// The splatter phase: shamblers, gore decals, particles. The ball is the weapon;
// tennis scoring keeps running via gameplay.splatPoint. Zombies advance toward
// your baseline — one crossing it is a point for THEM.
// (zombies <-> gameplay is a runtime-only import cycle, same pattern as input.)

import { TUNE, COURT } from './config.js';
import { G, ball, sendBoy } from './state.js';
import { splat, moan, pock } from './audio.js';
import { splatPoint } from './gameplay.js';

export const zombies = []; // {x, z, v, walkT, variant: 'a'|'b'|'c'}
export const gore = [];    // lawn decals {x, z, r, a}
export const parts = [];   // splatter particles {x, y, z, vx, vy, vz, t}

let spawnT = 1.5, moanT = 3;

export function spawnZombie(x, z, variant) {
  zombies.push({ x, z, v: TUNE.zSpeed * (0.8 + Math.random() * 0.4), walkT: Math.random() * 9, variant });
}

function splatter(i) {
  const zb = zombies[i];
  zombies.splice(i, 1);
  gore.push({ x: zb.x, z: zb.z, r: 0.45 + Math.random() * 0.35, a: 0.85 });
  if (gore.length > 40) gore.shift();
  for (let k = 0; k < 14; k++) parts.push({
    x: zb.x, y: 0.9, z: zb.z,
    vx: (Math.random() * 2 - 1) * 3.5, vy: 1 + Math.random() * 3.5, vz: (Math.random() * 2 - 1) * 3.5,
    t: 0.4 + Math.random() * 0.4,
  });
  splat();
  ball.vx *= 0.5; ball.vz *= 0.5; // the kill takes pace off the ball
  sendBoy(zb.x, zb.z);            // a boy sprints out to mop
  splatPoint('P');
}

export function updateZombies(dt) {
  moanT -= dt;
  if (moanT <= 0) { moan(); moanT = 2.5 + Math.random() * 4; }

  if (G.mode === 'splatter') { // transition spawns are scripted, not timed
    spawnT -= dt;
    if (spawnT <= 0 && zombies.length < TUNE.zMax) {
      spawnZombie((Math.random() * 2 - 1) * 4.8, -1.5 - Math.random(), Math.random() < 0.5 ? 'a' : 'b');
      spawnT = TUNE.zSpawnEvery;
    }
  }

  for (let i = zombies.length - 1; i >= 0; i--) {
    const zb = zombies[i];
    zb.walkT += dt;
    zb.z += zb.v * dt;
    zb.x += Math.sin(zb.walkT * 1.7) * 0.15 * dt; // shamblers don't walk straight lines
    if (ball.active && ball.lastHit === 'P' && ball.y < 1.9) {
      const d = Math.hypot(ball.x - zb.x, ball.z - zb.z);
      if (d < 0.55) {
        if ((ball.pow || 0) >= TUNE.zSplatQ) { splatter(i); continue; }
        zb.z -= TUNE.zPushback; // weak sitters only stagger them
        pock(0.6, 300);
        ball.vx *= 0.6; ball.vz *= 0.6; ball.lastHit = 'X'; // spent — one stagger per ball
      }
    }
    if (zb.z >= COURT.L + 0.7) { zombies.splice(i, 1); splatPoint('O'); } // it reached your baseline
  }

  for (let i = parts.length - 1; i >= 0; i--) {
    const p = parts[i];
    p.t -= dt; p.vy -= 14 * dt;
    p.x += p.vx * dt; p.y += p.vy * dt; p.z += p.vz * dt;
    if (p.y < 0) { p.y = 0; p.vy = 0; p.vx *= 0.5; p.vz *= 0.5; }
    if (p.t <= 0) parts.splice(i, 1);
  }

  const boy = G.boy; // the boy mops any gore he passes over
  for (let i = gore.length - 1; i >= 0; i--) {
    const d = gore[i];
    if (boy && Math.abs(boy.x - d.x) < 0.7 && Math.abs(boy.z - d.z) < 1.2) d.a -= dt * 1.6;
    if (d.a <= 0) gore.splice(i, 1);
  }
}