#!/usr/bin/env node
// DeepSeek CLI (Node.js version)
// Commands:
//   ds k <key>        设置/替换 API Key
//   ds s <prompt>     设置 system prompt
//   ds v              查看当前 prompt
//   ds c <text>       使用 deepseek-chat（流式）
//   ds r <text>       使用 deepseek-reasoner（流式，含思考）

import fs from 'fs';
import os from 'os';
import path from 'path';
import { TextDecoder } from 'util';

const CONFIG_DIR = path.join(os.homedir(), '.config', 'deepseek');
const CONFIG_FILE = path.join(CONFIG_DIR, 'config.json');
const DEFAULT_PROMPT = '你是Deepseek人工智能助手';

function ensureConfig() {
  if (!fs.existsSync(CONFIG_DIR)) fs.mkdirSync(CONFIG_DIR, { recursive: true });
  if (!fs.existsSync(CONFIG_FILE)) {
    fs.writeFileSync(CONFIG_FILE, JSON.stringify({ api_key: '', system_prompt: DEFAULT_PROMPT }, null, 2), 'utf8');
    fs.chmodSync(CONFIG_FILE, 0o600);
  }
}

function readConfig() {
  ensureConfig();
  try {
    const raw = fs.readFileSync(CONFIG_FILE, 'utf8');
    const data = JSON.parse(raw);
    return {
      apiKey: data.api_key || '',
      prompt: data.system_prompt || DEFAULT_PROMPT,
    };
  } catch {
    return { apiKey: '', prompt: DEFAULT_PROMPT };
  }
}

function saveConfig(apiKey, prompt) {
  ensureConfig();
  fs.writeFileSync(CONFIG_FILE, JSON.stringify({ api_key: apiKey, system_prompt: prompt }, null, 2), 'utf8');
  fs.chmodSync(CONFIG_FILE, 0o600);
}

function usage() {
  console.log(`用法:
  ds k <key>        设置/替换 API 密钥
  ds s <prompt>     设置系统提示词
  ds v              查看当前提示词
  ds c <text>       使用 deepseek-chat（流式）
  ds r <text>       使用 deepseek-reasoner（流式，含思考）
环境优先级: 命令行 > 环境变量 DEEPSEEK_API_KEY > 配置文件
默认模型: deepseek-reasoner`);
  process.exit(1);
}

const args = process.argv.slice(2);
if (args.length === 0 || ['-h', '--help'].includes(args[0])) usage();
const cmd = args.shift();

// ANSI blue for **bold**
const BLUE = '\x1b[34m';
const RESET = '\x1b[0m';
let inBold = false;
function renderChunk(text) {
  let out = '';
  for (let i = 0; i < text.length; i++) {
    if (text[i] === '*' && text[i + 1] === '*') {
      inBold = !inBold;
      out += inBold ? BLUE : RESET;
      i++;
      continue;
    }
    out += text[i];
  }
  return out;
}

async function streamChat({ model, apiKey, prompt, userInput }) {
  const body = {
    model,
    messages: [
      { role: 'system', content: prompt },
      { role: 'user', content: userInput },
    ],
    stream: true,
  };

  const res = await fetch('https://api.deepseek.com/chat/completions', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      Authorization: `Bearer ${apiKey}`,
    },
    body: JSON.stringify(body),
  });

  if (!res.ok) {
    const t = await res.text();
    console.error(`请求失败 ${res.status}: ${t}`);
    process.exit(1);
  }

  const decoder = new TextDecoder();
  let buffer = '';
  let sawReason = false;
  let sawContent = false;
  const enableReason = model === 'deepseek-reasoner';

  process.stdout.write(`发送中 (模型: ${model})...\n`);

  for await (const chunk of res.body) {
    buffer += decoder.decode(chunk, { stream: true });
    let lines = buffer.split(/\r?\n/);
    buffer = lines.pop(); // keep incomplete line
    for (const line of lines) {
      if (!line.startsWith('data: ')) continue;
      const data = line.slice(6);
      if (data === '[DONE]') {
        process.stdout.write('\n');
        return;
      }
      let delta;
      try {
        delta = JSON.parse(data)?.choices?.[0]?.delta || {};
      } catch {
        continue;
      }
      const rc = delta.reasoning_content || '';
      const ct = delta.content || '';

      if (enableReason && rc) {
        if (!sawReason) {
          process.stdout.write('思考：\n');
          sawReason = true;
        }
        process.stdout.write(renderChunk(rc));
      }

      if (ct) {
        if (!sawContent) {
          if (sawReason) process.stdout.write('\n\n');
          process.stdout.write('回复：\n');
          sawContent = true;
        }
        process.stdout.write(renderChunk(ct));
      }
    }
  }
  process.stdout.write('\n');
}

(async () => {
  switch (cmd) {
    case 'k': {
      if (args.length < 1) {
        console.error('请输入密钥');
        process.exit(1);
      }
      const cfg = readConfig();
      saveConfig(args[0], cfg.prompt);
      console.log(`API 密钥已保存到 ${CONFIG_FILE}`);
      break;
    }
    case 's': {
      if (args.length < 1) {
        console.error('请输入新的 system prompt');
        process.exit(1);
      }
      const cfg = readConfig();
      const prompt = args.join(' ');
      saveConfig(cfg.apiKey, prompt);
      console.log('system prompt 已更新。');
      break;
    }
    case 'v': {
      const cfg = readConfig();
      console.log('当前 system prompt:');
      console.log(cfg.prompt);
      break;
    }
    case 'c':
    case 'r': {
      if (args.length < 1) {
        console.error('请输入要发送的内容');
        process.exit(1);
      }
      const userInput = args.join(' ');
      const cfg = readConfig();
      const apiKey = process.env.DEEPSEEK_API_KEY || cfg.apiKey;
      if (!apiKey) {
        console.error('未设置 API 密钥，请先运行: ds k <key> 或设置环境变量 DEEPSEEK_API_KEY');
        process.exit(1);
      }
      const model = cmd === 'c' ? 'deepseek-chat' : 'deepseek-reasoner';
      await streamChat({ model, apiKey, prompt: cfg.prompt, userInput });
      break;
    }
    default:
      usage();
  }
})();