banktorrent

README

BankTorrent

BankTorrent is a distributed debt and payment tracking system. It allows groups of people to keep track of shared expenses and how much they owe each other.

Author: Jason D'Souza

Todo

• Write ability
  • remove users/ labels
    • only if there are no expenses/ transactions/ associated with them
    • cant remove if it would leave db in inconsistent state
  • make writing transactional
    • replace sql.Dx with sql.Tx
• Meddler
  • use the MoneyAmount type instead of ints
  • change expense and transaction structs to use MoneyAmount
  • make a meddler that converts from the int to MoneyAmount
• CLI
  • ability to backup db
  • remove expenses
  • get list of expenses
  • add labels
  • add users
  • get statistics
    • upcoming bills
    • potentially missing transactions
  • predictive user input
    • best guess based on input?
  • tests
• web frontend
  • graphs
    • visualization of transaction history
    • breakdown by label
• Tests
  • test coverage of all methods/ functions
• Integrate terminal prettying
  • https://github.com/wsxiaoys/terminal

Workflow

• easily add split/ simple transactions from command line
  • specify user/ label by name
  • enter amount in dollars and cents
• visual reassurance that the math works out
  • show users balance before and after
• easily correct a mistake
  • edit recently added expense?

Documentation

Overview

Package level documentation goes here!

Todo: - explain how the library works - architecture of the library

Index

• Constants
• func Connect(database string) (*sql.DB, error)
• type Expense
  • func CreateExpense(db meddler.DB, amount *MoneyAmount, label *Label, comment string, ...) (*Expense, error)
  • func GetExpenseById(db meddler.DB, id int64) (*Expense, error)
  • func GetExpensesByLabel(db meddler.DB, label *Label) ([]*Expense, error)
  • func (e *Expense) AddSimple(db meddler.DB, lender *User, debtor *User) (*Transaction, error)
  • func (e *Expense) AddSplit(db meddler.DB, lender *User, debtors []*User) ([]*Transaction, error)
  • func (e *Expense) Remove(db meddler.DB) error
  • func (e *Expense) String() string
  • func (e *Expense) Transactions(db meddler.DB) ([]*Transaction, error)
• type ExpenseType
  • func StringToExpenseType(etype string) (ExpenseType, error)
  • func (e ExpenseType) String() string
• type Label
  • func CreateLabel(db meddler.DB, name string) (*Label, error)
  • func GetLabelById(db meddler.DB, id int64) (*Label, error)
  • func GetLabelByName(db meddler.DB, name string) (*Label, error)
  • func (l *Label) String() string
• type MoneyAmount
  • func IntToMoney(amount int) *MoneyAmount
  • func StringToMoney(amount string) (*MoneyAmount, error)
  • func (m *MoneyAmount) Int() int
  • func (m *MoneyAmount) String() string
• type Transaction
  • func GetTransactionById(db meddler.DB, id int64) (*Transaction, error)
  • func (t *Transaction) String() string
• type User
  • func CreateUser(db meddler.DB, name string, email string, balance int) (*User, error)
  • func GetUserById(db meddler.DB, id int64) (*User, error)
  • func GetUserByName(db meddler.DB, name string) (*User, error)
  • func (u *User) Reload(db meddler.DB) error
  • func (u *User) String() string
  • func (u *User) UpdateBalance(db meddler.DB, delta int) error

Constants

const (
	DATE_FMT = "2006-01-02"
	TEST_DB  = "/tmp/banktorrent.test.db"
	PROD_DB  = "/Users/jason/Desktop/transactions.db"
)

Functions

func Connect

func Connect(database string) (*sql.DB, error)

Types

type Expense

type Expense struct {
	Id      int64  `meddler:"id,pk"`
	Amount  int    `meddler:"amount"`
	LabelId int64  `meddler:"label_id"`
	Comment string `meddler:"comment"`
	Date    string `meddler:"date"`
}

func CreateExpense

func CreateExpense(db meddler.DB, amount *MoneyAmount, label *Label, comment string, date time.Time) (*Expense, error)

Creates the expense in the db and gives it an ID

func GetExpenseById

func GetExpenseById(db meddler.DB, id int64) (*Expense, error)

func GetExpensesByLabel

func GetExpensesByLabel(db meddler.DB, label *Label) ([]*Expense, error)

func (*Expense) AddSimple

func (e *Expense) AddSimple(db meddler.DB, lender *User, debtor *User) (*Transaction, error)

Adds a single transaction. The entire expense amount is credited to the lender and charged to the debtor

func (*Expense) AddSplit

func (e *Expense) AddSplit(db meddler.DB, lender *User, debtors []*User) ([]*Transaction, error)

Adds 1 transaction per debtor. The amount is split evenly between everyone (penny errors can occur). This type of transaction is useful even with just 2 people (a debtor and a lender) because it behaves differently than a SimpleExpense. Namely, it splits the expense.Amount evenly between everyone, including the lender, allowing for "shared expenses" to be added easily

func (*Expense) Remove

func (e *Expense) Remove(db meddler.DB) error

Removes the expense by reversing all transactions associated with it, and deleting the expense from the db

func (*Expense) String

func (e *Expense) String() string

func (*Expense) Transactions

func (e *Expense) Transactions(db meddler.DB) ([]*Transaction, error)

type ExpenseType

type ExpenseType int

const (
	UNKNOWN_EXPENSE ExpenseType = iota
	SIMPLE_EXPENSE
	SPLIT_EXPENSE
)

Currently supported expense types

func StringToExpenseType

func StringToExpenseType(etype string) (ExpenseType, error)

func (ExpenseType) String

func (e ExpenseType) String() string

type Label

type Label struct {
	Id   int64  `meddler:"id,pk"`
	Name string `meddler:"name"`
}

func CreateLabel

func CreateLabel(db meddler.DB, name string) (*Label, error)

func GetLabelById

func GetLabelById(db meddler.DB, id int64) (*Label, error)

func GetLabelByName

func GetLabelByName(db meddler.DB, name string) (*Label, error)

func (*Label) String

func (l *Label) String() string

type MoneyAmount

type MoneyAmount struct {
	Dollars int
	Cents   int
}

func IntToMoney

func IntToMoney(amount int) *MoneyAmount

func StringToMoney

func StringToMoney(amount string) (*MoneyAmount, error)

func (*MoneyAmount) Int

func (m *MoneyAmount) Int() int

Return the money amount as a regular int useful for saving to the db until I figure out how to use Meddler to do it

func (*MoneyAmount) String

func (m *MoneyAmount) String() string

type Transaction

type Transaction struct {
	Id        int64  `meddler:"id,pk"`
	LenderId  int64  `meddler:"lender_id"`
	DebtorId  int64  `meddler:"debtor_id"`
	Amount    int    `meddler:"amount"`
	Date      string `meddler:"date"`
	ExpenseId int64  `meddler:"expense_id"`
}

func GetTransactionById

func GetTransactionById(db meddler.DB, id int64) (*Transaction, error)

func (*Transaction) String

func (t *Transaction) String() string

type User

type User struct {
	Id      int64  `meddler:"id,pk"`
	Name    string `meddler:"name"`
	Email   string `meddler:"email"`
	Balance int    `meddler:"balance"`
}

func CreateUser

func CreateUser(db meddler.DB, name string, email string, balance int) (*User, error)

func GetUserById

func GetUserById(db meddler.DB, id int64) (*User, error)

func GetUserByName

func GetUserByName(db meddler.DB, name string) (*User, error)

func (*User) Reload

func (u *User) Reload(db meddler.DB) error

func (*User) String

func (u *User) String() string

func (*User) UpdateBalance

func (u *User) UpdateBalance(db meddler.DB, delta int) error