Building a Chatbot based on Blockchain

---

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract Chatbot {

struct Message {

address sender;

string content;

}

Message[] public chatHistory;

event MessageSent(address sender, string content);

function sendMessage(string memory message) public {

Message memory newMessage = Message(msg.sender, message);

chatHistory.push(newMessage);

emit MessageSent(msg.sender, message);

}

function getChatHistoryLength() public view returns (uint) {

return chatHistory.length;

}

function getMessage(uint index) public view returns (address, string memory) {

require(index < chatHistory.length, "Invalid message index");

Message memory message = chatHistory[index];

return (message.sender, message.content);

}

}

const { ethers } = require("ethers");

const contractABI = require("./Chatbot.json"); // Contract ABI

const contractAddress = "0x002D7EF6B4Bd982eD4D05D56744401fbeC7703f4";

const provider = new ethers.JsonRpcProvider(

"https://sepolia.infura.io/v3/API_KEY"

);

const contract = new ethers.Contract(contractAddress, contractABI, provider);

async function contractEvents() {

contract.on("MessageSent", async (param1, param2, pair, amount, event) => {

const chatBotPrivateKey =

"";

const chatBotWallet = await connectWallet(chatBotPrivateKey);

await sendResponse(param1, param2, chatBotWallet);

});

}

async function connectWallet(walletPrivateKey) {

try {

const wallet = new ethers.Wallet(walletPrivateKey, provider);

const connectedWallet = wallet.connect(provider);

console.log("Wallet connected:", connectedWallet.address);

return connectedWallet;

} catch (error) {

console.error("Failed to connect with wallet:", error);

return null;

}

}

async function sendMessage(message, wallet) {

try {

const contractWithSigner = contract.connect(wallet);

const transaction = await contractWithSigner.sendMessage(message);

await transaction.wait();

console.log("Message sent to the blockchain:", transaction.hash);

} catch (error) {

console.error("Failed to send the message:", error);

}

}

async function sendResponse(param1, param2, chatBotWallet) {

if (param1 !== "0x06C2479D95AEe2C66e3369440A92EC0AA2885Ea0") {

if (param2.includes("Hello") || param2.includes("Hii")) {

try {

const contractWithSigner = contract.connect(chatBotWallet);

const transaction = await contractWithSigner.sendMessage(

"Hello! How can I assist you today?"

);

await transaction.wait();

console.log("Message sent to the blockchain:", transaction.hash);

} catch (error) {

console.error("Failed to send the message:", error);

}

} else {

try {

const contractWithSigner = contract.connect(chatBotWallet);

const transaction = await contractWithSigner.sendMessage(

"I'm sorry, but I'm having trouble understanding your message. It seems to be a random string of characters. If you have any specific questions or need assistance with something, please let me know, and I'll be happy to help!"

);

await transaction.wait();

console.log("Message sent to the blockchain:", transaction.hash);

} catch (error) {

console.error("Failed to send the message:", error);

}

}

}

}

async function main() {

const walletPrivateKey =

""; // Replace with your private key

const wallet = await connectWallet(walletPrivateKey);

if (wallet) {

await contractEvents();

await sendMessage("Hello, blockchain!", wallet);

}

}

main();