"use strict";

// Layer: simulation/helpers
// Shared, UI-free helpers used by the concrete simulation systems.
(function (global) {
  const policy = global.TarinaiItemUpdatePolicy;

  function forScheduledItems(worldRef, visitor) {
    return policy.forScheduledItems(worldRef, visitor);
  }

  function updateItemsScheduled(worldRef, dt) {
    return global.TarinaiItemRuntime.updateScheduled(worldRef, dt);
  }

  function trackSpatialEntityMoved(entity, thresholdSq) {
    if (!entity || entity.dead) return false;
    const x = Number.isFinite(entity.x) ? entity.x : 0;
    const y = Number.isFinite(entity.y) ? entity.y : 0;
    const oldX = entity._spatialTrackX;
    const oldY = entity._spatialTrackY;
    if (!Number.isFinite(oldX) || !Number.isFinite(oldY)) {
      entity._spatialTrackX = x;
      entity._spatialTrackY = y;
      return true;
    }
    const dx = x - oldX;
    const dy = y - oldY;
    if (dx * dx + dy * dy <= thresholdSq) return false;
    entity._spatialTrackX = x;
    entity._spatialTrackY = y;
    return true;
  }

  function markSpatialDirtyIfMoved(worldRef, list, reason = "moved", threshold = 0.35) {
    if (!worldRef || !Array.isArray(list) || !list.length) return false;
    const thresholdSq = threshold * threshold;
    let moved = false;
    for (const entity of list) moved = trackSpatialEntityMoved(entity, thresholdSq) || moved;
    if (moved) worldRef.markSpatialDirty?.(reason);
    return moved;
  }

  function markScheduledItemsMoved(worldRef, reason = "items-moved", threshold = 0.35) {
    if (!worldRef) return false;
    const thresholdSq = threshold * threshold;
    let moved = false;
    const tracked = global.TarinaiItemRuntime.trackedDynamicItems(worldRef);
    const source = tracked && tracked.length ? tracked : null;
    const visit = (entity) => { moved = trackSpatialEntityMoved(entity, thresholdSq) || moved; };
    if (source) for (const entity of source) visit(entity);
    else forScheduledItems(worldRef, visit);
    if (moved) worldRef.markSpatialDirty?.(reason);
    return moved;
  }

  function updateVisibleWorldRect(worldRef, margin = 120) {
    const scale = worldRef.viewScale ? worldRef.viewScale() : 1;
    const vw = (worldRef.viewportW || worldRef.w || 1000) / Math.max(0.01, scale);
    const vh = (worldRef.viewportH || worldRef.h || 720) / Math.max(0.01, scale);
    const cameraX = worldRef.cameraX || 0;
    const cameraY = worldRef.cameraY || 0;
    return { left: cameraX - margin, top: cameraY - margin, right: cameraX + vw + margin, bottom: cameraY + vh + margin };
  }

  function pointInRect(x, y, rect) {
    return x >= rect.left && x <= rect.right && y >= rect.top && y <= rect.bottom;
  }

  const helpers = Object.freeze({
    updateItemsScheduled,
    markSpatialDirtyIfMoved,
    markScheduledItemsMoved,
    trackSpatialEntityMoved,
    updateVisibleWorldRect,
    pointInRect,
  });

  global.TarinaiSimulationRuntime = Object.freeze({
    helpers
  });
})(typeof window !== "undefined" ? window : globalThis);