// Store in-app billing (Cafe Bazaar / Myket) for coin packs.
//
// - **Bazaar** (embedded PWA): pure deep-link flow. We navigate to
//   `bazaar://in_app?...&sku=...&redirect_url=...`; Bazaar processes payment and
//   reopens the app at redirect_url with `?purchaseToken=...`. We stash the SKU
//   first, then on return POST the token to `/api/coins/iab/verify`.
// - **Myket**: native AIDL billing. A Capacitor plugin must inject
//   `window.MyketBilling` (see ANDROID.md). We call `.purchase(sku)` and POST the
//   returned token to verify. Without the bridge, Myket is "unavailable".
//
// The active store is the build flavor `NEXT_PUBLIC_STORE` (bazaar|myket|web),
// overridden at runtime if the Myket native bridge is present.

import { CoinPack } from "./online/types";

export type StoreId = "bazaar" | "myket" | "web";

const ENV_STORE = ((process.env.NEXT_PUBLIC_STORE as StoreId | undefined) ?? "web");
const PACKAGE = process.env.NEXT_PUBLIC_APP_PACKAGE ?? "com.bargevasat.app";
const PENDING_SKU_KEY = "iab_pending_sku";

/** Native bridge contract a Myket Capacitor plugin must fulfil. */
interface MyketBridge {
  available?: boolean;
  purchase: (sku: string) => Promise<{ purchaseToken: string; productId?: string }>;
  consume?: (token: string) => Promise<void>;
}
declare global {
  interface Window {
    MyketBilling?: MyketBridge;
    Capacitor?: { isNativePlatform?: () => boolean; getPlatform?: () => string };
  }
}

export function getStore(): StoreId {
  if (typeof window === "undefined") return ENV_STORE;
  // Myket's native bridge wins when present (a Myket-flavored build).
  if (window.MyketBilling?.available) return "myket";
  // Honor an explicit build flavor.
  if (ENV_STORE !== "web") return ENV_STORE;
  // Otherwise, inside the Android app shell (Capacitor) default to Cafe Bazaar
  // IAB — the APK ships to Bazaar, which requires its own billing. The web build
  // stays on the web (ZarinPal) gateway.
  if (window.Capacitor?.isNativePlatform?.()) return "bazaar";
  return ENV_STORE;
}

/** True when coin purchases should go through a store (not the web ZarinPal gateway). */
export function isStoreBilling(): boolean {
  return getStore() !== "web";
}

function skuFor(pack: CoinPack): string {
  return pack.sku ?? pack.id;
}

export type PurchaseStart =
  | { kind: "redirect" } // Bazaar — the app navigated away; result arrives on return
  | { kind: "token"; store: StoreId; productId: string; token: string } // Myket — verify now
  | { kind: "unavailable" };

/** Begin a store purchase for a coin pack. */
export async function purchaseViaStore(pack: CoinPack): Promise<PurchaseStart> {
  const store = getStore();
  const sku = skuFor(pack);

  if (store === "bazaar") {
    try {
      localStorage.setItem(PENDING_SKU_KEY, sku);
    } catch {
      /* ignore storage errors */
    }
    const redirect = encodeURIComponent(window.location.origin + window.location.pathname);
    window.location.href =
      `bazaar://in_app?package_name=${encodeURIComponent(PACKAGE)}` +
      `&sku=${encodeURIComponent(sku)}&redirect_url=${redirect}`;
    return { kind: "redirect" };
  }

  if (store === "myket" && window.MyketBilling) {
    const res = await window.MyketBilling.purchase(sku);
    return { kind: "token", store: "myket", productId: res.productId ?? sku, token: res.purchaseToken };
  }

  return { kind: "unavailable" };
}

/**
 * On app load, capture a Bazaar redirect (`?purchaseToken=...`). Returns the
 * pending purchase to verify, or null. Also clears the stashed SKU.
 */
export function captureBazaarRedirect(): { store: StoreId; productId: string; token: string } | null {
  if (typeof window === "undefined") return null;
  const params = new URLSearchParams(window.location.search);
  const token = params.get("purchaseToken");
  if (!token) return null;
  let productId = params.get("sku") ?? params.get("productId") ?? "";
  if (!productId) {
    try {
      productId = localStorage.getItem(PENDING_SKU_KEY) ?? "";
    } catch {
      /* ignore */
    }
  }
  try {
    localStorage.removeItem(PENDING_SKU_KEY);
  } catch {
    /* ignore */
  }
  return { store: "bazaar", productId, token };
}