/**
 * Script to generate an llms.txt file following the specification
 * This script generates a single llms.txt file in the build directory
 * with links to all the markdown files that have been copied to the /llm directory
 */

const fs = require('fs');
const path = require('path');
const { glob } = require('glob');

// Base docs directory
const baseDocsDir = path.join(__dirname, '../docs');
// Output directory for LLM markdown files
const llmDir = path.join(__dirname, '../build/llm');
// Output file path for llms.txt
const outputFilePath = path.join(__dirname, '../build/llms.txt');

// Get all subdirectories to create sections
async function getDirectorySections() {
  const directories = new Set();

  // Find all subdirectories that contain markdown files
  const markdownFiles = await glob(`${llmDir}/**/*.md`);

  markdownFiles.forEach((filePath) => {
    // Get the relative directory from the llm dir
    const relativePath = path.relative(llmDir, filePath);
    const dirPath = path.dirname(relativePath);

    // Add to set if it's not in the root
    if (dirPath !== '.') {
      // Get the top-level directory
      const topDir = dirPath.split(path.sep)[0];
      directories.add(topDir);
    }
  });

  return Array.from(directories).sort();
}

// Generate links for a specific section
async function generateSectionLinks(section) {
  const sectionPath = path.join(llmDir, section);
  const links = [];

  // Get all markdown files for this section
  const markdownFiles = await glob(`${sectionPath}/**/*.md`);

  for (const filePath of markdownFiles) {
    // Get the relative path from the llm dir
    const relativePath = path.relative(llmDir, filePath);

    // Read the file to extract title
    const content = fs.readFileSync(filePath, 'utf8');

    // Try to extract title from frontmatter or first heading
    let title = '';
    const frontmatterTitleMatch = content.match(/title:\s*([^\n]+)/);
    const firstHeadingMatch = content.match(/# ([^\n]+)/);

    if (frontmatterTitleMatch) {
      title = frontmatterTitleMatch[1].trim();
      // Remove quotes if present
      title = title.replace(/^["'](.*)["']$/, '$1');
    } else if (firstHeadingMatch) {
      title = firstHeadingMatch[1].trim();
    } else {
      // Use filename as fallback
      title = path.basename(filePath, '.md');
    }

    // Get summary from frontmatter if available
    let summary = '';
    const summaryMatch = content.match(/summary:\s*([^\n]+)/);
    if (summaryMatch) {
      summary = summaryMatch[1].trim();
      // Remove quotes if present
      summary = summary.replace(/^["'](.*)["']$/, '$1');
    }

    // Create URL for the file (relative to site root)
    const url = `/llm/${relativePath}`;

    // Add to links
    links.push({
      title,
      url,
      summary,
    });
  }

  return links.sort((a, b) => a.title.localeCompare(b.title));
}

// Generate the full llms.txt content
async function generateLlmsTxt() {
  let content = '';

  // Add title
  content += '# OHIF Viewer\n\n';

  // Add description blockquote
  content +=
    '> OHIF (Open Health Imaging Foundation) Viewer is an open-source, web-based, zero-footprint DICOM viewer platform designed for medical imaging. It provides a highly configurable and extensible framework for building diagnostic quality medical imaging applications. OHIF Viewer supports various imaging formats (primarily DICOM), offers advanced visualization tools, customizable workflows, and integration capabilities with different data sources.\n\n';

  // Add general information
  content +=
    'The OHIF Viewer is built with a modular architecture that includes extensions, modes, and services. It leverages Cornerstone3D for rendering capabilities and provides a comprehensive framework for building medical imaging applications with features like hanging protocols, segmentation, measurements, and advanced visualization tools.\n\n';
  content += 'The documentation is organized into the following sections:\n\n';

  // Get all sections
  const sections = await getDirectorySections();

  // Process each section
  for (const section of sections) {
    // Get all links for this section
    const links = await generateSectionLinks(section);

    if (links.length > 0) {
      // Add section header
      content += `## ${section.charAt(0).toUpperCase() + section.slice(1)}\n\n`;

      // Add links for this section
      for (const link of links) {
        content += `- [${link.title}](https://docs.ohif.org${link.url})`;
        if (link.summary) {
          content += `: ${link.summary}`;
        }
        content += '\n';
      }

      content += '\n';
    }
  }

  // Write the llms.txt file
  fs.writeFileSync(outputFilePath, content);
  console.log(`Generated llms.txt file at ${outputFilePath}`);
}

// Run the script
generateLlmsTxt();