backend

Documentation

Index

• Variables
• type FakeStock
  • func GetFakeStock() *FakeStock
  • func (stock *FakeStock) GetAll(ctx context.Context) (items []*StockItem, err error)
  • func (stock *FakeStock) GetItem(ctx context.Context, ID string) (*StockItem, error)
  • func (stock *FakeStock) ReserveItem(ctx context.Context, ID string) error
  • func (stock *FakeStock) UpdateItem(ctx context.Context, ID string, status vend.Result) error
• type FakeStockItem
  • func (item *FakeStockItem) GetStockItem() *StockItem
• type FakeTransaction
  • func (txn *FakeTransaction) GetTransaction() *Transaction
• type FakeTransactions
  • func NewFakeTransactions(ctx context.Context) *FakeTransactions
  • func (txmgr *FakeTransactions) Get(ctx context.Context, ID string) (*Transaction, error)
  • func (txmgr *FakeTransactions) New(ctx context.Context, item *StockItem, user string) (*Transaction, error)
  • func (txmgr *FakeTransactions) Update(ctx context.Context, txn *Transaction) error
• type Stock
• type StockItem
  • func (item *StockItem) CanVend() bool
  • func (item *StockItem) FormattedPrice() string
• type Transaction
• type TransactionState
  • func (st TransactionState) MarshalJSON() ([]byte, error)
  • func (st TransactionState) String() string
• type Transactions

Variables

var (
	// ErrNotAnItem is what happens if you try to vend an item what not be there
	ErrNotAnItem = errors.New("invalid item ID")
	// ErrItemEmpty is if you vend something that's out
	ErrItemEmpty = errors.New("no stock available")
	// ErrItemBroken in if you vend something that's
	ErrItemBroken = errors.New("item is jammed")
)

Types

type FakeStock

type FakeStock struct {
	Items map[string]*FakeStockItem
}

FakeStock is an in-memory Stock

func GetFakeStock

func GetFakeStock() *FakeStock

GetFakeStock returns a Stock with a bunch of fake items in it

func (*FakeStock) GetAll

func (stock *FakeStock) GetAll(ctx context.Context) (items []*StockItem, err error)

GetAll returns all items currently in the vending machine (available or not)

func (*FakeStock) GetItem

func (stock *FakeStock) GetItem(ctx context.Context, ID string) (*StockItem, error)

GetItem returns information specific to a single item

func (*FakeStock) ReserveItem

func (stock *FakeStock) ReserveItem(ctx context.Context, ID string) error

ReserveItem indicates that you are queued to vend an item and it's unavailable for other vends TODO: This should probably have a saner way of exhibiting reservations (eg grants?)

func (*FakeStock) UpdateItem

func (stock *FakeStock) UpdateItem(ctx context.Context, ID string, status vend.Result) error

UpdateItem updates the stock with the result of your recent vend attempt.

type FakeStockItem

type FakeStockItem struct {
	StockItem
	sync.RWMutex
}

FakeStockItem is a data store for FakeStock

func (*FakeStockItem) GetStockItem

func (item *FakeStockItem) GetStockItem() *StockItem

GetStockItem returns a copy of the stock item

type FakeTransaction

type FakeTransaction struct {
	Transaction
	sync.RWMutex
}

FakeTransaction is the memory backing store for FakeTransactions

func (*FakeTransaction) GetTransaction

func (txn *FakeTransaction) GetTransaction() *Transaction

GetTransaction returns a copy of the transaction

type FakeTransactions

type FakeTransactions struct {
	// contains filtered or unexported fields
}

FakeTransactions handles syncing transactions with the database etc

func NewFakeTransactions

func NewFakeTransactions(ctx context.Context) *FakeTransactions

NewFakeTransactions does the needful

func (*FakeTransactions) Get

func (txmgr *FakeTransactions) Get(ctx context.Context, ID string) (*Transaction, error)

Get retrieves an existing transaction

func (*FakeTransactions) New

func (txmgr *FakeTransactions) New(ctx context.Context, item *StockItem, user string) (*Transaction, error)

New sets up a new transaction starting now

func (*FakeTransactions) Update

func (txmgr *FakeTransactions) Update(ctx context.Context, txn *Transaction) error

Update stores the new transaction state in the database

type Stock

type Stock interface {
	// GetAll returns all items currently in the vending machine (available or not)
	GetAll(context.Context) ([]*StockItem, error)
	// GetItem returns information specific to a single item
	GetItem(ctx context.Context, ID string) (*StockItem, error)
	// ReserveItem indicates that you are queued to vend an item and it's unavailable for other vends
	ReserveItem(ctx context.Context, ID string) error
	// UpdateItem updates the stock with the result of your recent vend attempt.
	UpdateItem(ctx context.Context, ID string, status vend.Result) error
}

Stock is a storage container for items in the vending machine

type StockItem

type StockItem struct {
	ID       string
	Name     string
	Quantity uint8
	Reserved uint8
	Image    string
	Price    uint64
	Location uint8
	Broken   bool
}

StockItem represents the current state of an item in the vending machine. It should not be retained as any changes to the stock (eg vends) will not be propagated

func (*StockItem) CanVend

func (item *StockItem) CanVend() bool

CanVend checks stock availability

func (*StockItem) FormattedPrice

func (item *StockItem) FormattedPrice() string

FormattedPrice returns the price as a currency string

type Transaction

type Transaction struct {
	ID         uuid.UUID        `json:"id"`
	Item       string           `json:"-"`
	Amount     uint64           `json:"-"`
	ProviderID string           `json:"-"`
	User       string           `json:"-"` // Name + email of person doing this
	State      TransactionState `json:"state"`
	Date       time.Time        `json:"-"`
	Reason     string           `json:"reason,omitempty"` // If something went wrong - what
}

Transaction represents a single transaction in the system It has a very minimal JSON footprint to improve transfers

type TransactionState

type TransactionState uint8

TransactionState describes the state of a transaction

const (
	// TransactionPending is when we have a token from Stripe but it's not been charged
	TransactionPending TransactionState = iota + 1

	// TransactionPaid is when stripe has confirmed the charge but we've not yet vended
	TransactionPaid

	// TransactionComplete is when we've successfully vended the item
	TransactionComplete

	// TransactionRejected is when Stripe declines us
	TransactionRejected
	// TransactionFailed is when something went wrong and we didn't vend
	TransactionFailed
)

func (TransactionState) MarshalJSON

func (st TransactionState) MarshalJSON() ([]byte, error)

MarshalJSON returns the value of String but lowercase

func (TransactionState) String

func (st TransactionState) String() string

type Transactions

type Transactions interface {
	// New creates a transaction from the passed info and returns it
	New(ctx context.Context, item *StockItem, user string) (*Transaction, error)
	// Get returns an existing transaction or nil if it doesn't exist
	Get(ctx context.Context, ID string) (*Transaction, error)
	// Update updates an existing transaction to the new state.
	// Note: It will only update the fields ProviderID, State and Reason.
	Update(ctx context.Context, txn *Transaction) error
}

Transactions looks after transactions