"use strict";
const superagent = require("superagent");
const http = require('http');
const https = require('https');
const crypto = require('crypto');
const { getFastGptToken } = require("../utils/fastgptToken");
const { buildFastgptEvents, reportUsage } = require('../services/dashboardReporter');

const ANONYMOUS_CLIENT_ANALYTICS = Object.freeze({
   'nanchangguidao-zay': {
      applicationId: 'ext-rail-transit-zay-chat',
      apiKeyId: 'fastgpt-nanchang-guidao-zay',
   },
       });

const getHeader = (ctx, name) => ctx.headers?.[name.toLowerCase()] || '';

const resolveAnalyticsApiKeyId = (config, appKey) => {
   const value = String(appKey || '').trim();
   if (!value) return '';
   try {
      const mapping = typeof config?.analytics?.fastgptKeyIds === 'string'
         ? JSON.parse(config.analytics.fastgptKeyIds)
         : config?.analytics?.fastgptKeyIds || {};
      const hash = crypto.createHash('sha256').update(value).digest('hex');
      return String(mapping[hash] || '').trim();
   } catch (error) {
      return '';
   }
};

const resolveAnalyticsUserId = (ctx) => String(getHeader(ctx, 'x-ai-center-user-id')).trim().slice(0, 64);

const parseSsePayload = (block) => {
   const lines = String(block).split(/\r?\n/);
   const event = lines.find((line) => line.startsWith('event:'))?.slice(6).trim() || '';
   const data = lines.filter((line) => line.startsWith('data:')).map((line) => line.slice(5).trim()).join('\n');
   if (!data || data === '[DONE]') return null;
   try { return { event, data: JSON.parse(data) }; } catch (error) { return null; }
};

const proxyFastgptStream = (ctx, { url, body, headers, applicationId, userId, apiKeyId, reportAnonymous = false }) => new Promise((resolve, reject) => {
   const target = new URL(url);
   const requestBody = JSON.stringify(body);
   const invocationId = crypto.randomUUID();
   const client = target.protocol === 'https:' ? https : http;
   const request = client.request({
      protocol: target.protocol, hostname: target.hostname, port: target.port,
      path: `${target.pathname}${target.search}`, method: 'POST',
      headers: { ...headers, 'Content-Length': Buffer.byteLength(requestBody), Accept: 'text/event-stream' },
   }, (response) => {
      const status = response.statusCode || 500;
      if (status < 200 || status >= 300) {
         const chunks = []; response.on('data', (chunk) => chunks.push(chunk));
         response.on('end', () => reject(new Error(Buffer.concat(chunks).toString('utf8') || 'FastGPT 请求失败')));
         return;
      }
      ctx.respond = false;
      ctx.res.writeHead(status, { 'Content-Type': response.headers['content-type'] || 'text/event-stream', 'Cache-Control': 'no-cache', Connection: 'keep-alive', 'X-Accel-Buffering': 'no' });
      let buffer = ''; let responseData = null;
      response.on('data', (chunk) => {
         const text = chunk.toString('utf8'); ctx.res.write(chunk); buffer += text;
         const blocks = buffer.split(/\n\n/); buffer = blocks.pop() || '';
         blocks.forEach((block) => {
            const payload = parseSsePayload(block);
            if (payload?.data?.responseData) responseData = payload.data.responseData;
            else if (payload?.event === 'flowResponses') responseData = payload.data;
         });
      });
      response.on('end', () => {
         const finalPayload = parseSsePayload(buffer);
         if (finalPayload?.data?.responseData) responseData = finalPayload.data.responseData;
         else if (finalPayload?.event === 'flowResponses') responseData = finalPayload.data;
         ctx.res.end();
         if (responseData && applicationId && (userId || reportAnonymous)) {
            const events = buildFastgptEvents({
               responseData, applicationId, userId, traceId: body.chatId,
               invocationId, occurredAt: new Date().toISOString(), apiKeyId,
            });
            reportUsage(ctx.app.fs.config, events, ctx.logger);
         }
         resolve();
      });
      response.on('error', reject);
   });
   request.on('error', reject);
   ctx.req.on('aborted', () => request.destroy());
   request.write(requestBody); request.end();
});
module.exports.token = async (ctx, next) => {
   try {
      const { status, forceRefresh } = ctx.request.query;
      const fastgptToken = await getFastGptToken(ctx.app.fs.config, forceRefresh === "true", status);
      ctx.status = 200;
      ctx.body = fastgptToken;
   } catch (error) {
      ctx.logger.log(error);
      ctx.status = 400;
      ctx.body = {
         message: typeof error == "string" ? error : "获取fastgpt Token失败",
      };
   }
};

module.exports.listDatasets = async (ctx, next) => {
   try {
      const config = ctx.app.fs.config.fastGpt;
      const apiUrl = config.apiUrl;
      // 使用应用 API key 
      const appKey = config.appKey || config.xiaoshangAppKey;
      const parentId = ctx.request.query.parentId || "";
      const res = await superagent
         .post(`${apiUrl}/api/core/dataset/list?parentId=${encodeURIComponent(parentId)}`)
         .set("Authorization", `Bearer ${appKey}`)
         .set("Content-Type", "application/json")
         .send({})
         .timeout(10000);
      const body = res.body || {};
      if (body.code === 200 && Array.isArray(body.data)) {
         ctx.body = body.data.map(d => ({ _id: d._id, name: d.name }));
      } else {
         ctx.body = [];
      }
      ctx.status = 200;
   } catch (error) {
      ctx.logger.log(error);
      ctx.status = 400;
      ctx.body = { message: "获取知识库列表失败" };
   }
};

module.exports.uploadToDataset = async (ctx, next) => {
   try {
      const { url, dataset_id, file_name, file_type } = ctx.request.body || {};
      if (!url || !dataset_id) {
         ctx.status = 400;
         ctx.body = { message: "缺少必要参数" };
         return;
      }

      const config = ctx.app.fs.config.fastGpt;
      const apiKey = config.appKey || config.xiaoshangAppKey;
      const apiUrl = config.apiUrl;

      // 1. 从 Qiniu 下载文件
      const fileResp = await superagent
         .get(url)
         .responseType("buffer")
         .timeout(30000);

      const fileName = file_name || `file.${file_type || "bin"}`;
      // URL 编码文件名，避免中文乱码
      const encodedFileName = encodeURIComponent(fileName);

      // 2. 上传到 FastGPT 知识库
      const uploadResp = await superagent
         .post(`${apiUrl}/api/core/dataset/collection/create/localFile`)
         .set("Authorization", `Bearer ${apiKey}`)
         .attach("file", fileResp.body, { filename: encodedFileName })
         .field("data", JSON.stringify({
            datasetId: dataset_id,
            parentId: null,
            trainingType: "chunk",
            chunkSize: 512,
         }))
         .timeout(60000);

      const body = uploadResp.body || {};
      if (body.code === 200) {
         ctx.body = { status: "success", collectionId: body.data?.collectionId };
      } else {
         ctx.status = 400;
         ctx.body = { message: body.message || "上传到知识库失败" };
      }
   } catch (error) {
      ctx.logger.log(error);
      ctx.status = 400;
      ctx.body = { message: "上传到知识库失败" };
   }
};

module.exports.getConfig = async (ctx, next) => {
   try {
      const { clientId } = ctx.request.query;
      const { fsAiClient } = ctx.app.fs.config;
      if (!clientId || !fsAiClient[clientId]) {
         throw "clientId不合法";
      }
      ctx.status = 200;
      ctx.body = fsAiClient[clientId];
   } catch (error) {
      ctx.logger.log(error);
      ctx.status = 400;
      ctx.body = {
         message: typeof error == "string" ? error : "获取client配置失败",
      };
   }
};

module.exports.chat = async (ctx, next) => {
   try {
      const { clientId, appKey, analyticsApplicationId } = ctx.request.query;
      const { fsAiClient } = ctx.app.fs.config;
      const body = ctx.request.body;
      if (!clientId || !fsAiClient[clientId]) {
         throw "clientId不合法";
      }
      if (fsAiClient[clientId].identity && body) {
         if (body.variables) {
            body.variables.identity = fsAiClient[clientId].identity;
         } else {
            body.variables = { identity: fsAiClient[clientId].identity };
         }
      }
      body.detail = true;
      const anonymousAnalytics = ANONYMOUS_CLIENT_ANALYTICS[clientId];
      const userId = anonymousAnalytics ? '' : resolveAnalyticsUserId(ctx);
      // Public clients must use their server-configured App Key. Browser query
      // parameters must not be able to change the reported API Key ownership.
      const effectiveAppKey = String(anonymousAnalytics ? fsAiClient[clientId].appKey : (appKey || fsAiClient[clientId].appKey || '')).trim();
      await proxyFastgptStream(ctx, {
          url: `${ctx.app.fs.config.fastGpt.apiUrl}/api/v1/chat/completions`, body,
          headers: { Authorization: `Bearer ${effectiveAppKey}`, 'Content-Type': 'application/json' },
          applicationId: anonymousAnalytics?.applicationId || String(analyticsApplicationId || 'superagent-chat'), userId,
          apiKeyId: anonymousAnalytics?.apiKeyId || resolveAnalyticsApiKeyId(ctx.app.fs.config, effectiveAppKey),
          reportAnonymous: Boolean(anonymousAnalytics),
       });
   } catch (error) {
      ctx.logger.log(error);
      ctx.status = 400;
      ctx.body = {
         message: typeof error == "string" ? error : "chat失败",
      };
   }
};

// The industry-plan page used to send its FastGPT key from the browser. Keep
// the key server-side and reuse the audited streaming proxy instead.
module.exports.solutionChat = async (ctx, next) => {
   try {
      const body = ctx.request.body || {};
      body.detail = true;
      const userId = resolveAnalyticsUserId(ctx);
      const appKey = String(ctx.app.fs.config.fastGpt?.solutionAppKey || '').trim();
      if (!appKey) throw '未配置 fastGpt.solutionAppKey';
      await proxyFastgptStream(ctx, {
         url: `${ctx.app.fs.config.fastGpt.apiUrl}/api/v1/chat/completions`, body,
         headers: { Authorization: `Bearer ${appKey}`, 'Content-Type': 'application/json' },
         applicationId: 'stable-industry', userId,
         apiKeyId: resolveAnalyticsApiKeyId(ctx.app.fs.config, appKey),
      });
   } catch (error) {
      ctx.logger.log(error);
      ctx.status = 400;
      ctx.body = { message: typeof error === 'string' ? error : '行业方案对话失败' };
   }
};

module.exports.solutionQuoteData = async (ctx, next) => {
   try {
      const quoteId = String(ctx.request.body?.id || '').trim();
      const appKey = String(ctx.app.fs.config.fastGpt?.solutionAppKey || '').trim();
      if (!quoteId) throw '缺少引用 ID';
      if (!appKey) throw '未配置 fastGpt.solutionAppKey';
      const res = await superagent
         .post(`${ctx.app.fs.config.fastGpt.apiUrl}/api/core/dataset/data/getQuoteData`)
         .send({ id: quoteId })
         .set({ Authorization: `Bearer ${appKey}`, 'Content-Type': 'application/json' })
         .timeout(10000);
      ctx.status = res.status || 200;
      ctx.body = res.body;
   } catch (error) {
      ctx.logger.log(error);
      ctx.status = error?.status || error?.response?.status || 400;
      ctx.body = error?.response?.body || { message: typeof error === 'string' ? error : '获取引用详情失败' };
   }
};