Create rudimentary poll backend

This is currently untested, but the backend allows creating a new poll,
getting results of an existing poll, voting and retrieving info of a
poll for display purposes.
Recaptcha is not yet implemented at this stage.

.gitignore

@@ -110,4 +110,6 @@ testing/
 *.sqlite
 *.sqlite3
 *.db
-*.db3
+*.db3
+# Data directory
+data/

package-lock.json

@@ -11,16 +11,20 @@
       "dependencies": {
         "commander": "^8.3.0",
         "compression": "^1.7.4",
-        "express": "^4.17.2"
+        "cookie-parser": "^1.4.6",
+        "express": "^4.17.2",
+        "node-persist": "^3.1.0"
       },
       "devDependencies": {
         "@types/chai": "^4.2.22",
         "@types/chai-as-promised": "^7.1.4",
         "@types/compression": "^1.7.2",
+        "@types/cookie-parser": "^1.4.2",
         "@types/express": "^4.17.13",
         "@types/fs-extra": "^9.0.13",
         "@types/mocha": "^9.0.0",
         "@types/node": "^16.11.10",
+        "@types/node-persist": "^3.1.2",
         "@typescript-eslint/eslint-plugin": "^5.4.0",
         "@typescript-eslint/parser": "^5.4.0",
         "chai": "^4.3.4",
@@ -199,6 +203,15 @@
         "@types/node": "*"
       }
     },
+    "node_modules/@types/cookie-parser": {
+      "version": "1.4.2",
+      "resolved": "https://registry.npmjs.org/@types/cookie-parser/-/cookie-parser-1.4.2.tgz",
+      "integrity": "sha512-uwcY8m6SDQqciHsqcKDGbo10GdasYsPCYkH3hVegj9qAah6pX5HivOnOuI3WYmyQMnOATV39zv/Ybs0bC/6iVg==",
+      "dev": true,
+      "dependencies": {
+        "@types/express": "*"
+      }
+    },
     "node_modules/@types/express": {
       "version": "4.17.13",
       "resolved": "https://registry.npmjs.org/@types/express/-/express-4.17.13.tgz",
@@ -255,6 +268,15 @@
       "integrity": "sha512-3aRnHa1KlOEEhJ6+CvyHKK5vE9BcLGjtUpwvqYLRvYNQKMfabu3BwfJaA/SLW8dxe28LsNDjtHwePTuzn3gmOA==",
       "dev": true
     },
+    "node_modules/@types/node-persist": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/@types/node-persist/-/node-persist-3.1.2.tgz",
+      "integrity": "sha512-aLFUB1951wOfR+tZ4f3TudLPblo9+PfnduMh6feuOTijD0Q6YkMdqPXSgQIjI23FGmCuoZaIZ9x6cvEG/TdiSg==",
+      "dev": true,
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/@types/qs": {
       "version": "6.9.7",
       "resolved": "https://registry.npmjs.org/@types/qs/-/qs-6.9.7.tgz",
@@ -926,6 +948,18 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/cookie-parser": {
+      "version": "1.4.6",
+      "resolved": "https://registry.npmjs.org/cookie-parser/-/cookie-parser-1.4.6.tgz",
+      "integrity": "sha512-z3IzaNjdwUC2olLIB5/ITd0/setiaFMLYiZJle7xg5Fe9KWAceil7xszYfHHBtDFYLSgJduS2Ty0P1uJdPDJeA==",
+      "dependencies": {
+        "cookie": "0.4.1",
+        "cookie-signature": "1.0.6"
+      },
+      "engines": {
+        "node": ">= 0.8.0"
+      }
+    },
     "node_modules/cookie-signature": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
@@ -2164,6 +2198,14 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/node-persist": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/node-persist/-/node-persist-3.1.0.tgz",
+      "integrity": "sha512-/j+fd/u71wNgKf3V2bx4tnDm+3GvLnlCuvf2MXbJ3wern+67IAb6zN9Leu1tCWPlPNZ+v1hLSibVukkPK2HqJw==",
+      "engines": {
+        "node": ">=10.12.0"
+      }
+    },
     "node_modules/normalize-path": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",
@@ -3201,6 +3243,15 @@
         "@types/node": "*"
       }
     },
+    "@types/cookie-parser": {
+      "version": "1.4.2",
+      "resolved": "https://registry.npmjs.org/@types/cookie-parser/-/cookie-parser-1.4.2.tgz",
+      "integrity": "sha512-uwcY8m6SDQqciHsqcKDGbo10GdasYsPCYkH3hVegj9qAah6pX5HivOnOuI3WYmyQMnOATV39zv/Ybs0bC/6iVg==",
+      "dev": true,
+      "requires": {
+        "@types/express": "*"
+      }
+    },
     "@types/express": {
       "version": "4.17.13",
       "resolved": "https://registry.npmjs.org/@types/express/-/express-4.17.13.tgz",
@@ -3257,6 +3308,15 @@
       "integrity": "sha512-3aRnHa1KlOEEhJ6+CvyHKK5vE9BcLGjtUpwvqYLRvYNQKMfabu3BwfJaA/SLW8dxe28LsNDjtHwePTuzn3gmOA==",
       "dev": true
     },
+    "@types/node-persist": {
+      "version": "3.1.2",
+      "resolved": "https://registry.npmjs.org/@types/node-persist/-/node-persist-3.1.2.tgz",
+      "integrity": "sha512-aLFUB1951wOfR+tZ4f3TudLPblo9+PfnduMh6feuOTijD0Q6YkMdqPXSgQIjI23FGmCuoZaIZ9x6cvEG/TdiSg==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*"
+      }
+    },
     "@types/qs": {
       "version": "6.9.7",
       "resolved": "https://registry.npmjs.org/@types/qs/-/qs-6.9.7.tgz",
@@ -3748,6 +3808,15 @@
       "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.4.1.tgz",
       "integrity": "sha512-ZwrFkGJxUR3EIoXtO+yVE69Eb7KlixbaeAWfBQB9vVsNn/o+Yw69gBWSSDK825hQNdN+wF8zELf3dFNl/kxkUA=="
     },
+    "cookie-parser": {
+      "version": "1.4.6",
+      "resolved": "https://registry.npmjs.org/cookie-parser/-/cookie-parser-1.4.6.tgz",
+      "integrity": "sha512-z3IzaNjdwUC2olLIB5/ITd0/setiaFMLYiZJle7xg5Fe9KWAceil7xszYfHHBtDFYLSgJduS2Ty0P1uJdPDJeA==",
+      "requires": {
+        "cookie": "0.4.1",
+        "cookie-signature": "1.0.6"
+      }
+    },
     "cookie-signature": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
@@ -4680,6 +4749,11 @@
       "resolved": "https://registry.npmjs.org/negotiator/-/negotiator-0.6.2.tgz",
       "integrity": "sha512-hZXc7K2e+PgeI1eDBe/10Ard4ekbfrrqG8Ep+8Jmf4JID2bNg7NvCPOZN+kfF574pFQI7mum2AUqDidoKqcTOw=="
     },
+    "node-persist": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/node-persist/-/node-persist-3.1.0.tgz",
+      "integrity": "sha512-/j+fd/u71wNgKf3V2bx4tnDm+3GvLnlCuvf2MXbJ3wern+67IAb6zN9Leu1tCWPlPNZ+v1hLSibVukkPK2HqJw=="
+    },
     "normalize-path": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/normalize-path/-/normalize-path-3.0.0.tgz",

package.json

@@ -35,10 +35,12 @@
     "@types/chai": "^4.2.22",
     "@types/chai-as-promised": "^7.1.4",
     "@types/compression": "^1.7.2",
+    "@types/cookie-parser": "^1.4.2",
     "@types/express": "^4.17.13",
     "@types/fs-extra": "^9.0.13",
     "@types/mocha": "^9.0.0",
     "@types/node": "^16.11.10",
+    "@types/node-persist": "^3.1.2",
     "@typescript-eslint/eslint-plugin": "^5.4.0",
     "@typescript-eslint/parser": "^5.4.0",
     "chai": "^4.3.4",
@@ -56,6 +58,8 @@
   "dependencies": {
     "commander": "^8.3.0",
     "compression": "^1.7.4",
-    "express": "^4.17.2"
+    "cookie-parser": "^1.4.6",
+    "express": "^4.17.2",
+    "node-persist": "^3.1.0"
   }
 }

src/backend.ts

@@ -1,7 +1,158 @@
 "use strict";
 
 import { Router } from "express";
+import persist from "node-persist";
+import { program } from "commander";
 
-export default function init(router: Router): void {
+type Poll = {
+    id: string,
+    title: string,
+    options: {
+        [option: string]: number
+    },
+    dupeCheckMode: "none" | "ip" | "cookie",
+    dupeData: null | string[] | string,
+    multiSelect: boolean,
+    captcha: boolean,
+    creationTime: Date,
+};
 
+function randomString(length = 10, charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789") {
+    let result = "";
+    for (let i = 0; i < length; i++) {
+        result += charset.charAt(Math.floor(Math.random() * charset.length));
+    }
+    return result;
+}
+
+export default async function init(router: Router): Promise<void> {
+    const polls = await persist.create({
+        dir: program.opts().dataDirectory
+    });
+    await polls.init();
+    
+    router.get("/poll/:id", async (req, res) => {
+        try {
+            const id = req.params.id;
+            const poll: (Poll | undefined) = await polls.getItem(id);
+            if (!poll) return res.status(404).json({ error: "Poll not found" });
+            res.json(Object.assign({}, poll, {
+                options: Object.keys(poll.options),
+                dupeData: null
+            }));
+        } catch (error) {
+            console.error(error);
+            if (error instanceof Error) res.status(500).json({
+                error: error.message
+            });
+            else res.status(500).json({
+                error: error
+            });
+        }
+    });
+
+    router.get("/poll-result/:id", async (req, res) => {
+        try {
+            const id = req.params.id;
+            const poll: (Poll | undefined) = await polls.getItem(id);
+            if (!poll) return res.status(404).json({ error: "Poll not found" });
+            res.json({
+                title: poll.title,
+                votes: poll.options
+            });
+        } catch (error) {
+            console.error(error);
+            if (error instanceof Error) res.status(500).json({
+                error: error.message
+            });
+            else res.status(500).json({
+                error: error
+            });
+        }
+    });
+
+    router.post("/poll", async (req, res) => {
+        try {
+            const options = req.body.options;
+            if (!Array.isArray(options) || options.filter(i => i).length < 2)
+                return res.status(400).json({ error: "Options must be an array and have at least 2 entries" });
+            let id = randomString(6);
+            while (await polls.getItem(id)) id = randomString(6);
+            await polls.setItem(id, {});
+            const dupeCheckMode = ["none", "ip", "cookie"].includes(req.body.dupeCheckMode) ? req.body.dupeCheckMode : "ip";
+            const dupeData =
+                dupeCheckMode === "none" ? null :
+                dupeCheckMode === "ip" ? [] :
+                dupeCheckMode === "cookie" ? randomString(16) : null;
+            const poll: Poll = {
+                id,
+                title: req.body.title || "",
+                options: (() => {
+                    const result: { [option: string]: number } = {};
+                    for (const option of options) {
+                        result[option] = 0;
+                    }
+                    return result;
+                })(),
+                dupeCheckMode,
+                dupeData,
+                multiSelect: req.body.multiSelect || false,
+                captcha: req.body.captcha || false,
+                creationTime: new Date()
+            };
+            await polls.setItem(id, poll);
+            res.json({
+                id: id
+            });
+        } catch (error) {
+            console.error(error);
+            if (error instanceof Error) res.status(500).json({
+                error: error.message
+            });
+            else res.status(500).json({
+                error: error
+            });
+        }
+    });
+
+    router.post("/vote/:id", async (req, res) => {
+        try {
+            const id = req.params.id;
+            const poll: (Poll | undefined) = await polls.getItem(id);
+            if (!poll) return res.status(404).json({ error: "Poll not found" });
+            
+            const votes = req.body.votes;
+            const possibleVotes = Object.keys(poll.options);
+            if (!Array.isArray(votes) || votes.filter(i => i && possibleVotes.includes(i)).length < 1)
+                return res.status(400).json({ error: "Votes must be an array and have at least 1 entry" });
+            if (!poll.multiSelect && votes.filter(i => i && possibleVotes.includes(i)).length > 1)
+                return res.status(400).json({ error: "Single-select polls can only have one vote" });
+
+            if (poll.dupeCheckMode === "ip") {
+                const ip = req.headers["x-forwarded-for"] || req.socket.remoteAddress || "";
+                if (Array.isArray(poll.dupeData) && poll.dupeData.includes(ip as string)) return res.status(200).json({ status: "ok", id });
+                if (Array.isArray(poll.dupeData)) poll.dupeData.push(ip as string);
+            } else if (poll.dupeCheckMode === "cookie") {
+                const cookie = req.cookies[poll.dupeData as string];
+                if (cookie) return res.status(200).json({ status: "ok", id });
+                res.cookie(poll.dupeData as string, "1", {
+                    httpOnly: true,
+                    maxAge: (1000 * 60 * 60 * 24 * 365) / 2
+                });
+            }
+
+            votes.filter(i => i && possibleVotes.includes(i)).forEach(vote => poll.options[vote]++);
+            await polls.setItem(id, poll);
+
+            res.json({ status: "ok", id });
+        } catch (error) {
+            console.error(error);
+            if (error instanceof Error) res.status(500).json({
+                error: error.message
+            });
+            else res.status(500).json({
+                error: error
+            });
+        }
+    });
 }

src/main.ts

@@ -4,12 +4,14 @@ import loadConfig from "./config-loader";
 import { program } from "commander";
 import express from "express";
 import compression from "compression";
+import cookiepaser from "cookie-parser";
 import { resolve } from "path";
 
 async function main(): Promise<void> {
     await loadConfig([
         ["--no-frontend", "Do not start the frontend server"],
         ["--no-backend", "Do not start the backend server"],
+        ["-d, --data-directory <path>", "Path to the data directory", "../data"],
         ["-p, --port <port>", "Port to listen on", (port: any) => parseInt(port), 6969],
         ["--backend-base-url <url>", "Base URL for the backend server", null],
     ], ".poll-horse-config");
@@ -18,6 +20,7 @@ async function main(): Promise<void> {
     const app = express();
     app.use(express.json());
     app.use(compression());
+    app.use(cookiepaser());
 
     if (opts.backend) {
         console.log(`Mounting backend`);