import {
  SignInWithWalletErrorType,
  SignInWithWalletMessage,
} from "@mezo-org/sign-in-with-wallet"
import { ONE_DAY_MS } from "./time"

const SESSION_EXPIRATION_DURATION_MS = 14 * ONE_DAY_MS

type NetworkFamily = "evm" | "bitcoin"

export function createSignInWithWalletMessage(
  address: string,
  nonce: string,
  networkFamily: NetworkFamily,
  chainId?: number,
) {
  const { host: domain, origin: uri } = window.location

  let siwwMessage
  try {
    siwwMessage = new SignInWithWalletMessage({
      domain,
      address, // if "bitcoin" this should be btc address, not underlaying eth address
      uri,
      nonce,
      issuedAt: new Date().toISOString(),
      expirationTime: new Date(
        Date.now() + SESSION_EXPIRATION_DURATION_MS,
      ).toISOString(),
      version: "1",
      chainId: networkFamily === "evm" ? chainId : undefined,
      networkFamily,
    })
  } catch (error) {
    throw new Error(`Failed to create sign in with wallet message: ${error}`)
  }

  return siwwMessage.prepareMessage()
}

class SIWWDomainError extends Error {
  constructor(message: string) {
    super(`Error when verifying domain in SIWW message: ${message}`)
    this.name = "SIWWDomainError"
  }
}

export async function verifyDomainInSignInWithWalletMessage(
  message: string,
  signature: string,
  nonce: string,
) {
  const { host: domain } = window.location
  let siwwMessage: SignInWithWalletMessage
  try {
    siwwMessage = new SignInWithWalletMessage(message)
  } catch (error) {
    throw new SIWWDomainError("Failed to parse SIWW message")
  }

  if (!siwwMessage.expirationTime) {
    throw new SIWWDomainError("SIWW messages must have an expiration time set")
  }

  const result = await siwwMessage.verify(
    {
      signature,
      // Nonce has to match the session ID carried in the request.
      nonce,
      domain,
      // Time is used as a reference to verify the expiration time set in the
      // message.
      time: new Date().toISOString(),
    },
    { suppressExceptions: true },
  )

  if (
    result.error &&
    result.error.type === SignInWithWalletErrorType.DOMAIN_MISMATCH
  ) {
    throw new SIWWDomainError(
      "Domain does not match provided domain for verification.",
    )
  }
}