# LingcheChi

**Repository Path**: chi-lingche/LingcheChi

## Basic Information

- **Project Name**: LingcheChi
- **Description**: Mini Banking System
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-05-02
- **Last Updated**: 2025-05-11

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Mini Banking System

**Author**: 池泠澈 (Lingche Chi)\
**Student ID**: 2023901707\
**English Name**: Lingche Chi

## Overview

The Mini Banking System is a C++17 console application that simulates a banking environment. It enables users to register customers, manage savings and checking accounts, perform transactions (deposits, withdrawals, and transfers), and generate transaction reports. The system enforces account-specific restrictions (e.g., no deposits or withdrawals for savings accounts) and provides a menu-driven interface with robust input validation. Built with object-oriented principles, the project emphasizes modularity, encapsulation, and clean code practices.

## Features

- **Customer Management**: Register customers with unique names, each assigned a savings and checking account.
- **Account Operations**:
  - Checking accounts support deposits, withdrawals, and transfers to any account.
  - Savings accounts are restricted to transfers to the same customer's checking account (no deposits or withdrawals).
- **Transaction Recording**: Logs transactions with unique IDs, types (Deposit, Withdrawal, Transfer), amounts, account IDs, notes, and timestamps.
- **Reports**:
  - **Global Transaction Report**: Exports all transactions to a file.
  - **Customer Report**: Exports transactions for a specific customer.
  - **Bank Account Report**: Exports transactions for a specific account.
- **Account ID Management**: Uses predefined IDs from `account_ids.txt` or defaults (e.g., `6221-0000-0000-0000`) if the file is unavailable.
- **User Interface**: Interactive menu with input validation for names (alphanumeric with spaces) and amounts.

## Compilation and Execution

### Prerequisites

- A C++17-compatible compiler (e.g., `g++`).
- Optional: Create `account_ids.txt` in the project directory with unique account IDs in the format `62XX-YYYY-ZZZZ-AAAA` (e.g., `6221-1234-5678-9012` for savings, `6222-1234-5678-9012` for checking). Example content:

  ```
  6221-1234-5678-9012
  6222-1234-5678-9012
  6221-9876-5432-1098
  6222-9876-5432-1098
  ```

  If missing, the system uses default IDs, which may trigger duplicate ID warnings.

### Build Instructions

1. **Compile the Program**: Create a build directory and compile all source files:

   ```bash
   mkdir -p build
   g++ -std=c++17 BankingSystem.cpp Customer.cpp BankAccount.cpp Transaction.cpp -o build/banking_system
   ```

2. **Run the Program**:

   - On Unix-like systems:

     ```bash
     ./build/banking_system
     ```
   - On Windows:

     ```bash
     build\banking_system.exe
     ```

## Class Descriptions

### `BankAccount`

- **Purpose**: Manages a bank account with an ID and balance.
- **Attributes**:
  - `accountId_` (std::string): Unique identifier (e.g., `6221-0000-0000-0000`).
  - `balance_` (double): Current balance.
- **Methods**:
  - `BankAccount(const std::string& id)`: Constructor with a default ID.
  - `getAccountId()`: Returns the account ID.
  - `getBalance()`: Returns the balance.
  - `setAccountId(const std::string& id)`: Updates the account ID.
  - `deposit(double amount)`: Adds funds if positive.
  - `withdraw(double amount)`: Removes funds if sufficient balance exists.

### `Customer`

- **Purpose**: Represents a customer with savings and checking accounts.
- **Attributes**:
  - `name_` (std::string): Customer’s name.
  - `savingsAccount_` (BankAccount): Savings account instance.
  - `checkingAccount_` (BankAccount): Checking account instance.
- **Methods**:
  - `Customer(const std::string& name)`: Initializes with default account IDs.
  - `getName()`: Returns the customer’s name.
  - `getSavingsAccount()`: Returns a reference to the savings account (const and non-const).
  - `getCheckingAccount()`: Returns a reference to the checking account (const and non-const).

### `Transaction`

- **Purpose**: Records a financial transaction.
- **Attributes**:
  - `transactionId_` (std::string): Unique ID (e.g., `T001`).
  - `type_` (std::string): Transaction type (Deposit, Withdrawal, Transfer).
  - `amount_` (double): Transaction amount.
  - `sourceAccountId_` (std::string): Source account ID.
  - `destinationAccountId_` (std::string): Destination account ID (empty for non-transfers).
  - `note_` (std::string): Optional note.
  - `timestamp_` (std::string): Transaction time.
- **Methods**:
  - `Transaction(...)`: Initializes with all attributes.
  - `getTransactionId()`: Returns the transaction ID.
  - `getSourceAccountId()`: Returns the source account ID.
  - `getDestinationAccountId()`: Returns the destination account ID.
  - `operator<<`: Formats transaction details for output.

### `BankingSystem`

- **Purpose**: Manages the banking system, including customers and transactions.
- **Attributes**:
  - `customers_` (std::vector): List of customers.
  - `transactions_` (std::vector): List of transactions.
  - `availableIds_` (std::vectorstd::string): Pool of available account IDs.
- **Methods**:
  - `run()`: Runs the main menu loop.
  - `registerCustomer()`: Registers a new customer with unique accounts.
  - `accessCustomer()`: Manages account operations and reports.
  - `displayAllAccounts()`: Lists all accounts.
  - `generateTransactionReport()`: Creates a global transaction report.
  - `findCustomer(string)`: Finds a customer by name.
  - `findAccount(string)`: Finds an account by ID.

## Architecture

- **Modularity**: Classes are split into header (`.h`) and implementation (`.cpp`) files for maintainability.
- **Encapsulation**: Private attributes are accessed via public methods, with const correctness.
- **Namespace**: All code is within the `Banking` namespace.
- **Data Management**: Uses `std::vector` for in-memory storage of customers and transactions.
- **Error Handling**: Validates inputs and handles exceptions for critical errors.
- **File Output**: Generates reports as `.txt` files with timestamps.

## Design Decisions

- **Unified** `BankAccount` **Class**: Savings and checking accounts share the same class, with restrictions enforced in `BankingSystem` for simplicity.
- **Centralized Transactions**: Stored in `BankingSystem` for easy reporting.
- **Account ID Assignment**: Relies on `account_ids.txt` or defaults, avoiding random generation to ensure predictability.
- **In-Memory Storage**: No persistence between runs, keeping the system lightweight.
- **Report Filenames**: Sanitizes customer names (spaces to underscores, non-alphanumeric removed) for valid file names.

## Repository

Hosted on Gitee: `https://gitee.com/chi-lingche/LingcheChi` .

## Notes

- **Account Restrictions**: Enforced at the UI level; savings accounts are limited to transfers to the same customer’s checking account.
- **Report Output**: Saved as `transactions_<name_or_id>_<YYYY-MM-DD>.txt` in the project directory.
- **C++17 Features**: Uses modern C++ for string handling and I/O.
- **Testing**: Tested for registration, transactions, and report generation with edge cases (e.g., invalid inputs).

## Troubleshooting

- **Duplicate Errors**: Ensure unique customer names and a valid `account_ids.txt` with sufficient IDs.
- **Missing** `account_ids.txt`: Create the file or expect default IDs with potential duplicate warnings.
- **Compilation Issues**: Verify all `.cpp` and `.h` files are present and use a C++17 compiler.

## Contributing

Fork the repository on Gitee, make improvements, and submit pull requests. Discuss major changes via issues first.