first commit

backend/index.js

@@ -0,0 +1,119 @@
+const path = "./csv";
+const data = {};
+const column = {};
+let files = [];
+
+const fs = require("fs");
+const papa = require("papaparse");
+const chokidar = require("chokidar");
+
+chokidar.watch(path).on("all", () => {
+    console.log("File changed. Reloading ...");
+    files = fs.readdirSync(`${path}`).filter((file) => file.endsWith(".csv"));
+    for (const file of files) {
+        const csv = fs.readFileSync(`${path}/${file}`, {
+            encoding: "utf8",
+        });
+        const parsed = papa.parse(csv, {
+            skipEmptyLines: true,
+        }).data;
+
+        const header = parsed[0];
+        column[file] = [];
+        for (const h of header) {
+            column[file].push({
+                key: h,
+                text: h,
+                sorting: "",
+            });
+        }
+
+        const converted = [];
+        for (let j = 1; j < parsed.length; ++j) {
+            const d = parsed[j];
+            const e = {};
+            for (let i = 0; i < d.length; ++i) {
+                e[header[i]] = d[i];
+            }
+            converted.push(e);
+        }
+        data[file] = converted;
+    }
+});
+
+const express = require("express");
+
+const app = express();
+
+const cors = require("cors");
+
+app.use(cors());
+
+const port = 3000;
+
+app.get("/files", (_, res) => {
+    res.send(files);
+});
+
+function compare(a, b) {
+    const m = a - b;
+    if (isNaN(m)) {
+        if (a > b) {
+            return 1;
+        }
+        if (a < b) {
+            return -1;
+        }
+        return 0;
+    }
+    return m;
+}
+
+app.get("/csv/:file", (req, res) => {
+    const {
+        file
+    } = req.params;
+    const raw = data[file];
+    const col = column[file];
+    let processed = raw;
+    let query_key = "";
+    let key = "";
+
+    const c = col.find((ele) => {
+        key = ele.key;
+        query_key = `sort_${key}`;
+        return query_key in req.query;
+    });
+    if (!(c === "undefined")) {
+        processed = [...raw];
+        if (req.query[query_key] == "ASC") {
+            processed.sort((a, b) => compare(a[key], b[key]));
+        } else {
+            processed.sort((a, b) => compare(b[key], a[key]));
+        }
+    }
+
+    if ("pSize" in req.query && "cPage" in req.query) {
+        const size = req.query.pSize;
+        const page = req.query.cPage;
+        processed = processed.slice((page - 1) * size, page * size);
+    }
+
+    res.send({
+        totals: raw.length,
+        data: processed,
+    });
+});
+
+app.use(express.static("public"));
+
+app.get("/column/:file", (req, res) => {
+    const {
+        file
+    } = req.params;
+    res.send(column[file]);
+});
+
+app.listen(port, () => {
+    console.log(`Listening at http://localhost:${port}`);
+});