const SALES_WEBHOOK_URL = (process.env.DISCORD_WEBHOOK_SALES_URL || '').trim();
const DOWNLOADS_WEBHOOK_URL = (process.env.DISCORD_WEBHOOK_DOWNLOADS_URL || '').trim();

const PURCHASE_EVENT_TYPES = new Set([
  'INITIAL_PURCHASE',
  'RENEWAL',
  'NON_RENEWING_PURCHASE',
  'PRODUCT_CHANGE',
]);

const PLAN_NAMES_BY_PRODUCT = {
  monthly_pro: 'Pro (monatlich)',
  yearly_pro: 'Pro (jährlich)',
  topup_small: 'Top-up Small (30 Credits)',
  topup_medium: 'Top-up Medium (100 Credits)',
  topup_large: 'Top-up Large (250 Credits)',
};

const EMBED_COLOR_SALE = 0x2ecc71;
const EMBED_COLOR_NEW_USER = 0x3498db;
const EMBED_COLOR_DOWNLOAD = 0x9b59b6;

const isPurchaseEventType = (eventType) =>
  PURCHASE_EVENT_TYPES.has(String(eventType || '').toUpperCase());

// Header/payload values end up in Discord embeds; strip markdown-relevant
// characters and cap length so user-controlled input cannot break or spoof
// the embed (Discord rejects fields over 1024 chars).
const sanitizeEmbedText = (value, maxLength = 64) =>
  String(value ?? '').replace(/[\r\n`]/g, ' ').trim().slice(0, maxLength);

const formatStore = (store) => {
  const normalized = String(store || '').toUpperCase();
  if (normalized === 'APP_STORE' || normalized === 'MAC_APP_STORE') return 'iOS';
  if (normalized === 'PLAY_STORE') return 'Android';
  return normalized || 'Unbekannt';
};

const formatPlatform = (platform) => {
  const normalized = String(platform || '').toLowerCase();
  if (normalized === 'ios') return 'iOS';
  if (normalized === 'android') return 'Android';
  return 'Unbekannt';
};

const formatPrice = (price, currency) => {
  if (typeof price !== 'number' || !Number.isFinite(price)) return '–';
  return `${price.toFixed(2)} ${String(currency || 'USD').toUpperCase()}`;
};

const sendDiscordEmbed = (webhookUrl, embed) => {
  if (!webhookUrl) return;
  fetch(webhookUrl, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ embeds: [embed] }),
    signal: AbortSignal.timeout(5000),
  })
    // Drain the body so undici can release the connection back to the pool.
    .then((response) => response.arrayBuffer())
    .catch(() => {});
};

const notifyPurchase = ({ productId, price, currency, store, isTrial, isRenewal, isSandbox } = {}) => {
  const safeProductId = sanitizeEmbedText(productId);
  const planName = Object.hasOwn(PLAN_NAMES_BY_PRODUCT, safeProductId)
    ? PLAN_NAMES_BY_PRODUCT[safeProductId]
    : safeProductId || 'Unbekannt';
  const title = isTrial
    ? '🛍️ Trial gestartet'
    : isRenewal
      ? '🔁 Abo verlängert'
      : '🛍️ Neuer Kauf';
  sendDiscordEmbed(SALES_WEBHOOK_URL, {
    title: isSandbox ? `${title} (Sandbox)` : title,
    color: EMBED_COLOR_SALE,
    fields: [
      { name: 'Produkt', value: `${planName} (\`${safeProductId || '–'}\`)`, inline: true },
      { name: 'Preis', value: isTrial ? 'Trial' : formatPrice(price, currency), inline: true },
      { name: 'Gerät', value: formatStore(store), inline: true },
    ],
    timestamp: new Date().toISOString(),
  });
};

const notifyNewUser = ({ platform, appVersion, provider } = {}) => {
  sendDiscordEmbed(DOWNLOADS_WEBHOOK_URL, {
    title: '📲 Neuer User',
    color: EMBED_COLOR_NEW_USER,
    fields: [
      { name: 'Gerät', value: formatPlatform(platform), inline: true },
      { name: 'App-Version', value: sanitizeEmbedText(appVersion) || 'Unbekannt', inline: true },
      { name: 'Anmeldung', value: String(provider || 'Unbekannt'), inline: true },
    ],
    timestamp: new Date().toISOString(),
  });
};

const notifyDownload = ({ platform, appVersion } = {}) => {
  sendDiscordEmbed(DOWNLOADS_WEBHOOK_URL, {
    title: '⬇️ Neuer Download',
    color: EMBED_COLOR_DOWNLOAD,
    fields: [
      { name: 'Gerät', value: formatPlatform(platform), inline: true },
      { name: 'App-Version', value: sanitizeEmbedText(appVersion) || 'Unbekannt', inline: true },
    ],
    timestamp: new Date().toISOString(),
  });
};

module.exports = {
  isPurchaseEventType,
  notifyPurchase,
  notifyNewUser,
  notifyDownload,
};