const axios = require('axios');
const makeLinks = require('../../shared/hateoas');
const { v4: uuidv4 } = require('uuid');
const qs = require('qs');
require('dotenv').config();
process.env.NODE_TLS_REJECT_UNAUTHORIZED = '0';

// 获取GigaChat access_token，严格按官方文档
async function getGigaChatToken() {
  const apiKey = '78359123-4447-481a-9028-861f53b24ed1:04a4f1e9-1349-4a84-85f9-0c6c687c0974';
  const scope = process.env.GIGACHAT_SCOPE || 'GIGACHAT_API_PERS';
  if (!apiKey) throw new Error('GIGACHAT_API_KEY 未配置');

  const rqUID = uuidv4();
  const auth = Buffer.from(apiKey.trim()).toString('base64');

  try {
    const resp = await axios.post(
      'https://ngw.devices.sberbank.ru:9443/api/v2/oauth',
      new URLSearchParams({ scope }),
      {
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Accept': 'application/json',
          'RqUID': rqUID,
          'Authorization': `Basic ${auth}`,
        },
        timeout: 10000,
      }
    );
    if (!resp.data.access_token) {
      console.error('GigaChat token响应异常:', resp.data);
      throw new Error('GigaChat token响应异常');
    }
    return resp.data.access_token;
  } catch (err) {
    if (err.response) {
      console.error('获取access_token失败:', err.response.status, err.response.data);
    } else {
      console.error('获取access_token异常:', err.message);
    }
    throw new Error('获取access_token失败');
  }
}

// 调用chat生成图片描述
async function fetchChatContent(accessToken, prompt) {
  try {
    const chatResp = await axios.post(
      'https://gigachat.devices.sberbank.ru/api/v1/chat/completions',
      {
        model: "GigaChat",
        messages: [
          { role: "system", content: "Ты — Василий Кандинский" },
          { role: "user", content: prompt }
        ],
        stream: false,
        function_call: 'auto'
      },
      {
        headers: {
          'Authorization': `Bearer ${accessToken}`,
          'Content-Type': 'application/json',
          'RqUID': uuidv4(),
        }
      }
    );
    const content = chatResp.data.choices[0].message.content;
    console.log('GigaChat返回内容:', content);
    return content;
  } catch (err) {
    console.error('AI生成图片出错: chat接口失败');
    if (err.response) {
      console.error('status:', err.response.status);
      console.error('headers:', err.response.headers);
      console.error('data:', err.response.data);
      console.error('config:', err.config);
    } else {
      console.error('AI生成图片出错:', err.message);
    }
    throw new Error('chat接口失败: ' + err.message);
  }
}

// 获取图片内容
async function fetchImageContent(accessToken, imageId) {
  try {
    const imageResp = await axios.get(
      `https://gigachat.devices.sberbank.ru/api/v1/files/${imageId}/content`,
      {
        headers: {
          'Authorization': `Bearer ${accessToken}`,
          'RqUID': uuidv4(),
        },
        responseType: 'arraybuffer'
      }
    );
    return imageResp.data;
  } catch (err) {
    console.error('AI生成图片出错: 获取图片内容失败');
    if (err.response) {
      console.error('status:', err.response.status);
      console.error('headers:', err.response.headers);
      console.error('data:', err.response.data);
      console.error('config:', err.config);
    } else {
      console.error('AI生成图片出错:', err.message);
    }
    throw new Error('获取图片内容失败: ' + err.message);
  }
}

exports.generate = async (req, res) => {
  const { prompt } = req.query;
  if (!prompt) {
    return res.status(400).json({ error: 'Prompt parameter is required' });
  }
  let accessToken;
  try {
    accessToken = await getGigaChatToken();
  } catch (e) {
    return res.status(500).json({ error: e.message });
  }
  try {
    const content = await fetchChatContent(accessToken, prompt);
    const match = content.match(/<img src=\"(.*?)\"/);
    if (!match) {
      console.error('AI生成图片出错: GigaChat未返回图片标签');
      return res.status(500).json({ error: 'No image generated' });
    }
    const imageId = match[1];
    const imageData = await fetchImageContent(accessToken, imageId);
    res.set('Content-Type', 'image/jpeg');
    res.set('X-HATEOAS', JSON.stringify(makeLinks('/gigachat', { self: '/prompt' })));
    res.send(imageData);
  } catch (err) {
    console.error('AI生成图片出错: 未知错误', err);
    res.status(500).json({ error: err.message });
  }
};