import type { AppDetails, AppQuery, ChartEntry, ChartQuery, ScraperLib } from "./api.ts";

/** Subset of `app-store-scraper` we use. Allows injecting a mock in tests. */
export interface AppleScraperLib {
  list(opts: { collection: string; country: string; num: number }): Promise<unknown[]>;
  app(opts: { id?: string; appId?: string; country: string }): Promise<unknown>;
  collection: Record<string, string>;
}

const APPLE_COLLECTION_MAP: Record<string, string> = {
  "top-grossing": "TOP_GROSSING_IOS",
  "top-free": "TOP_FREE_IOS",
  "top-paid": "TOP_PAID_IOS",
};

function normalizeAppleEntry(raw: unknown): ChartEntry {
  const o = raw as Record<string, unknown>;
  // Bundle ID (e.g., "com.google.ios.youtube") is what we store as `appId`.
  // Older lib versions exposed it under `id`; newer ones under `appId`.
  const id = o.appId ?? o.id ?? o.trackId;
  // Numeric track id (e.g., "284882215"). Required by apps.apple.com URLs
  // (`/id<trackId>`). Apple's lib surfaces it under `trackId` on per-app
  // results; chart list() entries surface the same numeric value under `id`
  // when the lib hasn't been upgraded to expose `appId` separately.
  const trackIdRaw = o.trackId ?? o.id;
  const trackId =
    typeof trackIdRaw === "string"
      ? trackIdRaw
      : typeof trackIdRaw === "number"
        ? String(trackIdRaw)
        : undefined;
  return {
    appId: String(id ?? ""),
    trackId,
    title: typeof o.title === "string" ? o.title : (o.trackName as string | undefined),
    developer: typeof o.developer === "string" ? o.developer : (o.artistName as string | undefined),
    primaryGenre:
      typeof o.primaryGenre === "string" ? o.primaryGenre : (o.genre as string | undefined),
    genre: typeof o.genre === "string" ? o.genre : undefined,
    price: typeof o.price === "number" ? o.price : undefined,
    currency: typeof o.currency === "string" ? o.currency : undefined,
    free: typeof o.free === "boolean" ? o.free : undefined,
    score: typeof o.score === "number" ? o.score : undefined,
    reviews: typeof o.reviews === "number" ? o.reviews : undefined,
    ratings: typeof o.ratings === "number" ? o.ratings : undefined,
    icon: typeof o.icon === "string" ? o.icon : undefined,
    description: typeof o.description === "string" ? o.description : undefined,
    screenshots: Array.isArray(o.screenshots) ? (o.screenshots as string[]) : undefined,
    released: typeof o.released === "string" ? o.released : undefined,
    updated: typeof o.updated === "string" ? o.updated : undefined,
  };
}

export function createAppleScraperLib(lib: AppleScraperLib): ScraperLib {
  return {
    async fetchChart(query: ChartQuery): Promise<ChartEntry[]> {
      if (query.store !== "apple") {
        throw new Error(`apple client received non-apple query: ${query.store}`);
      }
      const collectionKey = APPLE_COLLECTION_MAP[query.collection];
      if (!collectionKey) {
        throw new Error(`unsupported apple collection: ${query.collection}`);
      }
      // `app-store-scraper` validates `list({collection})` against its own
      // enum *values* (e.g. "topgrossingapplications"), not the key strings
      // ("TOP_GROSSING_IOS"). Look up the value on the lib's own collection
      // map so we tolerate any value-string drift between releases.
      const collection = lib.collection[collectionKey];
      if (!collection) {
        throw new Error(`apple-store-scraper has no collection enum value for "${collectionKey}"`);
      }
      const raw = await lib.list({
        collection,
        country: query.market.toLowerCase(),
        num: query.limit,
      });
      return raw.map(normalizeAppleEntry);
    },
    async fetchApp(query: AppQuery): Promise<AppDetails> {
      if (query.store !== "apple") {
        throw new Error(`apple client received non-apple query: ${query.store}`);
      }
      // `app-store-scraper`'s `app()` takes EITHER `id` (numeric trackId
      // like "544007664") OR `appId` (bundle ID like "com.google.ios.youtube").
      // Passing a bundle ID as `id` fails — the lib looks it up as a
      // numeric trackId and gets nothing. M7's first demo-refresh run
      // caught this (100% Apple enrichment failure across 10 apps); the
      // smoke gate didn't catch it because smoke topN=1 + Google enriching
      // = 1 Google candidate ranked, masking the Apple failure. We use
      // a heuristic: numeric strings → `id`, anything else → `appId`.
      const isNumericId = /^\d+$/.test(query.appId);
      const lookup = isNumericId
        ? { id: query.appId, country: query.market.toLowerCase() }
        : { appId: query.appId, country: query.market.toLowerCase() };
      const raw = await lib.app(lookup);
      const entry = normalizeAppleEntry(raw);
      const o = raw as Record<string, unknown>;
      return {
        ...entry,
        inAppPurchases: typeof o.inAppPurchases === "boolean" ? o.inAppPurchases : undefined,
      };
    },
  };
}

/** Convenience: load the real `app-store-scraper` and return a wired-up client. */
export async function loadDefaultAppleClient(): Promise<ScraperLib> {
  const mod = await import("app-store-scraper");
  const lib =
    (mod as unknown as { default?: AppleScraperLib }).default ??
    (mod as unknown as AppleScraperLib);
  return createAppleScraperLib(lib);
}