src/scrollingTranscript/hooks.ts

import { useState, useEffect, useRef } from 'react';
import { Section } from '../types/Conversation';

export const useScrollTimer = (sections: Section[]) => {
  const [activeIndex, setActiveIndex] = useState(0);
  const timerRef = useRef<number | null>(null);

  const startTimer = () => {
    if (sections.length <= 1) return;
    
    const nextSection = () => {
      setActiveIndex((prevIndex) => (prevIndex + 1) % sections.length);
    };

    // Clear any existing timer
    if (timerRef.current !== null) {
      window.clearTimeout(timerRef.current);
    }

    // Set new timer based on current section's duration
    const currentDuration = sections[activeIndex]?.duration || 10;
    timerRef.current = window.setTimeout(nextSection, currentDuration * 1000);
  };

  // Start/restart timer when activeIndex changes or component mounts
  useEffect(() => {
    startTimer();
    
    // Cleanup timer on unmount
    return () => {
      if (timerRef.current !== null) {
        window.clearTimeout(timerRef.current);
      }
    };
  }, [activeIndex, sections]);

  const goToSection = (index: number) => {
    if (index >= 0 && index < sections.length) {
      setActiveIndex(index);
    }
  };

  return {
    activeIndex,
    goToSection
  };
};