEN_DASHBOARD_SEED_ONLY === "1";

const quoteUrl = "https://query1.finance.yahoo.com/v7/finance/quote";
const chartUrl = "https://query1.finance.yahoo.com/v8/finance/chart";
const stooqQuoteUrl = "https://stooq.com/q/l/";

let memoryCache = null;

function nyDate(date = new Date()) {
  const parts = new Intl.DateTimeFormat("en-US", {
    timeZone: "America/New_York",
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
  }).formatToParts(date);
  const byType = Object.fromEntries(parts.map((part) => [part.type, part.value]));
  return `${byType.year}-${byType.month}-${byType.day}`;
}

function isoDate(date) {
  return date.toISOString().slice(0, 10);
}

function toYahooSymbol(symbol) {
  if (!symbol) return "";
  if (symbol === "NDX") return "^NDX";
  if (symbol === "VIX") return "^VIX";
  return String(symbol).replace(".", "-").trim();
}

function toStooqSymbol(symbol) {
  if (!symbol || String(symbol).startsWith("^") || symbol === "BTC-USD") return null;
  return `${String(symbol).replace(".", "-").toLowerCase()}.us`;
}

function percentFromQuote(value) {
  return Number.isFinite(value) ? value / 100 : null;
}

function number(value) {
  return Number.isFinite(value) ? value : null;
}

function uniq(values) {
  return [...new Set(values.filter(Boolean))];
}

function chunk(values, size) {
  const groups = [];
  for (let i = 0; i < values.length; i += size) groups.push(values.slice(i, i + size));
  return groups;
}

async function readJson(filePath, fallback = null) {
  try {
    return JSON.parse(await fs.readFile(filePath, "utf8"));
  } catch {
    return fallback;
  }
}

async function writeJson(filePath, data) {
  await fs.mkdir(path.dirname(filePath), { recursive: true });
  await fs.writeFile(filePath, `${JSON.stringify(data, null, 2)}\n`, "utf8");
}

async function fetchJson(url, timeoutMs = 9000) {
  const controller = new AbortController();
  const timeout = setTimeout(() => controller.abort(), timeoutMs);
  try {
    const response = await fetch(url, {
      signal: controller.signal,
      headers: {
        "user-agent":
          "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124 Safari/537.36",
        accept: "application/json,text/plain,*/*",
      },
    });
    if (!response.ok) throw new Error(`HTTP ${response.status}`);
    return await response.json();
  } finally {
    clearTimeout(timeout);
  }
}

async function fetchYahooQuotes(symbols) {
  if (!symbols.length) return new Map();
  const groups = chunk(uniq(symbols).map(toYahooSymbol), 80);
  const results = await Promise.allSettled(
    groups.map(async (group) => {
      const url = `${quoteUrl}?symbols=${encodeURIComponent(group.join(","))}`;
      const json = await fetchJson(url);
      return json?.quoteResponse?.result || [];
    }),
  );

  const quotes = new Map();
  for (const result of results) {
    if (result.status !== "fulfilled") continue;
    for (const quote of result.value) {
      quotes.set(quote.symbol, quote);
    }
  }
  return quotes;
}

function parseCsv(text) {
  return text
    .trim()
    .split(/\r?\n/)
    .map((line) => line.split(",").map((cell) => cell.trim()));
}

function toFinite(value) {
  const parsed = Number(value);
  return Number.isFinite(parsed) ? parsed : null;
}

async function fetchStooqQuotes(symbols) {
  const symbolMap = new Map();
  for (const symbol of symbols) {
    const stooq = toStooqSymbol(symbol);
    if (stooq) symbolMap.set(stooq.toUpperCase(), toYahooSymbol(symbol));
  }
  if (!symbolMap.size) return new Map();

  const groups = chunk([...symbolMap.keys()].map((symbol) => symbol.toLowerCase()), 80);
  const results = await Promise.allSettled(
    groups.map(async (group) => {
      const params = new URLSearchParams({ s: group.join(" "), f: "sd2t2ohlcvp", h: "", e: "csv" });
      const text = await fetch(`${stooqQuoteUrl}?${params.toString()}`, {
        headers: { "user-agent": "Mozilla/5.0", accept: "text/csv,*/*" },
      }).then((response) => {
        if (!response.ok) throw new Error(`HTTP ${response.status}`);
        return response.text();
      });
      return parseCsv(text).slice(1);
    }),
  );

  const quotes = new Map();
  for (const result of results) {
    if (result.status !== "fulfilled") continue;
    for (const row of result.value) {
      const [stooqSymbol, date, , , , , closeRaw, volumeRaw, prevRaw] = row;
      if (!stooqSymbol || date === "N/D") continue;
      const symbol = symbolMap.get(stooqSymbol.toUpperCase());
      const close = toFinite(closeRaw);
      const previous = toFinite(prevRaw);
      const volume = toFinite(volumeRaw);
      if (!symbol || !Number.isFinite(close)) continue;
      quotes.set(symbol, {
        symbol,
        regularMarketPrice: close,
        regularMarketPreviousClose: previous,
        regularMarketChangePercent:
          Number.isFinite(previous) && previous !== 0 ? ((close - previous) / previous) * 100 : null,
        regularMarketVolume: volume,
        source: "stooq",
      });
    }
  }
  return quotes;
}

async function fetchQuotes(symbols) {
  const wanted = uniq(symbols);
  const yahooQuotes = await fetchYahooQuotes(wanted).catch(() => new Map());
  const missing = wanted.filter((symbol) => !yahooQuotes.has(toYahooSymbol(symbol)));
  if (missing.length) {
    const stooqQuotes = await fetchStooqQuotes(missing).catch(() => new Map());
    for (const [symbol, quote] of stooqQuotes) yahooQuotes.set(symbol, quote);
  }
  return yahooQuotes;
}

async function fetchChart(symbol, { range, interval = "1d", period1, period2 } = {}) {
  const params = new URLSearchParams({ interval });
  if (range) {
    params.set("range", range);
  } else {
    params.set("period1", String(period1));
    params.set("period2", String(period2 || Math.floor(Date.now() / 1000)));
  }
  const json = await fetchJson(`${chartUrl}/${encodeURIComponent(toYahooSymbol(symbol))}?${params.toString()}`);
  const result = json?.chart?.result?.[0];
  if (!result?.timestamp?.length) return null;
  const quote = result.indicators?.quote?.[0] || {};
  const closes = quote.close || [];
  const volumes = quote.volume || [];
  return result.timestamp
    .map((timestamp, index) => ({
      date: isoDate(new Date(timestamp * 1000)),
      close: number(closes[index]),
      volume: number(volumes[index]),
    }))
    .filter((point) => point.close !== null);
}

function quoteLookup(quotes, symbol) {
  return quotes.get(toYahooSymbol(symbol)) || null;
}

function quoteChange(quotes, symbol) {
  return percentFromQuote(quoteLookup(quotes, symbol)?.regularMarketChangePercent);
}

function quotePrice(quotes, symbol) {
  return number(quoteLookup(quotes, symbol)?.regularMarketPrice);
}

function enrichHolding(holding, quotes, snapshot = null) {
  const quote = quoteLookup(quotes, holding.ticker);
  const volume = number(quote?.regularMarketVolume);
  const avgVolume = number(quote?.averageDailyVolume3Month) || number(quote?.averageDailyVolume10Day);
  return {
    ...holding,
    sector: holding.sector ?? snapshot?.sector ?? null,
    price: number(quote?.regularMarketPrice) ?? snapshot?.price ?? null,
    change: percentFromQuote(quote?.regularMarketChangePercent) ?? snapshot?.change ?? null,
    range: snapshot?.range ?? holding.range ?? null,
    volume: volume ?? null,
    avgVolume: avgVolume ?? null,
    volumeRatio: Number.isFinite(volume) && Number.isFinite(avgVolume) && avgVolume ? volume / avgVolume : null,
    fiftyTwoWeekHigh: number(quote?.fiftyTwoWeekHigh),
    fiftyTwoWeekLow: number(quote?.fiftyTwoWeekLow),
  };
}

function breadth(holdings) {
  const tracked = holdings.filter((item) => Number.isFinite(item.change));
  const advance = tracked.filter((item) => item.change > 0).length;
  const decline = tracked.filter((item) => item.change < 0).length;
  const unchanged = tracked.filter((item) => item.change === 0).length;
  return { advance, decline, unchanged, total: tracked.length || holdings.length };
}

function topMovers(holdings) {
  const valid = holdings.filter((item) => Number.isFinite(item.change));
  return {
    losers: [...valid].sort((a, b) => a.change - b.change).slice(0, 10),
    gainers: [...valid].sort((a, b) => b.change - a.change).slice(0, 10),
  };
}

function topRangeRows(holdings) {
  return holdings
    .map((item) => {
      const high = item.fiftyTwoWeekHigh;
      const low = item.fiftyTwoWeekLow;
      let range = item.range;
      if (Number.isFinite(item.price) && Number.isFinite(high) && Number.isFinite(low) && high !== low) {
        range = (item.price - low) / (high - low);
      }
      return { ...item, range };
    })
    .filter((item) => item.ticker && Number.isFinite(item.range))
    .sort((a, b) => (b.weight || 0) - (a.weight || 0))
    .slice(0, 18);
}

function topContributions(holdings) {
  return holdings
    .filter((item) => Number.isFinite(item.weight) && Number.isFinite(item.change))
    .sort((a, b) => b.weight - a.weight)
    .slice(0, 10)
    .map((item) => ({ ...item, contribution: item.weight * item.change }));
}

function buildRangeDistribution(holdings) {
  const bins = [
    { label: "0-20%", min: 0, max: 0.2 },
    { label: "20-40%", min: 0.2, max: 0.4 },
    { label: "40-60%", min: 0.4, max: 0.6 },
    { label: "60-80%", min: 0.6, max: 0.8 },
    { label: "80-100%", min: 0.8, max: 1.01 },
  ].map((bin) => ({ ...bin, count: 0, weight: 0 }));

  for (const holding of holdings) {
    const range = Number(holding.range);
    if (!Number.isFinite(range)) continue;
    const bin = bins.find((item) => range >= item.min && range < item.max);
    if (!bin) continue;
    bin.count += 1;
    bin.weight += Number.isFinite(holding.weight) ? holding.weight : 0;
  }

  return bins.map(({ label, count, weight }) => ({ label, count, weight }));
}

function buildLeadershipMap(holdings) {
  return holdings
    .filter((item) => item.ticker && Number.isFinite(item.range) && Number.isFinite(item.change))
    .map((item) => ({
      ticker: item.ticker,
      range: item.range,
      change: item.change,
      weight: Number.isFinite(item.weight) ? item.weight : 0,
      sector: item.sector || "",
      price: Number.isFinite(item.price) ? item.price : null,
    }))
    .sort((a, b) => b.weight - a.weight)
    .slice(0, 140);
}

function buildUnusualVolume(spyHoldings, qqqHoldings, sectors) {
  const seen = new Set();
  const stockRows = [...qqqHoldings, ...spyHoldings]
    .filter((item) => {
      if (!item.ticker || seen.has(item.ticker)) return false;
      seen.add(item.ticker);
      return Number.isFinite(item.change) && Number.isFinite(item.volumeRatio);
    })
    .map((item) => ({
      ticker: item.ticker,
      change: item.change,
      volumeRatio: item.volumeRatio,
      weight: Number.isFinite(item.weight) ? item.weight : 0,
    }))
    .sort((a, b) => b.volumeRatio - a.volumeRatio)
    .slice(0, 40);

  if (stockRows.length >= 8) return { mode: "stocks", rows: stockRows };

  return {
    mode: "sector-etfs",
    rows: sectors
      .filter((item) => Number.isFinite(item.change) && Number.isFinite(item.volumeAvgRatio))
      .map((item) => ({
        ticker: item.symbol || item.name,
        change: item.change,
        volumeRatio: item.volumeAvgRatio,
        weight: Number.isFinite(item.volumeM) ? item.volumeM : 0,
      }))
      .sort((a, b) => b.volumeRatio - a.volumeRatio),
  };
}

function buildRiskRegime(spyTrend, summary) {
  const labels = spyTrend?.labels || [];
  const values = spyTrend?.series?.[0]?.values || [];
  const drawdown =
    spyTrend?.drawdown ||
    values.map((value, index) => {
      const priorValues = values.slice(0, index + 1).filter(Number.isFinite);
      const runningMax = Math.max(...priorValues);
      return Number.isFinite(value) && Number.isFinite(runningMax) && runningMax > 0 ? value / runningMax - 1 : null;
    });
  const returns = values
    .map((value, index) => (index > 0 && Number.isFinite(value) && Number.isFinite(values[index - 1]) ? value / values[index - 1] - 1 : null))
    .filter(Number.isFinite);
  const recentReturns = returns.slice(-20);
  const mean = recentReturns.reduce((sum, value) => sum + value, 0) / Math.max(1, recentReturns.length);
  const variance =
    recentReturns.reduce((sum, value) => sum + (value - mean) ** 2, 0) / Math.max(1, recentReturns.length - 1);
  const realizedVol = recentReturns.length > 1 ? Math.sqrt(variance) * Math.sqrt(252) : null;
  const latestDrawdown = drawdown.filter(Number.isFinite).at(-1) ?? null;
  const maxDrawdown = Math.min(...drawdown.filter(Number.isFinite));
  return {
    labels,
    series: [
      { name: "SPY drawdown", values: drawdown },
      { name: "VIX", values: labels.map(() => summary?.vix?.price ?? null) },
    ],
    metrics: {
      currentDrawdown: latestDrawdown,
      maxDrawdown: Number.isFinite(maxDrawdown) ? maxDrawdown : null,
      realizedVol,
      vix: summary?.vix?.price ?? null,
    },
  };
}

function breadthPoint(date, summary) {
  const spyTotal = summary?.spy?.total || 0;
  const qqqTotal = summary?.qqq?.total || 0;
  return {
    date,
    spyAdvanceRatio: spyTotal ? summary.spy.advance / spyTotal : null,
    qqqAdvanceRatio: qqqTotal ? summary.qqq.advance / qqqTotal : null,
    spyNetRatio: spyTotal ? (summary.spy.advance - summary.spy.decline) / spyTotal : null,
    qqqNetRatio: qqqTotal ? (summary.qqq.advance - summary.qqq.decline) / qqqTotal : null,
  };
}

async function updateBreadthHistory(date, summary) {
  const current = breadthPoint(date, summary);
  const existing = await readJson(breadthHistoryPath, []);
  const history = Array.isArray(existing) ? existing.filter((point) => point?.date !== date) : [];
  history.push(current);
  history.sort((a, b) => String(a.date).localeCompare(String(b.date)));
  const clipped = history.slice(-90);
  await writeJson(breadthHistoryPath, clipped);
  const rows = clipped.slice(-60);
  return {
    labels: rows.map((point) => point.date),
    series: [
      { name: "SPY Adv%", values: rows.map((point) => point.spyAdvanceRatio) },
      { name: "QQQ Adv%", values: rows.map((point) => point.qqqAdvanceRatio) },
      { name: "SPY Net", values: rows.map((point) => point.spyNetRatio) },
      { name: "QQQ Net", values: rows.map((point) => point.qqqNetRatio) },
    ],
  };
}

function normalizeSeedCharts(seed) {
  const mag7Labels = seed.charts.mag7.history.map((point) => String(point.index));
  const mag7Series = seed.charts.mag7.names
    .map((name, index) => ({
      name,
      values: seed.charts.mag7.history.map((point) => point.values[index]),
    }))
    .filter((series) => series.name);

  const relativeLabels = seed.charts.relative.history.map((point) => String(point.index));
  const relativeSeries = seed.charts.relative.names
    .map((name, index) => ({
      name,
      values: seed.charts.relative.history.map((point) => point.values[index]),
    }))
    .filter((series) => series.name);

  return {
    mag7: { labels: mag7Labels, series: mag7Series },
    relative: { labels: relativeLabels, series: relativeSeries },
    spyTrend: {
      labels: seed.charts.spyTrend.map((point) => point.date),
      series: [{ name: "SPY", values: seed.charts.spyTrend.map((point) => point.value) }],
      drawdown: seed.charts.spyTrend.map((point) => point.drawdown ?? null),
    },
    beta: seed.charts.beta,
  };
}

function withLatestPrice(chart, asOf, latestPrice) {
  if (!chart || !Number.isFinite(latestPrice)) return chart;
  const labels = [...(chart.labels || [])];
  const series = (chart.series || []).map((item) => ({ ...item, values: [...(item.values || [])] }));
  if (!labels.length || !series.length) return chart;

  const lastIndex = labels.length - 1;
  if (labels[lastIndex] === asOf) {
    series[0].values[lastIndex] = latestPrice;
  } else {
    labels.push(asOf);
    series[0].values.push(latestPrice);
  }

  const values = series[0].values;
  const drawdown = values.map((value, index) => {
    const priorValues = values.slice(0, index + 1).filter(Number.isFinite);
    const runningMax = Math.max(...priorValues);
    return Number.isFinite(value) && Number.isFinite(runningMax) && runningMax > 0 ? value / runningMax - 1 : null;
  });

  return { ...chart, labels, series, drawdown };
}

function fallbackDashboard(seed, reason = "Using Excel cached data") {
  const qqqContributions = seed.qqqContributions;
  const charts = normalizeSeedCharts(seed);
  const dailyByTicker = new Map([...seed.snapshots.ndx, ...seed.snapshots.spx].map((row) => [row.ticker, row.change]));
  const mag7Daily = ["NVDA", "GOOG", "AMZN", "AAPL", "META", "MSFT", "TSLA"].map((ticker) => ({
    ticker,
    change: dailyByTicker.get(ticker) ?? null,
  }));
  return {
    mode: "seed",
    source: "Excel cache",
    status: reason,
    asOf: seed.seedAsOf,
    generatedAt: new Date().toISOString(),
    nextAutoRefresh: "On next New York trading date or manual refresh",
    summary: seed.summary,
    sectors: seed.sectors,
    topMovers: seed.topMovers,
    qqqContributions,
    qqqContributionTotal: qqqContributions.reduce((sum, row) => sum + (row.contribution || 0), 0),
    rangeRows: seed.snapshots.spx.slice(0, 18),
    charts: {
      ...charts,
      mag7Daily,
      rangeDistribution: buildRangeDistribution(seed.snapshots.spx),
      leadershipMap: buildLeadershipMap(seed.snapshots.spx),
      unusualVolume: buildUnusualVolume(seed.snapshots.spx, seed.snapshots.ndx, seed.sectors),
    },
  };
}

function normalizedPerformance(historyBySymbol, symbols) {
  const labels = historyBySymbol.get(symbols[0])?.map((point) => point.date) || [];
  const series = [];
  for (const symbol of symbols) {
    const history = historyBySymbol.get(symbol) || [];
    const base = history.find((point) => Number.isFinite(point.close))?.close;
    if (!base) continue;
    series.push({
      name: symbol.replace("^", ""),
      values: history.map((point) => ((point.close / base) - 1) * 100),
    });
  }
  return { labels, series };
}

async function buildLiveDashboard(seed) {
  if (seedOnly) return fallbackDashboard(seed, "Seed-only mode");

  const quoteSymbols = uniq([
    "SPY",
    "QQQ",
    "^VIX",
    ...seed.sectors.map((sector) => sector.symbol),
    ...seed.holdings.spy.map((holding) => holding.ticker),
    ...seed.holdings.qqq.map((holding) => holding.ticker),
  ]);

  const quotes = await fetchQuotes(quoteSymbols);
  if (!quotes.size) throw new Error("No quote data returned");

  const spxSnapshotByTicker = new Map(seed.snapshots.spx.map((row) => [row.ticker, row]));
  const ndxSnapshotByTicker = new Map(seed.snapshots.ndx.map((row) => [row.ticker, row]));
  const spyHoldings = seed.holdings.spy.map((holding) =>
    enrichHolding(holding, quotes, spxSnapshotByTicker.get(holding.ticker)),
  );
  const qqqHoldings = seed.holdings.qqq.map((holding) =>
    enrichHolding(holding, quotes, ndxSnapshotByTicker.get(holding.ticker)),
  );

  const spyBreadth = breadth(spyHoldings);
  const qqqBreadth = breadth(qqqHoldings);
  const sectors = seed.sectors.map((sector) => {
    const quote = quoteLookup(quotes, sector.symbol);
    const volume = number(quote?.regularMarketVolume);
    const avgVolume = number(quote?.averageDailyVolume3Month) || number(quote?.averageDailyVolume10Day);
    return {
      ...sector,
      change: percentFromQuote(quote?.regularMarketChangePercent) ?? sector.change,
      volumeM: Number.isFinite(volume) ? volume / 1_000_000 : sector.volumeM,
      volumeAvgRatio: Number.isFinite(volume) && Number.isFinite(avgVolume) && avgVolume
        ? volume / avgVolume
        : sector.volumeAvgRatio,
    };
  });

  const mag7Symbols = ["NVDA", "GOOG", "AMZN", "AAPL", "META", "MSFT", "TSLA", "^NDX"];
  const relativeSymbols = ["SPY", "QQQ", "GLD", "BTC-USD"];
  const start2025 = Math.floor(Date.UTC(2025, 0, 1) / 1000);
  const thisYear = Math.floor(Date.UTC(new Date().getUTCFullYear(), 0, 1) / 1000);

  const chartRequests = [
    ...mag7Symbols.map((symbol) => fetchChart(symbol, { range: "1mo" }).then((history) => [symbol, history])),
    ...relativeSymbols.map((symbol) =>
      fetchChart(symbol, { period1: start2025 }).then((history) => [symbol, history]),
    ),
    fetchChart("SPY", { period1: thisYear }).then((history) => ["SPY_TREND", history]),
  ];

  const chartResults = await Promise.allSettled(chartRequests);
  const historyBySymbol = new Map();
  for (const result of chartResults) {
    if (result.status === "fulfilled" && result.value?.[1]?.length) historyBySymbol.set(result.value[0], result.value[1]);
  }

  const seedCharts = normalizeSeedCharts(seed);
  const mag7Live = normalizedPerformance(historyBySymbol, mag7Symbols);
  const relativeLive = normalizedPerformance(historyBySymbol, relativeSymbols);
  const spyTrendHistory = historyBySymbol.get("SPY_TREND");
  const spyTrendSeed = withLatestPrice(seedCharts.spyTrend, nyDate(), quotePrice(quotes, "SPY"));
  const betaByTicker = new Map(seed.charts.beta.map((row) => [row.ticker, row]));
  const betaRows = qqqHoldings
    .map((holding) => {
      const beta = betaByTicker.get(holding.ticker)?.beta;
      return Number.isFinite(beta) && Number.isFinite(holding.change)
        ? { ticker: holding.ticker, beta, change: holding.change }
        : null;
    })
    .filter(Boolean)
    .slice(0, 80);

  const qqqContributions = topContributions(qqqHoldings);
  const mag7Daily = ["NVDA", "GOOG", "AMZN", "AAPL", "META", "MSFT", "TSLA"].map((ticker) => {
    const holding = qqqHoldings.find((item) => item.ticker === ticker) || spyHoldings.find((item) => item.ticker === ticker);
    return { ticker, change: quoteChange(quotes, ticker) ?? holding?.change ?? null };
  });
  return {
    mode: "live",
    source: "Yahoo/Stooq live quotes with Excel holdings",
    status: "Live market data",
    asOf: nyDate(),
    generatedAt: new Date().toISOString(),
    nextAutoRefresh: "Daily, keyed to the New York market date",
    summary: {
      spy: { ...spyBreadth, change: quoteChange(quotes, "SPY") ?? seed.summary.spy.change },
      qqq: { ...qqqBreadth, change: quoteChange(quotes, "QQQ") ?? seed.summary.qqq.change },
      vix: {
        price: quotePrice(quotes, "^VIX") ?? seed.summary.vix.price,
        change: quoteChange(quotes, "^VIX") ?? seed.summary.vix.change,
      },
    },
    sectors,
    topMovers: {
      spyLosers: topMovers(spyHoldings).losers,
      spyGainers: topMovers(spyHoldings).gainers,
      qqqLosers: topMovers(qqqHoldings).losers,
      qqqGainers: topMovers(qqqHoldings).gainers,
    },
    qqqContributions,
    qqqContributionTotal: qqqContributions.reduce((sum, row) => sum + row.contribution, 0),
    rangeRows: topRangeRows(spyHoldings),
    charts: {
      mag7: mag7Live.series.length >= 2 ? mag7Live : seedCharts.mag7,
      relative: relativeLive.series.length >= 2 ? relativeLive : seedCharts.relative,
      spyTrend: spyTrendHistory?.length
        ? {
            labels: spyTrendHistory.map((point) => point.date),
            series: [{ name: "SPY", values: spyTrendHistory.map((point) => point.close) }],
          }
        : spyTrendSeed,
      beta: betaRows.length ? betaRows : seedCharts.beta,
      mag7Daily,
      rangeDistribution: buildRangeDistribution(spyHoldings),
      leadershipMap: buildLeadershipMap(spyHoldings),
      unusualVolume: buildUnusualVolume(spyHoldings, qqqHoldings, sectors),
    },
  };
}

async function getDashboard(forceRefresh = false) {
  const today = nyDate();
  const sourceMode = seedOnly ? "seed-only" : "normal";
  if (!forceRefresh && memoryCache?.cacheDate === today) return memoryCache.data;

  const diskCache = await readJson(cachePath);
  if (!forceRefresh && diskCache?.cacheDate === today && diskCache?.sourceMode === sourceMode && diskCache?.data) {
    memoryCache = diskCache;
    return diskCache.data;
  }

  const seed = await readJson(seedPath);
  if (!seed) throw new Error("Missing data/seed-data.json. Run npm run seed first.");

  let data;
  try {
    data = await buildLiveDashboard(seed);
  } catch (error) {
    data = fallbackDashboard(seed, `Live refresh failed: ${error.message}`);
  }

  data.charts = data.charts || {};
  data.charts.breadthTrend = await updateBreadthHistory(data.asOf || today, data.summary);
  data.charts.riskRegime = buildRiskRegime(data.charts.spyTrend, data.summary);

  memoryCache = { cacheDate: today, sourceMode, data };
  await writeJson(cachePath, memoryCache);
  return data;
}

function sendJson(res, status, data) {
  const body = JSON.stringify(data);
  res.writeHead(status, {
    "content-type": "application/json; charset=utf-8",
    "cache-control": "no-store",
  });
  res.end(body);
}

function contentType(filePath) {
  const ext = path.extname(filePath);
  return (
    {
      ".html": "text/html; charset=utf-8",
      ".css": "text/css; charset=utf-8",
      ".js": "text/javascript; charset=utf-8",
      ".json": "application/json; charset=utf-8",
      ".svg": "image/svg+xml",
    }[ext] || "application/octet-stream"
  );
}

async function serveStatic(req, res, pathname) {
  const cleanPath = pathname === "/" ? "/index.html" : decodeURIComponent(pathname);
  const filePath = path.normalize(path.join(publicDir, cleanPath));
  if (!filePath.startsWith(publicDir)) {
    res.writeHead(403);
    res.end("Forbidden");
    return;
  }
  try {
    const body = await fs.readFile(filePath);
    res.writeHead(200, {
      "content-type": contentType(filePath),
      "cache-control": "no-cache",
    });
    res.end(body);
  } catch {
    res.writeHead(404);
    res.end("Not found");
  }
}

const server = http.createServer(async (req, res) => {
  const url = new URL(req.url, `http://${req.headers.host}`);
  if (url.pathname === "/api/dashboard") {
    try {
      const data = await getDashboard(url.searchParams.get("refresh") === "1");
      sendJson(res, 200, data);
    } catch (error) {
      sendJson(res, 500, { error: error.message });
    }
    return;
  }
  await serveStatic(req, res, url.pathname);
});

server.listen(port, host, () => {
  const displayHost = host === "0.0.0.0" ? "127.0.0.1" : host;
  console.log(`Gen Dashboard page: http://${displayHost}:${port}`);
});

setInterval(() => {
  getDashboard(false).catch((error) => {
    console.error("Scheduled refresh failed:", error.message);
  });
}, 60 * 60 * 1000);