import { NextRequest, NextResponse } from "next/server";
import { auth } from "@/app/(auth)/auth";
import { generateText } from "ai";
import { getEnabledAiModelsWithProvider, getAiProviderById } from "@/lib/db/queries";
import { createOpenAI } from "@ai-sdk/openai";

export async function POST(request: NextRequest) {
  console.log("[Auto-title] API called");
  
  try {
    const session = await auth();
    if (!session?.user?.id) {
      console.log("[Auto-title] Unauthorized");
      return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
    }

    const { imageUrl } = await request.json();
    console.log("[Auto-title] Image URL:", imageUrl);

    if (!imageUrl) {
      return NextResponse.json({ error: "Image URL is required" }, { status: 400 });
    }

    // 从数据库获取支持视觉的模型（查找包含 qwen-vl 或 vision 的模型）
    const models = await getEnabledAiModelsWithProvider();
    console.log("[Auto-title] Available models count:", models.length);
    
    // 查找千问VL模型（优先 qwen-vl-max，其次 qwen-vl-plus）
    const visionModel = models.find(m => 
      m.modelId?.toLowerCase().includes('qwen-vl') || 
      m.modelId?.toLowerCase().includes('qwen3-vl') ||
      m.modelId?.toLowerCase().includes('vision')
    );
    
    console.log("[Auto-title] Found vision model:", visionModel?.modelId);

    if (!visionModel || !visionModel.providerId) {
      console.log("[Auto-title] No vision model found, using default title");
      return NextResponse.json({ title: "未命名画布" });
    }

    // 获取 provider 配置
    const provider = await getAiProviderById(visionModel.providerId);
    if (!provider || !provider.apiKey || !provider.baseUrl) {
      console.log("[Auto-title] Provider not configured");
      return NextResponse.json({ title: "未命名画布" });
    }

    console.log("[Auto-title] Using provider:", provider.name, "baseUrl:", provider.baseUrl);

    // 构造 Prompt
    const prompt = "请用2-4个字概括这张图片的主体内容，作为文件标题。直接返回标题，不要包含任何标点符号或其他文字。";

    // 使用数据库配置的 provider
    const openai = createOpenAI({
      apiKey: provider.apiKey,
      baseURL: provider.baseUrl,
    });

    const { text } = await generateText({
      model: openai(visionModel.modelId),
      messages: [
        {
          role: 'user',
          content: [
            { type: 'text', text: prompt },
            { type: 'image', image: imageUrl },
          ],
        },
      ],
    });

    console.log("[Auto-title] Generated title:", text.trim());
    return NextResponse.json({ title: text.trim() });

  } catch (error) {
    console.error("[Auto-title] Error:", error);
    // 失败时返回默认标题，不报错中断流程
    return NextResponse.json({ title: "新画布" });
  }
}