import { createServer } from 'node:http';
import { readFile } from 'node:fs/promises';
import { extname, join, normalize } from 'node:path';
import { fileURLToPath } from 'node:url';
import { CATEGORIES, readCatalog } from '../src/db/catalog';
import { imageUrl, readImages } from '../src/db/images';
import { CONTENT_PAGES } from '../src/db/seed';
import { BRAND, DELIVERY, STORE, STORE_CURRENCY } from '../src/store/constants';
import { ensureBrandLogo } from './fetch-logo';
import { ensureBrandFavicon, isPng } from './fetch-favicon';

/**
 * Minimal storefront server for the basic frontend stage.
 *
 * The full Next.js application shell is a later layer (docs/PLAN.md §8, card #57).
 * Until it lands this keeps the dev container green AND lets the storefront show the
 * real seeded catalog: it serves `public/` plus one read-only JSON endpoint built from
 * the same seed sources as the database (`db/seed/catalog.tsv` + `db/seed/images.tsv`).
 *
 * At boot it also mirrors the store wordmark (scripts/fetch-logo.ts) so the header and
 * footer logo is served from `public/images/brand/logo_footer.png`, not hotlinked.
 *
 * Routes:
 *   GET /api/catalog        → { currency, count, priceRange, badges, delivery, categories[], products[] }
 *   GET /api/pages          → { pages[] } (info/FAQ content from the seed)
 *   GET /favicon.ico        → the mirrored site icon (PNG payload, served as image/png)
 *   GET /images/...          → product gallery files from public/
 *   GET /<route without ext> → index.html (client-side route, SPA fallback)
 *   GET /<file with ext>     → public/<file> or 404
 */

const PUBLIC_DIR = fileURLToPath(new URL('../public', import.meta.url));
const INDEX_HTML = join(PUBLIC_DIR, 'index.html');

function readPort(): number {
  const inline = process.argv.find((arg) => arg.startsWith('--port='));
  if (inline) return Number(inline.split('=')[1]);
  const idx = process.argv.indexOf('--port');
  if (idx >= 0 && process.argv[idx + 1]) return Number(process.argv[idx + 1]);
  return Number(process.env.PORT ?? 3000);
}

const CONTENT_TYPES: Record<string, string> = {
  '.html': 'text/html; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.mjs': 'text/javascript; charset=utf-8',
  '.json': 'application/json; charset=utf-8',
  '.map': 'application/json; charset=utf-8',
  '.txt': 'text/plain; charset=utf-8',
  '.svg': 'image/svg+xml',
  '.jpg': 'image/jpeg',
  '.jpeg': 'image/jpeg',
  '.png': 'image/png',
  '.webp': 'image/webp',
  '.gif': 'image/gif',
  '.avif': 'image/avif',
  '.ico': 'image/x-icon',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2',
};

/**
 * Content type for a file on disk. `/favicon.ico` is the one exception: the mirrored
 * icon is a PNG payload under an `.ico` name (that is how the source site ships it), so
 * the signature is sniffed and the file labelled `image/png` — browsers accept either
 * for `<link rel="icon">`, and a truthful type beats a wrong one.
 */
function contentTypeFor(filePath: string, body: Buffer): string {
  const ext = extname(filePath).toLowerCase();
  if (ext === '.ico' && isPng(body)) return 'image/png';
  return CONTENT_TYPES[ext] ?? 'application/octet-stream';
}

interface ApiImage {
  url: string;
  alt: string;
  position: number;
}

interface ApiVariant {
  label: string;
  priceMinor: number;
  stock: number;
}

interface ApiCategory {
  slug: string;
  name: string;
  description: string | null;
  /** R13: hidden source categories stay reachable by direct URL but never in the menu. */
  visible: boolean;
  count: number;
}

interface ApiProduct {
  n: number;
  slug: string;
  name: string;
  description: string;
  composition: string;
  care: string;
  priceMinor: number;
  oldPriceMinor: number | null;
  currency: string;
  badge: 'hit' | 'new' | 'sale' | null;
  stock: number;
  stems: number | null;
  heightCm: number;
  deliveryTime: string;
  occasion: string;
  categories: string[];
  images: ApiImage[];
  variants: ApiVariant[];
}

interface ApiCatalog {
  currency: string;
  count: number;
  priceRange: { minMinor: number; maxMinor: number };
  badges: { hit: number; new: number; sale: number };
  delivery: {
    freeOverMinor: number;
    courierFeeMinor: number;
    leadTimeText: string;
    outsideMkadText: string;
    pickupAddress: string;
    workingHours: string;
    phone1: string;
    phone2: string;
    email: string;
    whatsapp: string;
    telegram: string;
  };
  categories: ApiCategory[];
  products: ApiProduct[];
}

/** Variants seeded in src/db/seed.ts §5 (source PDP «15/19/25 роз»). */
const PRODUCT_VARIANTS: Record<string, ApiVariant[]> = {
  'buket-iz-krasnykh-roz-s-evkaliptom': [
    { label: '15 роз', priceMinor: 198_00, stock: 10 },
    { label: '19 роз', priceMinor: 240_00, stock: 6 },
    { label: '25 роз', priceMinor: 325_00, stock: 4 },
  ],
};

/** Occasion facet, same mapping the seed writes to product_feature (§5). */
function occasionFor(categories: string[]): string {
  if (categories.includes('svadebnye-bukety-nevesty')) return 'Невесте';
  if (categories.includes('monobuket')) return 'Любимой';
  if (
    categories.includes('kompozitsii') ||
    categories.includes('tsvety-v-korzine') ||
    categories.includes('tsvety-v-yashchike')
  ) {
    return 'Коллеге, Партнёру';
  }
  return 'Любимой, Маме, Другу';
}

/** Build the storefront payload from the same seed files the database is seeded from. */
function buildCatalog(): ApiCatalog {
  const imagesBySlug = new Map<string, ApiImage[]>();
  for (const image of readImages()) {
    const list = imagesBySlug.get(image.slug) ?? [];
    list.push({ url: imageUrl(image.slug, image.position), alt: image.alt, position: image.position });
    imagesBySlug.set(image.slug, list);
  }

  const products: ApiProduct[] = readCatalog().map((product) => ({
    n: product.n,
    slug: product.slug,
    name: product.name,
    description: product.description,
    composition: product.composition,
    care: product.care,
    priceMinor: product.priceMinor,
    oldPriceMinor: product.oldPriceMinor,
    currency: product.currency,
    badge: product.badge,
    stock: product.stock,
    stems: product.stems,
    heightCm: product.heightCm,
    deliveryTime: product.deliveryTime,
    occasion: occasionFor(product.categories),
    categories: product.categories,
    images: (imagesBySlug.get(product.slug) ?? []).sort((a, b) => a.position - b.position),
    variants: PRODUCT_VARIANTS[product.slug] ?? [],
  }));

  const countByCategory = new Map<string, number>();
  for (const product of products) {
    for (const slug of new Set(product.categories)) {
      countByCategory.set(slug, (countByCategory.get(slug) ?? 0) + 1);
    }
  }

  const prices = products.map((product) => product.priceMinor);

  return {
    currency: STORE_CURRENCY,
    count: products.length,
    priceRange: {
      minMinor: prices.length ? Math.min(...prices) : 0,
      maxMinor: prices.length ? Math.max(...prices) : 0,
    },
    badges: {
      hit: products.filter((product) => product.badge === 'hit').length,
      new: products.filter((product) => product.badge === 'new').length,
      sale: products.filter((product) => product.badge === 'sale').length,
    },
    delivery: {
      freeOverMinor: DELIVERY.freeOverMinor,
      courierFeeMinor: DELIVERY.courierFeeMinor,
      leadTimeText: DELIVERY.leadTimeText,
      outsideMkadText: DELIVERY.outsideMkadText,
      pickupAddress: STORE.pickupAddress,
      workingHours: STORE.workingHours,
      phone1: STORE.phone1,
      phone2: STORE.phone2,
      email: STORE.email,
      whatsapp: STORE.whatsapp,
      telegram: STORE.telegram,
    },
    categories: CATEGORIES.map((category) => ({
      slug: category.slug,
      name: category.name,
      description: category.description,
      visible: category.visible,
      count: countByCategory.get(category.slug) ?? 0,
    })),
    products,
  };
}

const catalog = buildCatalog();
const pages = CONTENT_PAGES.map(({ slug, title, body }) => ({ slug, title, body }));

// Brand assets: keep the local copies of the wordmark and the site icon in place.
// Non-fatal — if a source is unreachable we log it and keep serving (both files are
// normally committed already).
try {
  const logo = await ensureBrandLogo();
  if (logo === 'downloaded') console.log(`dev-server: fetched the store logo (${BRAND.logoLocalPath})`);
} catch (error) {
  console.warn(`dev-server: store logo unavailable — ${(error as Error).message}`);
}
try {
  const icon = await ensureBrandFavicon();
  if (icon === 'downloaded') console.log(`dev-server: fetched the site icon (${BRAND.faviconLocalPath})`);
} catch (error) {
  console.warn(`dev-server: site icon unavailable — ${(error as Error).message}`);
}

function sendJson(res: import('node:http').ServerResponse, status: number, body: unknown): void {
  res.writeHead(status, { 'content-type': 'application/json; charset=utf-8', 'cache-control': 'no-store' });
  res.end(JSON.stringify(body));
}

function sendBody(res: import('node:http').ServerResponse, status: number, body: Buffer | string, type: string): void {
  // Dev shell: never cache assets, so a plain refresh always shows the latest
  // public/app.js + public/styles.css instead of a stale heuristically cached copy.
  res.writeHead(status, { 'content-type': type, 'cache-control': 'no-store' });
  res.end(body);
}

const server = createServer(async (req, res) => {
  const requestPath = decodeURIComponent((req.url ?? '/').split('?')[0]);

  if (requestPath === '/api/catalog' || requestPath === '/api/catalog/') {
    sendJson(res, 200, catalog);
    return;
  }

  if (requestPath === '/api/pages' || requestPath === '/api/pages/') {
    sendJson(res, 200, { pages });
    return;
  }

  const relative = normalize(requestPath === '/' ? '/index.html' : requestPath).replace(/^(\.\.[/\\])+/, '');
  const filePath = join(PUBLIC_DIR, relative);
  try {
    const body = await readFile(filePath);
    sendBody(res, 200, body, contentTypeFor(filePath, body));
    return;
  } catch {
    // Client-side routes (e.g. /product/<slug>) have no file extension: serve the shell.
    if (!extname(requestPath)) {
      try {
        const shell = await readFile(INDEX_HTML);
        sendBody(res, 200, shell, CONTENT_TYPES['.html']);
        return;
      } catch {
        // fall through to 404
      }
    }
    sendBody(res, 404, 'Not found', 'text/plain; charset=utf-8');
  }
});

const port = readPort();
server.listen(port, () => {
  console.log(`La Rose storefront listening on http://localhost:${port} (${catalog.count} products)`);
});