import type {
  NbDnsNameserverGroup,
  NbEvent,
  NbGroup,
  NbNetwork,
  NbNetworkResource,
  NbNetworkRouter,
  NbPeer,
  NbPolicy,
  NbPostureCheck,
  NbRoute,
  NbSetupKey,
  NbUser,
} from "./types.ts";

/** Narrowed fetch signature used for dependency injection. */
export type FetchFn = (
  input: string | URL | Request,
  init?: RequestInit,
) => Promise<Response>;

/** Thrown when the NetBird API returns a non-2xx status. */
export class NetbirdApiError extends Error {
  constructor(
    public readonly status: number,
    public readonly method: string,
    public readonly path: string,
    public readonly body: unknown,
  ) {
    super(`NetBird API error: ${method} ${path} returned ${status}`);
    this.name = "NetbirdApiError";
  }
}

/**
 * Thin HTTP client for the NetBird Management API.
 *
 * Accepts an injectable fetch function so callers (and tests) can swap
 * the transport without touching the client logic.
 */
export class NetbirdClient {
  constructor(
    private readonly baseUrl: string,
    private readonly token: string,
    private readonly fetchFn: FetchFn = fetch,
  ) {}

  // ---------------------------------------------------------------------------
  // Internal
  // ---------------------------------------------------------------------------

  private async request<T>(
    method: string,
    path: string,
    body?: unknown,
  ): Promise<T> {
    const url = `${this.baseUrl}${path}`;
    const headers: Record<string, string> = {
      "Authorization": `Token ${this.token}`,
      "Accept": "application/json",
    };
    if (body !== undefined) {
      headers["Content-Type"] = "application/json";
    }

    const resp = await this.fetchFn(url, {
      method,
      headers,
      body: body !== undefined ? JSON.stringify(body) : undefined,
    });

    if (!resp.ok) {
      const text = await resp.text();
      let errorBody: unknown;
      try {
        errorBody = JSON.parse(text);
      } catch {
        errorBody = text;
      }
      throw new NetbirdApiError(resp.status, method, path, errorBody);
    }

    // 204 No Content — nothing to parse
    if (resp.status === 204) {
      return undefined as T;
    }

    return (await resp.json()) as T;
  }

  // ---------------------------------------------------------------------------
  // Groups
  // ---------------------------------------------------------------------------

  listGroups(): Promise<NbGroup[]> {
    return this.request("GET", "/groups");
  }

  createGroup(data: { name: string; peers?: string[] }): Promise<NbGroup> {
    return this.request("POST", "/groups", data);
  }

  updateGroup(
    id: string,
    data: { name?: string; peers?: string[] },
  ): Promise<NbGroup> {
    return this.request("PUT", `/groups/${id}`, data);
  }

  deleteGroup(id: string): Promise<void> {
    return this.request("DELETE", `/groups/${id}`);
  }

  // ---------------------------------------------------------------------------
  // Setup Keys
  // ---------------------------------------------------------------------------

  listSetupKeys(): Promise<NbSetupKey[]> {
    return this.request("GET", "/setup-keys");
  }

  createSetupKey(data: {
    name: string;
    type: "one-off" | "reusable";
    expires_in: number;
    auto_groups?: string[];
    usage_limit?: number;
  }): Promise<NbSetupKey> {
    return this.request("POST", "/setup-keys", data);
  }

  deleteSetupKey(id: number | string): Promise<void> {
    return this.request("DELETE", `/setup-keys/${id}`);
  }

  // ---------------------------------------------------------------------------
  // Peers
  // ---------------------------------------------------------------------------

  listPeers(): Promise<NbPeer[]> {
    return this.request("GET", "/peers");
  }

  updatePeer(
    id: string,
    data: {
      name?: string;
      ssh_enabled?: boolean;
      login_expiration_enabled?: boolean;
      inactivity_expiration_enabled?: boolean;
    },
  ): Promise<NbPeer> {
    return this.request("PUT", `/peers/${id}`, data);
  }

  deletePeer(id: string): Promise<void> {
    return this.request("DELETE", `/peers/${id}`);
  }

  // ---------------------------------------------------------------------------
  // Policies
  // ---------------------------------------------------------------------------

  listPolicies(): Promise<NbPolicy[]> {
    return this.request("GET", "/policies");
  }

  createPolicy(data: Omit<NbPolicy, "id">): Promise<NbPolicy> {
    return this.request("POST", "/policies", data);
  }

  updatePolicy(id: string, data: Omit<NbPolicy, "id">): Promise<NbPolicy> {
    return this.request("PUT", `/policies/${id}`, data);
  }

  deletePolicy(id: string): Promise<void> {
    return this.request("DELETE", `/policies/${id}`);
  }

  // ---------------------------------------------------------------------------
  // Routes
  // ---------------------------------------------------------------------------

  listRoutes(): Promise<NbRoute[]> {
    return this.request("GET", "/routes");
  }

  createRoute(data: Omit<NbRoute, "id">): Promise<NbRoute> {
    return this.request("POST", "/routes", data);
  }

  updateRoute(id: string, data: Omit<NbRoute, "id">): Promise<NbRoute> {
    return this.request("PUT", `/routes/${id}`, data);
  }

  deleteRoute(id: string): Promise<void> {
    return this.request("DELETE", `/routes/${id}`);
  }

  // ---------------------------------------------------------------------------
  // DNS Nameserver Groups
  // ---------------------------------------------------------------------------

  listDnsNameserverGroups(): Promise<NbDnsNameserverGroup[]> {
    return this.request("GET", "/dns/nameservers");
  }

  createDnsNameserverGroup(
    data: Omit<NbDnsNameserverGroup, "id">,
  ): Promise<NbDnsNameserverGroup> {
    return this.request("POST", "/dns/nameservers", data);
  }

  updateDnsNameserverGroup(
    id: string,
    data: Omit<NbDnsNameserverGroup, "id">,
  ): Promise<NbDnsNameserverGroup> {
    return this.request("PUT", `/dns/nameservers/${id}`, data);
  }

  deleteDnsNameserverGroup(id: string): Promise<void> {
    return this.request("DELETE", `/dns/nameservers/${id}`);
  }

  // ---------------------------------------------------------------------------
  // Events
  // ---------------------------------------------------------------------------

  listEvents(): Promise<NbEvent[]> {
    return this.request("GET", "/events/audit");
  }

  // ---------------------------------------------------------------------------
  // Posture Checks
  // ---------------------------------------------------------------------------

  listPostureChecks(): Promise<NbPostureCheck[]> {
    return this.request("GET", "/posture-checks");
  }

  createPostureCheck(
    data: Omit<NbPostureCheck, "id">,
  ): Promise<NbPostureCheck> {
    return this.request("POST", "/posture-checks", data);
  }

  updatePostureCheck(
    id: string,
    data: Omit<NbPostureCheck, "id">,
  ): Promise<NbPostureCheck> {
    return this.request("PUT", `/posture-checks/${id}`, data);
  }

  deletePostureCheck(id: string): Promise<void> {
    return this.request("DELETE", `/posture-checks/${id}`);
  }

  // ---------------------------------------------------------------------------
  // Networks
  // ---------------------------------------------------------------------------

  listNetworks(): Promise<NbNetwork[]> {
    return this.request("GET", "/networks");
  }

  createNetwork(
    data: { name: string; description?: string },
  ): Promise<NbNetwork> {
    return this.request("POST", "/networks", data);
  }

  updateNetwork(
    id: string,
    data: { name: string; description?: string },
  ): Promise<NbNetwork> {
    return this.request("PUT", `/networks/${id}`, data);
  }

  deleteNetwork(id: string): Promise<void> {
    return this.request("DELETE", `/networks/${id}`);
  }

  // ---------------------------------------------------------------------------
  // Network Resources
  // ---------------------------------------------------------------------------

  listNetworkResources(networkId: string): Promise<NbNetworkResource[]> {
    return this.request("GET", `/networks/${networkId}/resources`);
  }

  createNetworkResource(
    networkId: string,
    data: {
      name: string;
      description?: string;
      address: string;
      enabled: boolean;
      groups: string[];
    },
  ): Promise<NbNetworkResource> {
    return this.request("POST", `/networks/${networkId}/resources`, data);
  }

  updateNetworkResource(
    networkId: string,
    resourceId: string,
    data: {
      name: string;
      description?: string;
      address: string;
      enabled: boolean;
      groups: string[];
    },
  ): Promise<NbNetworkResource> {
    return this.request(
      "PUT",
      `/networks/${networkId}/resources/${resourceId}`,
      data,
    );
  }

  deleteNetworkResource(
    networkId: string,
    resourceId: string,
  ): Promise<void> {
    return this.request(
      "DELETE",
      `/networks/${networkId}/resources/${resourceId}`,
    );
  }

  // ---------------------------------------------------------------------------
  // Network Routers
  // ---------------------------------------------------------------------------

  listNetworkRouters(networkId: string): Promise<NbNetworkRouter[]> {
    return this.request("GET", `/networks/${networkId}/routers`);
  }

  createNetworkRouter(
    networkId: string,
    data: Omit<NbNetworkRouter, "id">,
  ): Promise<NbNetworkRouter> {
    return this.request("POST", `/networks/${networkId}/routers`, data);
  }

  updateNetworkRouter(
    networkId: string,
    routerId: string,
    data: Omit<NbNetworkRouter, "id">,
  ): Promise<NbNetworkRouter> {
    return this.request(
      "PUT",
      `/networks/${networkId}/routers/${routerId}`,
      data,
    );
  }

  deleteNetworkRouter(
    networkId: string,
    routerId: string,
  ): Promise<void> {
    return this.request(
      "DELETE",
      `/networks/${networkId}/routers/${routerId}`,
    );
  }

  // ---------------------------------------------------------------------------
  // Users
  // ---------------------------------------------------------------------------

  listUsers(): Promise<NbUser[]> {
    return this.request("GET", "/users");
  }

  createUser(data: {
    email: string;
    name?: string;
    role: string;
    auto_groups: string[];
    is_service_user: boolean;
  }): Promise<NbUser> {
    return this.request("POST", "/users", data);
  }

  updateUser(
    id: string,
    data: { name?: string; role?: string; auto_groups?: string[] },
  ): Promise<NbUser> {
    return this.request("PUT", `/users/${id}`, data);
  }

  deleteUser(id: string): Promise<void> {
    return this.request("DELETE", `/users/${id}`);
  }
}