const BASE = process.env.NEXT_PUBLIC_API_URL ?? "http://localhost:8000";
const PREFIX = "/api/v1";

if (typeof window !== "undefined") {
  console.log("[API] base URL:", `${BASE}${PREFIX}`);
}

// ── Token management ──────────────────────────────────────────────────────────

export function getToken(): string | null {
  if (typeof window === "undefined") return null;
  return localStorage.getItem("bado_token");
}

export function setTokens(access: string, refresh: string) {
  localStorage.setItem("bado_token", access);
  localStorage.setItem("bado_refresh", refresh);
}

export function clearTokens() {
  localStorage.removeItem("bado_token");
  localStorage.removeItem("bado_refresh");
}

// ── Error ─────────────────────────────────────────────────────────────────────

export class ApiError extends Error {
  code: string;
  status: number;
  details?: unknown;
  constructor(code: string, message: string, status: number, details?: unknown) {
    super(message);
    this.code = code;
    this.status = status;
    this.details = details;
  }
}

// ── Paginated result shape ────────────────────────────────────────────────────

export interface PaginatedResult<T> {
  data: T[];
  meta: { total: number; page: number; per_page: number; pages: number };
}

// ── Core request ──────────────────────────────────────────────────────────────

async function request<T>(path: string, init: RequestInit = {}): Promise<T> {
  const token = getToken();
  const method = (init.method ?? "GET").toUpperCase();
  const headers: Record<string, string> = {
    ...(init.headers as Record<string, string>),
  };
  if (method !== "GET" && method !== "DELETE" && !(init.body instanceof FormData)) {
    headers["Content-Type"] = "application/json";
  }
  if (token) headers["Authorization"] = `Bearer ${token}`;

  const res = await fetch(`${BASE}${PREFIX}${path}`, { ...init, headers });

  if (res.status === 204) return undefined as unknown as T;

  const body = await res.json();

  if (body.success === false) {
    const err = body.error ?? {};
    throw new ApiError(
      err.code ?? "UNKNOWN",
      err.message ?? "Une erreur est survenue",
      res.status,
      err.details
    );
  }

  if ("meta" in body) {
    return { data: body.data, meta: body.meta } as T;
  }

  return body.data as T;
}

export const api = {
  get: <T>(path: string) => request<T>(path),
  post: <T>(path: string, data?: unknown) =>
    request<T>(path, {
      method: "POST",
      body: data !== undefined ? JSON.stringify(data) : undefined,
    }),
  put: <T>(path: string, data?: unknown) =>
    request<T>(path, { method: "PUT", body: JSON.stringify(data) }),
  patch: <T>(path: string, data?: unknown) =>
    request<T>(path, { method: "PATCH", body: JSON.stringify(data) }),
  del: <T = void>(path: string) => request<T>(path, { method: "DELETE" }),
  upload: <T>(path: string, formData: FormData) =>
    request<T>(path, { method: "POST", body: formData }),
};