import React, { useEffect, useRef, useState } from 'react';
import { clsx } from 'clsx';

export interface PopoverProps {
  trigger: React.ReactNode;
  content: React.ReactNode;
  open?: boolean;
  onOpenChange?: (open: boolean) => void;
  align?: 'start' | 'center' | 'end';
  side?: 'top' | 'bottom' | 'left' | 'right';
  className?: string;
  triggerClassName?: string;
  modal?: boolean;
}

const alignClasses = {
  start: 'start-0',
  center: 'left-1/2 -translate-x-1/2',
  end: 'end-0',
};

const sideClasses = {
  top: 'bottom-full mb-2',
  bottom: 'top-full mt-2',
  left: 'right-full mr-2',
  right: 'left-full ml-2',
};

/**
 * Popover component - contextual popup (different from Tooltip)
 */
export const Popover = ({
  trigger,
  content,
  open: controlledOpen,
  onOpenChange,
  align = 'center',
  side = 'bottom',
  className,
  triggerClassName,
  modal = false,
}: PopoverProps) => {
  const [internalOpen, setInternalOpen] = useState(false);
  const popoverRef = useRef<HTMLDivElement>(null);
  const triggerRef = useRef<HTMLDivElement>(null);

  const isControlled = controlledOpen !== undefined;
  const open = isControlled ? controlledOpen : internalOpen;

  const setOpen = (value: boolean) => {
    if (!isControlled) {
      setInternalOpen(value);
    }
    onOpenChange?.(value);
  };

  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (
        popoverRef.current &&
        triggerRef.current &&
        !popoverRef.current.contains(event.target as Node) &&
        !triggerRef.current.contains(event.target as Node)
      ) {
        setOpen(false);
      }
    };

    const handleEscape = (event: KeyboardEvent) => {
      if (event.key === 'Escape' && open) {
        setOpen(false);
      }
    };

    if (open) {
      document.addEventListener('mousedown', handleClickOutside);
      document.addEventListener('keydown', handleEscape);
    }

    return () => {
      document.removeEventListener('mousedown', handleClickOutside);
      document.removeEventListener('keydown', handleEscape);
    };
  }, [open]);

  return (
    <div className={clsx('relative inline-block', className)}>
      <div
        ref={triggerRef}
        onClick={() => setOpen(!open)}
        className={clsx('cursor-pointer', triggerClassName)}
        role="button"
        aria-haspopup="true"
        aria-expanded={open}
      >
        {trigger}
      </div>

      {open && (
        <>
          {modal && (
            <div className="fixed inset-0 z-40" onClick={() => setOpen(false)} aria-hidden="true" />
          )}
          <div
            ref={popoverRef}
            className={clsx(
              'absolute z-50',
              'bg-background border rounded-lg shadow-lg',
              'p-4 min-w-[200px]',
              'animate-in fade-in-0 zoom-in-95 duration-200',
              alignClasses[align],
              sideClasses[side]
            )}
            role="dialog"
          >
            {content}
          </div>
        </>
      )}
    </div>
  );
};