How to Build a Youtube Video Generator

// Fetch trending and high-performing topics via YouTube Data API
  async function researchNiche(query, apiKey) {
  const searchUrl = `https://www.googleapis.com/youtube/v3/search?part=snippet&q=${encodeURIComponent(query)}&type=video&order=viewCount&maxResults=25&publishedAfter=${getThirtyDaysAgo()}&key=${apiKey}`;

  const searchRes = await fetch(searchUrl);
  const { items } = await searchRes.json();

  const videoIds = items.map(i => i.id.videoId).join(',');
  const statsUrl = `https://www.googleapis.com/youtube/v3/videos?part=statistics,contentDetails&id=${videoIds}&key=${apiKey}`;

  const statsRes = await fetch(statsUrl);
  const { items: videos } = await statsRes.json();

  return items.map((item, idx) => ({
    title: item.snippet.title,
    channel: item.snippet.channelTitle,
    views: parseInt(videos[idx]?.statistics?.viewCount || '0'),
    likes: parseInt(videos[idx]?.statistics?.likeCount || '0'),
    duration: parseDuration(videos[idx]?.contentDetails?.duration),
    publishedAt: item.snippet.publishedAt,
    engagementRate: calcEngagement(videos[idx]?.statistics)
  }));
  }

  function calcEngagement(stats) {
  if (!stats) return 0;
  const views = parseInt(stats.viewCount || '0');
  const likes = parseInt(stats.likeCount || '0');
  const comments = parseInt(stats.commentCount || '0');
  return views > 0 ? ((likes + comments) / views * 100).toFixed(2) : 0;
  }

  // Generate script outline with retention hooks
  function generateScriptOutline(topic, targetMinutes = 10) {
  const segments = [
    { time: '0:00-0:30', section: 'Hook', note: 'Bold claim or question that creates a curiosity gap' },
    { time: '0:30-1:30', section: 'Context', note: 'Why this matters right now, establish credibility' },
    { time: '1:30-3:00', section: 'Setup', note: 'Frame the problem or opportunity' },
    { time: '3:00-7:00', section: 'Core Content', note: 'Deliver the main value in 3-5 distinct points' },
    { time: '7:00-8:30', section: 'Pattern Interrupt', note: 'Story, demo, or unexpected angle to re-engage' },
    { time: '8:30-9:30', section: 'Payoff', note: 'The big takeaway or transformation' },
    { time: '9:30-10:00', section: 'CTA + Loop', note: 'Clear next action, tease related video for session time' }
  ];

  return {
    topic,
    targetLength: `${targetMinutes} minutes`,
    segments,
    titleFormulas: [
      `I Tried ${topic} for 30 Days (Here's What Happened)`,
      `${topic}: What Nobody Tells You`,
      `The ${topic} Mistake 90% of People Make`,
      `How ${topic} Actually Works (Not What You Think)`
    ],
    thumbnailNotes: 'High contrast, 3 words max, expressive face or before/after'
  };
  }