/**
 * 10Gtek.com Scraper — Chinese OEM Transceiver Vendor
 *
 * 10gtek.com is a direct competitor to FS.com at lower price points.
 * Uses plain fetch (server-rendered HTML).
 * Rate limited: 1 req/2sec.
 *
 * Categories: SFP, SFP+, SFP28, QSFP+, QSFP28, QSFP-DD, OSFP
 */
import { pool, findOrCreateScrapedTransceiver, ensureVendor, upsertPriceObservation } from "../utils/db";
import { contentHash, parsePrice } from "../utils/hash";

const BASE = "https://www.10gtek.com";
const HEADERS = {
  "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
  Accept: "text/html,application/xhtml+xml",
};

const CATEGORIES = [
  { path: "/sfp", formFactor: "SFP", speed: "1G", speedGbps: 1 },
  { path: "/10g-sfp+", formFactor: "SFP+", speed: "10G", speedGbps: 10 },
  { path: "/sfp28", formFactor: "SFP28", speed: "25G", speedGbps: 25 },
  { path: "/qsfp", formFactor: "QSFP+", speed: "40G", speedGbps: 40 },
  { path: "/qsfp28", formFactor: "QSFP28", speed: "100G", speedGbps: 100 },
  { path: "/qsfpdd", formFactor: "QSFP-DD", speed: "400G", speedGbps: 400 },
  { path: "/xfp", formFactor: "XFP", speed: "10G", speedGbps: 10 },
];

interface Product {
  partNumber: string;
  name: string;
  url: string;
  price?: number;
  currency?: string;
  formFactor: string;
  speed: string;
  speedGbps: number;
  reachLabel?: string;
  reachMeters?: number;
  fiberType?: string;
}

function sleep(ms: number): Promise<void> {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

function detectReach(text: string): { label: string; meters: number } | undefined {
  const patterns: [RegExp, string, number][] = [
    [/\b80\s*km\b/i, "80km", 80000],
    [/\b40\s*km\b/i, "40km", 40000],
    [/\b20\s*km\b/i, "20km", 20000],
    [/\b10\s*km\b/i, "10km", 10000],
    [/\b2\s*km\b/i, "2km", 2000],
    [/\b500\s*m\b/i, "500m", 500],
    [/\b300\s*m\b/i, "300m", 300],
    [/\b100\s*m\b/i, "100m", 100],
    [/\bLR4\b/, "10km", 10000],
    [/\bLR\b/, "10km", 10000],
    [/\bER\b/, "40km", 40000],
    [/\bZR\b/, "80km", 80000],
    [/\bSR4?\b/, "100m", 100],
    [/\bDR4?\b/, "500m", 500],
    [/\bFR4?\b/, "2km", 2000],
  ];
  for (const [regex, label, meters] of patterns) {
    if (regex.test(text)) return { label, meters };
  }
  return undefined;
}

function detectFiber(text: string): string {
  if (/single.?mode|smf|[^a-z]lx[^a-z]|[^a-z]lr[^a-z]|[^a-z]er[^a-z]|[^a-z]zr[^a-z]|bidi|cwdm|dwdm/i.test(text)) return "SMF";
  if (/multi.?mode|mmf|[^a-z]sx[^a-z]|[^a-z]sr[^a-z]/i.test(text)) return "MMF";
  return "";
}

/** Strip HTML tags and decode common entities */
function stripHtml(s: string): string {
  return s.replace(/<[^>]+>/g, "").replace(/&amp;/g, "&").replace(/&lt;/g, "<")
    .replace(/&gt;/g, ">").replace(/&nbsp;/g, " ").replace(/&deg;/g, "°")
    .replace(/&#\d+;/g, "").trim();
}

function parseDistance(text: string): { label: string; meters: number } | undefined {
  const km = text.match(/(\d+)\s*km/i);
  if (km) return { label: `${km[1]}km`, meters: parseInt(km[1]) * 1000 };
  const m = text.match(/(\d+)\s*m\b/i);
  if (m) return { label: `${m[1]}m`, meters: parseInt(m[1]) };
  return undefined;
}

function parseProductList(html: string, cat: typeof CATEGORIES[number]): Product[] {
  const products: Product[] = [];

  // 10Gtek uses HTML tables with columns:
  // Part No. | Spec | Data Rate | Wavelength | Fiber Type | Distance | Optical Comp. | Tx Power | E.R | Rx Sens. | Temp.
  // Extract all <tr> rows and parse cells
  const rowRegex = /<tr[^>]*>([\s\S]*?)<\/tr>/gi;
  let rowMatch;
  while ((rowMatch = rowRegex.exec(html)) !== null) {
    const rowHtml = rowMatch[1];
    // Extract all <td> cell contents
    const cellRegex = /<td[^>]*>([\s\S]*?)<\/td>/gi;
    const cells: string[] = [];
    let cellMatch;
    while ((cellMatch = cellRegex.exec(rowHtml)) !== null) {
      cells.push(stripHtml(cellMatch[1]));
    }

    // Need at least 6 columns, first cell must look like a part number (starts with A or contains letters+digits)
    if (cells.length < 6) continue;
    const partNumber = cells[0];
    if (!partNumber || partNumber.length < 3) continue;
    // Skip header rows
    if (/^Part\s*No/i.test(partNumber) || /^Spec/i.test(partNumber)) continue;
    // Part numbers typically start with A (ASF, AXS, AXQ, AQS, etc.) or contain alphanumeric
    if (!/^[A-Z][A-Z0-9]/i.test(partNumber)) continue;

    const spec = cells[1] || "";
    const dataRate = cells[2] || "";
    const wavelength = cells.length >= 4 ? cells[3] : "";
    const fiberType = cells.length >= 5 ? cells[4] : "";
    const distance = cells.length >= 6 ? cells[5] : "";
    const txPower = cells.length >= 8 ? cells[7] : "";

    // Build descriptive name
    const name = `${partNumber} ${spec} ${dataRate}`.trim();
    const reach = parseDistance(distance) || detectReach(spec + " " + distance);

    // Determine fiber type from table cell or spec
    let fiber = "";
    if (/SMF|single/i.test(fiberType)) fiber = "SMF";
    else if (/MMF|multi/i.test(fiberType)) fiber = "MMF";
    else if (/CAT|RJ|copper/i.test(fiberType)) fiber = "Copper";
    else fiber = detectFiber(spec);

    // Extract wavelength
    const wl = wavelength.replace(/[^0-9]/g, "");

    products.push({
      partNumber,
      name,
      url: `${BASE}${cat.path}#${partNumber}`,
      formFactor: cat.formFactor,
      speed: cat.speed,
      speedGbps: cat.speedGbps,
      reachLabel: reach?.label,
      reachMeters: reach?.meters,
      fiberType: fiber,
    });
  }

  // Dedupe by part number
  const seen = new Set<string>();
  return products.filter((p) => {
    if (seen.has(p.partNumber)) return false;
    seen.add(p.partNumber);
    return true;
  });
}

async function fetchPage(url: string): Promise<string> {
  const resp = await fetch(url, { headers: HEADERS, signal: AbortSignal.timeout(30000) });
  if (!resp.ok) throw new Error(`HTTP ${resp.status} for ${url}`);
  return resp.text();
}

export async function scrape10Gtek(): Promise<void> {
  console.log("=== 10Gtek Scraper Starting ===\n");

  const vendorId = await ensureVendor("10Gtek", "compatible", "https://www.10gtek.com", "https://www.10gtek.com");

  let totalProducts = 0;
  let priceUpdates = 0;

  for (const cat of CATEGORIES) {
    console.log(`\n--- ${cat.formFactor} (${cat.speed}) ---`);

    try {
      const html = await fetchPage(BASE + cat.path);
      const catProducts = parseProductList(html, cat);
      console.log(`  Found ${catProducts.length} products`);

      for (const product of catProducts) {
        try {
          const txId = await findOrCreateScrapedTransceiver({
            partNumber: product.partNumber,
            vendorId,
            formFactor: product.formFactor,
            speedGbps: product.speedGbps,
            speed: product.speed,
            reachMeters: product.reachMeters,
            reachLabel: product.reachLabel,
            fiberType: product.fiberType,
            category: "DataCenter",
          });

          if (product.price && product.price > 0) {
            const hash = contentHash(JSON.stringify({ price: product.price, part: product.partNumber }));
            const updated = await upsertPriceObservation({
              transceiverId: txId,
              sourceVendorId: vendorId,
              price: product.price,
              currency: product.currency || "USD",
              stockLevel: "in_stock",
              url: product.url,
              contentHash: hash,
            });
            if (updated) priceUpdates++;
          }

          totalProducts++;
        } catch (err) {
          console.warn(`    Error: ${(err as Error).message.slice(0, 80)}`);
        }
      }
    } catch (err) {
      console.error(`  Category failed: ${(err as Error).message}`);
    }

    await sleep(2000);
  }

  console.log(`\n=== 10Gtek Complete: ${totalProducts} products, ${priceUpdates} prices ===`);
}

if (require.main === module) {
  scrape10Gtek()
    .then(() => pool.end())
    .catch((err) => { console.error("Fatal:", err); pool.end(); process.exit(1); });
}