import './style.css';

const COMMAND = 'ssh portfolio@keshavanand.net';

const typedEl = document.getElementById('typed') as HTMLSpanElement;
const userEl = document.getElementById('userInput') as HTMLSpanElement;
const caretEl = document.getElementById('caret') as HTMLSpanElement;
const commandBox = document.getElementById('commandBox') as HTMLDivElement;
const actionBtn = document.getElementById('actionBtn') as HTMLButtonElement;
const iconPath = document.getElementById('iconPath') as unknown as SVGPathElement;
const docsLink = document.getElementById('docsLink') as HTMLAnchorElement;

const reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

/* ---------- icons ---------- */

const COPY_PATH =
  'M8 16H6a2 2 0 01-2-2V6a2 2 0 012-2h8a2 2 0 012 2v2m-6 12h8a2 2 0 002-2v-8a2 2 0 00-2-2h-8a2 2 0 00-2 2v8a2 2 0 002 2z';
// "↵" return arrow — a hooked left arrow (very recognizable as Enter)
const ENTER_PATH = 'M9 10l-5 5m0 0l5 5m-5-5h12a4 4 0 004-4V5';
const CHECK_PATH = 'M5 13l4 4L19 7';

function setIcon(d: string) {
  iconPath.setAttribute('d', d);
}

/* ---------- state ---------- */

let userInput = '';
let inputEnabled = false; // true once typewriter completes
let isAutoTyping = false; // true while clicking-how-it-works animation runs

function refreshUI() {
  userEl.textContent = userInput;
  if (userInput.length > 0) {
    setIcon(ENTER_PATH);
    actionBtn.setAttribute('aria-label', 'Run command');
    commandBox.classList.add('armed');
  } else {
    setIcon(COPY_PATH);
    actionBtn.setAttribute('aria-label', 'Copy command');
    commandBox.classList.remove('armed');
  }
}

/* ---------- typewriter intro (with scramble) ---------- */

const SCRAMBLE = '!<>-_\\/[]{}—=+*^?#abcdef0123456789';

function sleep(ms: number) {
  return new Promise<void>((r) => setTimeout(r, ms));
}

function typeIntro(target: string, onDone?: () => void) {
  let resolved = '';
  let i = 0;

  function nextChar() {
    if (i >= target.length) {
      // append a trailing space so the caret rests one char past the prompt
      typedEl.textContent = resolved + ' ';
      onDone?.();
      return;
    }
    let cycles = target[i] === ' ' ? 0 : 1 + Math.floor(Math.random() * 2);
    function flicker() {
      if (cycles <= 0) {
        resolved += target[i];
        typedEl.textContent = resolved;
        i++;
        setTimeout(nextChar, 8 + Math.random() * 18);
        return;
      }
      const ch = SCRAMBLE[Math.floor(Math.random() * SCRAMBLE.length)];
      typedEl.textContent = resolved + ch;
      cycles--;
      setTimeout(flicker, 14);
    }
    flicker();
  }
  nextChar();
}

if (reduceMotion) {
  typedEl.textContent = COMMAND + ' ';
  inputEnabled = true;
} else {
  setTimeout(() => typeIntro(COMMAND, () => {
    inputEnabled = true;
  }), 180);
}

/* ---------- copy ---------- */

let iconResetTimer: number | undefined;

async function copyCommand() {
  try {
    await navigator.clipboard.writeText(COMMAND);
    setIcon(CHECK_PATH);
    window.clearTimeout(iconResetTimer);
    iconResetTimer = window.setTimeout(() => {
      // only reset if user hasn't started typing in the meantime
      if (userInput.length === 0) setIcon(COPY_PATH);
    }, 1100);
  } catch {
    /* clipboard can be blocked */
  }
}

/* ---------- submit ---------- */

function submit() {
  const cmd = userInput.trim().toLowerCase();
  if (cmd === '') return;

  if (cmd === '-h' || cmd === '--help' || cmd === 'h' || cmd === 'help') {
    // brief flash, then navigate
    commandBox.classList.add('submit');
    setTimeout(() => {
      window.location.href = '/docs.html';
    }, 260);
    return;
  }

  if (cmd === 'clear' || cmd === 'cls') {
    userInput = '';
    refreshUI();
    return;
  }

  // unknown command — shake, then clear after a beat
  commandBox.classList.remove('shake');
  // force reflow so the animation restarts on rapid presses
  void commandBox.offsetWidth;
  commandBox.classList.add('shake');
  setTimeout(() => {
    commandBox.classList.remove('shake');
    userInput = '';
    refreshUI();
  }, 420);
}

/* ---------- keyboard input (after typewriter completes) ---------- */

function onKeydown(e: KeyboardEvent) {
  if (!inputEnabled || isAutoTyping) return;
  // let browser shortcuts pass
  if (e.metaKey || e.ctrlKey || e.altKey) return;
  // ignore navigation keys we don't care about
  if (
    e.key === 'Tab' || e.key === 'ArrowLeft' || e.key === 'ArrowRight' ||
    e.key === 'ArrowUp' || e.key === 'ArrowDown' || e.key === 'Shift' ||
    e.key === 'CapsLock' || e.key === 'Meta' || e.key === 'Control' ||
    e.key === 'Alt'
  ) return;

  if (e.key === 'Enter') {
    e.preventDefault();
    submit();
    return;
  }
  if (e.key === 'Backspace') {
    e.preventDefault();
    if (userInput.length > 0) {
      userInput = userInput.slice(0, -1);
      refreshUI();
    }
    return;
  }
  if (e.key === 'Escape') {
    e.preventDefault();
    userInput = '';
    refreshUI();
    return;
  }
  if (e.key.length === 1) {
    e.preventDefault();
    // cap input length so it doesn't overflow
    if (userInput.length < 32) {
      userInput += e.key;
      refreshUI();
    }
  }
}

document.addEventListener('keydown', onKeydown);

/* ---------- click handlers on the box / action button ---------- */

function actionClick() {
  if (userInput.length > 0) submit();
  else copyCommand();
}

actionBtn.addEventListener('click', (e) => {
  e.stopPropagation();
  actionClick();
});

commandBox.addEventListener('click', (e) => {
  // don't double-fire when clicking the button
  if ((e.target as HTMLElement).closest('.action-btn')) return;
  actionClick();
});

/* ---------- auto-type from "how it works" link ---------- */

function rand<T>(a: ArrayLike<T>): T {
  return a[Math.floor(Math.random() * a.length)];
}

async function autoTypeHelp() {
  if (!inputEnabled || isAutoTyping) return;
  isAutoTyping = true;

  // clear current input, arm the box
  userInput = '';
  refreshUI();
  commandBox.classList.add('armed');

  // ripple from where the user clicked the link
  const linkRect = docsLink.getBoundingClientRect();
  spawnRipple(linkRect.left + linkRect.width / 2, linkRect.top + linkRect.height / 2);

  await sleep(90);

  // PHASE 1 — heavy glitch flicker across both character slots,
  // with a tiny box jitter for chromatic-aberration energy
  commandBox.classList.add('glitch');
  const glitchSteps = 14;
  for (let s = 0; s < glitchSteps; s++) {
    const a = rand(SCRAMBLE);
    const b = Math.random() > 0.4 ? rand(SCRAMBLE) : '';
    userEl.textContent = a + b;
    // micro-jitter the box
    const jx = (Math.random() - 0.5) * 3;
    const jy = (Math.random() - 0.5) * 1.5;
    commandBox.style.transform = `translate(${jx.toFixed(2)}px, ${jy.toFixed(2)}px)`;
    await sleep(28 + Math.random() * 18);
  }
  commandBox.style.transform = '';
  commandBox.classList.remove('glitch');

  // PHASE 2 — settle to "-h" with a brief micro-flicker on each char
  userInput = '';
  for (const ch of '-h') {
    // 1-2 quick scramble flickers, then resolve
    for (let c = 0; c < 2; c++) {
      userEl.textContent = userInput + rand(SCRAMBLE);
      await sleep(34);
    }
    userInput += ch;
    refreshUI();
    await sleep(60);
  }

  // PHASE 3 — let the user read "-h" before it fires, then ripple from the box
  await sleep(850);
  const boxRect = commandBox.getBoundingClientRect();
  spawnRipple(boxRect.right - 24, boxRect.top + boxRect.height / 2);

  // PHASE 4 — Enter "press": punch the action icon down + a confirming ripple
  actionBtn.style.transition = 'transform 90ms ease-out';
  actionBtn.style.transform = 'scale(0.78)';
  await sleep(110);
  actionBtn.style.transform = 'scale(1)';
  await sleep(140);
  actionBtn.style.transition = '';
  actionBtn.style.transform = '';

  isAutoTyping = false;
  submit();
}

docsLink.addEventListener('click', (e) => {
  e.preventDefault();
  autoTypeHelp();
});

/* ---------- cursor-reactive dot field + click ripples ---------- */

const canvas = document.getElementById('field') as HTMLCanvasElement;
const ctx = canvas.getContext('2d')!;

type Dot = { bx: number; by: number; ox: number; oy: number };

let dots: Dot[] = [];
let dpr = Math.max(1, window.devicePixelRatio || 1);
let w = 0;
let h = 0;

const SPACING = 26;
const RADIUS = 170;
const PUSH = 18;

let targetX = -9999;
let targetY = -9999;
let curX = -9999;
let curY = -9999;
let active = false;

type Ripple = { x: number; y: number; born: number };
const ripples: Ripple[] = [];
const RIPPLE_LIFE = 900;
const RIPPLE_MAX = 520;
const RIPPLE_BAND = 70;
const RIPPLE_PUSH = 36;

function build() {
  dpr = Math.max(1, window.devicePixelRatio || 1);
  w = window.innerWidth;
  h = window.innerHeight;
  canvas.width = Math.floor(w * dpr);
  canvas.height = Math.floor(h * dpr);
  canvas.style.width = w + 'px';
  canvas.style.height = h + 'px';
  ctx.setTransform(dpr, 0, 0, dpr, 0, 0);

  dots = [];
  const pad = SPACING;
  for (let y = -pad; y < h + pad; y += SPACING) {
    for (let x = -pad; x < w + pad; x += SPACING) {
      dots.push({ bx: x, by: y, ox: 0, oy: 0 });
    }
  }
}

function onMove(x: number, y: number) {
  targetX = x;
  targetY = y;
  active = true;
}

function spawnRipple(x: number, y: number) {
  ripples.push({ x, y, born: performance.now() });
  if (ripples.length > 8) ripples.shift();
}

window.addEventListener('mousemove', (e) => onMove(e.clientX, e.clientY), { passive: true });
window.addEventListener('mouseleave', () => { active = false; });
window.addEventListener('click', (e) => spawnRipple(e.clientX, e.clientY));
window.addEventListener('touchmove', (e) => {
  if (e.touches[0]) onMove(e.touches[0].clientX, e.touches[0].clientY);
}, { passive: true });
window.addEventListener('touchstart', (e) => {
  if (e.touches[0]) spawnRipple(e.touches[0].clientX, e.touches[0].clientY);
}, { passive: true });
window.addEventListener('touchend', () => { active = false; });
window.addEventListener('resize', build);

build();

const BASE_RGB = '230, 230, 230';
const ACCENT_RGB = '166, 227, 161';
const BASE_ALPHA = 0.11;
const PEAK_ALPHA = 0.9;

function frame() {
  const now = performance.now();

  if (!active) {
    targetX = -9999;
    targetY = -9999;
  }
  curX += (targetX - curX) * 0.18;
  curY += (targetY - curY) * 0.18;

  for (let i = ripples.length - 1; i >= 0; i--) {
    if (now - ripples[i].born > RIPPLE_LIFE) ripples.splice(i, 1);
  }

  const rippleState = ripples.map((rp) => {
    const p = (now - rp.born) / RIPPLE_LIFE;
    return { x: rp.x, y: rp.y, radius: p * RIPPLE_MAX, fade: 1 - p };
  });

  ctx.clearRect(0, 0, w, h);

  const r2 = RADIUS * RADIUS;

  for (let i = 0; i < dots.length; i++) {
    const d = dots[i];

    const dx = d.bx - curX;
    const dy = d.by - curY;
    const d2 = dx * dx + dy * dy;

    let tx = 0;
    let ty = 0;
    let strength = 0;

    if (d2 < r2) {
      const dist = Math.sqrt(d2) || 0.0001;
      const t = 1 - dist / RADIUS;
      strength = t * t;
      tx = (dx / dist) * strength * PUSH;
      ty = (dy / dist) * strength * PUSH;
    }

    let rippleStrength = 0;
    for (let k = 0; k < rippleState.length; k++) {
      const rp = rippleState[k];
      const rdx = d.bx - rp.x;
      const rdy = d.by - rp.y;
      const rdist = Math.sqrt(rdx * rdx + rdy * rdy) || 0.0001;
      const delta = Math.abs(rdist - rp.radius);
      if (delta < RIPPLE_BAND) {
        const ringT = 1 - delta / RIPPLE_BAND;
        const s = ringT * ringT * rp.fade;
        tx += (rdx / rdist) * s * RIPPLE_PUSH;
        ty += (rdy / rdist) * s * RIPPLE_PUSH;
        if (s > rippleStrength) rippleStrength = s;
      }
    }

    d.ox += (tx - d.ox) * 0.22;
    d.oy += (ty - d.oy) * 0.22;

    const px = d.bx + d.ox;
    const py = d.by + d.oy;

    const visStrength = Math.min(1, strength + rippleStrength);
    const alpha = BASE_ALPHA + (PEAK_ALPHA - BASE_ALPHA) * visStrength;
    const size = 1 + visStrength * 1.6;

    if (visStrength > 0.04) {
      const blend = visStrength;
      const r = Math.round(230 * (1 - blend) + 166 * blend);
      const g = Math.round(230 * (1 - blend) + 227 * blend);
      const b = Math.round(230 * (1 - blend) + 161 * blend);
      ctx.fillStyle = `rgba(${r}, ${g}, ${b}, ${alpha})`;
    } else {
      ctx.fillStyle = `rgba(${BASE_RGB}, ${alpha})`;
    }

    ctx.fillRect(px - size / 2, py - size / 2, size, size);
  }

  if (active) {
    const grad = ctx.createRadialGradient(curX, curY, 0, curX, curY, RADIUS);
    grad.addColorStop(0, `rgba(${ACCENT_RGB}, 0.10)`);
    grad.addColorStop(1, `rgba(${ACCENT_RGB}, 0)`);
    ctx.fillStyle = grad;
    ctx.fillRect(curX - RADIUS, curY - RADIUS, RADIUS * 2, RADIUS * 2);
  }

  for (let k = 0; k < rippleState.length; k++) {
    const rp = rippleState[k];
    if (rp.radius < 4) continue;
    ctx.strokeStyle = `rgba(${ACCENT_RGB}, ${0.16 * rp.fade})`;
    ctx.lineWidth = 1;
    ctx.beginPath();
    ctx.arc(rp.x, rp.y, rp.radius, 0, Math.PI * 2);
    ctx.stroke();
  }

  requestAnimationFrame(frame);
}

if (!reduceMotion) {
  requestAnimationFrame(frame);
} else {
  ctx.fillStyle = `rgba(${BASE_RGB}, ${BASE_ALPHA})`;
  for (const d of dots) ctx.fillRect(d.bx, d.by, 1, 1);
}

void caretEl;