// Keyboard + one-handed touch. Exposes movement axes and the flick-aim for gameplay.
// Note: input <-> gameplay is an intentional import cycle; both only call each other's
// functions at runtime, never during module evaluation.

import { cv } from './dom.js';
import { audio } from './audio.js';
import { G, score } from './state.js';
import { keyPressed, dragServe } from './gameplay.js';
import { togglePanel } from './panel.js';

const keys = {};
addEventListener('keydown', e => {
  if (['ArrowUp', 'ArrowDown', 'ArrowLeft', 'ArrowRight', ' '].includes(e.key)) e.preventDefault();
  if (e.key === 't' || e.key === 'T') togglePanel();
  if (!keys[e.code]) keyPressed(e.code);
  keys[e.code] = true;
});
addEventListener('keyup', e => keys[e.code] = false);

const touchAxis = { x: 0, z: 0 };
export const axisX = () => touchAxis.x || (keys.ArrowRight || keys.KeyD ? 1 : 0) - (keys.ArrowLeft || keys.KeyA ? 1 : 0);
export const axisZ = () => touchAxis.z || (keys.ArrowUp || keys.KeyW ? -1 : 0) + (keys.ArrowDown || keys.KeyS ? 1 : 0);

// One-handed touch: hold-drag = run, quick FLICK = swing aimed in the flick direction,
// plain tap = neutral swing / toss / serve. Extra finger tap still swings (two-thumb play).
let stick = null;      // {id, x0, y0, t0, moved}
let flickAim = null;   // {ax, az, t} aim override for the swing just triggered
const DEAD = 14;

// gameplay consumes the flick at contact; returns null if none or expired
export function takeFlickAim(maxAgeMs = 450) {
  if (flickAim && performance.now() - flickAim.t < maxAgeMs) {
    const aim = flickAim; // carries ax/az (lanes, tennis) AND fx/fy/mag (splatter free-aim)
    flickAim = null;
    return aim;
  }
  return null;
}

// the two-stage serve: a drag that STARTS at a serveable pretoss aims a visible reticle
// (G.aim, drawn by render); release fires the serve there, dragging back home cancels.
const canAimServe = () =>
  G.mode === 'splatter' && G.phase === 'pretoss' && score.server === 'P'
  && !G.horde && !(G.mgT > 0) && !G.changeover && !(G.interlude && G.interlude.introT > 0);

let steerPX = null; // live absolute finger x (-1..1 across the canvas) — machine-gun steering reads it
export const touchPX = () => steerPX;

cv.addEventListener('touchstart', e => {
  e.preventDefault(); audio();
  for (const t of e.changedTouches) {
    if (!stick) {
      stick = { id: t.identifier, x0: t.clientX, y0: t.clientY, t0: performance.now(),
                moved: false, aimable: canAimServe() }; // context locked at touch start — a movement drag never morphs into a serve
      // the reticle appears the moment the thumb lands: mag 0 = auto-target the most advanced
      if (stick.aimable) G.aim = { fx: 0, fy: 0, mag: 0 };
      else { const r = cv.getBoundingClientRect(); steerPX = (t.clientX - r.left) / r.width * 2 - 1; }
    }
    else keyPressed('Space');
  }
}, { passive: false });

cv.addEventListener('touchmove', e => {
  e.preventDefault();
  if (!stick) return;
  for (const t of e.changedTouches) {
    if (t.identifier !== stick.id) continue;
    const dx = t.clientX - stick.x0, dy = t.clientY - stick.y0, dist = Math.hypot(dx, dy);
    if (dist > DEAD) stick.moved = true;
    if (stick.aimable) { // aiming, not steering: the reticle tracks the thumb (home = auto-target)
      G.aim = dist > DEAD ? { fx: dx / dist, fy: dy / dist, mag: dist } : { fx: 0, fy: 0, mag: 0 };
      continue;
    }
    const r = cv.getBoundingClientRect();
    steerPX = (t.clientX - r.left) / r.width * 2 - 1;
    touchAxis.x = Math.abs(dx) > DEAD ? Math.sign(dx) : 0;
    touchAxis.z = Math.abs(dy) > DEAD ? Math.sign(dy) : 0;
  }
}, { passive: false });

const endTouch = e => {
  e.preventDefault();
  for (const t of e.changedTouches) {
    if (!stick || t.identifier !== stick.id) continue;
    const dt = performance.now() - stick.t0;
    const dx = t.clientX - stick.x0, dy = t.clientY - stick.y0, dist = Math.hypot(dx, dy);
    const aim = G.aim; G.aim = null; steerPX = null;
    if (stick.aimable && (stick.moved || dt >= 250)) {                     // two-stage release
      // a pure HOLD (never moved) fires at the auto-target; a drag fires at the reticle;
      // a drag walked back home cancels — the tin stays in stock
      if (aim && (!stick.moved || dist > DEAD * 1.5)) dragServe(aim);
    }
    else if (!stick.moved && dt < 250) keyPressed('Space');                // tap
    else if (dt < 300 && dist > 28) {                                      // flick = aimed swing
      flickAim = { ax: Math.abs(dx) > dist * 0.38 ? Math.sign(dx) : 0,
                   az: Math.abs(dy) > dist * 0.38 ? Math.sign(dy) : 0,
                   fx: dx / dist, fy: dy / dist, mag: dist,                // raw vector: splatter free-aim
                   t: performance.now() };
      keyPressed('Space');
    }
    stick = null; touchAxis.x = 0; touchAxis.z = 0;
  }
};
cv.addEventListener('touchend', endTouch, { passive: false });
cv.addEventListener('touchcancel', endTouch, { passive: false });