/* ISLE SLINGERS -- physics/rules/index.js (submodule: rules)
 * Modularization pass (behavior-neutral split of the original
 * js/core.js monolith). Installs its units into ONE shared physics scope `P`
 * that every physics submodule sees -- the same single-scope semantics the
 * monolith had. Must load before js/physics/index.js (the aggregator that
 * attaches the public ISLE_CORE API). Surface installed: checkEndStates, birdsRemaining, starsFor.
 */
(function (root, factory) {
  var part = factory();
  if (typeof module !== 'undefined' && module.exports) module.exports = part;
  else (root.ISLE_PHYSICS_PARTS = root.ISLE_PHYSICS_PARTS || []).push(part);
})(typeof globalThis !== 'undefined' ? globalThis : this, function () {
  'use strict';
  return function (P) {
  P.checkEndStates = function(g) {
    if (g.status === 'won' || g.status === 'lost') return;
    var alive = 0;
    for (var i = 0; i < g.enemies.length; i++) if (!g.enemies[i].dead) alive++;
    if (g.hadEnemies && alive === 0 && g.launched > 0) {
      g.status = 'won';
      g.wonAt = g.time;
      g.score += P.BIRD_BONUS * P.birdsRemaining(g);
      g.events.push({ type: 'level_won', x: g.camera.x, y: 400 });
      return;
    }
    var b = P.activeBird(g);
    var inFlight = false;
    // S-5: a LANDED bird is still a live body (it can fall, smash, and kill
    // while it exists) -- the level must not be declared lost while one is out
    // in the world.
    var landedOut = false;
    for (var k = 0; k < g.birds.length; k++) {
      if (g.birds[k].state === 'flying') inFlight = true;
      if (g.birds[k].state === 'landed') landedOut = true;
    }
    if (!inFlight && !landedOut && !b && g.status === 'flying') {
      // last bird spent, enemies remain
      g.status = 'lost';
      g.lostAt = g.time;
      g.events.push({ type: 'level_lost', x: g.camera.x, y: 400 });
    }
  }

  P.birdsRemaining = function(g) {
    var n = 0;
    for (var i = 0; i < g.birds.length; i++) if (g.birds[i].state === 'queued') n++;
    return n;
  }

  P.starsFor = function(g) {
    var th = g.level.stars;
    if (!th) return 0;
    if (g.score >= th[2]) return 3;
    if (g.score >= th[1]) return 2;
    if (g.score >= th[0] || g.status === 'won') return 1;
    return 0;
  }
  };
});