index.js

#!/usr/bin/env node

import axios from "axios";
import boxen from "boxen";
import chalk from "chalk";
import { exec } from "child_process";
import { marked } from "marked";
import { markedTerminal } from "marked-terminal";
import readline from "readline";
import { promisify } from "util";
import yargs from "yargs";
import { hideBin } from "yargs/helpers";

// =============================================================================
// --- CONFIGURATION & CONSTANTS ---
// =============================================================================

const CONSTANTS = {
  API_URL: "https://openrouter.ai/api/v1/chat/completions",
  API_REFERER: "https://github.com/aaurelions/agent51",
  APP_TITLE: "Agent 51mpson",
  PROMPT_HEADER: "🍩: ",
  EXIT_COMMANDS: ["quit", "exit", "close"],
  HISTORY_MAX_MESSAGES: 20,
  HISTORY_TRIM_COUNT: 5,
  SYSTEM_PROMPT:
    "You are an AI assistant 'agent51' (Agent 51mpson, `51` like `SI`) with a Simpson-like personality. Say things like `D'oh!`, `Woo Hoo!`, `Aaargh!`, `¡Ay, caramba!`, and be awkwardly enthusiastic. For multi-step tasks, combine commands with && (e.g. `echo content > file.py && python3 file.py`). Use the provided `execute_command` function for all shell tasks. Answer questions briefly, accurately and in a quirky Simpson-like manner using markdown text formatting. Never run interactive scripts that require user input.",
};

/**
 * Static definition of the tool the AI can use.
 */
const EXECUTE_COMMAND_TOOL = {
  type: "function",
  function: {
    name: "execute_command",
    description: "Execute a shell command and return its output.",
    parameters: {
      type: "object",
      properties: {
        command: {
          type: "string",
          description: "The shell command to execute.",
        },
      },
      required: ["command"],
    },
  },
};

const config = {
  model: "qwen/qwen3-coder",
  temperature: 0.1,
  maxTokens: 1500,
  apiKey: process.env.OPENROUTER_API_KEY || process.env.OR_KEY || "",
  showCommand: true,
  showOutput: true,
  showAgent: true,
  apiTimeout: 60000, // 60 seconds
  commandTimeout: 15000, // 15 seconds
};

// =============================================================================
// --- AGENT STATE ---
// =============================================================================

const agent = {
  messages: [],
};

// =============================================================================
// --- UTILITIES & HELPERS ---
// =============================================================================

const execAsync = promisify(exec);

marked.setOptions({ breaks: true });
marked.use(markedTerminal());

/**
 * Normalizes newlines in a string for consistent output.
 * @param {string} text The input string.
 * @returns {string} The normalized string.
 */
const normalizeNewlines = (text) => {
  return text
    ? text.replace(/(\s*\r\n\s*|\s*\n\s*|\s*\r\s*)+/g, "\n").trim()
    : "";
};

// =============================================================================
// --- UI COMPONENTS ---
// =============================================================================

/**
 * Creates a base configuration object for a boxen box.
 * @returns {object} A base boxen configuration object.
 */
const getBaseBoxenOptions = () => ({
  padding: 1,
  borderStyle: "round",
  titleAlignment: "center",
  width: process.stdout.columns,
});

/**
 * Displays a formatted box in the terminal.
 * @param {string} content The text content to display inside the box.
 * @param {{title: string, color: string}} options The title and border color for the box.
 */
const displayBox = (content, { title, color }) => {
  console.log(
    boxen(content, {
      ...getBaseBoxenOptions(),
      borderColor: color,
      title: chalk.bold[color](title),
    })
  );
};

/**
 * Displays a formatted box for commands.
 * @param {string} command The command to display.
 */
const displayCommand = (command) => {
  if (config.showCommand) {
    displayBox(chalk.white(`$ ${command}`), { title: "Command", color: "red" });
  }
};

/**
 * Displays a formatted box for command output.
 * @param {string} output The output to display.
 */
const displayOutput = (output) => {
  if (config.showOutput) {
    displayBox(output, { title: "Output", color: "green" });
  }
};

/**
 * Displays a formatted box for the agent's final response.
 * @param {string} content The markdown content from the agent.
 */
const displayAgentResponse = (content) => {
  if (config.showAgent) {
    const finalContent = marked.parse(content).trim();
    displayBox(finalContent, { title: "Agent", color: "cyan" });
  }
};

/**
 * Displays a formatted error message.
 * @param {string} message The error message.
 * @param {string} [title="Error"] The title for the error box.
 */
const displayError = (message, title = "Error") => {
  displayBox(chalk.yellow(message), { title, color: "yellow" });
};

/**
 * Displays a formatted informational message.
 * @param {string} message The message to display.
 * @param {string} [title="Info"] The title for the box.
 */
const displayInfo = (message, title = "Info") => {
  displayBox(chalk.magenta(message), { title, color: "magenta" });
};

// =============================================================================
// --- CORE SERVICES ---
// =============================================================================

/**
 * Makes an API request to the OpenRouter service.
 * @param {object[]} messages The history of messages for the API call.
 * @returns {Promise<object>} The API response data.
 * @throws {Error} If the API request fails.
 */
async function openRouterRequest(messages) {
  const payload = {
    model: config.model,
    messages,
    temperature: config.temperature,
    max_tokens: config.maxTokens,
    stream: false,
    tool_choice: "auto",
    tools: [EXECUTE_COMMAND_TOOL],
  };

  try {
    const response = await axios.post(CONSTANTS.API_URL, payload, {
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${config.apiKey}`,
        "HTTP-Referer": CONSTANTS.API_REFERER,
        "X-Title": CONSTANTS.APP_TITLE,
      },
      timeout: config.apiTimeout,
    });
    return response.data;
  } catch (error) {
    const message = error.response?.data?.error?.message ?? error.message;
    const status = error.response?.status ? `${error.response.status} - ` : "";
    throw new Error(`API Request Failed: ${status}${message}`);
  }
}

/**
 * Extracts a command from the AI response and executes it.
 * @param {object} toolCall The tool_call object from the API response.
 * @returns {Promise<string>} The result of the command execution.
 */
async function executeShellCommand(toolCall) {
  if (toolCall?.function?.name !== "execute_command") {
    return "Invalid tool call. Aaargh!";
  }

  try {
    const { command } = JSON.parse(toolCall.function.arguments);
    if (!command) {
      return "No command provided. D'oh!";
    }

    displayCommand(command);

    const { stdout, stderr } = await execAsync(command, {
      timeout: config.commandTimeout,
    });

    const output =
      stdout || stderr || "Command executed successfully with no output.";
    const formattedOutput = normalizeNewlines(output);
    displayOutput(formattedOutput);
    return formattedOutput;
  } catch (error) {
    const errorMessage =
      error.signal === "SIGTERM"
        ? `Command timed out after ${
            config.commandTimeout / 1000
          } seconds. Aaargh!`
        : `Command execution failed: ${error.message}`;
    displayError(errorMessage);
    return `Error: ${errorMessage}`;
  }
}

// =============================================================================
// --- AGENT ORCHESTRATION ---
// =============================================================================

/**
 * Initializes the agent with a system prompt.
 */
function initAgent() {
  agent.messages.push({
    role: "system",
    content: CONSTANTS.SYSTEM_PROMPT,
  });
}

/**
 * Manages the conversation history to stay within limits.
 */
function manageHistory() {
  if (agent.messages.length >= CONSTANTS.HISTORY_MAX_MESSAGES) {
    // Remove oldest messages, keeping the system prompt at index 0
    agent.messages.splice(1, CONSTANTS.HISTORY_TRIM_COUNT);
  }
}

/**
 * Processes a single turn of the agent's logic.
 * @param {string} task The user's input task.
 */
async function processAgentTurn(task) {
  manageHistory();
  agent.messages.push({ role: "user", content: task });

  try {
    let response = await openRouterRequest(agent.messages);
    let message = response?.choices?.[0]?.message;

    if (message?.tool_calls) {
      const toolCall = message.tool_calls[0];
      agent.messages.push(message); // Add assistant's decision to use a tool

      const toolResult = await executeShellCommand(toolCall);

      agent.messages.push({
        role: "tool",
        tool_call_id: toolCall.id,
        name: toolCall.function.name,
        content: toolResult,
      });

      // Get the final response from the agent after the tool has run
      response = await openRouterRequest(agent.messages);
      message = response?.choices?.[0]?.message;
    }

    const content = message?.content;
    if (content) {
      displayAgentResponse(content);
      agent.messages.push({ role: "assistant", content });
    } else {
      displayError("The agent returned an empty response. D'oh!");
    }
  } catch (error) {
    displayError(error.message, "Agent Processing Error");
  }
}

// =============================================================================
// --- APPLICATION ENTRY POINT ---
// =============================================================================

/**
 * Parses command-line arguments and updates the application configuration.
 * @returns {string[]} Positional arguments from the command line.
 */
function setupConfigFromArgs() {
  const argv = yargs(hideBin(process.argv))
    .option("no-command", {
      alias: "c",
      type: "boolean",
      description: "Hides the executed shell command box.",
    })
    .option("no-output", {
      alias: "o",
      type: "boolean",
      description: "Hides the shell command's output box.",
    })
    .option("no-agent", {
      alias: "a",
      type: "boolean",
      description: "Hides the agent's final response box.",
    })
    .option("model", {
      alias: "m",
      type: "string",
      description: "Specify the OpenRouter model to use.",
    })
    .help()
    .alias("h", "help")
    .parse();

  if (typeof argv.command === "boolean") config.showCommand = argv.command;
  if (typeof argv.noCommand === "boolean") config.showCommand = !argv.noCommand;
  if (typeof argv.output === "boolean") config.showOutput = argv.output;
  if (typeof argv.noOutput === "boolean") config.showOutput = !argv.noOutput;
  if (typeof argv.agent === "boolean") config.showAgent = argv.agent;
  if (typeof argv.noAgent === "boolean") config.showAgent = !argv.noAgent;

  config.model = argv.model || process.env.OPENROUTER_MODEL || config.model;

  // Use argv._ for positional arguments, as shown in the yargs documentation
  return argv._;
}

/**
 * Runs the Command Line Interface for interactive sessions.
 */
function runCli() {
  console.log(
    boxen(chalk.cyan(CONSTANTS.APP_TITLE), {
      ...getBaseBoxenOptions(),
      title: "🍩",
      textAlignment: "center",
      borderColor: "magenta",
    })
  );

  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
  });

  rl.on("SIGINT", () => {
    displayInfo("D'oh! Stupid Flanders.", "Exit");
    rl.close();
  });

  const ask = () => {
    rl.question(chalk.cyan(CONSTANTS.PROMPT_HEADER), async (input) => {
      const command = input.trim();
      if (CONSTANTS.EXIT_COMMANDS.includes(command.toLowerCase())) {
        displayInfo("¡Ay, caramba!", "Exit");
        rl.close();
        return;
      }

      if (command) {
        rl.pause();
        await processAgentTurn(command);
        rl.resume();
      }

      ask();
    });
  };

  ask();
}

/**
 * Main application entry point.
 */
async function main() {
  if (!config.apiKey) {
    displayError(
      "OPENROUTER_API_KEY environment variable is required.",
      "Configuration Error"
    );
    process.exit(1);
  }

  const promptArgs = setupConfigFromArgs();

  initAgent();

  if (promptArgs.length > 0) {
    // Run in one-shot mode for a single task
    const task = promptArgs.join(" ");
    await processAgentTurn(task);
  } else {
    // Run in interactive CLI mode
    runCli();
  }
}

main().catch((error) => {
  displayError(`A critical error occurred: ${error.message}`, "Critical Error");
  process.exit(1);
});