export type Hex = `0x${string}`

export type P256Credential = {
  id: string
  publicKey: Hex
  raw: PublicKeyCredential
}

export type PublicKey = {
  prefix?: number | undefined
  x: bigint
  y: bigint
}

export type WebAuthnData = {
  authenticatorData: Hex
  challengeIndex: number
  clientDataJSON: string
  typeIndex: number
  userVerificationRequired: boolean
}

export type Signature = {
  r: bigint
  s: bigint
}

////////////////////////////////////////////////////////////////////////
// Utilities
////////////////////////////////////////////////////////////////////////

export type Prettify<T> = {
  [K in keyof T]: T[K]
} & {}

export type OneOf<
  union extends object,
  fallback extends object | undefined = undefined,
  ///
  keys extends KeyofUnion<union> = KeyofUnion<union>,
> = union extends infer Item
  ? Prettify<
      Item & {
        [_K in Exclude<keys, keyof Item>]?: fallback extends object
          ? // @ts-ignore
            fallback[_K]
          : undefined
      }
    >
  : never
type KeyofUnion<type> = type extends type ? keyof type : never

////////////////////////////////////////////////////////////////////////
// Web Authentication API
////////////////////////////////////////////////////////////////////////

type AttestationConveyancePreference =
  | 'direct'
  | 'enterprise'
  | 'indirect'
  | 'none'
type AuthenticatorAttachment = 'cross-platform' | 'platform'
type AuthenticatorTransport = 'ble' | 'hybrid' | 'internal' | 'nfc' | 'usb'
type COSEAlgorithmIdentifier = number
type CredentialMediationRequirement =
  | 'conditional'
  | 'optional'
  | 'required'
  | 'silent'
type PublicKeyCredentialType = 'public-key'
type ResidentKeyRequirement = 'discouraged' | 'preferred' | 'required'
type UserVerificationRequirement = 'discouraged' | 'preferred' | 'required'
type LargeBlobSupport = {
  support: 'required' | 'preferred'
}
type BufferSource = ArrayBufferView | ArrayBuffer
type PrfExtension = Record<'eval', Record<'first', Uint8Array>>
interface AuthenticationExtensionsClientInputs {
  appid?: string
  credProps?: boolean
  hmacCreateSecret?: boolean
  minPinLength?: boolean
  prf?: PrfExtension
  largeBlob?: LargeBlobSupport
}

interface AuthenticatorSelectionCriteria {
  authenticatorAttachment?: AuthenticatorAttachment
  requireResidentKey?: boolean
  residentKey?: ResidentKeyRequirement
  userVerification?: UserVerificationRequirement
}

export interface Credential {
  readonly id: string
  readonly type: string
}

export interface CredentialCreationOptions {
  publicKey?: PublicKeyCredentialCreationOptions
  signal?: AbortSignal
}

export interface CredentialRequestOptions {
  mediation?: CredentialMediationRequirement
  publicKey?: PublicKeyCredentialRequestOptions
  signal?: AbortSignal
}

export interface PublicKeyCredential extends Credential {
  readonly authenticatorAttachment: string | null
  readonly rawId: ArrayBuffer
  readonly response: AuthenticatorResponse
  getClientExtensionResults(): AuthenticationExtensionsClientOutputs
}

export interface PublicKeyCredentialCreationOptions {
  attestation?: AttestationConveyancePreference
  authenticatorSelection?: AuthenticatorSelectionCriteria
  challenge: BufferSource
  excludeCredentials?: PublicKeyCredentialDescriptor[]
  extensions?: AuthenticationExtensionsClientInputs
  pubKeyCredParams: PublicKeyCredentialParameters[]
  rp: PublicKeyCredentialRpEntity
  timeout?: number
  user: PublicKeyCredentialUserEntity
}

interface PublicKeyCredentialDescriptor {
  id: BufferSource
  transports?: AuthenticatorTransport[]
  type: PublicKeyCredentialType
}

interface PublicKeyCredentialEntity {
  name: string
}

interface PublicKeyCredentialParameters {
  alg: COSEAlgorithmIdentifier
  type: PublicKeyCredentialType
}

interface PublicKeyCredentialRequestOptions {
  allowCredentials?: PublicKeyCredentialDescriptor[]
  challenge: BufferSource
  extensions?: AuthenticationExtensionsClientInputs
  rpId?: string
  timeout?: number
  userVerification?: UserVerificationRequirement
}

interface PublicKeyCredentialRpEntity extends PublicKeyCredentialEntity {
  id?: string
}

interface PublicKeyCredentialUserEntity extends PublicKeyCredentialEntity {
  displayName: string
  id: BufferSource
}