import { useState, useCallback } from "react";

export function useEmailQueue() {
  const [queue, setQueue] = useState([]);
  const [currentIndex, setCurrentIndex] = useState(0);
  const [stats, setStats] = useState({
    queued: 0,
    researching: 0,
    generated: 0,
    approved: 0,
    sent: 0,
    skipped: 0,
    failed: 0,
  });

  const initQueue = useCallback((recipientList) => {
    const items = recipientList
      .filter((p) => p.trim())
      .map((p, i) => ({
        index: i,
        input: p.trim(),
        status: "queued",
        contactData: null,
        emailContent: null,
        htmlBody: null,
        error: null,
      }));
    setQueue(items);
    setCurrentIndex(0);
    setStats({ ...stats, queued: items.length });
    return items;
  }, []);

  const updateItem = useCallback((index, updates) => {
    setQueue((prev) =>
      prev.map((item) =>
        item.index === index ? { ...item, ...updates } : item
      )
    );
  }, []);

  const nextItem = useCallback(() => {
    setCurrentIndex((prev) => {
      const next = prev + 1;
      return next < queue.length ? next : prev;
    });
  }, [queue.length]);

  const currentItem = queue[currentIndex] || null;

  const recalcStats = useCallback(() => {
    const s = {
      queued: 0,
      researching: 0,
      generated: 0,
      approved: 0,
      sent: 0,
      skipped: 0,
      failed: 0,
    };
    queue.forEach((item) => {
      if (s[item.status] !== undefined) s[item.status]++;
    });
    setStats(s);
  }, [queue]);

  return {
    queue,
    currentIndex,
    currentItem,
    stats,
    initQueue,
    updateItem,
    nextItem,
    setCurrentIndex,
    recalcStats,
  };
}