import { EventEmitter } from "eventemitter3"

export type EventName =
  | "message"
  | "connect"
  | "disconnect"
  | "accountsChanged"
  | "chainChanged"

type ProviderMessage = {
  readonly type: string
  readonly data: unknown
}

type ProviderConnectInfo = {
  readonly chainId: string
}

export type EventCallbackByEventName = {
  message: (message: ProviderMessage) => void
  connect: (connectInfo: ProviderConnectInfo) => void
  disconnect: () => void
  accountsChanged: (accounts: string[]) => void
  chainChanged: (chainId: string) => void
}

export const emitter = new EventEmitter()

type EventMessage = {
  event: EventName
  data?: unknown
}

export const isEventMessage = (message: unknown): message is EventMessage =>
  !!message &&
  typeof message === "object" &&
  "type" in message &&
  message.type === "event" &&
  "event" in message &&
  typeof message.event === "string"