Atm StateMachine Using XState

atm_machine.ts

import { setup } from "xstate";

export const machine = setup({
  types: {
    context: {} as {},
    events: {} as
      | { type: "enter_amount" }
      | { type: "enter_national_id" }
      | { type: "account_is_valid" }
      | { type: "account_is_invalid" }
      | { type: "dest_account_is_valid" }
      | { type: "dest_account_is_invalid" }
      | { type: "select_account_transfer" }
      | { type: "select_register_stolen_card" }
      | { type: "confirmed" }
      | { type: "not_confirmed" }
      | { type: "valid_password" }
      | { type: "invalid_pin" }
      | { type: "successful_account_transfer" }
      | { type: "finish_card_less" },
  },
}).createMachine({
  context: {},
  id: "atmMachine",
  initial: "idle",
  states: {
    idle: {
      on: {
        insert_card: {
          target: "card_inserted",
        },
        cardless_button: {
          target: "cardless",
        },
      },
      description:
        "The ATM is idle, waiting for a customer to insert their card.",
    },
    card_inserted: {
      on: {
        enter_pin: {
          target: "pin_entered",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "The ATM has detected a card insertion and is prompting for PIN entry.",
    },
    cardless: {
      on: {
        select_register_stolen_card: {
          target: "register_stolen_card",
        },
        cancel: {
          target: "idle",
        },
        select_account_transfer: {
          target: "request_account_transfer",
        },
      },
      description:
        "The user has chosen the cardless option. The ATM prompts for the next action.",
    },
    pin_entered: {
      on: {
        pin_valid: {
          target: "select_transaction",
        },
        pin_invalid: {
          target: "pin_error",
        },
      },
      description: "The ATM has received the PIN and is verifying it.",
    },
    register_stolen_card: {
      on: {
        registration_complete: {
          target: "idle",
        },
        registration_error: {
          target: "transaction_error",
        },
      },
      description: "The user is registering a stolen card.",
    },
    request_account_transfer: {
      on: {
        enter_national_id: {
          target: "select_account",
        },
      },
      description: "user asked for source and dest accounts",
    },
    select_transaction: {
      on: {
        select_withdrawal: {
          target: "withdrawal",
        },
        select_balance: {
          target: "balance_inquiry",
        },
        select_deposit: {
          target: "deposit",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "The PIN is valid. The ATM prompts the user to select a transaction type.",
    },
    pin_error: {
      on: {
        reenter_pin: {
          target: "card_inserted",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "The entered PIN is invalid. The ATM prompts the user to re-enter the PIN or eject the card.",
    },
    transaction_error: {
      on: {
        retry: {
          target: "select_transaction",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "An error occurred during the transaction. The ATM displays an error message.",
    },
    select_account: {
      on: {
        account_is_valid: {
          target: "enter_destination_account",
        },
        account_is_invalid: {
          target: "transaction_error",
        },
      },
      description: "List of accounts displayed and asked user to select",
    },
    withdrawal: {
      on: {
        enter_amount: {
          target: "process_withdrawal",
        },
        cancel: {
          target: "select_transaction",
        },
      },
      description:
        "The user has selected a withdrawal. The ATM prompts for the amount to withdraw.",
    },
    balance_inquiry: {
      on: {
        balance_retrieved: {
          target: "display_balance",
        },
        inquiry_error: {
          target: "transaction_error",
        },
      },
      description:
        "The user has selected a balance inquiry. The ATM is retrieving the account balance.",
    },
    deposit: {
      on: {
        enter_amount: {
          target: "process_deposit",
        },
        cancel: {
          target: "select_transaction",
        },
      },
      description:
        "The user has selected a deposit. The ATM prompts for the deposit amount.",
    },
    enter_destination_account: {
      on: {
        dest_account_is_valid: {
          target: "account_transfer",
        },
        dest_account_is_invalid: {
          target: "transaction_error",
        },
      },
      description: "user is asked to enter destination account number",
    },
    process_withdrawal: {
      on: {
        withdrawal_success: {
          target: "dispense_cash",
        },
        insufficient_funds: {
          target: "insufficient_funds",
        },
        withdrawal_error: {
          target: "transaction_error",
        },
      },
      description: "The ATM is processing the withdrawal request.",
    },
    display_balance: {
      on: {
        continue: {
          target: "select_transaction",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "The ATM displays the retrieved account balance to the user.",
    },
    process_deposit: {
      on: {
        deposit_success: {
          target: "deposit_complete",
        },
        deposit_error: {
          target: "transaction_error",
        },
      },
      description: "The ATM is processing the deposit request.",
    },
    account_transfer: {
      on: {
        enter_amount: {
          target: "transfer_confirmation",
        },
      },
      description: "ask user to enter amount",
    },
    dispense_cash: {
      on: {
        cash_dispensed: {
          target: "transaction_complete",
        },
      },
      description: "The ATM is dispensing cash to the user.",
    },
    insufficient_funds: {
      on: {
        retry: {
          target: "select_transaction",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "The account has insufficient funds for the requested withdrawal amount.",
    },
    deposit_complete: {
      on: {
        continue: {
          target: "select_transaction",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "The deposit transaction is complete. The ATM prompts the user for the next action.",
    },
    transfer_confirmation: {
      on: {
        confirmed: {
          target: "ask_for_otp_password",
        },
        not_confirmed: {
          target: "transaction_error",
        },
      },
      description: "user confirms operation",
    },
    transaction_complete: {
      on: {
        continue: {
          target: "select_transaction",
        },
        eject_card: {
          target: "idle",
        },
      },
      description:
        "The transaction is complete. The ATM prompts the user for the next action.",
    },
    ask_for_otp_password: {
      on: {
        valid_password: {
          target: "process_account_transfer",
        },
        invalid_pin: {
          target: "transaction_error",
        },
      },
    },
    process_account_transfer: {
      on: {
        successful_account_transfer: {
          target: "account_transfer_complete",
        },
      },
      description: "send transaction request to server",
    },
    account_transfer_complete: {
      on: {
        finish_card_less: {
          target: "idle",
        },
      },
    },
  },
});