import "server-only";
import { getValidSession } from "@/lib/auth/session";
import { ApiError, type WinofyErrorDetails } from "./errors";
import { logWinofyRequest, logWinofyResponse } from "./dev-logger";

const BASE_URL = process.env.WINOFY_API_BASE_URL!;

interface WinofyFetchOptions extends Omit<RequestInit, "body"> {
  /** Attach the caller's bearer token. Defaults to true — set false for public endpoints. */
  auth?: boolean;
  params?: Record<string, string | number | boolean | undefined>;
  body?: unknown;
}

export interface PaginatedResponse<T> {
  count: number;
  next: string | null;
  previous: string | null;
  results: T[];
}

export async function winofyFetch<T>(path: string, options: WinofyFetchOptions = {}): Promise<T> {
  const { auth = true, params, headers, body, ...rest } = options;
  const method = rest.method ?? "GET";

  const url = new URL(BASE_URL.replace(/\/$/, "") + path);
  if (params) {
    for (const [key, value] of Object.entries(params)) {
      if (value !== undefined) url.searchParams.set(key, String(value));
    }
  }

  const finalHeaders = new Headers(headers);
  const hasBody = body !== undefined;
  if (hasBody && !finalHeaders.has("Content-Type")) {
    finalHeaders.set("Content-Type", "application/json");
  }

  if (auth) {
    const session = await getValidSession();
    if (session) finalHeaders.set("Authorization", `Bearer ${session.accessToken}`);
  }

  logWinofyRequest(method, url.toString(), body);

  const res = await fetch(url.toString(), {
    ...rest,
    headers: finalHeaders,
    body: hasBody ? JSON.stringify(body) : undefined,
    cache: "no-store",
  });

  if (res.status === 204) {
    logWinofyResponse(method, url.toString(), res.status, null);
    return undefined as T;
  }

  const data = await res.json().catch(() => null);
  logWinofyResponse(method, url.toString(), res.status, data);

  if (!res.ok) {
    const envelope = data as { status_message?: string; details?: WinofyErrorDetails } | null;
    throw new ApiError(res.status, envelope?.status_message ?? res.statusText, envelope?.details ?? null);
  }

  return data as T;
}

export { ApiError };