Version control and retrieval endpoints

src/controllers/topicController.ts

@@ -1,5 +1,6 @@
 import { Request, Response, NextFunction } from 'express';
 import { topics, Topic } from '../models/topic';
+import { finder } from '../utils'
 
 // Create a topic
 export const createTopic = (req: Request, res: Response, next: NextFunction) => {
@@ -24,7 +25,7 @@ export const createTopic = (req: Request, res: Response, next: NextFunction) =>
   }
 };
 
-// Read all topics
+// Retrieve all topics
 export const getTopics = (req: Request, res: Response, next: NextFunction) => {
   try {
     res.json(topics);
@@ -33,7 +34,7 @@ export const getTopics = (req: Request, res: Response, next: NextFunction) => {
   }
 };
 
-// Read single topic
+// Retrieve single topic
 export const getTopicById = (req: Request, res: Response, next: NextFunction) => {
   try {
     const id = parseInt(req.params.id, 10);
@@ -48,6 +49,39 @@ export const getTopicById = (req: Request, res: Response, next: NextFunction) =>
   }
 };
 
+// Retrieve single version of a topic
+export const getTopicByIdVersion = (req: Request, res: Response, next: NextFunction) => {
+  try {
+    const id = parseInt(req.params.id, 10);
+    const version = parseInt(req.params.version, 10)
+    const topic = topics.find((i) => i.id === id && i.version === version);
+    if (!topic) {
+      res.status(404).json({ message: 'Topic not found' });
+      return;
+    }
+    res.json(topic);
+  } catch (error) {
+    next(error);
+  }
+};
+
+// Retrive topic and all subtopics recursively
+export const getTopicByIdRecursive = (req: Request, res: Response, next: NextFunction) => {
+  try {
+    const id = parseInt(req.params.id, 10);
+    const topic = topics.find((i) => i.id === id);
+    if (!topic) {
+      res.status(404).json({ message: 'Topic not found' });
+      return;
+    }
+    const result = finder(topic.id)
+
+    res.json(result);
+  } catch (error) {
+    next(error);
+  }
+};
+
 // Update a topic (create nenw version)
 export const updateTopic = (req: Request, res: Response, next: NextFunction) => {
   try {

src/routes/topicRoutes.ts

@@ -3,14 +3,18 @@ import {
   createTopic,
   getTopics,
   getTopicById,
+  getTopicByIdVersion,
+  getTopicByIdRecursive,
   updateTopic,
-  deleteTopic,
+  deleteTopic
 } from '../controllers/topicController';
 
 const router = Router();
 
-router.get('/', getTopics);
+router.get('/recursive/:id', getTopicByIdRecursive);
 router.get('/:id', getTopicById);
+router.get('/:id/:version', getTopicByIdVersion);
+router.get('/', getTopics);
 router.post('/', createTopic);
 router.put('/:id', updateTopic);
 router.delete('/:id', deleteTopic);

src/utils.ts

@@ -0,0 +1,33 @@
+import { topics, Topic } from './models/topic'
+
+class TopicNode {
+  node: Topic
+  childNode?: [TopicNode?]
+
+  constructor(node: Topic, childNode: TopicNode) {
+    this.node = node
+    this.childNode = childNode ? [childNode] : []
+  }
+}
+
+// Search all topics' children and return them as a tree
+export const finder = (id: number) => {
+  const recursive = (topics: Topic[], id: number, node?: TopicNode) => {
+    const topic = topics.find((i) => i.id === id)
+    if (!node) {
+      node = new TopicNode(topic, null)
+    }
+    const topicChildren = topics.filter((i) => i.parentTopicId === id)
+
+    topicChildren.forEach(t => {
+      const turn = recursive(topics, t.id)
+      node.childNode.push(turn)
+    })
+
+    return (node)
+  }
+
+  const result = recursive(topics, id)
+
+  return (result)
+}