import { useEffect, useRef } from "react";

// Generic right-click context menu for the sidebar tree. Each call site
// (directive folder, contract row, step row, task row, …) builds its own
// items array. Lifts the viewport-clamping + click-outside / Esc logic
// out of the deleted DirectiveContextMenu so we don't end up with one
// component per entity type.

export interface ContextMenuItem {
  /** Display text. Empty for separators. */
  label: string;
  /** Click handler. Ignored when `separator` is true. */
  onClick?: () => void;
  /** Render in red — for destructive operations (delete, archive). */
  danger?: boolean;
  /** Render as a thin divider instead of a button. */
  separator?: boolean;
  /** Greyed out, non-clickable. Used for items whose preconditions
   *  aren't met (e.g. "Reopen" on an already-draft contract). */
  disabled?: boolean;
}

interface SidebarContextMenuProps {
  x: number;
  y: number;
  items: ContextMenuItem[];
  onClose: () => void;
}

export function SidebarContextMenu({ x, y, items, onClose }: SidebarContextMenuProps) {
  const menuRef = useRef<HTMLDivElement>(null);

  // Close on click outside or Esc.
  useEffect(() => {
    const handleClickOutside = (e: MouseEvent) => {
      if (menuRef.current && !menuRef.current.contains(e.target as Node)) {
        onClose();
      }
    };
    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key === "Escape") onClose();
    };
    document.addEventListener("mousedown", handleClickOutside);
    document.addEventListener("keydown", handleKeyDown);
    return () => {
      document.removeEventListener("mousedown", handleClickOutside);
      document.removeEventListener("keydown", handleKeyDown);
    };
  }, [onClose]);

  // Clamp into viewport if the menu would overflow off the right or
  // bottom edge.
  useEffect(() => {
    if (menuRef.current) {
      const rect = menuRef.current.getBoundingClientRect();
      const viewportWidth = window.innerWidth;
      const viewportHeight = window.innerHeight;
      if (rect.right > viewportWidth) {
        menuRef.current.style.left = `${x - rect.width}px`;
      }
      if (rect.bottom > viewportHeight) {
        menuRef.current.style.top = `${y - rect.height}px`;
      }
    }
  }, [x, y]);

  const baseItemClass =
    "w-full px-3 py-1.5 text-left text-xs font-mono flex items-center gap-2";
  const enabledClass = "text-[#9bc3ff] hover:bg-[rgba(117,170,252,0.1)]";
  const dangerClass = "text-red-400 hover:bg-[rgba(239,68,68,0.1)]";
  const disabledClass = "text-[#3a4a6a] cursor-not-allowed";
  const dividerClass = "border-t border-[rgba(117,170,252,0.2)] my-1";

  return (
    <div
      ref={menuRef}
      className="fixed z-50 min-w-[180px] bg-[#0a1628] border border-[rgba(117,170,252,0.3)] rounded shadow-lg py-1"
      style={{ left: x, top: y }}
      onContextMenu={(e) => e.preventDefault()}
    >
      {items.map((item, i) => {
        if (item.separator) {
          return <div key={`sep-${i}`} className={dividerClass} />;
        }
        const cls = item.disabled
          ? disabledClass
          : item.danger
          ? dangerClass
          : enabledClass;
        return (
          <button
            key={`item-${i}-${item.label}`}
            type="button"
            disabled={item.disabled}
            onClick={() => {
              if (item.disabled) return;
              item.onClick?.();
              onClose();
            }}
            className={`${baseItemClass} ${cls}`}
          >
            {item.label}
          </button>
        );
      })}
    </div>
  );
}
