import { EventEmitter } from 'eventemitter3';

export interface RequestArguments {
  readonly method: string;
  readonly params?: readonly unknown[] | object;
}

export interface ProviderRpcError extends Error {
  message: string;
  code: number;
  data?: unknown;
}

interface ProviderConnectInfo {
  readonly chainId: string;
}

type ProviderEventMap = {
  connect: ProviderConnectInfo;
  disconnect: ProviderRpcError;
  chainChanged: string; // hex string
  accountsChanged: string[];
};

export class ProviderEventEmitter extends EventEmitter<
  keyof ProviderEventMap
> {}

export interface ProviderInterface extends ProviderEventEmitter {
  request(args: RequestArguments): Promise<unknown>;
  disconnect(): Promise<void>;
  emit<K extends keyof ProviderEventMap>(
    event: K,
    ...args: [ProviderEventMap[K]]
  ): boolean;
  on<K extends keyof ProviderEventMap>(
    event: K,
    listener: (_: ProviderEventMap[K]) => void
  ): this;
}