URL Processing

/**
 * Validates if string matches YouTube video ID format
 * @param {string} id - String to validate as video ID
 * @returns {boolean} - Whether string is valid video ID format
 */
function validateID(id);

// Valid video IDs
console.log(ytdl.validateID('aqz-KE-bpKQ')); // true
console.log(ytdl.validateID('dQw4w9WgXcQ')); // true

// Invalid video IDs
console.log(ytdl.validateID('too-short'));   // false
console.log(ytdl.validateID('too-long-id')); // false
console.log(ytdl.validateID('invalid@chars')); // false
console.log(ytdl.validateID(''));            // false

/**
 * Validates if URL can be parsed to extract video ID
 * @param {string} url - URL to validate
 * @returns {boolean} - Whether URL is valid YouTube URL
 */
function validateURL(url);

// Valid YouTube URLs
console.log(ytdl.validateURL('https://www.youtube.com/watch?v=aqz-KE-bpKQ')); // true
console.log(ytdl.validateURL('https://youtu.be/aqz-KE-bpKQ'));                // true
console.log(ytdl.validateURL('https://m.youtube.com/watch?v=aqz-KE-bpKQ'));   // true

// Invalid URLs
console.log(ytdl.validateURL('https://example.com/video'));     // false
console.log(ytdl.validateURL('https://youtube.com/invalid'));   // false
console.log(ytdl.validateURL('not-a-url'));                     // false

/**
 * Extracts video ID from YouTube URL
 * @param {string} url - YouTube URL
 * @returns {string} - 11-character video ID
 * @throws {Error} - If URL is invalid or no video ID found
 * @throws {TypeError} - If extracted ID doesn't match expected format
 */
function getURLVideoID(url);

// Standard watch URLs
const id1 = ytdl.getURLVideoID('https://www.youtube.com/watch?v=aqz-KE-bpKQ');
console.log(id1); // 'aqz-KE-bpKQ'

// Shortened URLs
const id2 = ytdl.getURLVideoID('https://youtu.be/dQw4w9WgXcQ');
console.log(id2); // 'dQw4w9WgXcQ'

// Embed URLs
const id3 = ytdl.getURLVideoID('https://www.youtube.com/embed/aqz-KE-bpKQ');
console.log(id3); // 'aqz-KE-bpKQ'

// Mobile URLs
const id4 = ytdl.getURLVideoID('https://m.youtube.com/watch?v=aqz-KE-bpKQ&t=30s');
console.log(id4); // 'aqz-KE-bpKQ'

// Music URLs
const id5 = ytdl.getURLVideoID('https://music.youtube.com/watch?v=aqz-KE-bpKQ&list=PLrAXtmRdnEQy4Qg8SU5U6QP0X3bL5T8lN');
console.log(id5); // 'aqz-KE-bpKQ'

// URLs with extra parameters are handled
const id6 = ytdl.getURLVideoID('https://www.youtube.com/watch?v=aqz-KE-bpKQ&list=PLxxx&index=1&t=120s');
console.log(id6); // 'aqz-KE-bpKQ'

/**
 * Gets video ID from URL or validates if already an ID
 * @param {string} str - URL or video ID string
 * @returns {string} - 11-character video ID
 * @throws {Error} - If unable to extract valid video ID
 * @throws {TypeError} - If extracted ID doesn't match expected format
 */
function getVideoID(str);

// Works with URLs
const id1 = ytdl.getVideoID('https://www.youtube.com/watch?v=aqz-KE-bpKQ');
console.log(id1); // 'aqz-KE-bpKQ'

// Works with direct video IDs
const id2 = ytdl.getVideoID('aqz-KE-bpKQ');
console.log(id2); // 'aqz-KE-bpKQ'

// Automatically detects format
function processVideo(input) {
  try {
    const videoId = ytdl.getVideoID(input);
    console.log(`Processing video: ${videoId}`);
    return ytdl.getInfo(videoId);
  } catch (error) {
    console.error('Invalid video input:', error.message);
  }
}

processVideo('https://youtu.be/dQw4w9WgXcQ');  // Works
processVideo('dQw4w9WgXcQ');                   // Also works
processVideo('invalid-input');                 // Throws error

// All of these extract the same video ID
ytdl.getVideoID('https://www.youtube.com/watch?v=aqz-KE-bpKQ');
ytdl.getVideoID('https://www.youtube.com/watch?v=aqz-KE-bpKQ&t=30s');
ytdl.getVideoID('https://www.youtube.com/watch?list=PLxxx&v=aqz-KE-bpKQ&index=2');
ytdl.getVideoID('https://www.youtube.com/watch?feature=youtu.be&v=aqz-KE-bpKQ');

try {
  const videoId = ytdl.getVideoID(userInput);
} catch (error) {
  if (error.message.includes('Not a YouTube domain')) {
    console.error('URL is not from YouTube');
  } else if (error.message.includes('No video id found')) {
    console.error('URL does not contain a video ID'); 
  } else if (error.message.includes('does not match expected format')) {
    console.error('Video ID format is invalid');
  } else {
    console.error('Unknown URL parsing error:', error.message);
  }
}

function sanitizeVideoInput(input) {
  if (!input || typeof input !== 'string') {
    throw new Error('Input must be a non-empty string');
  }
  
  // Trim whitespace
  input = input.trim();
  
  // Check if it looks like a URL
  if (input.includes('youtube.com') || input.includes('youtu.be')) {
    // Validate URL format
    if (!ytdl.validateURL(input)) {
      throw new Error('Invalid YouTube URL format');
    }
    return ytdl.getURLVideoID(input);
  } else {
    // Assume it's a video ID
    if (!ytdl.validateID(input)) {
      throw new Error('Invalid video ID format');
    }
    return input;
  }
}

// Usage
try {
  const videoId = sanitizeVideoInput(userInput);
  const info = await ytdl.getInfo(videoId);
} catch (error) {
  console.error('Invalid input:', error.message);
}

async function processVideoURLs(urls) {
  const results = [];
  
  for (const url of urls) {
    try {
      const videoId = ytdl.getVideoID(url);
      const info = await ytdl.getBasicInfo(videoId);
      
      results.push({
        url,
        videoId,
        title: info.videoDetails.title,
        success: true
      });
    } catch (error) {
      results.push({
        url,
        error: error.message,
        success: false
      });
    }
  }
  
  return results;
}

// Process mixed input
const urls = [
  'https://www.youtube.com/watch?v=aqz-KE-bpKQ',
  'https://youtu.be/dQw4w9WgXcQ',
  'invalid-url',
  'aqz-KE-bpKQ'
];

const results = await processVideoURLs(urls);
results.forEach(result => {
  if (result.success) {
    console.log(`✓ ${result.title} (${result.videoId})`);
  } else {
    console.log(`✗ ${result.url}: ${result.error}`);
  }
});

function normalizeYouTubeURL(input) {
  const videoId = ytdl.getVideoID(input);
  return `https://www.youtube.com/watch?v=${videoId}`;
}

// All of these become the same normalized URL
console.log(normalizeYouTubeURL('https://youtu.be/aqz-KE-bpKQ'));
console.log(normalizeYouTubeURL('https://m.youtube.com/watch?v=aqz-KE-bpKQ'));
console.log(normalizeYouTubeURL('aqz-KE-bpKQ'));
// All output: https://www.youtube.com/watch?v=aqz-KE-bpKQ

class YouTubeProcessor {
  async process(input) {
    try {
      // Flexible input handling
      const videoId = ytdl.getVideoID(input);
      
      console.log(`Processing video ID: ${videoId}`);
      
      // Check if video exists and is accessible
      const basicInfo = await ytdl.getBasicInfo(videoId);
      
      if (basicInfo.videoDetails.isPrivate) {
        throw new Error('Video is private');
      }
      
      return basicInfo;
      
    } catch (error) {
      throw new Error(`Failed to process input "${input}": ${error.message}`);
    }
  }
}