[ADD] Export survey to CSV

src/app/api/export/route.ts

@@ -0,0 +1,12 @@
+import { NextRequest, NextResponse } from "next/server";
+import { survey2csv } from "@/lib/firebase/export/exportSurvey";
+
+export async function POST(req: NextRequest) {
+    const body = await req.json();
+    try {
+        const csv = await survey2csv(body.surveyIds);
+        return NextResponse.json(csv, {status: 200}); 
+    } catch (err) {
+        return NextResponse.json({error: 'error creating csv file'}, {status: 500});
+    }
+}

src/lib/firebase/export/exportSurvey.ts

@@ -0,0 +1,73 @@
+import os from "os";
+import { db } from "../firebaseConfig";
+import { collection, query, where, getDocs } from "firebase/firestore";
+
+type flattenDoc = {
+    [key: string]: any
+}
+
+export async function survey2csv(surveyIds: string[]) {
+    const csv = [];
+    const surveyCollection = collection(db, "surveys");
+    const q = query(surveyCollection, where("formId", "in", surveyIds));
+    const snapshot = await getDocs(q);
+
+    // Define CSV fields and fix its order
+    const flattenDoc = flattenDocument(snapshot.docs[0].data(), []);
+    const fields = Object.keys(flattenDoc);
+    const idx = fields.indexOf("formId");
+    if (idx != 0) {
+        [fields[0], fields[idx]] = [fields[idx], fields[0]];
+    }
+    csv.push(fields.join(","));
+
+    // Fix the order of fields of map in items field
+    let itemsOrder: string[];
+    const items = snapshot.docs[0].data().items;
+    if (items.length > 0) {
+        const flattenItem = flattenDocument(items[0], []);
+        itemsOrder = Object.keys(flattenItem);
+    }
+
+    // For each document, create each row
+    snapshot.docs.map((doc) => {
+        const surveyDoc = doc.data();
+        const surveyDocFlatten = flattenDocument(surveyDoc, itemsOrder);
+        const survey = fields.map(field => {
+            return surveyDocFlatten[field];
+        });
+        csv.push(survey.join(","));
+    });
+
+    return csv.join(os.EOL);
+}
+
+function flattenDocument(obj: object, order: string[], prefix = '') {
+    let result: flattenDoc = {};
+
+    for (const [key, value] of Object.entries(obj)) {
+        const newKey = prefix ? `${prefix}.${key}` : key;
+        if (value !== null && typeof value === 'object' && !Array.isArray(value)) { 
+            Object.assign(result, flattenDocument(value, order, newKey));
+        } else if (Array.isArray(value)) {
+            result[newKey] = value.map((item) => {
+                if (typeof item === 'object') {
+                    const flatten = flattenDocument(item, order, '');
+                    const orderRevised: flattenDoc = {};
+                    order.forEach((field) => {
+                        if (field in flatten) {
+                            orderRevised[field] = flatten[field];
+                        }
+                    });
+                    return JSON.stringify(orderRevised).replace(",", "; ");
+                } else {
+                    return item.toString();
+                }
+            }).join(' | ');
+        } else {
+            result[newKey] = value;
+        }
+    }
+
+    return result;
+}