implement core foundation

go/internal/billing/models.go

@@ -0,0 +1,57 @@
+package billing
+
+import "time"
+
+type Cadence string
+
+const (
+	CadenceMonthly Cadence = "monthly"
+	CadenceAnnual  Cadence = "annual"
+)
+
+func (c Cadence) IsValid() bool {
+	return c == CadenceMonthly || c == CadenceAnnual
+}
+
+type Plan string
+
+const (
+	PlanFree Plan = "free"
+	PlanPro  Plan = "pro"
+)
+
+// Subscription is the persisted projection of a Stripe subscription,
+// reconciled on every webhook event.
+type Subscription struct {
+	ID                 string
+	NetworkID          string
+	StripeCustomerID   string
+	Status             string
+	PriceID            string
+	Cadence            Cadence
+	Quantity           int
+	CancelAtPeriodEnd  bool
+	CurrentPeriodStart time.Time
+	CurrentPeriodEnd   time.Time
+	CreatedAt          time.Time
+	UpdatedAt          time.Time
+}
+
+type Status struct {
+	Plan              Plan       `json:"plan"`
+	PlanStatus        string     `json:"plan_status"`
+	Cadence           *Cadence   `json:"cadence"`
+	Seats             int        `json:"seats"` // 0 on free plan; sub.Quantity on pro
+	CurrentPeriodEnd  *time.Time `json:"current_period_end"`
+	CancelAtPeriodEnd bool       `json:"cancel_at_period_end"`
+	PriceMonthlyCents int64      `json:"price_monthly_cents"`
+	PriceAnnualCents  int64      `json:"price_annual_cents"`
+}
+
+type CheckoutParams struct {
+	NetworkID    string
+	AdminHumanID string
+	AdminEmail   string
+	Cadence      Cadence
+	Seats        int
+}