import dayjs from 'dayjs'
import { Keyring } from 'wallet/src/features/wallet/Keyring/Keyring'
import {
  AccountType,
  BackupType,
  SignerMnemonicAccount,
} from 'wallet/src/features/wallet/accounts/types'

/**
 * Takes a list of existing mnemonic accounts to use as reference for pulling the next derivation index
 */
export const createOnboardingAccount = async (
  sortedMnemonicAccounts: SignerMnemonicAccount[],
  password?: string
): Promise<SignerMnemonicAccount> => {
  const { nextDerivationIndex, mnemonicId, existingBackups } = await getNewAccountParams(
    sortedMnemonicAccounts,
    password
  )
  const address = await Keyring.generateAndStorePrivateKey(mnemonicId, nextDerivationIndex)
  return {
    type: AccountType.SignerMnemonic,
    address,
    timeImportedMs: dayjs().valueOf(),
    derivationIndex: nextDerivationIndex,
    mnemonicId,
    backups: existingBackups,
    name: `Wallet ${nextDerivationIndex + 1}`,
  }
}

export async function getNewAccountParams(
  sortedAccounts: SignerMnemonicAccount[],
  password?: string
): Promise<{
  nextDerivationIndex: number
  mnemonicId: string
  existingBackups?: BackupType[]
}> {
  if (sortedAccounts.length === 0 || !sortedAccounts[0]) {
    const mnemonicId = await Keyring.generateAndStoreMnemonic(password)
    return { nextDerivationIndex: 0, mnemonicId }
  }
  return {
    nextDerivationIndex: getNextDerivationIndex(sortedAccounts),
    mnemonicId: sortedAccounts[0].mnemonicId,
    existingBackups: sortedAccounts[0].backups,
  }
}

export function getNextDerivationIndex(sortedAccounts: SignerMnemonicAccount[]): number {
  // if there is a missing index in the series (0, 1, _, 3), return this missing index
  let nextIndex = 0
  for (const account of sortedAccounts) {
    if (account.derivationIndex !== nextIndex) {
      return Math.min(account.derivationIndex, nextIndex)
    }
    nextIndex += 1
  }
  // if all exist, nextDerivation = sortedMnemonicAccounts.length + 1
  return nextIndex
}
