server.js

const express = require("express");
const app = express();
const bodyParser = require("body-parser");
const training = require("./training.js");
const axios = require('axios').default;
const {NlpManager} = require('node-nlp');

const manager = new NlpManager({languages: ['en'], nlu: {useNoneFeature: false}});

const knex = require("knex")({
    client: "pg",
    searchPath: ["hack_21_0ui"],
    connection: {
        database: "hack_21_0ui",
        host: "hack-21-0ui-1.cbh1nk2bl81k.ap-southeast-2.rds.amazonaws.com",
        port: 5432,
        user: "postgres",
        password: "uB7mUnQ2xRdrTl",
    }
})

training(manager);

app.use(bodyParser.json({limit: "5mb"}));

app.get("/", ((req, res) => {
        const response = manager.process('en', req.query.q).then(res => {
            // select conversation_id = 1 from chat_state


            let row = knex("chat_state").select('*').where('conversation_id', 'xxxxxxxx').then(res => {
                console.log(res);
            }).catch(err => {
                console.log(err);
            })
        });

        // send response hello world
        res.send("Hello World");
    }
));

app.post("/", async (req, res) => {
    const body = req.body;
    const senderId = body.data.message.senderId;
    const options = {weekday: 'long', year: 'numeric', month: 'long', day: 'numeric'};
    let incomingMessageText = body.data.message.text;

    if (senderId === "1") {
        console.log('this stopped')
        return;
    }
    let row = await knex("chat_state").select('*').where('conversation_id', body.data.message.conversationId);
    if (row.length === 0) {
        // get random from 10 to 20
        let random = Math.floor(Math.random() * 10) + 10;
        let data = {
            leave: random
        }
        await knex("chat_state").insert({conversation_id: body.data.message.conversationId, data: data});
        row = await knex("chat_state").select('*').where('conversation_id', body.data.message.conversationId);
        console.log(row);
    }
    row = row[0];

    console.log(row);

    console.log(incomingMessageText);
    incomingMessageText = incomingMessageText.toLowerCase();


    if (incomingMessageText.includes("apply") && incomingMessageText.includes("leave")) {
        const res = await manager.process('en', incomingMessageText);
        let startDate = false;
        let endDate = false;
        let days = false;
        for (let entity in res.entities) {
            if (res.entities[entity].entity === 'daterange') {
                console.log(res.entities[entity].entity);
                startDate = new Date(res.entities[entity].resolution.start).toLocaleDateString("en-AU", options);
                endDate = new Date(res.entities[entity].resolution.end).toLocaleDateString("en-AU", options);

                // exclude weekends
                let start = new Date(res.entities[entity].resolution.start);
                let end = new Date(res.entities[entity].resolution.end);
                let count = 0;
                while (start <= end) {
                    if (start.getDay() !== 0 && start.getDay() !== 6) {
                        count++;
                    }
                    start.setDate(start.getDate() + 1);
                }
                days = count;
            }
        }

        if (!startDate) {
            return answerMessage("Did you mean to apply for leave? I didn't understand your date range", body);
        }

        // get difference between start and end date

        console.log(days);

        if (row.data.leave >= days) {
            // update leave
            let newLeave = row.data.leave - days;
            row.data.pendingLeave = newLeave;
            row.data.lastMessage = 'apply';

            await knex("chat_state").update({data: row.data}).where('conversation_id', row.conversation_id);
            //await knex("chat_state").update({data: {leave: newLeave}}).where('conversation_id', body.data.message.conversationId);
            // send response
            return answerMessage("Do you want to apply for leave from "
                + startDate + " to " + endDate + "? This will take a total of " + days
                + " days from your current leave, leaving you with a leave balance of " + newLeave + " days", body);
        } else {
            return answerMessage("You don't have enough leave to fulfill your request, your current leave balance is " + row.data.leave + " days", body);
        }
    }

    if (incomingMessageText.includes("yes") && row.data.lastMessage === 'apply') {
        row.data.leave = row.data.pendingLeave;
        row.data.pendingLeave = null;
        row.data.lastMessage = null;

        await knex("chat_state").update({data: row.data}).where('conversation_id', row.conversation_id);
        answerMessage("Awesome, your leave is applied, I hope you have a great time, your resulting leave balance is: NULL days", body);
        // timeout for 2 seconds
        setTimeout(() => {
            answerMessage("Just kidding you have still " + row.data.leave + " days of leave 😀", body);
        }, 3000);

        return;
    }

    if (incomingMessageText.includes("no") && row.data.lastMessage === 'apply') {
        return answerMessage("Oh I must have misunderstood something, you can try again anytime you like", body);
    }

    if ((incomingMessageText.includes("what") || incomingMessageText.includes("how much")) && incomingMessageText.includes("leave")) {
        return answerMessage('Your leave balance is: ' + row.data.leave + " days", body);
    }

    if ((incomingMessageText.includes("paid") || incomingMessageText.includes("pay") || incomingMessageText.includes("salary"))
        && incomingMessageText.includes("when")
    ) {
        return answerMessage('Your next payment is due at 24th of December', body);
    }

    if ((incomingMessageText.includes("paid") || incomingMessageText.includes("pay") || incomingMessageText.includes("salary"))
        && incomingMessageText.includes("how much")
    ) {
        return answerMessage('Your payment will be a total $100.000 and will be deposited on your account at 24th of December', body);
    }

    return answerMessage(
        "Sorry I didn't understand that, I can help you check your leave balance or apply for leave or check when is your next payment due",
        body
    );

    function answerMessage(text, body) {
        axios.post("https://api.talkjs.com/v1/" + process.env.TALK_JS_APP_ID + "/conversations/" + body.data.message.conversationId + "/messages", [
            {
                "text": text,
                "sender": "1",
                "type": "UserMessage"
            }
        ], {
            headers: {
                'Authorization': 'Bearer ' + process.env.TALK_JS_API_TOKEN,
                'Content-Type': 'application/json'
            }
        }).then(response => {
            console.log(response.data);
            res.send(response.data);
        }).catch(error => {
            console.log(error);
            res.send(error);
        });
    }


})

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => console.log(`Sever listening at http://localhost:${PORT}`));