feat: Added support for coinmarketcap service for collecting cryptocurrency currency rate

config.sample.hjson

@@ -5,7 +5,7 @@
         name: DATABASE_NAME
         password: DATABASE_PASSWORD
     }
-    currecy: {
+    currency: {
         collecting: {
             fiat: true
             crypto: false
@@ -27,6 +27,9 @@
             USDT,
             TON
         ]
+        api_keys: {
+            coinmarketcap: TOKEN_COINMARKETCAP
+        }
     }
     schedule: 30 8 * * *
 }

database/data.js

@@ -1,8 +1,6 @@
 const pg = require('pg');
 const fs = require('fs');
-const hjson = require('hjson');
+const config = require('../utils/load_config.js')();
-
-const config = hjson.parse(fs.readFileSync('config.hjson', 'utf-8'));
 
 const pool = new pg.Pool({
   user: config['database']['user'],

main.js

@@ -1,12 +1,11 @@
 const fs = require('fs');
 const path = require('path');
-const hjson = require('hjson');
 const schedule = require('node-schedule');
 const cron = require('cron-validator');
 
 const { validateCurrency } = require('./models/Currency.js');
 const { create_table, pool } = require('./database/data.js');
-const config = hjson.parse(fs.readFileSync('config.hjson', 'utf-8'));
+const config = require('./utils/load_config.js')();
 
 async function main() {
     if (!config['schedule']) 
@@ -34,29 +33,29 @@ async function main() {
         console.log('Running scheduled task at:', new Date());
 
         for (const srv of services) {
-            try {
+            const results = await srv.parseCurrencies();
-                const result = await srv.parseCurrencies();
+
-  
+            if (Array.isArray(results) && results.length > 0) {
-                if (result) {
+                for (const result of results) {
                     try {
                         const currency = await validateCurrency(result);
-
+            
                         await pool.query(
-                            'INSERT INTO currency (from_currency, conv_currency, rate, date) ' +
+                            'INSERT INTO currency (from_currency, conv_currency, rate, date) VALUES ($1, $2, $3, $4)', 
-                            'VALUES ($1, $2, $3, $4)', 
                             [
                                 currency.from_currency,
                                 currency.conv_currency,
                                 currency.rate,
                                 currency.date,
-                            ]);
+                            ]
+                        );
                     } catch (validationError) {
                         console.error(validationError);
                     }
                 }
-            } catch (err) {
+            } else {
-                console.error(`Error in service ${srv.name || 'unknown'}:`, err);
+                console.error("Data not received for writing to the database.");
-            }
+            }            
         }
     });
 

models/Currency.js

@@ -1,14 +1,16 @@
 const Joi = require('joi');
 
 const currencySchema = Joi.object({
-    from_currency: Joi.string().length(3).required().messages({
+    from_currency: Joi.string().min(3).max(4).required().messages({
         'string.base': 'from_currency must be a string',
-        'string.length': 'from_currency must be exactly 3 characters long',
+        'string.min': 'from_currency must be at least 3 characters long',
+        'string.max': 'from_currency must be no more than 4 characters long',
         'any.required': 'from_currency is required'
     }),
-    conv_currency: Joi.string().length(3).required().messages({
+    conv_currency: Joi.string().min(3).max(4).required().messages({
         'string.base': 'conv_currency must be a string',
-        'string.length': 'conv_currency must be exactly 3 characters long',
+        'string.min': 'conv_currency must be at least 3 characters long',
+        'string.max': 'conv_currency must be no more than 4 characters long',
         'any.required': 'conv_currency is required'
     }),
     date: Joi.date().iso().required().messages({

services/coinmarketcap.js

@@ -0,0 +1,47 @@
+const axios = require('axios');
+const config = require('../utils/load_config.js')();
+const { truncate_number } = require('../utils/truncate_number.js');
+
+module.exports = {
+    parseCurrencies: async () => {
+        const promises = config['currency']['crypto'].map(fromCurrency => {
+            return config['currency']['crypto'].map(convCurrency => {
+                if (fromCurrency === convCurrency) return Promise.resolve(null);
+
+                return axios.get(
+                    'https://pro-api.coinmarketcap.com/v1/cryptocurrency/quotes/latest',
+                    {
+                        params: {
+                            symbol: fromCurrency,
+                            convert: convCurrency,
+                        },
+                        headers: {
+                            'X-CMC_PRO_API_KEY': config['currency']['api_keys']['coinmarketcap'],
+                        }
+                    }
+                )
+                .then((res) => {
+                    const data = res.data.data[fromCurrency].quote[convCurrency];
+                    const truncatedPriceStr = truncate_number(data.price, 3);
+                    const rate = parseFloat(truncatedPriceStr);
+
+                    return {
+                        from_currency: fromCurrency,
+                        conv_currency: convCurrency,
+                        rate: rate,
+                        date: new Date(data['last_updated']).toISOString().substring(0, 10),
+                    };
+                })
+                .catch((err) => {
+                    console.error(err.respone.data);
+                    return null;
+                });
+            });
+        });
+
+        const flattenedPromises = promises.flat();
+        const results = await Promise.all(flattenedPromises);
+
+        return results.filter(result => result !== null);
+    }
+};

utils/load_config.js

@@ -0,0 +1,10 @@
+const fs = require('fs');
+const hjson = require('hjson');
+
+const config = () => {
+    if (!fs.existsSync('../config.hjson')) throw new Error('Config not found');
+
+    return hjson.parse(fs.readFileSync('../config.hjson', 'utf-8'));
+}
+
+module.exports = config;

utils/truncate_number.js

@@ -0,0 +1,14 @@
+function truncate_number(value, decimals) {
+  const valueStr = value.toString();
+  const dotIndex = valueStr.indexOf('.');
+  if (dotIndex === -1) return valueStr;
+  const desiredLength = dotIndex + decimals + 1;
+  let truncated = valueStr.slice(0, desiredLength);
+
+  if (parseFloat(truncated) === 0 && value > 0) {
+      return valueStr;
+  }
+  return truncated;
+}
+
+module.exports = { truncate_number };