import { useState, useCallback, useEffect } from 'react';

// Define disclaimer priorities - empty by default, will be populated by groups
export const DISCLAIMER_PRIORITIES: { [key: string]: number } = {};

type DisclaimerId = string;

interface DisclaimerQueueItem {
  id: DisclaimerId;
  isOpen: boolean;
  priority: number;
}

const STORAGE_KEY = 'im-disclaimer-accepted';

export const useDisclaimerQueue = () => {
  const [queue, setQueue] = useState<DisclaimerQueueItem[]>([]);
  const [activeDisclaimer, setActiveDisclaimer] = useState<DisclaimerId | null>(null);

  // Load accepted disclaimers from localStorage
  useEffect(() => {
    const acceptedDisclaimers = localStorage.getItem(STORAGE_KEY);
    if (acceptedDisclaimers) {
      const accepted = new Set(JSON.parse(acceptedDisclaimers));
      // Filter out accepted disclaimers from the queue
      setQueue(prev => prev.filter(item => !accepted.has(item.id)));
    }
  }, []);

  const addToQueue = useCallback((id: DisclaimerId) => {
    // Check if disclaimer was already accepted
    const acceptedDisclaimers = localStorage.getItem(STORAGE_KEY);
    const accepted = acceptedDisclaimers ? new Set(JSON.parse(acceptedDisclaimers)) : new Set();
    
    if (accepted.has(id)) {
      return; // Don't add if already accepted
    }

    setQueue(prev => {
      // Don't add if already in queue
      if (prev.some(item => item.id === id)) {
        return prev;
      }

      const priority = DISCLAIMER_PRIORITIES[id];
      const newQueue = [...prev, { id, isOpen: false, priority }].sort((a, b) => a.priority - b.priority);
      
      // If no active disclaimer, activate the highest priority one
      if (!activeDisclaimer) {
        const highestPriority = newQueue[0];
        if (highestPriority) {
          setActiveDisclaimer(highestPriority.id);
        }
      }
      
      return newQueue;
    });
  }, [activeDisclaimer]);

  const removeFromQueue = useCallback((id: DisclaimerId) => {
    // Add to accepted disclaimers in localStorage
    const acceptedDisclaimers = localStorage.getItem(STORAGE_KEY);
    const accepted = acceptedDisclaimers ? new Set(JSON.parse(acceptedDisclaimers)) : new Set();
    accepted.add(id);
    localStorage.setItem(STORAGE_KEY, JSON.stringify(Array.from(accepted)));

    setQueue(prev => {
      const newQueue = prev.filter(item => item.id !== id);
      
      // If this was the active disclaimer, activate the next highest priority one
      if (activeDisclaimer === id) {
        const nextItem = newQueue[0];
        if (nextItem) {
          setActiveDisclaimer(nextItem.id);
        } else {
          setActiveDisclaimer(null);
        }
      }
      
      return newQueue;
    });
  }, [activeDisclaimer]);

  const isDisclaimerActive = useCallback((id: DisclaimerId) => {
    return activeDisclaimer === id;
  }, [activeDisclaimer]);

  return {
    addToQueue,
    removeFromQueue,
    isDisclaimerActive,
    hasActiveDisclaimer: activeDisclaimer !== null,
    getActiveDisclaimer: () => activeDisclaimer
  };
};