implement-behavior-tree

1. Overview

Generates high-performance BT engine for NPC/AI decision-making. Focuses on correct mathematical definitions for composite nodes and multi-tick async operations via strict Running state handling.

2. Core Pattern

1. Platform Detection: Scan config for target language/platform.
2. Core Nodes: Generate Node interface (with tick() method) + Status enum (Success/Failure/Running).
3. Composite & Leaf Nodes: SelectorNode (short-circuiting), SequenceNode (progress tracking), ConditionNode, ActionNode.
4. Context & Factory: BTContext object for entity/game state + specialized factory functions.
5. Tree Definitions (MANDATORY): Read behavior_tree_spec.md Section 3. For EACH tree:
   • Generate <TreeName>Tree.ts or <EnemyType>AI.ts
   • Create exact node hierarchy (Selector → Sequence → Condition/Action)
   • Implement all conditions/actions from Section 2 as concrete classes
   • Condition/action nodes read/write ECS exclusively through BTContext
6. Enemy AI Factories (MANDATORY): For each enemy tier in spec:
   • Accept entity ID + optional config → return root node
   • Accept BTContext for per-entity state
   • Export from single file (e.g., src/ai/enemyFactories.ts)
   • Include factories for each tier (e.g., createSwarmMeleeAI(), createEliteRangedAI())

3. Interaction Protocol

• [Running Status]: Node missing Running state support → "Node needs async/multi-tick capability. Adding Running state?"
• [Broken Composite]: Selector/Sequence deviates from definition → "[Node Type] must follow its logical definition. Refactor?"

Guidance: All composites must follow mathematical definitions using Status enum transitions. Prioritize Running status for multi-tick async actions.

4. Red Flags

• Running State Support: All nodes handle Running status for multi-tick async actions
• Correct Composite Definitions: Selectors short-circuit on success, Sequences track progress
• Clean State Management: Nodes clean up global state modifications

5. Final Integrity Audit

• Composite nodes (Selector, Sequence) follow mathematical definitions
• Leaf nodes interact with BTContext (no direct ECS access)
• Running status handled for multi-tick async actions
• All tree hierarchies from Section 3 implemented as concrete definitions
• All condition/action nodes from Section 2 as concrete classes
• Enemy AI factories for each enemy tier
• src/ai/ not empty — contains all tree defs and factories