import type { AbiEvent, AbiFunction } from 'abitype'

import { type ToBytesErrorType, toBytes } from '../encoding/toBytes.js'
import type { ErrorType } from '../errors/utils.js'
import { type Keccak256ErrorType, keccak256 } from './keccak256.js'
import { type ToSignatureErrorType, toSignature } from './toSignature.js'

export type ToSignatureHashErrorType =
  | Keccak256ErrorType
  | ToBytesErrorType
  | ToSignatureErrorType
  | ErrorType

/**
 * Returns the hash (of the function/event signature) for a given event or function definition.
 */
export function toSignatureHash(fn: string | AbiFunction | AbiEvent) {
  return keccak256(toBytes(toSignature(fn)))
}