import { generateText } from "ai";
import { getLanguageModelById } from "@/lib/ai/dynamic-provider";

export async function buildDirectAgentImageAnalysisAnswer(params: {
  question: string;
  summary: string;
  modelId?: string;
}) {
  const normalizedQuestion = String(params.question || "").trim();
  const normalizedSummary = String(params.summary || "").trim();

  if (!normalizedSummary) {
    return "";
  }

  const buildFallbackAnswer = () => {
    const intro = normalizedQuestion
      ? "我先根据当前锁定图片给你一个直接结论："
      : "我先根据当前锁定图片做一个直接分析：";
    return [
      intro,
      normalizedSummary,
      normalizedQuestion
        ? "如果你要，我可以继续往主体构图、风格、问题点或优化建议里再拆细。"
        : "",
    ]
      .filter(Boolean)
      .join("\n\n");
  };

  const candidateModelIds = Array.from(
    new Set(
      [params.modelId]
        .map((value) => String(value || "").trim())
        .filter(Boolean),
    ),
  );

  for (const candidateModelId of candidateModelIds) {
    try {
      const model = await getLanguageModelById(candidateModelId);
      if (!model) continue;

      const { text } = await generateText({
        model,
        system: [
          "你是无限画布里的图片分析助手。",
          "只能根据给定的图像观察摘要回答，不要编造图片中不可见的事实。",
          "如果用户问题超出已知信息，要明确说信息不足，不要硬猜。",
          "优先给出直接结论，再补充2到4条简洁依据或建议。",
        ].join("\n"),
        prompt: [
          normalizedQuestion ? `用户问题：${normalizedQuestion}` : "用户要求：请分析当前图片。",
          `图像观察摘要：\n${normalizedSummary}`,
          "请用中文直接回答，不要复述“根据摘要/根据图片”，也不要输出多余寒暄。",
        ].join("\n\n"),
        temperature: 0.2,
        maxTokens: 320,
        abortSignal: AbortSignal.timeout(20_000),
      } as any);

      const normalizedText = String(text || "").trim();
      if (normalizedText) {
        return normalizedText;
      }
    } catch (error) {
      console.warn("[Direct Agent Analysis Answer] generation failed:", {
        modelId: candidateModelId,
        error,
      });
    }
  }

  return buildFallbackAnswer();
}