import { invoke } from '@tauri-apps/api/core';
import { listen as tauriListen } from '@tauri-apps/api/event';
import type { RpcEventSchema, RpcSchema } from '@yaakapp-internal/proxy-lib';

export type Req<K extends keyof RpcSchema> = RpcSchema[K][0];
export type Res<K extends keyof RpcSchema> = RpcSchema[K][1];

export async function rpc<K extends keyof RpcSchema>(cmd: K, payload: Req<K>): Promise<Res<K>> {
  return invoke('rpc', { cmd, payload }) as Promise<Res<K>>;
}

/** Subscribe to a backend event. Returns an unsubscribe function. */
export function listen<K extends keyof RpcEventSchema>(
  event: K & string,
  callback: (payload: RpcEventSchema[K]) => void,
): () => void {
  let unsub: (() => void) | null = null;
  tauriListen<RpcEventSchema[K]>(event, (e) => callback(e.payload))
    .then((fn) => {
      unsub = fn;
    })
    .catch(console.error);
  return () => unsub?.();
}