sync-redirects.js

const fs = require('fs');
const path = require('path');

/**
 * Main function to sync redirects from the appropriate docs version to static directory
 */
function syncRedirects() {
  try {
    const isDevMode = checkDevelopmentMode();
    const staticRedirectsPath = getStaticRedirectsPath();
    
    // Try to copy from current version if in development mode
    if (isDevMode && tryCopyFromCurrentDocs(staticRedirectsPath)) {
      return;
    }
    
    // Otherwise use the latest versioned docs
    copyFromVersionedDocs(staticRedirectsPath);
    
  } catch (error) {
    console.error('Error syncing redirects:', error);
    process.exit(1);
  }
}

/**
 * Check if we're in development mode with current version included
 * @returns {boolean} True if in development mode
 */
function checkDevelopmentMode() {
  return process.env.DOCS_INCLUDE_CURRENT_VERSION === 'true';
}

/**
 * Get the destination path for redirects in static directory
 * @returns {string} Path to the static _redirects file
 */
function getStaticRedirectsPath() {
  return path.join(__dirname, '../static/_redirects');
}

/**
 * Try to copy redirects from current docs (development version)
 * @param {string} destPath Path to copy the redirects file to
 * @returns {boolean} True if successful, false otherwise
 */
function tryCopyFromCurrentDocs(destPath) {
  const currentRedirectsPath = path.join(__dirname, '../docs/_redirects');
  
  if (fs.existsSync(currentRedirectsPath)) {
    copyRedirectsFile(currentRedirectsPath, destPath);
    appendSourceComment(destPath, 'current development version');
    console.log('Successfully copied _redirects from current version to static directory');
    return true;
  }
  
  console.warn('Current version _redirects file not found, falling back to latest versioned docs');
  return false;
}

/**
 * Copy redirects from the latest versioned docs
 * @param {string} destPath Path to copy the redirects file to
 */
function copyFromVersionedDocs(destPath) {
  const latestVersion = getLatestVersion();
  const redirectsSourcePath = path.join(
    __dirname, 
    `../versioned_docs/version-${latestVersion}/_redirects`
  );
  
  if (!fs.existsSync(redirectsSourcePath)) {
    console.error(`_redirects file not found in version ${latestVersion}`);
    process.exit(1);
  }
  
  copyRedirectsFile(redirectsSourcePath, destPath);
  appendSourceComment(destPath, `version-${latestVersion}`);
  console.log(`Successfully copied _redirects from version ${latestVersion} to static directory`);
}

/**
 * Get the latest version from versions.json
 * @returns {string} Latest version number
 */
function getLatestVersion() {
  const versionsPath = path.join(__dirname, '../versions.json');
  
  if (!fs.existsSync(versionsPath)) {
    console.error('versions.json not found. Are you sure you have versioned docs?');
    process.exit(1);
  }
  
  const versions = JSON.parse(fs.readFileSync(versionsPath, 'utf8'));
  const latestVersion = versions[0]; // First version in the array is the latest
  
  if (!latestVersion) {
    console.error('No versions found in versions.json');
    process.exit(1);
  }
  
  console.log(`Latest version: ${latestVersion}`);
  return latestVersion;
}

/**
 * Copy a file from source to destination
 * @param {string} sourcePath Source file path
 * @param {string} destPath Destination file path
 */
function copyRedirectsFile(sourcePath, destPath) {
  fs.copyFileSync(sourcePath, destPath);
}

/**
 * Append a source comment to the redirects file
 * @param {string} filePath Path to the redirects file
 * @param {string} source Source identifier
 */
function appendSourceComment(filePath, source) {
  fs.appendFileSync(
    filePath,
    `\n\n# This file was automatically copied from ${source}. DO NOT EDIT DIRECTLY.\n`
  );
}

// Execute the function
syncRedirects();