'use strict';

class MiniElement {
  constructor(tagName = 'div') {
    this.tagName = String(tagName).toUpperCase();
    this.nodeType = this.tagName === '#TEXT' ? 3 : 1;
    this.parentNode = null;
    this.children = [];
    this.attributes = {};
    this.dataset = {};
    this.listeners = {};
    this.offsetLeft = 0;
    this.offsetTop = 0;
    this.offsetHeight = 0;
    this.offsetWidth = 0;
    this.scrollHeight = 0;
    this.scrollWidth = 0;
    this.clientWidth = 0;
    this.scrollLeft = 0;
    this.rectTop = 0;
    this.rectLeft = 0;
    this.rectWidth = 0;
    this.visible = true;
    this.scrollCalls = [];
    this._text = '';
    this._classes = new Set();
    this.classList = {
      add: (...tokens) => tokens.forEach((token) => this._classes.add(token)),
      remove: (...tokens) => tokens.forEach((token) => this._classes.delete(token)),
      contains: (token) => this._classes.has(token),
      toggle: (token, force) => {
        const shouldAdd = force === undefined ? !this._classes.has(token) : Boolean(force);
        if (shouldAdd) this._classes.add(token);
        else this._classes.delete(token);
        return shouldAdd;
      },
    };
  }

  get className() { return Array.from(this._classes).join(' '); }
  set className(value) { this._classes = new Set(String(value || '').split(/\s+/).filter(Boolean)); }
  get id() { return this.getAttribute('id') || ''; }
  set id(value) { this.setAttribute('id', value); }
  get type() { return this.getAttribute('type') || ''; }
  set type(value) { this.setAttribute('type', value); }
  get parentElement() { return this.parentNode && this.parentNode.tagName !== '#DOCUMENT' ? this.parentNode : null; }
  get firstChild() { return this.children[0] || null; }
  get firstElementChild() { return this.children.find((child) => child.nodeType === 1) || null; }
  get nextElementSibling() {
    if (!this.parentNode) return null;
    const siblings = this.parentNode.children.filter((child) => child.nodeType === 1);
    return siblings[siblings.indexOf(this) + 1] || null;
  }
  get textContent() { return this._text + this.children.map((child) => child.textContent).join(''); }
  set textContent(value) { this._text = String(value); this.replaceChildren(); }
  get innerHTML() { return this.children.map((child) => child.outerHTML || child.textContent).join(''); }
  set innerHTML(markup) {
    this._text = '';
    this.replaceChildren();
    parseMarkup(String(markup || ''), this);
  }

  setAttribute(name, value) {
    const text = String(value);
    this.attributes[name] = text;
    if (name === 'class') this.className = text;
    if (name.startsWith('data-')) this.dataset[toDatasetKey(name.slice(5))] = text;
  }

  getAttribute(name) { return Object.hasOwn(this.attributes, name) ? this.attributes[name] : null; }
  hasAttribute(name) { return Object.hasOwn(this.attributes, name); }
  removeAttribute(name) {
    delete this.attributes[name];
    if (name === 'class') this.className = '';
    if (name.startsWith('data-')) delete this.dataset[toDatasetKey(name.slice(5))];
  }

  appendChild(child) {
    if (child.parentNode) child.remove();
    child.parentNode = this;
    child.ownerDocument = this.ownerDocument;
    this.children.push(child);
    return child;
  }

  insertBefore(child, anchor) {
    if (!anchor || anchor.parentNode !== this) return this.appendChild(child);
    if (child.parentNode) child.remove();
    child.parentNode = this;
    child.ownerDocument = this.ownerDocument;
    this.children.splice(this.children.indexOf(anchor), 0, child);
    return child;
  }

  replaceChildren(...nodes) {
    this.children.forEach((child) => { child.parentNode = null; });
    this.children = [];
    nodes.forEach((node) => this.appendChild(node));
  }

  remove() {
    if (!this.parentNode) return;
    const siblings = this.parentNode.children;
    const index = siblings.indexOf(this);
    if (index !== -1) siblings.splice(index, 1);
    this.parentNode = null;
  }

  addEventListener(type, callback, options = {}) {
    (this.listeners[type] ||= []).push({ callback, once: Boolean(options && options.once) });
  }

  removeEventListener(type, callback) {
    this.listeners[type] = (this.listeners[type] || []).filter((item) => item.callback !== callback);
  }

  dispatch(type, properties = {}) {
    const event = {
      type,
      target: this,
      defaultPrevented: false,
      preventDefault() { this.defaultPrevented = true; },
      stopPropagation() { this.propagationStopped = true; },
      ...properties,
    };
    let node = this;
    while (node) {
      const listeners = (node.listeners[type] || []).slice();
      for (const listener of listeners) {
        listener.callback(event);
        if (listener.once) node.removeEventListener(type, listener.callback);
      }
      if (event.propagationStopped) break;
      node = node.parentNode;
    }
    return event;
  }

  dispatchEvent(event) { return this.dispatch(event.type, event); }
  click() { return this.dispatch('click'); }
  focus() { this.ownerDocument.activeElement = this; }

  closest(selector) {
    for (let node = this; node; node = node.parentNode) {
      if (matchesSelector(node, selector)) return node;
    }
    return null;
  }

  matches(selector) { return matchesSelector(this, selector); }

  querySelectorAll(selector) {
    const directOnly = selector.startsWith(':scope > ');
    const query = directOnly ? selector.slice(9) : selector;
    const nodes = directOnly ? this.children.slice() : descendants(this);
    return nodes.filter((node) => matchesSelector(node, query));
  }

  querySelector(selector) { return this.querySelectorAll(selector)[0] || null; }

  insertAdjacentHTML(position, markup) {
    const fragment = this.ownerDocument.createElement('div');
    fragment.innerHTML = markup;
    const nodes = fragment.children.slice();
    if (position === 'afterbegin') nodes.reverse().forEach((node) => this.insertBefore(node, this.firstChild));
    else if (position === 'beforebegin' && this.parentNode) nodes.forEach((node) => this.parentNode.insertBefore(node, this));
    else nodes.forEach((node) => this.appendChild(node));
  }

  scrollTo(options) { this.scrollCalls.push(options); }
  getBoundingClientRect() { return { top: this.rectTop, left: this.rectLeft, width: this.rectWidth || this.offsetWidth }; }
  getClientRects() { return this.visible ? [this.getBoundingClientRect()] : []; }
}

class MiniDocument extends MiniElement {
  constructor() {
    super('#document');
    this.nodeType = 9;
    this.ownerDocument = this;
    this.readyState = 'complete';
    this.body = this.createElement('body');
    this.appendChild(this.body);
    this.activeElement = null;
  }

  createElement(tagName) {
    const element = new MiniElement(tagName);
    element.ownerDocument = this;
    return element;
  }

  getElementById(id) { return descendants(this).find((node) => node.id === String(id)) || null; }
}

function toDatasetKey(value) { return value.replace(/-([a-z])/g, (_match, letter) => letter.toUpperCase()); }

function descendants(node) {
  return node.children.flatMap((child) => [child, ...descendants(child)]);
}

function matchesCompound(node, selector) {
  if (!selector || selector === '*') return true;
  const tag = selector.match(/^[a-z][a-z0-9-]*/i);
  if (tag && node.tagName.toLowerCase() !== tag[0].toLowerCase()) return false;
  const id = selector.match(/#([a-zA-Z_][\w-]*)/);
  if (id && node.getAttribute('id') !== id[1]) return false;
  for (const [, className] of selector.matchAll(/\.([a-zA-Z_][\w-]*)/g)) {
    if (!node.classList.contains(className)) return false;
  }
  for (const [, name, operator, expected] of selector.matchAll(/\[([\w-]+)(\^=|\$=|\*=|=)?(?:\s*["']?([^\]"']*)["']?)?\]/g)) {
    if (!node.hasAttribute(name)) return false;
    if (operator === '=') {
      if (node.getAttribute(name) !== expected) return false;
    } else if (operator === '^=' && !node.getAttribute(name).startsWith(expected)) return false;
    else if (operator === '$=' && !node.getAttribute(name).endsWith(expected)) return false;
    else if (operator === '*=' && !node.getAttribute(name).includes(expected)) return false;
  }
  return true;
}

function matchesSingleSelector(node, selector) {
  const tokens = selector.replace(/>/g, ' > ').trim().split(/\s+/);
  let cursor = node;
  if (!matchesCompound(cursor, tokens.pop())) return false;
  while (tokens.length) {
    const combinator = tokens.pop();
    const previous = combinator === '>' ? tokens.pop() : combinator;
    if (combinator === '>') {
      cursor = cursor.parentNode;
      if (!cursor || !matchesCompound(cursor, previous)) return false;
    } else {
      cursor = cursor.parentNode;
      while (cursor && !matchesCompound(cursor, previous)) cursor = cursor.parentNode;
      if (!cursor) return false;
    }
  }
  return true;
}

function matchesSelector(node, selector) {
  return String(selector).split(',').some((part) => matchesSingleSelector(node, part.trim()));
}

function parseMarkup(markup, parent) {
  const tokens = markup.match(/<!--[\s\S]*?-->|<[^>]+>|[^<]+/g) || [];
  const stack = [parent];
  const voidTags = new Set(['area', 'base', 'br', 'col', 'embed', 'hr', 'img', 'input', 'link', 'meta', 'param', 'source', 'track', 'wbr']);
  for (const token of tokens) {
    if (token.startsWith('<!--') || token.trim() === '') continue;
    if (token.startsWith('</')) {
      if (stack.length > 1) stack.pop();
      continue;
    }
    if (!token.startsWith('<')) {
      const textNode = parent.ownerDocument.createElement('#text');
      textNode._text = token;
      stack[stack.length - 1].appendChild(textNode);
      continue;
    }
    const open = token.match(/^<([a-z][\w-]*)([\s\S]*?)\/?\s*>$/i);
    if (!open) continue;
    const node = parent.ownerDocument.createElement(open[1]);
    for (const [, name, doubleQuoted, singleQuoted, bare] of open[2].matchAll(/([\w-]+)(?:\s*=\s*(?:"([^"]*)"|'([^']*)'|([^\s>]+)))?/g)) {
      node.setAttribute(name, doubleQuoted ?? singleQuoted ?? bare ?? '');
    }
    stack[stack.length - 1].appendChild(node);
    if (!voidTags.has(node.tagName.toLowerCase()) && !token.endsWith('/>')) stack.push(node);
  }
}

module.exports = { MiniDocument, MiniElement };