Сервис получения графика через chartjs-image

2025-02-23 20:51:25 +03:00 · 2024-08-02 15:41:16 +03:00 · 2024-08-02 15:41:16 +03:00 · 01aa886943
commit 01aa886943
parent 6d241ffd11
4 changed files with 134 additions and 0 deletions
--- a/chart/main.js
+++ b/chart/main.js
@ -0,0 +1,67 @@
+const ChartJSImage = require('chart.js-image');
+const pool = require('../database/postgresql.js');
+
+async function gen_chart(from_currency, conv_currency, start_date, end_date) {
+    const data = await pool.query('SELECT date, rate FROM currency WHERE ' +
+        '(date BETWEEN $3 AND $4) AND from_currency = $1 AND conv_currency = $2 ORDER BY date ', [
+        from_currency.toUpperCase(),
+        conv_currency.toUpperCase(),
+        start_date,
+        end_date
+    ]);
+
+    if (!data) return new Error('Missing data');
+
+    const date = [];
+    const rate = [];
+
+    for (let i = 0; i < data.rows.length; i++) {
+        date.push(data.rows[i].date.toLocaleDateString());
+        rate.push(data.rows[i].rate);
+    }
+
+    const chart = ChartJSImage().chart({
+        type: 'line',
+        options: {
+              title: {
+                  display: true,
+                  text: `${from_currency} / ${conv_currency}`,
+              },
+        },
+        data: {
+            labels: date,
+            datasets: [
+                {
+                    label: 'rate',
+                    borderColor: rate[rate.length-2] < rate[rate.length-1] ? 'rgb(24, 218, 39)' : 'rgb(243, 85, 50)',
+                    backgroundColor:  rate[rate.length-2] < rate[rate.length-1] ? 'rgb(36, 175, 47)' : 'rgb(218, 56, 24)',
+                    data: rate,
+                    borderWidth: 2,
+                },
+            ],
+        },
+        scales: {
+           xAxes: [
+               {
+                   scaleLabel: {
+                       display: true,
+                       labelString: 'Day'
+                   },
+               },
+           ],
+            yAxes: [
+                {
+                    stacked: false,
+                    scaleLabel: {
+                        display: true,
+                        labelString: 'Rate'
+                    },
+                },
+            ],
+        },
+    }).width(1000).height(1000);
+
+    return chart.toURL();
+}
+
+module.exports = { gen_chart }