import type { NextApiRequest } from 'next';
import crypto from 'crypto';
import jwt from 'jsonwebtoken';
import { ChatItemType } from '@/types/chat';
import { encode } from 'gpt-token-utils';
import { OpenApi, User } from '../mongo';
import { formatPrice } from '@/utils/user';
import { ERROR_ENUM } from '../errorCode';

/* 密码加密 */
export const hashPassword = (psw: string) => {
  return crypto.createHash('sha256').update(psw).digest('hex');
};

/* 生成 token */
export const generateToken = (userId: string) => {
  const key = process.env.TOKEN_KEY as string;
  const token = jwt.sign(
    {
      userId,
      exp: Math.floor(Date.now() / 1000) + 60 * 60 * 24 * 7
    },
    key
  );
  return token;
};

/* 校验 token */
export const authToken = (token?: string): Promise<string> => {
  return new Promise((resolve, reject) => {
    if (!token) {
      reject('缺少登录凭证');
      return;
    }
    const key = process.env.TOKEN_KEY as string;

    jwt.verify(token, key, function (err, decoded: any) {
      if (err || !decoded?.userId) {
        reject('凭证无效');
        return;
      }
      resolve(decoded.userId);
    });
  });
};

/* 校验 open api key */
export const authOpenApiKey = async (req: NextApiRequest) => {
  const { apikey: apiKey } = req.headers;

  if (!apiKey) {
    return Promise.reject(ERROR_ENUM.unAuthorization);
  }

  try {
    const openApi = await OpenApi.findOne({ apiKey });
    if (!openApi) {
      return Promise.reject(ERROR_ENUM.unAuthorization);
    }
    const userId = String(openApi.userId);

    // 余额校验
    const user = await User.findById(userId);
    if (!user) {
      return Promise.reject(ERROR_ENUM.unAuthorization);
    }
    if (formatPrice(user.balance) <= 0) {
      return Promise.reject('Insufficient account balance');
    }

    // 更新使用的时间
    await OpenApi.findByIdAndUpdate(openApi._id, {
      lastUsedTime: new Date()
    });

    return {
      apiKey: process.env.OPENAIKEY as string,
      userId
    };
  } catch (error) {
    return Promise.reject(error);
  }
};

/* 代理 */
export const httpsAgent = (fast: boolean) =>
  fast ? global.httpsAgentFast : global.httpsAgentNormal;

/* tokens 截断 */
export const openaiChatFilter = (prompts: ChatItemType[], maxTokens: number) => {
  const formatPrompts = prompts.map((item) => ({
    obj: item.obj,
    value: item.value
      // .replace(/[\u3000\u3001\uff01-\uff5e\u3002]/g, ' ') // 中文标点改空格
      .replace(/\n+/g, '\n') // 连续空行
      .replace(/[^\S\r\n]+/g, ' ') // 连续空白内容
      .trim()
  }));

  let res: ChatItemType[] = [];

  let systemPrompt: ChatItemType | null = null;

  //  System 词保留
  if (formatPrompts[0]?.obj === 'SYSTEM') {
    systemPrompt = formatPrompts.shift() as ChatItemType;
    maxTokens -= encode(formatPrompts[0].value).length;
  }

  // 从后往前截取
  for (let i = formatPrompts.length - 1; i >= 0; i--) {
    const tokens = encode(formatPrompts[i].value).length;
    res.unshift(formatPrompts[i]);
    /* 整体 tokens 超出范围 */
    if (tokens >= maxTokens) {
      break;
    }

    maxTokens -= tokens;
  }

  return systemPrompt ? [systemPrompt, ...res] : res;
};

/* system 内容截断 */
export const systemPromptFilter = (prompts: string[], maxTokens: number) => {
  let splitText = '';

  // 从前往前截取
  for (let i = 0; i < prompts.length; i++) {
    const prompt = prompts[i];

    splitText += `${prompt}\n`;
    const tokens = encode(splitText).length;
    if (tokens >= maxTokens) {
      break;
    }
  }

  return splitText.slice(0, splitText.length - 1);
};