// Festival templates and calendar (N03). Lunar-calendar dates are approximate: the UI asks the merchant to
// check them against their local calendar before publishing.

export interface Festival {
  key: string;
  name: string;
  /** main day, YYYY-MM-DD */
  date: string;
  approximate: boolean;
  /** days the offer starts before / ends after the main day */
  leadDays: number;
  tailDays: number;
}

export const FESTIVALS: Festival[] = [
  { key: "navaratri-2026", name: "Navaratri", date: "2026-10-11", approximate: true, leadDays: 7, tailDays: 9 },
  { key: "diwali-2026", name: "Diwali", date: "2026-11-08", approximate: true, leadDays: 21, tailDays: 1 },
  { key: "black-friday-2026", name: "Black Friday", date: "2026-11-27", approximate: false, leadDays: 0, tailDays: 3 },
  { key: "christmas-2026", name: "Christmas", date: "2026-12-25", approximate: false, leadDays: 21, tailDays: 1 },
  { key: "pongal-2027", name: "Pongal / Makar Sankranti", date: "2027-01-14", approximate: true, leadDays: 10, tailDays: 3 },
  { key: "lunar-new-year-2027", name: "Lunar New Year", date: "2027-02-06", approximate: true, leadDays: 14, tailDays: 7 },
  { key: "eid-al-fitr-2027", name: "Eid al-Fitr", date: "2027-03-10", approximate: true, leadDays: 14, tailDays: 3 },
  { key: "holi-2027", name: "Holi", date: "2027-03-22", approximate: true, leadDays: 10, tailDays: 1 },
  { key: "eid-al-adha-2027", name: "Eid al-Adha", date: "2027-05-17", approximate: true, leadDays: 10, tailDays: 3 },
  { key: "navaratri-2027", name: "Navaratri", date: "2027-09-30", approximate: true, leadDays: 7, tailDays: 9 },
  { key: "diwali-2027", name: "Diwali", date: "2027-10-29", approximate: true, leadDays: 21, tailDays: 1 },
];

export interface OfferTemplate {
  key: string;
  festival: string; // Festival.name or "Everyday"
  name: string;
  badge: string;
  description: string;
  type: "fixed" | "mix" | "bxgy";
  discountType: "percent" | "amount" | "fixed_price";
  discountValue: number;
  mixQty?: number;
  buyQty?: number;
  getQty?: number;
  getPercent?: number;
  hint: string;
}

export const TEMPLATES: OfferTemplate[] = [
  { key: "diwali-puja-kit", festival: "Diwali", name: "Diwali Puja Kit", badge: "Diwali Special", type: "fixed", discountType: "percent", discountValue: 15,
    description: "Everything you need for Lakshmi Puja, in one bundle.", hint: "Add the diya, camphor, kumkum and incense products with their quantities." },
  { key: "diwali-sweets", festival: "Diwali", name: "Any 3 Diwali Sweets", badge: "Festival offer", type: "mix", discountType: "fixed_price", discountValue: 20, mixQty: 3,
    description: "Mix and match your favourite mithai.", hint: "Add your sweets collection." },
  { key: "navaratri-golu", festival: "Navaratri", name: "Navaratri Golu Set", badge: "Navaratri", type: "fixed", discountType: "amount", discountValue: 10,
    description: "A ready-made golu display set.", hint: "Add the dolls and steps that make up the set." },
  { key: "garlands-b2g1", festival: "Navaratri", name: "Buy 2 Garlands, Get 1 Free", badge: "Festival offer", type: "bxgy", discountType: "percent", discountValue: 0, buyQty: 2, getQty: 1, getPercent: 100,
    description: "Fresh garlands for every day of the festival.", hint: "Use the same garland collection for Buy and Get." },
  { key: "pongal-essentials", festival: "Pongal / Makar Sankranti", name: "Pongal Essentials", badge: "Pongal", type: "fixed", discountType: "percent", discountValue: 10,
    description: "Rice, jaggery, ghee and more for Pongal.", hint: "Add the essentials and quantities." },
  { key: "eid-gift-box", festival: "Eid al-Fitr", name: "Eid Gift Box", badge: "Eid Mubarak", type: "mix", discountType: "percent", discountValue: 15, mixQty: 4,
    description: "Pick any 4 treats for a gift box.", hint: "Add dates, sweets and dry fruit collections." },
  { key: "holi-colours", festival: "Holi", name: "Holi Colours Pack", badge: "Happy Holi", type: "mix", discountType: "fixed_price", discountValue: 15, mixQty: 5,
    description: "Any 5 colour packs.", hint: "Add your gulal / colour collection." },
  { key: "lny-gift", festival: "Lunar New Year", name: "Lunar New Year Gift Set", badge: "New Year", type: "fixed", discountType: "percent", discountValue: 12,
    description: "A festive gift set.", hint: "Add the products of the gift set." },
  { key: "christmas-hamper", festival: "Christmas", name: "Christmas Hamper", badge: "Christmas", type: "fixed", discountType: "fixed_price", discountValue: 49,
    description: "A hamper of seasonal favourites.", hint: "Add the hamper contents." },
  { key: "black-friday-bogo", festival: "Black Friday", name: "Black Friday: Buy 1 Get 1 50% Off", badge: "Black Friday", type: "bxgy", discountType: "percent", discountValue: 0, buyQty: 1, getQty: 1, getPercent: 50,
    description: "Our biggest deal of the year.", hint: "Pick the collections that are part of the sale." },
  { key: "everyday-mix", festival: "Everyday", name: "Any 3 for a bundle price", badge: "Bundle & Save", type: "mix", discountType: "fixed_price", discountValue: 25, mixQty: 3,
    description: "Mix and match any 3.", hint: "Add the products or collections that count." },
];

export function festivalByName(name: string) {
  const today = new Date().toISOString().slice(0, 10);
  return FESTIVALS.filter((f) => f.name === name && f.date >= today).sort((a, b) => a.date.localeCompare(b.date))[0];
}

/** Offer dates for a festival, as shop-local "YYYY-MM-DDTHH:mm" strings. */
export function festivalWindow(f: Festival) {
  const day = new Date(`${f.date}T00:00:00Z`);
  const start = new Date(day.getTime() - f.leadDays * 86400000);
  const end = new Date(day.getTime() + f.tailDays * 86400000);
  return { start: `${start.toISOString().slice(0, 10)}T00:00`, end: `${end.toISOString().slice(0, 10)}T23:59` };
}

export function upcomingFestivals(now = new Date(), days = 365) {
  const today = now.toISOString().slice(0, 10);
  const until = new Date(now.getTime() + days * 86400000).toISOString().slice(0, 10);
  return FESTIVALS.filter((f) => f.date >= today && f.date <= until).sort((a, b) => a.date.localeCompare(b.date));
}