import type { LucideIcon } from "lucide-react";
import { useEffect, useLayoutEffect, useRef, useState } from "react";
import { createPortal } from "react-dom";
import { cn } from "~/lib/utils.ts";

export type MenuItem =
  | {
      key: string;
      label: string;
      icon?: LucideIcon;
      /** 快捷键提示 */
      hint?: string;
      /** 禁用原因(显示为 title,并在行内小字说明) */
      disabled?: string | null;
      destructive?: boolean;
      onSelect: () => void;
    }
  | { key: string; separator: true };

export type MenuAnchor = { x: number; y: number };

/**
 * 右键菜单 / 行 ⋯ 菜单共用的浮层(pg-float)。按坐标定位,越界自动翻转;
 * 点外面、Esc、滚动、失焦都会关闭;↑↓ 在可用项间移动,Enter 执行。
 */
export function ContextMenu({
  anchor,
  items,
  onClose,
  label = "操作",
}: {
  anchor: MenuAnchor | null;
  items: MenuItem[];
  onClose: () => void;
  label?: string;
}) {
  const ref = useRef<HTMLDivElement>(null);
  const [pos, setPos] = useState<{ left: number; top: number } | null>(null);
  const [active, setActive] = useState(-1);

  useLayoutEffect(() => {
    if (!anchor || !ref.current) return;
    const r = ref.current.getBoundingClientRect();
    const vw = window.innerWidth;
    const vh = window.innerHeight;
    const left = anchor.x + r.width > vw - 8 ? Math.max(8, anchor.x - r.width) : anchor.x;
    const top = anchor.y + r.height > vh - 8 ? Math.max(8, anchor.y - r.height) : anchor.y;
    setPos({ left, top });
    ref.current.focus();
  }, [anchor]);

  useEffect(() => {
    if (!anchor) return;
    const close = (e: Event) => {
      if (e.type === "mousedown" && ref.current?.contains(e.target as Node)) return;
      onClose();
    };
    window.addEventListener("mousedown", close);
    window.addEventListener("resize", close);
    window.addEventListener("blur", close);
    document.addEventListener("scroll", close, true);
    return () => {
      window.removeEventListener("mousedown", close);
      window.removeEventListener("resize", close);
      window.removeEventListener("blur", close);
      document.removeEventListener("scroll", close, true);
    };
  }, [anchor, onClose]);

  useEffect(() => {
    if (!anchor) {
      setPos(null);
      setActive(-1);
    }
  }, [anchor]);

  if (!anchor || typeof document === "undefined") return null;
  const actionable = items
    .map((it, i) => ({ it, i }))
    .filter(({ it }) => !("separator" in it) && !it.disabled)
    .map(({ i }) => i);

  const onKeyDown = (e: React.KeyboardEvent) => {
    if (e.key === "Escape") {
      e.preventDefault();
      onClose();
    } else if (e.key === "ArrowDown" || e.key === "ArrowUp") {
      e.preventDefault();
      if (!actionable.length) return;
      const cur = actionable.indexOf(active);
      const next =
        e.key === "ArrowDown"
          ? actionable[(cur + 1) % actionable.length]
          : actionable[(cur - 1 + actionable.length) % actionable.length];
      setActive(next ?? -1);
    } else if (e.key === "Enter" && active >= 0) {
      e.preventDefault();
      const it = items[active];
      if (it && !("separator" in it) && !it.disabled) {
        onClose();
        it.onSelect();
      }
    }
  };

  return createPortal(
    <div
      ref={ref}
      role="menu"
      aria-label={label}
      tabIndex={-1}
      onKeyDown={onKeyDown}
      onContextMenu={(e) => e.preventDefault()}
      style={{ left: pos?.left ?? anchor.x, top: pos?.top ?? anchor.y, visibility: pos ? "visible" : "hidden" }}
      className="pg-float fixed z-50 min-w-52 max-w-72 animate-pg-pop rounded-2xl p-1.5 outline-none"
    >
      {items.map((it, i) =>
        "separator" in it ? (
          <hr key={it.key} className="my-1 border-0 border-t border-border" />
        ) : (
          <button
            key={it.key}
            type="button"
            role="menuitem"
            aria-disabled={!!it.disabled}
            title={it.disabled ?? undefined}
            onMouseEnter={() => setActive(i)}
            onClick={() => {
              if (it.disabled) return;
              onClose();
              it.onSelect();
            }}
            className={cn(
              "flex w-full items-start gap-2.5 rounded-lg px-2.5 py-1.5 text-left text-body transition-colors duration-micro",
              it.disabled
                ? "cursor-not-allowed opacity-50"
                : it.destructive
                  ? "text-foreground hover:bg-destructive/10 hover:text-destructive"
                  : "text-foreground hover:bg-foreground/[0.06]",
              active === i &&
                !it.disabled &&
                (it.destructive ? "bg-destructive/10 text-destructive" : "bg-foreground/[0.06]"),
            )}
          >
            {it.icon ? <it.icon className="mt-0.5 h-4 w-4 shrink-0 text-muted-foreground" /> : <span className="w-4" />}
            <span className="min-w-0 flex-1">
              <span className="block truncate">{it.label}</span>
              {it.disabled ? <span className="block text-meta text-muted-foreground">{it.disabled}</span> : null}
            </span>
            {it.hint ? <kbd className="mt-0.5 font-mono text-meta text-muted-foreground">{it.hint}</kbd> : null}
          </button>
        ),
      )}
    </div>,
    document.body,
  );
}