/**
 * 节点共用的几何交互容器：绘制旋转后的内容、选择样式、拉伸手柄及模式提示，协调一次手势的预览/提交/取消。
 * 拖动节点位置仍由外层ReactFlow处理；此处主要处理旋转与尺寸变化，通过NodeEditing而非直接写文档。
 */
"use client";

import { useEffect, useRef, type PointerEvent, type ReactNode } from "react";
import { useReactFlow, useViewport, type NodeProps, type XYPosition } from "@xyflow/react";
import { Grip, Maximize2, RotateCw } from "lucide-react";
import { elementCapabilities } from "@/lib/canvas-elements";
import type { CanvasNode } from "@/lib/canvas";
import { resizeFromPointer, rotationFromPointer, type NodeTransform, type ResizeDirection } from "@/lib/canvas-geometry";
import type { EditingLease } from "./editing-lease";
import { NodeStyleToolbar } from "./node-style-toolbar";
import { MembershipBadge } from "./frame-feedback";
import { ContentHandles } from "./content-handles";
import {ownsPointerCapture,acquirePointerCapture,releasePointerCapture} from "@/lib/canvas-bindings/pointer-capture";
import {canvasKeyContext,routeCanvasKey} from "@/lib/canvas-bindings/input-router";
import styles from "./canvas.module.css";
import {useNodeInternalsUpdate} from "./node-internals";

export {NodeEditing} from "./node-editing";
import {useScopedNodeEditing} from "./node-editing";
/** 保存手势起始节点快照与画布坐标，防止每帧以已预览结果为基准累积误差；pointerId/capture限定事件所有权。
 * 新版lease绑定具体交互，旧版则使用上下文的begin/transform/finish/cancel适配。 */
type Gesture = { lease?: EditingLease<NodeTransform>; node: CanvasNode; start: XYPosition; direction: ResizeDirection | "rotate"; capture: HTMLElement; pointerId: number };

/** children决定内容显示，hideStyleToolbar允许分区使用专属设置栏；className补充类型外观。
 * 能否缩放/旋转由elementCapabilities和当前选中/模式共同决定，不在每个节点组件重复实现。 */
export function TransformableNode(props: NodeProps<CanvasNode> & { children: ReactNode; className?: string; hideStyleToolbar?: boolean }) {
  const { id, data, selected, width, height, children, className = "" } = props;
  const editing = useScopedNodeEditing(id,data.__headlessTarget);
  const flow = useReactFlow<CanvasNode>();
  const update = useNodeInternalsUpdate(id);
  const { zoom } = useViewport();
  const frame = useRef<HTMLDivElement>(null);
  const gesture = useRef<Gesture | null>(null);
  // 用ref让只挂载一次的window blur监听调用最新cancelGesture；失焦和卸载均取消尚未结束的交互。
  const interrupt=useRef(()=>{});interrupt.current=()=>cancelGesture();
  useEffect(()=>{const blur=()=>interrupt.current();window.addEventListener('blur',blur);return()=>{window.removeEventListener('blur',blur);interrupt.current();};},[]);
  const rotation = data.rotation || 0;
  const plain = data.kind === "plain-text" || data.kind === "icon" || data.kind === "plain-image";
  const capabilities = elementCapabilities(data.kind);
  const resizing = capabilities.resizable && editing.resizing === id && selected;
  const rotating = capabilities.rotatable && editing.rotating === id && selected;
  // 几何、旋转或选中变化后请求批量更新ReactFlow连接点内部数据，避免端点仍留在旧位置。
  useEffect(() => { update(); }, [id, rotation, width, height, selected, update]);
  // 仅在变换模式启用时监听外部点击与Escape；退出/切换模式拆除监听。
  useEffect(() => {
    if (!rotating && !resizing) return;
    /** 点击容器与对应模式按钮之外退出模式；事件用捕获阶段观察，不要求控件把事件冒泡出来。 */
    const outside = (event: globalThis.PointerEvent) => {
      if (!frame.current?.contains(event.target as Node) && !(event.target as Element).closest?.('[data-rotate-toggle="' + id + '"], [data-resize-toggle="' + id + '"]')) { editing.rotate(null); editing.resize(null); }
    };
    /** 按统一输入路由判断Escape是否归工具，尊重文本/组合输入与已处理事件；认领后取消手势并退出模式。 */
    const escape = (event: KeyboardEvent) => {
      if(event.key!=="Escape")return;
      const claim=routeCanvasKey({key:event.key,composing:event.isComposing,defaultPrevented:event.defaultPrevented,...canvasKeyContext(event)},{tool:()=>{cancelGesture();editing.rotate(null);editing.resize(null);return true;}});
      if(claim==='tool'){event.preventDefault();event.stopPropagation();}
    };
    window.addEventListener("pointerdown", outside, true);
    window.addEventListener("keydown", escape);
    return () => { window.removeEventListener("pointerdown", outside, true); window.removeEventListener("keydown", escape); };
  }, [rotating, resizing, id, editing]);

  /** 主指针左键启动；旋转跳过文本输入目标，重复指针不得接管已有手势，另一指针到来先取消。
   * 取得起始节点和租约后捕获指针；捕获失败按取消路径恢复，成功才阻止默认行为与冒泡。 */
  function start(event: PointerEvent<HTMLElement>, direction: Gesture["direction"]) {
    if (event.button !== 0||event.defaultPrevented) return;
    if(direction==='rotate'&&event.target instanceof Element&&event.target.closest('input,textarea,[contenteditable]:not([contenteditable="false"]),[role="textbox"]'))return;
    if(gesture.current){if(gesture.current.pointerId!==event.pointerId)cancelGesture();return;}
    if(event.isPrimary===false)return;
    const node = flow.getNode(id);
    if (!node) return;
    // false表示动作层拒绝启动；缺少专用beginTransform时回退旧版begin，随后按需选中节点。
    const lease = editing.beginTransform?.(id); if (lease === false) return;
    if (!editing.beginTransform) editing.begin(id);
    if (!node.selected) editing.select(id);
    // node 是 flow.getNode 返回的引用，不深克隆；“起点快照”依赖外层不可变更新约定，不能原地修改该节点。
    gesture.current = { lease: lease && typeof lease === 'object' ? lease : undefined, node, direction, capture: event.currentTarget, pointerId: event.pointerId, start: flow.screenToFlowPosition({ x: event.clientX, y: event.clientY }) };
    if(!acquirePointerCapture(event.currentTarget,event.pointerId)){cancelGesture();return;}
    event.preventDefault();event.stopPropagation();
  }
  /** 只接受持有捕获的指针，把屏幕坐标变为画布坐标，再基于起始快照算旋转或尺寸变化。
   * 旋转Shift吸附由geometry函数处理；八向拉伸模式把Shift传入比例约束，普通角落拖动沿用默认行为。 */
  function move(event: PointerEvent<HTMLElement>) {
    if(!gesture.current)return;event.stopPropagation();
    if (!ownsPointerCapture(gesture.current,event)) return;
    const current = flow.screenToFlowPosition({ x: event.clientX, y: event.clientY });
    const { node, start, direction } = gesture.current!;
    // resizing 模式显式传 Shift 布尔值，未按 Shift 即解锁比例；普通角落传 undefined 沿用图片/图标默认比例规则。
    const change = direction === "rotate"
      ? { rotation: rotationFromPointer(node, start, current, event.shiftKey) }
      : resizeFromPointer(node, direction, { x: current.x - start.x, y: current.y - start.y }, resizing ? event.shiftKey : undefined);
    // 新版只预览当前lease，旧适配发transform；历史单元何时发布由Provider控制。
    if (gesture.current!.lease) gesture.current!.lease!.preview(change); else editing.transform(id, change);
  }
  /** 无事件参数可由失焦/卸载强制取消；有事件时先校验捕获归属，避免其它指针干扰。
   * 优先lease.cancel，其次cancelTransform；最旧接口缺少取消钩子时把起始几何写回，最后释放捕获。 */
  function cancelGesture(event?:{pointerId:number;type?:string;target?:unknown;stopPropagation?():void}) {
    if(event&&gesture.current)event.stopPropagation?.();
    if(event&&!ownsPointerCapture(gesture.current,event))return;
    const current = gesture.current; if (!current) return;
    gesture.current = null;
    // cancel/commit 调用与释放间没有 finally；Provider/lease 抛错时可能跳过 release，需要遵守动作异常契约。
    if (current.lease) current.lease.cancel(); else if (editing.cancelTransform) editing.cancelTransform(); else editing.transform(current.node.id, current.direction === "rotate" ? { rotation: current.node.data.rotation || 0 } : { position: current.node.position, width: current.node.width, height: current.node.height });
    releasePointerCapture(current.capture,current.pointerId);
  }
  /** 抬起时先采用最后一个指针位置，再清手势引用并提交；随后释放捕获不会误取消已结束交互。 */
  function finish(event: PointerEvent<HTMLElement>) {
    if(!gesture.current)return;event.stopPropagation();
    if (!ownsPointerCapture(gesture.current,event)) return; const current = gesture.current!; move(event); gesture.current = null;
    // 当前手势引用已清空；若 commit 抛错，不会自动恢复引用或执行后面的 capture 释放。
    if (current.lease) current.lease.commit(); else editing.finishTransform?.();
    releasePointerCapture(current.capture,current.pointerId);
  }
  // 模式关闭/取消选中本身不调用 cancelGesture；实际手势结束还依赖 pointerup/cancel、失焦或卸载。
  // 容器的CSS zoom使用viewScale，宽高同时除以viewScale，保持投影尺寸与内部显示坐标对应。
  // schema=2给纯文本/纯图片补四向连接点，非分区显示成员徽标；普通尺寸调整用右下角，模式内显示八向手柄。
  // 八向手柄的尺寸与边框反向抵消zoom和viewScale，使屏幕上大小稳定；方向决定位置及cursor。
  return <>
    {!props.hideStyleToolbar && <NodeStyleToolbar {...props} />}
    <div ref={frame} className={`${styles.transformFrame} ${selected ? styles.selectedFrame : ""} ${plain ? styles.plainFrame : ""} ${rotating ? styles.rotatingFrame + " nodrag nopan" : ""} ${className}`}
      onPointerDownCapture={rotating ? (event) => start(event, "rotate") : undefined}
      onPointerMove={move} onPointerUp={finish} onPointerCancel={cancelGesture}
      onLostPointerCapture={cancelGesture}
      style={{ zoom: data.viewScale || 1, width: (width || (data.kind === "frame" ? 640 : data.kind === "plain-image" ? 320 : data.kind === "icon" ? 80 : plain ? 240 : 260)) / (data.viewScale || 1), height: ( height || (data.kind === "frame" ? 400 : data.kind === "plain-image" ? 240 : data.kind === "icon" ? 80 : plain ? 72 : 200)) / (data.viewScale || 1), transform: `rotate(${rotation}deg)` }}>
      {children}
      {editing.schema === 2 && ["plain-text", "plain-image"].includes(data.kind) && <ContentHandles selected={selected} />}
      {data.kind !== "frame" && <MembershipBadge id={id} frameId={data.frameId} selected={selected} />}
      {capabilities.resizable && !resizing && <button type="button" className={`${styles.cornerResize} nodrag nopan`} tabIndex={rotating ? -1 : 0}
        aria-hidden={rotating} aria-label="拖动右下角调整大小" title="拖动调整大小"
        onPointerDown={(event) => start(event, "bottom-right")} onPointerMove={move} onPointerUp={finish} onPointerCancel={cancelGesture}>
        <Grip size={14} />
      </button>}
      {resizing && (["top-left", "top", "top-right", "right", "bottom-right", "bottom", "bottom-left", "left"] as const).map((direction) => {
        // 从方向名推导0%/50%/100%锚点：边中点只占一个方向，角点同时包含横纵方向。
        const left = direction.includes("left") ? "0%" : direction.includes("right") ? "100%" : "50%";
        const top = direction.includes("top") ? "0%" : direction.includes("bottom") ? "100%" : "50%";
        return <button type="button" key={direction} className={`${styles.resizeHandle} nodrag nopan`} data-resize-handle={direction} aria-label={`拉伸 ${direction}`} title="拖动拉伸 · Shift 固定比例" style={{ left, top, width: 10 / (zoom * (data.viewScale || 1)), height: 10 / (zoom * (data.viewScale || 1)), borderWidth: 1 / (zoom * (data.viewScale || 1)), cursor: direction === "top" || direction === "bottom" ? "ns-resize" : direction === "left" || direction === "right" ? "ew-resize" : direction === "top-left" || direction === "bottom-right" ? "nwse-resize" : "nesw-resize" }}
          onPointerDown={(event) => start(event, direction)} onPointerMove={move} onPointerUp={finish} onPointerCancel={cancelGesture}
          onKeyDown={(event) => {
            // 键盘每次方向键形成一次完整变换：默认一个viewScale单位，Ctrl/Meta放大十倍，Shift固定比例。
            const delta = { ArrowLeft: [-1, 0], ArrowRight: [1, 0], ArrowUp: [0, -1], ArrowDown: [0, 1] }[event.key]; if (!delta) return;
            event.preventDefault(); event.stopPropagation(); const node = flow.getNode(id); if (!node) return;
            const lease = editing.beginTransform?.(id); if (lease === false) return; if (!editing.beginTransform) editing.begin(id); const scale = (data.viewScale || 1) * (event.ctrlKey || event.metaKey ? 10 : 1);
            // 键盘按键没有 pointer capture，也不经过 move；preview/commit 同步连用，失败清理由租约实现承担。
            const change = resizeFromPointer(node, direction, { x: delta[0] * scale, y: delta[1] * scale }, event.shiftKey);
            if (lease && typeof lease === 'object') { lease.preview(change); lease.commit(); } else { editing.transform(id, change); editing.finishTransform?.(); }
          }} />;
      })}
      {resizing && <span className={styles.rotationHint}>拖动八向手柄 · Shift 固定比例 · Esc 退出</span>}
      {rotating && <span className={styles.rotationHint}><RotateCw size={12} /> {Math.round(rotation)}° · 拖动旋转，点击外部退出</span>}
    </div>
  </>;
}

/** 受控拉伸模式开关；aria-pressed反映当前节点是否处于模式，data标记供外部点击判定排除自身。 */
export function ResizeToggle({ id,renderedTarget }: { id: string;renderedTarget?:import("@/lib/canvas-bindings/compat-types").RenderedTarget }) {
  const editing = useScopedNodeEditing(id,renderedTarget);
  return <button type="button" data-resize-toggle={id} aria-label="八向拉伸模式" title="八向拉伸 · Shift 固定比例" aria-pressed={editing.resizing === id} onClick={() => editing.resize(editing.resizing === id ? null : id)}><Maximize2 size={16} /></button>;
}