// ============================================================================
// 065 — E-Commerce Order Pipeline
// ============================================================================
// Full order management: create, add items, process through stages.
//
// Run:   soma run 065_order_pipeline.cell demo
// Expect:
//   Order created for Alice
//   Added: Widget (x2)
//   Added: Gadget (x1)
//   Order submitted
//   Order approved
//   Order shipped
//   Final: delivered

cell OrderPipeline {

    memory {
        orders: Map<String, String> [persistent, consistent]
        items: Map<String, String> [persistent, consistent]
        status: Map<String, String> [persistent, consistent]
    }

    state order_flow {
        initial: draft

        draft -> submitted
        submitted -> approved
        approved -> shipped
        shipped -> delivered
        * -> cancelled
    }

    on create_order(customer: String) {
        let id = to_string(next_id())
        orders.set(id, customer)
        status.set(id, "draft")
        return id
    }

    on add_item(order_id: String, item: String, qty: Int) {
        let existing = items.get(order_id) ?? ""
        let qty_str = to_string(qty)
        let entry = concat(item, concat(" (x", concat(qty_str, ")")))
        if existing == "" {
            items.set(order_id, entry)
        } else {
            items.set(order_id, concat(existing, concat(", ", entry)))
        }
        return entry
    }

    on demo() {
        let id = create_order("Alice")
        print("Order created for Alice")

        let i1 = add_item(id, "Widget", 2)
        print("Added: {i1}")

        let i2 = add_item(id, "Gadget", 1)
        print("Added: {i2}")

        transition(id, "submitted")
        print("Order submitted")

        transition(id, "approved")
        print("Order approved")

        transition(id, "shipped")
        print("Order shipped")

        transition(id, "delivered")
        print("Final: delivered")

        return "done"
    }
}