"use strict";

// Layer: simulation/system-effects
// Owns frame updates for transient visual/effect entities.
(function (global) {
  function effectPriority(effect) {
    const type = String(effect?.type || "");
    if (type === "explosion" || type === "shoot_impact" || type === "bubble" || type === "heart" || type === "electric_shock") return 3;
    if (type === "ring" || type === "fall") return 2;
    return 1;
  }

  function compactEffectPressure(worldRef, effects) {
    if (!Array.isArray(effects) || !effects.length) return { compacted: 0, dropped: 0 };
    const before = effects.length;
    let write = 0;
    for (let i = 0; i < effects.length; i += 1) {
      const effect = effects[i];
      if (effect && !effect.dead) effects[write++] = effect;
      else if (effect) worldRef.releaseEffect?.(effect);
    }
    effects.length = write;
    const compacted = before - write;
    const cap = Math.max(1, Number(global.TarinaiPerf?.performanceProfile?.().effectCap || 220));
    let needDrop = Math.max(0, effects.length - cap);
    if (!needDrop) return { compacted, dropped: 0 };

    const dropMask = new Uint8Array(effects.length);
    for (let priority = 1; priority <= 3 && needDrop > 0; priority += 1) {
      for (let i = 0; i < effects.length && needDrop > 0; i += 1) {
        if (dropMask[i] || effectPriority(effects[i]) !== priority) continue;
        dropMask[i] = 1;
        needDrop -= 1;
      }
    }
    write = 0;
    let dropped = 0;
    for (let i = 0; i < effects.length; i += 1) {
      const effect = effects[i];
      if (dropMask[i]) {
        dropped += 1;
        worldRef.releaseEffect?.(effect);
      } else effects[write++] = effect;
    }
    effects.length = write;
    worldRef._effectPressureDroppedTotal = (worldRef._effectPressureDroppedTotal || 0) + dropped;
    return { compacted, dropped };
  }

  function effectUpdateBudgetFor(total) {
    const budget = Math.max(1, Number(global.TarinaiPerf?.performanceProfile?.().effectUpdateBudget || 84));
    return Math.min(total, budget);
  }

  function updateEffect(effect, dt, frameId = 0, runScale = 1) {
    if (!effect || effect.dead) return false;
    const runDt = Math.min(0.24, Math.max(0, dt * Math.max(1, Number(runScale) || 1)));
    effect._effectUpdatedFrame = frameId;
    effect.update(runDt);
    return true;
  }

  function updateEffects(worldRef, dt) {
    const effects = worldRef.effects || [];
    const beforePressure = effects.length;
    const pressure = compactEffectPressure(worldRef, effects);
    const total = effects.length;
    const frameId = (worldRef._effectUpdateFrameId || 0) + 1;
    worldRef._effectUpdateFrameId = frameId;

    let lightweight = 0;
    const budgeted = [];
    for (const effect of effects) {
      if (!effect || effect.dead) continue;
      if (effect.type === "ring") {
        effect.life -= dt;
        effect._effectUpdatedFrame = frameId;
        lightweight += 1;
      } else {
        budgeted.push(effect);
      }
    }

    const active = budgeted.length;
    const budget = effectUpdateBudgetFor(active);
    let updated = 0;
    let runScale = 1;
    if (budget >= active) {
      for (const ef of budgeted) {
        if (updateEffect(ef, dt, frameId, 1)) updated += 1;
      }
    } else if (active > 0) {
      runScale = Math.min(3.0, Math.max(1, active / Math.max(1, budget)));
      let cursor = Math.max(0, Math.floor(worldRef._effectUpdateCursor || 0)) % active;
      let scanned = 0;
      while (updated < budget && scanned < active) {
        const ef = budgeted[cursor];
        cursor = (cursor + 1) % active;
        scanned += 1;
        if (!ef || ef.dead) continue;
        updateEffect(ef, dt, frameId, runScale);
        updated += 1;
      }
      worldRef._effectUpdateCursor = cursor;
    }

    if (global.TarinaiPerf?.diagnosticsEnabled?.() === true) {
      const spawn = worldRef._effectSpawnStats || {};
      worldRef._effectUpdateStats = {
        total, beforePressure, updated: updated + lightweight, lightweight,
        skipped: Math.max(0, active - updated), budget,
        runScale: Number(runScale.toFixed(2)), compacted: pressure.compacted, dropped: pressure.dropped,
        droppedTotal: worldRef._effectPressureDroppedTotal || 0, batched: budget < active,
        spawnRequested: spawn.requested || 0, offscreenCulled: spawn.offscreenCulled || 0,
        poolEligible: spawn.poolEligible || 0, pooled: spawn.pooled || 0,
      };
    } else worldRef._effectUpdateStats = null;
  }

  global.TarinaiEffectsSimulationSystem = Object.freeze({
    phases: Object.freeze({ updateEffects }),
  });
})(typeof window !== "undefined" ? window : globalThis);