idempotency

type Config struct {
	Locker               Locker
	Repository           Repository
	IdempotencyKeyHeader string
}

type IdempotencyKey struct {
	Key                string
	RecoveryPoint      string
	RequestMethod      string
	RequestURLPath     string
	RequestURLRawQuery string
	RequestHeaders     http.Header
	RequestBodyHash    string
	ResponseStatusCode int
	ResponseHeaders    http.Header
	ResponseBody       string
}

type Locker interface {
	Lock(key string) bool
	Unlock(key string)
}

type Repository interface {
	// GetOrInsertKey returns the key if it exists, or inserts it if it doesn't.
	// If the key is inserted, the returned bool is true.
	GetOrInsert(*IdempotencyKey) (*IdempotencyKey, bool, error)
	// SetRecoveryPoint sets the recovery point for the key.
	SetRecoveryPoint(key string, recoveryPoint string) error
	// SetResponse sets the response fields for the key.
	SetResponse(key string, statusCode int, headers http.Header, body string) error
}