/**
 * CaTML (Cat Altered Text Markup Language)
 * A feline-powered HTML compiler & runtime interpreter.
 * 
 * Repository: https://git.p20.dev/christian/CaTML.git
 */

(function (global) {
  'use strict';

  // Tag translations: CaTML Tag -> HTML Tag
  const TAG_MAP = {
    'catworld': 'html',
    'catml': 'html',
    'whiskers': 'head',
    'collar': 'title',
    'fur': 'body',
    'box': 'div',
    'cardboard': 'div',
    'feather': 'span',
    'mouse': 'span',
    'meow1': 'h1',
    'meow2': 'h2',
    'meow3': 'h3',
    'meow4': 'h4',
    'meow5': 'h5',
    'meow6': 'h6',
    'purr': 'p',
    'scratch': 'a',
    'stare': 'img',
    'bap': 'button',
    'paw': 'button',
    'sniff': 'input',
    'yowl': 'textarea',
    'bowl': 'ul',
    'numbered-bowl': 'ol',
    'treat': 'li',
    'claw': 'strong',
    'hiss': 'em',
    'catnip': 'script',
    'groom': 'style',
    'litterbox': 'footer',
    'nap': 'hr',
    'door': 'form',
    'shelf': 'nav',
    'hammock': 'main',
    'tree': 'article',
    'perch': 'section',
    'curtain': 'header'
  };

  // Attribute translations: CaTML Attribute -> HTML Attribute
  const ATTR_MAP = {
    'catch': 'href',
    'prey': 'src',
    'scent': 'alt',
    'tag': 'id',
    'breed': 'class',
    'fluff': 'style',
    'on-bap': 'onclick',
    'on-sniff': 'oninput',
    'on-change': 'onchange',
    'on-stalk': 'onmouseover',
    'on-pounce': 'onmousedown',
    'treat-type': 'type',
    'kibble': 'value',
    'curiosity': 'placeholder',
    'collar-name': 'name',
    'target': 'target',
    'width': 'width',
    'height': 'height'
  };

  /**
   * Translates a single CaTML tag name to HTML tag name
   */
  function translateTag(tag) {
    const lower = tag.toLowerCase();
    return TAG_MAP[lower] || tag;
  }

  /**
   * Translates a single CaTML attribute name to HTML attribute name
   */
  function translateAttr(attr) {
    const lower = attr.toLowerCase();
    return ATTR_MAP[lower] || attr;
  }

  /**
   * Translates an attribute string of a tag
   * e.g. `breed="tabby" on-bap="alert(1)"` -> `class="tabby" onclick="alert(1)"`
   */
  function compileAttributes(attrString) {
    if (!attrString) return '';

    // Regex matching attribute key="value", key='value', or boolean key
    const attrRegex = /([a-zA-Z0-9_-]+)(?:=("[^"]*"|'[^']*'|[^\s"'>]+))?/g;
    return attrString.replace(attrRegex, (match, attrName, attrVal) => {
      const mappedName = translateAttr(attrName);
      if (attrVal !== undefined) {
        return `${mappedName}=${attrVal}`;
      }
      return mappedName;
    });
  }

  /**
   * Compiles CaTML markup into standard HTML string
   * Handles opening tags, closing tags, self-closing tags, and comments.
   */
  function compile(catmlSource) {
    if (typeof catmlSource !== 'string') return '';

    // Regex for HTML/CaTML tags:
    // Captures: 
    // 1: '/' if closing tag
    // 2: tag name
    // 3: attributes
    // 4: '/' if self-closing
    const tagRegex = /<\s*(\/?)\s*([a-zA-Z0-9_-]+)([\s\S]*?)(\/?)\s*>/g;

    return catmlSource.replace(tagRegex, (fullMatch, isClosing, tagName, attrString, isSelfClosing) => {
      // Don't modify standard DOCTYPE or XML headers
      if (tagName.toLowerCase() === '!doctype') {
        return fullMatch;
      }

      const mappedTag = translateTag(tagName);

      if (isClosing) {
        return `</${mappedTag}>`;
      }

      const compiledAttrs = compileAttributes(attrString);
      const trailingSlash = isSelfClosing ? ' /' : '';
      return `<${mappedTag}${compiledAttrs ? compiledAttrs : ''}${trailingSlash}>`;
    });
  }

  /**
   * Renders compiled CaTML directly into a DOM element or document
   */
  function render(catmlSource, targetElement) {
    const html = compile(catmlSource);
    if (!targetElement) {
      return html;
    }

    if (typeof targetElement === 'string') {
      targetElement = document.querySelector(targetElement);
    }

    if (targetElement && targetElement.innerHTML !== undefined) {
      targetElement.innerHTML = html;
      
      // Execute any script tags generated from <catnip> or <script>
      const scripts = targetElement.querySelectorAll('script');
      scripts.forEach(oldScript => {
        const newScript = document.createElement('script');
        Array.from(oldScript.attributes).forEach(attr => {
          newScript.setAttribute(attr.name, attr.value);
        });
        newScript.textContent = oldScript.textContent;
        oldScript.parentNode.replaceChild(newScript, oldScript);
      });
    }

    return html;
  }

  /**
   * In-place DOM Transformer:
   * Scans document DOM for CaTML custom tags and converts them into real HTML elements.
   */
  function transformDOM(rootNode) {
    const root = rootNode || document.body;
    if (!root) return;

    // List of custom tags to replace
    const catmlTags = Object.keys(TAG_MAP).filter(t => 
      !['html', 'head', 'title', 'body', 'script', 'style'].includes(TAG_MAP[t])
    );

    let foundElements = true;
    while (foundElements) {
      foundElements = false;
      for (const catTag of catmlTags) {
        const elements = root.getElementsByTagName(catTag);
        if (elements.length > 0) {
          foundElements = true;
          const el = elements[0];
          const newTagName = TAG_MAP[catTag];
          const replacement = document.createElement(newTagName);

          // Copy and translate attributes
          Array.from(el.attributes).forEach(attr => {
            const mappedName = translateAttr(attr.name);
            replacement.setAttribute(mappedName, attr.value);
          });

          // Move child nodes
          while (el.firstChild) {
            replacement.appendChild(el.firstChild);
          }

          el.parentNode.replaceChild(replacement, el);
          break; // restart query selector because DOM mutated
        }
      }
    }
  }

  /**
   * Automatic Bootstrapper:
   * Finds all <script type="text/catml"> and renders them or replaces them.
   */
  function autoBoot() {
    if (typeof document === 'undefined') return;

    // 1. Process <script type="text/catml">
    const catScripts = document.querySelectorAll('script[type="text/catml"]');
    catScripts.forEach(script => {
      const targetId = script.getAttribute('target') || script.getAttribute('data-target');
      const compiledHTML = compile(script.textContent);

      if (targetId) {
        const target = document.querySelector(targetId);
        if (target) {
          render(script.textContent, target);
        }
      } else {
        // Replace the script tag itself with a container or direct elements
        const container = document.createElement('div');
        container.className = 'catml-container';
        render(script.textContent, container);
        script.parentNode.insertBefore(container, script);
      }
    });

    // 2. Transform any custom elements in the body
    transformDOM(document.body);
  }

  // Public API
  const CatML = {
    compile: compile,
    parse: compile,
    render: render,
    transformDOM: transformDOM,
    autoBoot: autoBoot,
    TAG_MAP: TAG_MAP,
    ATTR_MAP: ATTR_MAP
  };

  // Auto-run when DOM is ready in browser
  if (typeof window !== 'undefined') {
    if (document.readyState === 'loading') {
      document.addEventListener('DOMContentLoaded', autoBoot);
    } else {
      setTimeout(autoBoot, 0);
    }
    window.CatML = CatML;
  }

  // CommonJS / Node export support
  if (typeof module !== 'undefined' && module.exports) {
    module.exports = CatML;
  }

})(typeof globalThis !== 'undefined' ? globalThis : this);