/**
 * Eoptolink Manufacturer Catalog Scraper
 *
 * Source: www.eoptolink.com — One of China's top-3 optical transceiver OEMs.
 *         (Finisar competitor, supplies tier-1 cloud hyperscalers)
 * Target: Discover all product families + part numbers, seed transceivers table
 *         as manufacturer=Eoptolink entries.
 *
 * Strategy:
 *   Phase 1: Fetch homepage → extract all /product-solutions/* category URLs (≈90)
 *   Phase 2: Fetch each category page → parse product name + Eoptolink part numbers
 *            (format: E[A-Z]{2,5}-\d{2,4}[A-Z0-9-]*)
 *
 * Note: Eoptolink does NOT publish retail prices (B2B OEM manufacturer).
 *       This scraper adds manufacturer catalog entries — no price_observations.
 *
 * Rate limit: 1 req/2s — polite crawl of OEM's website.
 */

import { pool, findOrCreateScrapedTransceiver, ensureVendor } from "../utils/db";

const BASE = "https://www.eoptolink.com";
const HEADERS = {
  "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36",
  Accept: "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
  "Accept-Language": "en-US,en;q=0.9",
};
const DELAY_MS = 2000;

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

async function fetchHtml(url: string): Promise<string> {
  const resp = await fetch(url, { headers: HEADERS, signal: AbortSignal.timeout(20_000) });
  if (!resp.ok) throw new Error(`HTTP ${resp.status} for ${url}`);
  return resp.text();
}

// ── Classification helpers ──────────────────────────────────────────────────

function speedFromSlug(slug: string): { speed: string; speedGbps: number } {
  if (/\b1\.?6t\b/i.test(slug))  return { speed: "1.6T",  speedGbps: 1600 };
  if (/\b800g\b/i.test(slug))    return { speed: "800G",   speedGbps: 800  };
  if (/\b400g\b/i.test(slug))    return { speed: "400G",   speedGbps: 400  };
  if (/\b200g\b/i.test(slug))    return { speed: "200G",   speedGbps: 200  };
  if (/\b100g\b/i.test(slug))    return { speed: "100G",   speedGbps: 100  };
  if (/\b50g\b/i.test(slug))     return { speed: "50G",    speedGbps: 50   };
  if (/\b40g\b/i.test(slug))     return { speed: "40G",    speedGbps: 40   };
  if (/\b32g\b/i.test(slug))     return { speed: "32G",    speedGbps: 32   };
  if (/\b25g\b/i.test(slug))     return { speed: "25G",    speedGbps: 25   };
  if (/\b16g\b/i.test(slug))     return { speed: "16G",    speedGbps: 16   };
  if (/\b10g\b/i.test(slug))     return { speed: "10G",    speedGbps: 10   };
  if (/\b8g\b/i.test(slug))      return { speed: "8G",     speedGbps: 8    };
  if (/\b4g\b/i.test(slug))      return { speed: "4G",     speedGbps: 4    };
  if (/\b1g\b/i.test(slug))      return { speed: "1G",     speedGbps: 1    };
  return { speed: "Unknown", speedGbps: 0 };
}

function formFactorFromText(text: string): string {
  const t = text.toUpperCase();
  if (/\bOSFP\b/.test(t))                          return "OSFP";
  if (/\bQSFP.?DD800\b|\bQSFP-DD800\b/.test(t))    return "QSFP-DD800";
  if (/\bQSFP.?DD\b/.test(t))                       return "QSFP-DD";
  if (/\bQSFP56\b/.test(t))                         return "QSFP56";
  if (/\bQSFP112\b/.test(t))                        return "QSFP112";
  if (/\bQSFP28\b/.test(t))                         return "QSFP28";
  if (/\bQSFP\+|\bQSFP PLUS\b/.test(t))             return "QSFP+";
  if (/\bSFP56.DD\b/.test(t))                       return "SFP56-DD";
  if (/\bSFP56\b/.test(t))                          return "SFP56";
  if (/\bSFP28\b/.test(t))                          return "SFP28";
  if (/\bSFP\+|SFP-PLUS|SFP PLUS\b/.test(t))        return "SFP+";
  if (/\bXFP\b/.test(t))                            return "XFP";
  if (/\bCFP4\b/.test(t))                           return "CFP4";
  if (/\bCFP2\b/.test(t))                           return "CFP2";
  if (/\bCFP\b/.test(t))                            return "CFP";
  if (/\bSFP\b/.test(t))                            return "SFP";
  return "SFP";
}

function fiberFromText(text: string): string {
  const t = text.toLowerCase();
  if (/multimode|mmf|sr|om[1-5]/i.test(t)) return "MMF";
  if (/single.?mode|smf|lr|er|zr|fr|dr|bidi|cwdm|dwdm|coherent/i.test(t)) return "SMF";
  return "SMF"; // OEM products default to SMF
}

function categoryFromText(text: string): string {
  const t = text.toLowerCase();
  if (/coherent|zr|dpsk/.test(t))   return "Coherent";
  if (/dwdm/.test(t))               return "DWDM";
  if (/cwdm/.test(t))               return "CWDM";
  if (/aoc/.test(t))                return "AOC";
  if (/dac/.test(t))                return "DAC";
  if (/pon|gpon|gepon/.test(t))     return "PON";
  return "DataCenter";
}

// ── Phase 1: Discover product solution URLs ──────────────────────────────────

async function fetchProductSolutionUrls(): Promise<string[]> {
  console.log(`  Fetching Eoptolink homepage for product solution links...`);
  const html = await fetchHtml(`${BASE}/`);
  const links = html.match(/href="(\/product-solutions\/[^"#?]+)"/gi) ?? [];
  const unique = [...new Set(links.map((l) => l.match(/href="([^"]+)"/)?.[1] ?? "").filter(Boolean))];
  // Skip OSA (optical sub-assemblies) and test-board entries — no transceiver catalog
  const filtered = unique.filter((u) =>
    !u.includes("/osa/") &&
    !u.includes("/other/") &&
    !u.endsWith("/400g/") &&
    !u.endsWith("/800g/") &&
    !u.endsWith("/product-solutions/")
  );
  console.log(`  Found ${filtered.length} product solution pages`);
  return filtered;
}

// ── Phase 2: Parse product detail page ──────────────────────────────────────

interface EoptolinkProduct {
  pageTitle: string;
  partNumbers: string[];
  speed: string;
  speedGbps: number;
  formFactor: string;
  fiberType: string;
  category: string;
  pageUrl: string;
}

function parseProductPage(html: string, pageUrl: string): EoptolinkProduct | null {
  // Page title
  const titleMatch = html.match(/<title>([^<]+)/i) || html.match(/<h1[^>]*>([^<]{5,80})</i);
  const pageTitle = (titleMatch?.[1] ?? "").replace(/\s*\|.*$/, "").replace(/[｜|]+[^｜|]*$/, "").trim();
  if (!pageTitle || pageTitle.length < 3) return null;

  // Eoptolink part numbers: format like EOLO-168HG-10-XDX, EOLQ-128HG-02-PX
  const pnRegex = /E[A-Z]{2,5}-\d{2,3}[A-Z0-9]{1,3}(?:-\d{1,3})?(?:-[A-Z0-9]{1,6})*/g;
  const partNumbers = [...new Set([...(html.matchAll(pnRegex) ?? [])].map((m) => m[0].trim()))];

  const slug = pageUrl.split("/").slice(-2).join("-");
  const { speed, speedGbps } = speedFromSlug(slug + " " + pageTitle);
  const formFactor = formFactorFromText(pageTitle + " " + slug);
  const fiberType = fiberFromText(pageTitle + " " + slug);
  const category = categoryFromText(pageTitle + " " + slug);

  return { pageTitle, partNumbers, speed, speedGbps, formFactor, fiberType, category, pageUrl };
}

// ── Main ────────────────────────────────────────────────────────────────────

export async function scrapeEoptolink(): Promise<void> {
  console.log("=== Eoptolink Manufacturer Catalog Scraper ===\n");

  const vendorId = await ensureVendor(
    "Eoptolink",
    "manufacturer",
    "https://www.eoptolink.com",
    "https://www.eoptolink.com/product-solutions/"
  );
  console.log(`  Vendor ID: ${vendorId}`);

  // Phase 1: Collect product solution URLs
  let productUrls: string[];
  try {
    productUrls = await fetchProductSolutionUrls();
  } catch (err) {
    console.error(`  Homepage fetch failed: ${(err as Error).message}`);
    return;
  }

  console.log(`\n[Phase 2] Fetching ${productUrls.length} product detail pages...\n`);

  let added = 0;
  let skipped = 0;
  let errors = 0;

  for (const relPath of productUrls) {
    await sleep(DELAY_MS);
    const url = `${BASE}${relPath}`;
    try {
      const html = await fetchHtml(url);
      const product = parseProductPage(html, relPath);
      if (!product || product.speedGbps === 0) {
        skipped++;
        continue;
      }

      // Use page title as the primary product entry; also seed one row per part number
      const namesToSeed: string[] = product.partNumbers.length > 0
        ? product.partNumbers.slice(0, 10) // max 10 part numbers per product family page
        : [product.pageTitle];

      for (const partNumber of namesToSeed) {
        try {
          await findOrCreateScrapedTransceiver({
            partNumber: partNumber.slice(0, 80),
            vendorId,
            formFactor: product.formFactor,
            speedGbps: product.speedGbps,
            speed: product.speed,
            fiberType: product.fiberType,
            category: product.category,
          });
          added++;
        } catch (dbErr) {
          // Duplicate or constraint error — expected for re-runs
        }
      }

      console.log(
        `  ✓ ${product.pageTitle.padEnd(45)} ff=${product.formFactor.padEnd(8)} speed=${product.speed.padEnd(5)} pn=${product.partNumbers.length}`
      );
    } catch (err: unknown) {
      errors++;
      if (errors <= 10) console.warn(`  ✗ Error ${relPath}: ${(err as Error).message.slice(0, 60)}`);
    }
  }

  console.log(`\n=== Eoptolink Catalog Scraper Complete ===`);
  console.log(`  Pages processed: ${productUrls.length - errors}`);
  console.log(`  Transceivers seeded: ${added}`);
  console.log(`  Skipped (no speed): ${skipped}`);
  console.log(`  Errors: ${errors}`);
}

// ── CLI ────────────────────────────────────────────────────────────────────

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