import { getIconSvg } from './icons.js';
import { marked } from 'marked';

export class PresentationRenderer {
  /**
   * Parses the XML output from the AI into a structured JS object.
   * @param {string} xmlString 
   * @returns {Object} { theme: Object, slides: Array }
   */
  static parseXML(xmlString) {
    const parser = new DOMParser();
    // Sometimes AI wraps it in markdown code blocks
    let cleanXml = xmlString.replace(/```xml/g, '').replace(/```/g, '').trim();
    // Ensure it has a root if missing
    if (!cleanXml.startsWith('<presentation>')) {
      const match = cleanXml.match(/<presentation>[\s\S]*<\/presentation>/i);
      if (match) cleanXml = match[0];
      else cleanXml = `<presentation>${cleanXml}</presentation>`;
    }
    
    const doc = parser.parseFromString(cleanXml, "text/html");
    
    // Parse Theme
    let theme = null;
    const themeNode = doc.querySelector('theme');
    if (themeNode) {
      theme = {
        background: themeNode.querySelector('background')?.textContent || null,
        accent: themeNode.querySelector('accent')?.textContent || null,
        font: themeNode.querySelector('font')?.textContent || null
      };
      
      // Inject Google Font if needed
      if (theme.font && theme.font.toLowerCase() !== 'inter') {
        const fontName = theme.font.trim();
        const fontId = 'font-' + fontName.replace(/\s+/g, '-').toLowerCase();
        if (!document.getElementById(fontId)) {
          const link = document.createElement('link');
          link.id = fontId;
          link.rel = 'stylesheet';
          link.href = `https://fonts.googleapis.com/css2?family=${fontName.replace(/\s+/g, '+')}:ital,wght@0,300;0,400;0,600;0,700;0,800;1,400&display=swap`;
          document.head.appendChild(link);
        }
      }
    }
    
    // Parse Slides
    const slideNodes = doc.querySelectorAll('slide');
    const slides = Array.from(slideNodes).map(node => {
      const layout = node.getAttribute('layout') || 'title';
      
      const slide = { layout };
      
      // Common elements
      const title = node.querySelector('title');
      if (title) slide.title = title.textContent;
      
      const subtitle = node.querySelector('subtitle');
      if (subtitle) slide.subtitle = subtitle.textContent;
      
      const icon = node.querySelector('icon');
      if (icon) slide.icon = icon.textContent;
      
      const quote = node.querySelector('quote');
      if (quote) slide.quote = quote.textContent;
      
      // For split/bullets layout
      const contentNode = node.querySelector('content');
      if (contentNode) {
        // Collect list items or raw HTML
        const listItems = contentNode.querySelectorAll('item');
        if (listItems.length > 0) {
          slide.bullets = Array.from(listItems).map(li => li.innerHTML);
        } else {
          slide.htmlContent = contentNode.innerHTML;
        }
      }
      
      // Visual elements (Mermaid or Images)
      const visualNode = node.querySelector('visual');
      if (visualNode) {
        const mermaid = visualNode.querySelector('mermaid');
        if (mermaid) slide.mermaid = mermaid.textContent;
        
        const image = visualNode.querySelector('image');
        if (image) slide.imageQuery = image.textContent.trim();
      }
      
      return slide;
    });
    
    return { theme, slides };
  }

  /**
   * Renders a slide object into a DOM element.
   * @param {Object} slideData 
   * @returns {HTMLElement}
   */
  static renderSlide(slideData) {
    const container = document.createElement('div');
    container.className = `slide-content-wrapper slide-layout-${slideData.layout}`;
    
    if (slideData.layout === 'title') {
      if (slideData.icon) {
        const iconSvg = getIconSvg(slideData.icon) || '';
        if (iconSvg) container.insertAdjacentHTML('beforeend', iconSvg);
      }
      if (slideData.title) container.insertAdjacentHTML('beforeend', `<h1>${slideData.title}</h1>`);
      if (slideData.subtitle) container.insertAdjacentHTML('beforeend', `<h2>${slideData.subtitle}</h2>`);
    } 
    else if (slideData.layout === 'quote') {
      if (slideData.quote) container.insertAdjacentHTML('beforeend', `<blockquote>${slideData.quote}</blockquote>`);
    }
    else if (slideData.layout === 'split') {
      const textSide = document.createElement('div');
      textSide.className = 'slide-text-side';
      if (slideData.title) textSide.insertAdjacentHTML('beforeend', `<h2 class="slide-title">${slideData.title}</h2>`);
      if (slideData.bullets) {
        const ul = document.createElement('ul');
        ul.className = 'slide-bullets';
        ul.innerHTML = slideData.bullets.map(b => `<li>${marked.parseInline(b)}</li>`).join('');
        textSide.appendChild(ul);
      } else if (slideData.htmlContent) {
        textSide.insertAdjacentHTML('beforeend', slideData.htmlContent);
      }
      
      const visualSide = document.createElement('div');
      visualSide.className = 'slide-visual-side';
      if (slideData.mermaid) {
        visualSide.insertAdjacentHTML('beforeend', `<div class="mermaid">${slideData.mermaid}</div>`);
      }
      
      container.appendChild(textSide);
      container.appendChild(visualSide);
    }
    else if (slideData.layout === 'image-split') {
      const textSide = document.createElement('div');
      textSide.className = 'slide-text-side';
      if (slideData.title) textSide.insertAdjacentHTML('beforeend', `<h2 class="slide-title">${slideData.title}</h2>`);
      if (slideData.bullets) {
        const ul = document.createElement('ul');
        ul.className = 'slide-bullets';
        ul.innerHTML = slideData.bullets.map(b => `<li>${marked.parseInline(b)}</li>`).join('');
        textSide.appendChild(ul);
      } else if (slideData.htmlContent) {
        textSide.insertAdjacentHTML('beforeend', slideData.htmlContent);
      }
      
      const visualSide = document.createElement('div');
      visualSide.className = 'slide-visual-side';
      if (slideData.imageQuery) {
        const imgUrl = `https://tse1.mm.bing.net/th?q=${encodeURIComponent(slideData.imageQuery)}&w=1000&h=1000&c=7&rs=1`;
        visualSide.insertAdjacentHTML('beforeend', `<div class="pres-image-wrapper"><img src="${imgUrl}" alt="${slideData.imageQuery}" /></div>`);
      }
      
      container.appendChild(textSide);
      container.appendChild(visualSide);
    }
    else if (slideData.layout === 'cover') {
      if (slideData.imageQuery) {
        const imgUrl = `https://tse1.mm.bing.net/th?q=${encodeURIComponent(slideData.imageQuery)}&w=1920&h=1080&c=7&rs=1`;
        container.style.backgroundImage = `url('${imgUrl}')`;
      }
      
      const overlay = document.createElement('div');
      overlay.className = 'slide-cover-overlay';
      if (slideData.title) overlay.insertAdjacentHTML('beforeend', `<h1>${slideData.title}</h1>`);
      if (slideData.subtitle) overlay.insertAdjacentHTML('beforeend', `<h2>${slideData.subtitle}</h2>`);
      if (slideData.quote) overlay.insertAdjacentHTML('beforeend', `<blockquote>${slideData.quote}</blockquote>`);
      
      container.appendChild(overlay);
    }
    else {
      // Default / Bullets
      if (slideData.title) container.insertAdjacentHTML('beforeend', `<h2 class="slide-title" style="text-align: center; margin-bottom: 4rem;">${slideData.title}</h2>`);
      if (slideData.bullets) {
        const ul = document.createElement('ul');
        ul.className = 'slide-bullets';
        ul.innerHTML = slideData.bullets.map(b => `<li>${marked.parseInline(b)}</li>`).join('');
        container.appendChild(ul);
      } else if (slideData.htmlContent) {
        container.insertAdjacentHTML('beforeend', slideData.htmlContent);
      }
    }
    
    return container;
  }
}