import React, { useState } from 'react';
import { clsx } from 'clsx';
import { ChevronDown } from 'lucide-react';

export interface AccordionItem {
  id: string;
  title: string;
  content: React.ReactNode;
  defaultOpen?: boolean;
  disabled?: boolean;
}

export interface AccordionProps {
  items: AccordionItem[];
  allowMultiple?: boolean;
  className?: string;
  itemClassName?: string;
}

/**
 * Accordion/Collapsible component
 */
export const Accordion = ({
  items,
  allowMultiple = false,
  className,
  itemClassName,
}: AccordionProps) => {
  const [openItems, setOpenItems] = useState<Set<string>>(
    new Set(items.filter((item) => item.defaultOpen).map((item) => item.id))
  );

  const toggleItem = (id: string) => {
    setOpenItems((prev) => {
      const newSet = new Set(prev);
      if (newSet.has(id)) {
        newSet.delete(id);
      } else {
        if (!allowMultiple) {
          newSet.clear();
        }
        newSet.add(id);
      }
      return newSet;
    });
  };

  return (
    <div className={clsx('space-y-2', className)}>
      {items.map((item) => {
        const isOpen = openItems.has(item.id);

        return (
          <div key={item.id} className={clsx('border rounded-lg overflow-hidden', itemClassName)}>
            <button
              type="button"
              onClick={() => !item.disabled && toggleItem(item.id)}
              disabled={item.disabled}
              className={clsx(
                'w-full flex items-center justify-between p-4',
                'text-left font-medium',
                'hover:bg-muted/50 transition-colors',
                'focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2',
                {
                  'opacity-50 cursor-not-allowed': item.disabled,
                }
              )}
              aria-expanded={isOpen}
              aria-controls={`accordion-content-${item.id}`}
            >
              <span>{item.title}</span>
              <ChevronDown
                className={clsx(
                  'h-4 w-4 text-muted-foreground transition-transform flex-shrink-0',
                  {
                    'rotate-180': isOpen,
                  }
                )}
              />
            </button>
            <div
              id={`accordion-content-${item.id}`}
              className={clsx('overflow-hidden transition-all duration-200', {
                'max-h-0': !isOpen,
                'max-h-[2000px]': isOpen,
              })}
            >
              <div className="p-4 pt-0 text-sm text-muted-foreground">{item.content}</div>
            </div>
          </div>
        );
      })}
    </div>
  );
};