gamedev-the-steward/docs/ACTION_SYSTEM_ARCHITECTURE.md

The Steward — Action System Architecture

Current flow

SimulationManager tick
    -> ActionExecutionSystem advances needs and working progress
    -> ActionSelectionSystem chooses an action when the NPC is idle
    -> SimulationManager stores the selected action
    -> npc_target_requested
    -> WorldViewManager supplies the active visual's current position
    -> ActionTargetResolver consumes simulation state + ActiveWorldAdapter facts
    -> SimulationManager stores/reserves the target
    -> npc_travel_requested
    -> WorldViewManager commands NpcVisual travel
    -> arrival/navigation failure returns to SimulationManager

Responsibilities

ActionSelectionSystem

• reads NPC and village state;
• queries RelationshipSystem after personal survival/schedule overrides, so a trusted starving acquaintance can redirect ordinary work toward food gathering while the pantry is low;
• evaluates current utility scores;
• consumes the NPC's deterministic decision RNG;
• returns an action ID, optional urgent-duration override, branch reason, compared utility scores, and definition-backed rejection reasons;
• does not mutate targets, navigation, or visuals.

ActionExecutionSystem

• advances hunger, energy, starvation, death, and working progress;
• marks an action complete when its duration elapses;
• does not select the next action or resolve a target.

ActionTargetResolver

• reads target metadata from ActionDefinition;
• consumes active-world facts through ActiveWorldAdapter;
• checks simulation-owned ResourceStateRecord availability;
• reserves and returns stable resource target IDs;
• skips full-capacity activity sites based on authoritative NPC target claims;
• returns typed activity-site, storage, or wander positions without owning presentation.

ActiveWorldAdapter

• exposes loaded resource interaction positions;
• exposes loaded storage and activity-site interaction positions;
• exposes activity-site capacity as an active-world fact;
• contains active-world query facts, not persistent mutable authority;
• does not choose actions or reserve resources.

WorldViewManager

• spawns and tracks NpcVisual instances;
• supplies a visual's current position when resolution is requested;
• applies travel commands;
• reports arrival, navigation failure, and visual death state;
• does not map actions, select targets, write target IDs, or mutate resources.

SimulationManager

SimulationManager remains the orchestrator and event boundary. It owns simulation records, invokes the focused systems, stores selected actions and targets, and translates presentation callbacks into simulation transitions. It also publishes the latest ActionSelectionResult for presentation; the UI does not recompute decisions. At completion it atomically pays any definition-backed stored-resource cost before applying the action effect. A late shortfall suppresses the effect and records a task_blocked fact. The manager also captures actor/nearby knowledge before forwarding newly recorded events into RelationshipSystem. It exposes knowledge, relationship, and cause queries without moving social authority into UI.

VillageEconomy

• owns storage and NPC-inventory transfer operations;
• keeps village.food and village.wood synchronized as aggregate views;
• validates and pays definition-backed completion costs;
• emits completed transaction facts without owning their history.

SimulationEventLog

• owns ordered economic and narrative event identity;
• answers recent-history, actor-history, and consumption-rate queries;
• restores persisted history without performing or replaying transactions.

EventKnowledgeSystem

• stores stable (knower_id, event_id) references separately from objective history;
• initially observes successful food-deposit events for the actor and living NPCs within a fixed proximity radius;
• captures evidence only when the event happens, never from current positions during restore;
• answers deterministic known-event and knower queries without formatting prose or choosing actions.

RelationshipSystem

• owns directed familiarity/trust records and stable relationship queries;
• applies a bounded trust gain when a hungry familiar NPC knows about a contributor's successful food-deposit event;
• stores the exact event ID as the trust cause and ignores replayed or older events;
• selects trusted starving subjects deterministically for action selection;
• does not choose actions, perform transactions, or format presentation text.

These collaborators are RefCounted rule services, not additional scene-tree managers. Further decomposition should follow measured pressure and a proven gameplay consumer.

Active-position contract

NpcVisual emits active position changes after successful movement. WorldViewManager forwards those facts through SimulationManager.synchronize_npc_position(). Arrival, navigation failure, and visual unload also perform a final synchronization.

SimNPC stores both authoritative position and the resolved travel destination. The destination is versioned simulation state, so reloading a visual resumes the same route request without rerolling wander, resolving another resource, or changing a reservation.

tests/npc_visual_lifecycle_test.gd proves that visual unload/reload preserves action, target ID, travel destination, resource reservation, position, and state checksum.

Unloaded NPCs do not yet resolve abstract travel time; they remain in their current task state until an active visual or a future simulation-LOD travel system advances them.