# Com / Fujitsu / Futurity ## Overview The `com.fujitsu.futurity` package is the top-level product family namespace for **Fujitsu Futurity**, a billing and pricing platform. Within this product family, the most prominent sub-structure is the **`bp` (billing/pricing)** domain — the financial engine responsible for rate-engineering, billing logic, pricing calculations, and associated configuration. The Futurity codebase appears designed around a **layered customization model**: core product behavior lives in base packages, while site-specific or client-specific logic is isolated under a `custom` qualifier. This pattern allows a single codebase to serve multiple deployments with different rate plans, billing rules, and feature requirements — a common requirement for enterprise billing platforms. As of the current code index, no source files have been collected for any module under this package. The documentation below is synthesized from package structure, naming conventions, and the child wiki pages available in the documentation repository. ## Sub-module Guide ### bp (Billing / Pricing) The `com.fujitsu.futurity.bp` package sits at the heart of the Futurity product family. It represents the **billing and pricing domain** — the financial engine of the system responsible for: - Rate-engineering and pricing calculations - Billing cycle management - Rate-plan configuration and evaluation - Financial rule evaluation Within `bp`, the `custom` sub-package provides a **customization layer** that extends or overrides standard Futurity billing behavior. This separation of standard from bespoke logic is deliberate — it keeps the core product stable while allowing site-specific requirements to evolve independently. ### bp / custom The `custom` sub-package is the primary child of `bp` and represents the **bespoke extension layer**. Code here is not always active; it appears to be engaged conditionally — perhaps gated by a feature flag, a deployment-specific configuration profile, or a client toggle. The standard Futurity billing behavior lives in parent packages, while `custom` provides deviations for particular clients. ### bp / custom / constant At the base of this hierarchy sits the `constant` sub-module. It consolidates all constant definitions used across the customization layer: - **Configuration property keys** — strings or identifiers used to look up settings from configuration files or external property stores. - **Domain-specific literals** — fixed values such as rate-plan codes, billing-cycle identifiers, or feature-flag markers. - **Error or status codes** — constants signaling specific billing or pricing conditions. These constants act as the **single source of truth** for values that multiple pieces of customization logic reference, avoiding magic strings scattered across files. ### How the Modules Relate The three-level nesting (`futurity` → `bp` → `custom` → `constant`) forms a **refinement cascade**: ```mermaid flowchart TD A["futurity (product family)"] --> B["bp (billing/pricing domain)"] B --> C["custom (customization layer)"] C --> D["constant (config values)"] style A fill:#e1f5fe style B fill:#fff3e0 style C fill:#e8f5e9 style D fill:#f3e5f5 ``` Each level narrows the scope further. At the top, `futurity` defines the product boundary. Below that, `bp` encapsulates the financial domain. The `custom` layer marks the divergence point between standard product behavior and client-specific extensions. At the base, `constant` provides the immutable values that the customization logic consumes. This is not just a directory tree — it is a **dependency chain**: `custom` depends on `constant` for its configuration values, `bp` provides the base billing logic that `custom` augments, and `futurity` serves as the overarching product namespace. ## Key Patterns and Architecture ### Constants-as-Configuration The most prominent and consistent pattern across this module is the use of a dedicated `constant` sub-module to centralize configurable values. Rather than scattering magic strings across multiple files, the codebase uses a single module as the authoritative source for configuration keys, rate-plan codes, and feature flags. In a billing system where correctness is critical, this pattern reduces the risk of typos or inconsistent values propagating across the codebase. ### Customization via Conditional Activation The `custom` qualifier in the package name strongly suggests a **conditional activation strategy**. This code is likely not always active — it may be gated by a feature flag, a deployment configuration profile, or a client-specific toggle. Standard Futurity behavior would live in parent packages (e.g., `com.fujitsu.futurity.bp`), while the `custom` layer overrides or augments it when the appropriate condition is met. This pattern is common in enterprise software where a single deployment must serve multiple clients with divergent requirements. ### Layered Abstraction The hierarchical nesting itself is an architectural pattern: - **`futurity`** — the product family level, shared across all Futurity domains. - **`bp`** — the billing/pricing domain, encapsulating financial logic specific to rates and charges. - **`custom`** — the customization boundary, separating standard from client-specific behavior. - **`constant`** — the value definitions layer, providing the foundational constants consumed by all customization logic. This separation allows the core product to remain stable while customization logic can evolve independently — a critical requirement for multi-tenant or multi-client billing platforms. ### Hierarchical Refinement Each nesting level in the package path narrows the scope further. This is a form of **hierarchical refinement**: the broader the package name, the more general the concern; the deeper the nesting, the more specific the responsibility. The `constant` submodule at the leaf of this hierarchy handles the most granular concern (individual values), while `futurity` at the root handles the broadest (the entire product). ## Dependencies and Integration ### Expected Dependencies No package dependencies were resolved for any module in this subtree, likely due to the absence of indexed source files. Based on the package naming alone, the expected dependency relationships are: - **`com.fujitsu.futurity.bp`** — the parent billing/pricing package, providing base classes, interfaces, and shared utilities for billing logic. The `custom` sub-package depends on this for the core behavior it augments. - **`com.fujitsu.futurity`** — the top-level product package, providing cross-domain shared types and utilities. ### Cross-Module Relationships No cross-module relationships were detected in the index. This module does not appear to export public APIs consumed by other modules, nor does it appear to be consumed by sibling modules. This suggests it is an **internal customization hook** with limited cross-module visibility — it likely operates as an isolated extension point within the broader billing system, contributing behavior through the parent `bp` package rather than through direct cross-package dependencies. ## Notes for Developers - **No source files indexed**: Neither this module nor its children have indexed source files (`.java` or otherwise). The code may exist in a different compilation unit, be loaded dynamically at runtime, or simply not yet be scanned by the documentation tooling. Check the build configuration and source roots to ensure this package path is included in indexing. - **Finding configuration values**: If you are looking for specific configuration keys, rate-plan codes, or feature flags, start with the `bp.custom.constant` sub-module — though its content has not yet been indexed. - **Understanding activation logic**: The `custom` qualifier implies this code may only be active under specific deployment configurations. Review the feature-toggle or configuration activation logic in the parent `com.fujitsu.futurity.bp` package to understand when this customization layer is engaged. - **Limited cross-module visibility**: There are no known consumers of this module's output in the current index. If this module is meant to contribute behavior to the broader billing system, those integration points have not been captured in the index. - **Missing dependency resolution**: The absence of resolved package dependencies likely reflects indexing gaps rather than actual independence. Expect this module to depend on core `futurity.bp` infrastructure classes. - **Documentation source**: This overview was synthesized from the child wiki pages for `bp` and `bp.custom`. No additional source files or structural metadata were available to enrich this document further.