utils/text.js

const MAX_TEXT_WIDTH = 950;
const MAX_FONT_SIZE = 80;
const MIN_SINGLE_LINE_SIZE = 65;

function slugifyTitle(title) {
  if (!title || typeof title !== "string") return "video";
  return title.normalize("NFKD").replace(/[^\w\s]/g, "").replace(/\s+/g, "").substring(0, 50) || "video";
}

function optimizeTextLayout(rawText) {
  const text = rawText.trim();
  const charCount = text.length;
  const CHAR_WIDTH_FACTOR = 0.55; // This is a rough estimate for variable width fonts
  const estimatedWidthMax = charCount * MAX_FONT_SIZE * CHAR_WIDTH_FACTOR;
  
  // 1. Try Single Line at Max Size
  if (estimatedWidthMax <= MAX_TEXT_WIDTH) return { lines: [text], fontSize: MAX_FONT_SIZE };
  
  // 2. Try Single Line with Reduced Size
  const requiredFontSize = MAX_TEXT_WIDTH / (charCount * CHAR_WIDTH_FACTOR);
  if (requiredFontSize >= MIN_SINGLE_LINE_SIZE) return { lines: [text], fontSize: Math.floor(requiredFontSize) };
  
  // 3. Split into Two Lines
  const words = text.split(" ");
  let splitIndex = Math.ceil(words.length / 2);
  
  // Attempt to balance line length by character count, not just word count
  let currentCount = 0;
  const totalChars = text.length;
  for(let i=0; i<words.length; i++) {
      currentCount += words[i].length;
      if (currentCount >= totalChars / 2) { splitIndex = i + 1; break; }
  }
  if (splitIndex === 0 || splitIndex === words.length) splitIndex = Math.ceil(words.length / 2);
  
  const line1 = words.slice(0, splitIndex).join(" ");
  const line2 = words.slice(splitIndex).join(" ");
  
  // Calculate font size based on the LONGER line
  const longestLineChars = Math.max(line1.length, line2.length);
  let doubleLineFontSize = MAX_TEXT_WIDTH / (longestLineChars * CHAR_WIDTH_FACTOR);
  
  // Cap the size
  if (doubleLineFontSize > MAX_FONT_SIZE) doubleLineFontSize = MAX_FONT_SIZE;
  
  // Ensure it doesn't get too tiny
  if (doubleLineFontSize < 40) doubleLineFontSize = 40; 
  
  return { lines: [line1, line2], fontSize: Math.floor(doubleLineFontSize) };
}

module.exports = { slugifyTitle, optimizeTextLayout };