import type { CanvasAgentContext } from "@/types/canvas/agent-protocol";

function trimText(value: unknown, maxLength: number) {
  return typeof value === "string" ? value.trim().slice(0, maxLength) : "";
}

function uniqueStrings(values: Array<string | undefined | null>) {
  return Array.from(
    new Set(values.map((value) => trimText(value, 160)).filter(Boolean))
  );
}

export function hasCanvasAgentAnnotationEditIntent(userText: string) {
  const text = trimText(userText, 1000);
  if (!text) return false;
  const annotationKeyword = "(?:批注|标注|箭头|框选|圈选|备注|annotation|note)";
  if (new RegExp(`(?:添加|新增|创建|加|写).{0,8}${annotationKeyword}`, "i").test(text)) {
    return false;
  }
  return (
    new RegExp(`(?:按|按照|根据|依据|依照|参考|基于).{0,18}${annotationKeyword}`, "i").test(
      text
    ) ||
    new RegExp(
      `${annotationKeyword}.{0,24}(?:修改|编辑|修图|改图|处理|调整|去掉|移除|换|生成|出图|执行)`,
      "i"
    ).test(text)
  );
}

export function buildCanvasAgentAnnotationEditPrompt(params: {
  context?: CanvasAgentContext | null;
  targetNodeIds?: string[];
  userText: string;
  maxAnnotations?: number;
}) {
  const context = params.context;
  if (!context || !hasCanvasAgentAnnotationEditIntent(params.userText)) {
    return "";
  }

  const targetNodeIds = uniqueStrings([
    ...(params.targetNodeIds || []),
    ...context.selectedNodeIds,
    ...context.selectedNodes.filter((node) => node.isSelected).map((node) => node.nodeId),
  ]);
  if (targetNodeIds.length === 0) return "";

  const targetSet = new Set(targetNodeIds);
  const annotations = context.annotations
    .filter((annotation) => targetSet.has(annotation.sourceNodeId))
    .slice(0, Math.max(1, params.maxAnnotations || 8));
  if (annotations.length === 0) return "";

  const lines = annotations.map((annotation, index) => {
    const parts = [
      `${index + 1}. 节点 ${annotation.sourceNodeId}`,
      `类型 ${annotation.type}`,
      annotation.text ? `说明：${annotation.text}` : "",
      annotation.bounds
        ? `框选区域：x=${annotation.bounds.x}, y=${annotation.bounds.y}, width=${annotation.bounds.width}, height=${annotation.bounds.height}`
        : "",
      annotation.targetPoint
        ? `目标点：x=${annotation.targetPoint.x}, y=${annotation.targetPoint.y}`
        : "",
    ].filter(Boolean);
    return parts.join("；");
  });

  return [
    "【画布批注编辑要求】用户要求按画布批注/标注执行编辑。请把以下批注作为本轮编辑的主要约束：",
    ...lines,
    "执行要求：优先修改批注指向或框选的区域；未被批注要求修改的主体、背景、构图与文字尽量保持不变；如果批注文字与用户当前文字冲突，以用户当前文字为准。",
  ].join("\n");
}