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 modelsData = await getEnabledAiModelsWithProvider();
    console.log("[Auto-title] Available models count:", modelsData.length);
    console.log("[Auto-title] All model IDs:", modelsData.map(m => m.model.modelId));
    
    // 查找千问VL模型（支持多种命名格式）
    const visionModelData = modelsData.find(m => {
      const id = m.model.modelId?.toLowerCase() || '';
      const name = m.model.displayName?.toLowerCase() || '';
      return id.includes('qwen-vl') || 
             id.includes('qwen3-vl') ||
             id.includes('qwen2.5-vl') ||
             id.includes('vision') ||
             name.includes('vl') ||
             name.includes('视觉');
    });
    
    console.log("[Auto-title] Found vision model:", visionModelData?.model.modelId, visionModelData?.model.displayName);

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

    // 直接使用返回的 provider 信息
    const provider = visionModelData.provider;
    const visionModel = visionModelData.model;
    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,
    });

    // 直接使用数据库中的模型 ID（阿里云支持 qwen3-vl-plus 等新模型 ID）
    const actualModelId = visionModel.modelId;
    console.log("[Auto-title] Using model ID:", actualModelId);

    const { text } = await generateText({
      model: openai(actualModelId),
      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" });
  }
}