dflike/server/src/systems/thoughtSystem.ts

import type { EntityId, Stats, Needs, SocialState } from '@dflike/shared';
import type { World } from '../ecs/World.js';
import type { LlmService } from '../llm/llmService.js';
import { generateBatchedThoughts, type ThoughtRequest } from '../llm/thoughtGenerator.js';
import { pickThoughtEmoji, type ThoughtContext } from '../llm/thoughtEmoji.js';
import { formatStatsForPrompt } from '../llm/backstoryGenerator.js';
import { thoughtConfig } from '../config/thoughtConfig.js';
import type { NarrationService } from '../llm/narrationService.js';
import type { EventMemoryService } from '../llm/eventMemoryService.js';

export interface Thought {
  text: string;
  emoji: string;
  tick: number;
}

export interface ThoughtSystem {
  update(world: World, followedEntityIds: Set<EntityId>, tick: number): void;
  onThought: ((data: { entityId: EntityId; text: string; emoji: string }) => void) | null;
}

export function createThoughtSystem(
  llmService: LlmService,
  narrationService?: NarrationService,
  eventMemoryService?: EventMemoryService,
): ThoughtSystem {
  const cooldowns = new Map<EntityId, number>();
  let lastPeriodicTick = 0;
  let pendingGeneration = false;

  const system: ThoughtSystem = {
    onThought: null,

    update(world: World, followedEntityIds: Set<EntityId>, tick: number): void {
      if (tick - lastPeriodicTick < thoughtConfig.periodicIntervalTicks) return;
      lastPeriodicTick = tick;

      if (pendingGeneration) return;

      const eligible: { entityId: EntityId; context: ThoughtContext }[] = [];
      const npcs = world.query('npcBrain', 'name', 'stats', 'needs');

      for (const entityId of npcs) {
        if (!followedEntityIds.has(entityId)) continue;

        const cooldownUntil = cooldowns.get(entityId) ?? 0;
        if (tick < cooldownUntil) continue;

        const needs = world.getComponent<Needs>(entityId, 'needs');
        const social = world.getComponent<SocialState>(entityId, 'socialState');
        const brain = world.getComponent<any>(entityId, 'npcBrain');
        const context = determineTrigger(needs, social, brain, tick);

        eligible.push({ entityId, context });

        if (eligible.length >= thoughtConfig.maxBatchSize) break;
      }

      if (eligible.length === 0) return;

      const requests: ThoughtRequest[] = eligible.map(({ entityId, context }) => {
        const name = world.getComponent<string>(entityId, 'name') ?? 'Unknown';
        const stats = world.getComponent<Stats>(entityId, 'stats');
        const needs = world.getComponent<Needs>(entityId, 'needs');
        const brain = world.getComponent<any>(entityId, 'npcBrain');

        const personality = stats ? formatStatsForPrompt(stats) : '';
        const currentState = describeState(needs, brain);
        const recentEvents = describeRecentEvents(entityId, narrationService, eventMemoryService, context.trigger);

        return { entityId, name, personality, currentState, recentEvents };
      });

      for (const { entityId } of eligible) {
        cooldowns.set(entityId, tick + thoughtConfig.perNpcCooldownTicks);
      }

      pendingGeneration = true;

      generateBatchedThoughts(requests, llmService)
        .then((results) => {
          for (const result of results) {
            const pending = eligible.find((p) => p.entityId === result.entityId);
            const emoji = pending ? pickThoughtEmoji(pending.context) : '\u{1F4AD}';

            const thought: Thought = {
              text: result.text,
              emoji,
              tick,
            };

            world.addComponent(result.entityId, 'thought', thought);
            system.onThought?.({ entityId: result.entityId, text: result.text, emoji });
          }
        })
        .catch(() => {})
        .finally(() => {
          pendingGeneration = false;
        });
    },
  };

  return system;
}

function determineTrigger(
  needs: Needs | undefined,
  social: SocialState | undefined,
  brain: any,
  tick: number,
): ThoughtContext {
  // Check for recent interaction (within last 100 ticks = 10 seconds)
  if (social?.lastOutcome && tick - social.lastOutcome.tick < 100) {
    return {
      trigger: 'post_interaction',
      interactionPositive: social.lastOutcome.outcome === 'positive',
    };
  }

  // Check for critical needs
  if (needs) {
    const { needCriticalThreshold } = thoughtConfig;
    if (needs.hunger < needCriticalThreshold || needs.energy < needCriticalThreshold) {
      return {
        trigger: 'need_critical',
        hunger: needs.hunger,
        energy: needs.energy,
      };
    }
  }

  // Check if idle/wandering
  if (!brain?.currentGoal || brain.currentGoal === 'wander') {
    return { trigger: 'idle' };
  }

  return { trigger: 'periodic' };
}

function describeState(needs: Needs | undefined, brain: any): string {
  const parts: string[] = [];
  if (needs) {
    if (needs.hunger < 30) parts.push('hungry');
    if (needs.energy < 30) parts.push('tired');
    if (parts.length === 0) parts.push('content');
  }
  if (brain?.currentGoal) {
    parts.push(brain.currentGoal === 'wander' ? 'wandering' : brain.currentGoal);
  }
  return parts.join(', ') || 'idle';
}

function describeRecentEvents(
  entityId: EntityId,
  narrationService?: NarrationService,
  eventMemoryService?: EventMemoryService,
  trigger?: ThoughtContext['trigger'],
): string {
  if (eventMemoryService) {
    const preferTypes = trigger === 'post_interaction'
      ? ['social_positive', 'social_negative', 'proposal_accepted', 'proposal_rejected'] as const
      : trigger === 'need_critical'
        ? ['need_crisis', 'need_recovery'] as const
        : undefined;

    const events = eventMemoryService.selectForPrompt(entityId, {
      maxCount: 5,
      preferTypes,
    });
    if (events.length > 0) {
      return events.map(e => `- ${e.detail}`).join('\n');
    }
  }
  // Fallback to narration service
  if (!narrationService) return 'none';
  const events = narrationService.getEventsForEntity(entityId);
  if (events.length === 0) return 'none';
  return events
    .slice(-2)
    .map((e) => e.narration)
    .join('; ');
}