gamedev-the-steward/docs/ARCHITECTURE_OVERVIEW.md

# The Steward — Architecture Overview

This project is organized around gameplay ownership, not scene-tree location.
Serializable simulation records are authoritative; loaded Godot nodes present
that state and contribute active-world facts such as positions and navigation
results.

## Runtime flow

```text
SimulationClock
    -> SimulationManager orchestrates one deterministic tick
        -> SimulationPopulationView indexes all/living/starving NPCs by stable ID
        -> ActionExecutionSystem advances needs and work
        -> VillageOpportunitySystem re-derives the current capable helper
        -> ActionSelectionSystem chooses an action
        -> ActionTargetResolver resolves a stable target ID
        -> VillageEconomy performs inventory/storage transactions
        -> AnimalCareSystem advances animal needs, routines, and feeding
        -> SimulationEventLog records completed facts
        -> EventKnowledgeSystem records, ranks, transfers, and retains bounded knowledge
        -> RelationshipSystem applies evidence-gated social consequences
        -> VillageOpportunitySystem projects one known unresolved need
        -> ConflictSystem advances indexed combatants and authoritative combat outcomes
    -> WorldViewManager presents travel, NPC state, and world-state cues
        -> ActiveWorldAdapter supplies loaded-world positions/capacity
            -> LoadedResourceSpatialIndex bounds finite-anchor discovery
        -> NpcVisual performs local navigation, animation, and transient reactions
        -> AnimalNode follows saved animal destinations through loaded navigation
        -> PantryStockVisual derives physical stock arrangement from storage state
```

`SimulationManager` is the scene-tree façade for the simulation. It owns the
tick lifecycle, authoritative NPC/village/resource records, reservations, and
the signals consumed by presentation. Focused collaborators own rules that
would otherwise obscure that lifecycle:

- `simulation/actions/` owns selection, progress, and target resolution;
- `simulation/economy/VillageEconomy.gd` owns storage/inventory transactions
  and keeps village resource summaries synchronized;
- `simulation/animals/animal_care_system.gd` owns animal records, hunger
  advancement, deterministic routine selection, loaded binding, feed
  reservations, exact NPC pantry-to-inventory-to-animal delivery, and the
  bounded direct player pantry-to-animal operation;
- `simulation/player/player_citizen_system.gd` owns the persisted
  `PlayerStateRecord` (hunger, energy, carried inventory), deterministic
  needs advancement, and the player's carry/deposit/eat transactions through
  the same storage and event contract as NPCs;
- `simulation/conflict/ConflictSystem.gd` owns combatants (health, weapons,
  factions, hostility), village/tribe faction records, wolf hostility, the
  tribe war motivation decision (desire + victory confidence), raid spawning,
  deterministic battle resolution, and real pantry-backed war consequences.
  Player commands are revalidated against authoritative life, faction, range,
  and cooldown state. Player attack readiness advances in unscaled presentation
  time; NPC battle cooldowns remain deterministic simulation ticks. Transient
  NPC and sorted-combatant indexes bound stable-ID callbacks without entering
  saves. It emits combat and war narrative facts
  and spawn/death signals that presentation binds to `HostileCombatant` visuals;
- `simulation/events/SimulationEventLog.gd` owns ordered event identity,
  history queries, and rate calculations;
- `simulation/knowledge/EventKnowledgeSystem.gd` owns per-NPC references to
  known objective events, immutable acquisition provenance, proximity witnesses
  at record time, one-hop direct fact transfer, and deterministic recent-fact
  retention/importance ranking. It can place the active opportunity trigger
  first without weakening its direct-source or one-hop checks;
- `simulation/relationships/RelationshipSystem.gd` owns directed relationship
  queries, event-driven trust changes, and deterministic social tie-breaking;
- `simulation/population/SimulationPopulationView.gd` owns a transient derived
  all/living/starving stable-ID index. The manager rebuilds it once at the tick
  boundary and refreshes it after each interleaved NPC update; relationship and
  action queries may read it, but it never enters save records;
- `simulation/opportunities/VillageOpportunitySystem.gd` observes immutable
  event references plus current NPC/storage state, then owns the bounded shared
  open/resolved/invalidated lifecycle for the proven pantry-food and blocked-
  work wood consumers. It also derives one ephemeral `OpportunityHelperResult`
  from knowledge, directed relationships, inventory, action definitions, and
  finite-resource state without changing resources or assigning tasks. The
  ordinary action selector consumes that result only for the matching idle NPC.
  When no such helper exists, it can separately derive an ephemeral
  `OpportunityPlayerResponseResult` from the real destination capacity and
  enabled player-usable finite sources;
- `simulation/persistence/` owns save-slot file safety;
- `simulation/state/` owns versioned serialized record contracts;
- `simulation/definitions/` owns stable IDs and immutable action/profession
  definitions.

`world/creatures/creature_visual.gd` is the shared root for creature
presentation: any `CreatureVisual` follows a simulation-owned position through
the navigation mesh, reports position changes, and plays a shared death
collapse. Failed paths keep their target and use bounded exponential retry
instead of querying navigation every physics frame. `HostileCombatant` extends it and builds its body from an
`EnemyDefinition`; `NpcVisual` and `AnimalNode` already follow the same
follow-the-authoritative-position contract, so future creatures (bears, boars,
archers) add a definition and a visual hook instead of a new movement system.

`world/resource_nodes/LoadedResourceSpatialIndex.gd` is a focused disposable
acceleration structure owned by `ActiveWorldAdapter`. It indexes loaded
interaction positions by action and horizontal cell, plus authoritative
metadata bounds copied at bind time. It does not own amounts, enabled state,
reservations, or persistence. `ResourceNode` enter/exit, bind, and transform
notifications keep it synchronized with the loaded presentation lifecycle.
Resource anchors may be nested inside authored presentation clusters: runtime
discovery uses their stable IDs and registration lifecycle, never a parent
path. Decorative siblings without a `ResourceNode` remain outside the index
and simulation state.

Player resource interaction uses the same radius-bounded loaded-anchor grid.
HUD proximity probes, the time dial, player status, and day/night environment
are presentation-only and update at human-readable rates rather than every
rendered frame. `JajceWorld` exposes reversible High, Balanced, and Low
presentation profiles with instance-local mutable render resources and owned
viewport scaling. The default Balanced tier reduces 3D scale, grass, shadow
coverage, and volumetric work, while Low can stop grass/effects without changing
simulation state or UI resolution. Forward+-only volumetric fog stays disabled
under Mobile and Compatibility feature selection, even when High is requested.

Outside the runtime lifecycle, `simulation/benchmark/` owns reusable,
schema-valid workload fixtures. CLI tools and headless scenarios consume those
fixtures; production simulation does not depend on benchmark code.

The manager deliberately remains a façade instead of being split into a
collection of scene-tree manager nodes. A new collaborator is justified when
one cohesive rule set has several real consumers or makes the tick lifecycle
hard to read.

## Folder ownership

| Path | Responsibility |
| --- | --- |
| `simulation/` | Headless-capable orchestration and core models |
| `simulation/actions/` | Action decisions, execution, and target queries |
| `simulation/animals/` | Animal lifecycle, target claims, and feeding transactions |
| `simulation/economy/` | Authoritative inventory and storage transactions |
| `simulation/events/` | Immutable event history and derived event queries |
| `simulation/knowledge/` | Per-NPC knowledge of objective event IDs |
| `simulation/relationships/` | Directed social consequences and relationship queries |
| `simulation/population/` | Transient per-tick population query indexes |
| `simulation/opportunities/` | Knowledge-gated unresolved-condition projections |
| `simulation/state/` | Versioned, serializable mutable records |
| `simulation/definitions/` | Stable IDs and immutable gameplay definitions |
| `simulation/persistence/` | Validated local save-file storage |
| `simulation/benchmark/` | Reproducible simulation and loaded-world query workloads |
| `world/` | Loaded-world interaction geometry and presentation adapters |
| `world/animals/` | Animal presentation binding, routine sites, and navigation reporting |
| `world/animals/goat/` | Self-contained goat scene, visual script, habitat, and lookdev scene |
| `world/resource_nodes/` | Finite resource presentation and disposable loaded-anchor index |
| `world/storage/` | Storage interaction geometry, never stored quantities |
| `world/activity/` | Rest/study/patrol interaction sites and capacity facts |
| `player/` | Player input, camera, and active NPC presentation |
| `tests/` | Deterministic headless gameplay scenarios |

Unrelated established model scripts keep their stable paths because Godot's
global class cache records `class_name` locations. This slice moves only the
animal files whose ownership changed, preserves their `.uid` files, and proves
the new paths through editor import and headless startup rather than expanding
the cleanup into cosmetic repository-wide churn.

Project-owned files use `snake_case` when they are newly added or deliberately
moved, while scene node names remain `PascalCase`. Reusable scene assets stay
beside the scene that owns them, so the goat's script, habitat, and lookdev
scene no longer sit in the broad Jajce level folder. Non-runtime documentation
is hidden from Godot with `docs/.gdignore`; baseline images therefore remain
review artifacts without tracked import sidecars. This follows Godot's
[project organization](https://docs.godotengine.org/en/stable/tutorials/best_practices/project_organization.html)
and [GDScript naming](https://docs.godotengine.org/en/stable/tutorials/scripting/gdscript/gdscript_styleguide.html)
guidance without turning established-path cleanup into unrelated churn.

## Dependency rules

- Simulation code must run without `main.tscn` or loaded world nodes.
- Persistent references are stable IDs, never `Node`, `NodePath`, or scene
  ownership.
- Presentation may report facts and submit commands; it does not choose NPC
  actions or own resource, storage, inventory, event, knowledge, relationship,
  opportunity, or reservation state.
- Inspector history is a read-only façade query over objective events and
  retained knowledge. Opportunity presentation is likewise query-only.
  Relationship cues, interested-villager concern, physical pantry stock, and
  refill feedback consume authoritative state or state-change signals and are
  intentionally absent from saves and checksums. The transient village-whisper
  HUD likewise formats need, player route, transfer, response, and resolution
  signals without owning them. It drops the player route when a capable helper
  emerges. Stable visuals are rebuilt from state after restore; transient
  reactions are not replayed.
- Resource changes go through `ResourceStateRecord`, NPC inventory, and
  `VillageEconomy`; `village.food` and `village.wood` are synchronized views.
- Animal identity, position, hunger, last feed tick, reservation, routine site,
  destination, and next due tick live in `AnimalStateRecord`. `AnimalNode`
  binds that state, contributes its loaded interaction point, follows the
  selected navigation path, and reports position/arrival facts. Routine and
  care candidates are currently scanned linearly; they do not enter the
  resource grid.
- New mutable features define serialization and deterministic continuation at
  the same time as their first gameplay use. Cross-record causes use stable
  event IDs rather than object references or prose.
- Benchmark fixtures use ordinary simulation records and must round-trip
  through the current state schema. They may control workload setup, but must
  not add benchmark-only fields or branches to production saves and ticks.
- Derived population indexes are disposable acceleration structures. NPC
  records remain authoritative, and rebuilding the view after initialization,
  restore, or a tick must produce the same decisions and checksum.
- The loaded-resource grid is likewise disposable. `ResourceStateRecord`
  remains authoritative while its scene node is absent; rebuilding or
  incrementally refreshing the grid must preserve the linear resolver's exact
  score winner and stable tie order.
- Camera-local grass, ambient butterflies, water animation, smoke, and foliage
  motion are presentation only. Grass consumes bounded real actor transforms;
  it does not write NPC positions or become persistent state.
- Opportunity records reference stable NPC, storage, resource, trigger-event,
  and resolution-event IDs. Their generator may observe authoritative state
  and history, but it does not mutate the economy or command NPC behavior. The
  manager re-queries capable helpers at idle selection boundaries; any selected
  supply task then follows the ordinary persisted NPC-task and target contracts.
- Prefer one tested vertical behavior over a generic framework with no proven
  consumers.

## Where new code goes

Put a rule beside the state it governs. A relationship consequence belongs in
a focused simulation system plus serialized relationship records; its icon or
animation belongs in presentation. Add a world node only when the behavior
needs loaded-world geometry. Add a stable ID or definition when content must be
referenced across saves, scenes, or unloaded simulation.

The architectural decision and detailed contracts live in
[ADR 0001](decisions/0001-simulation-authority-boundary.md),
[the action system architecture](ACTION_SYSTEM_ARCHITECTURE.md), and
[the simulation state schema](SIMULATION_STATE_SCHEMA.md).