Add JSON structures, API file

Author: WZWren

peerprep/api/gateway.ts

@@ -0,0 +1,47 @@
+import { Question, ErrorBody } from "./structs";
+
+const questions: { [key: string]: Question } = {
+  "0" : {
+    "id": 0,
+    "difficulty": 2,
+    "title": "Two Sum",
+    "description": "Given an array of integers, return indices of the two numbers such that they add up to a specific target.",
+    "test_cases": {
+	  	"[2, 7, 11, 15], 9" : "[0, 1]",
+  		"[3, 2, 4], 6"      : "[1, 2]",
+  		"[3, 3], 6"         : "[0, 1]"
+	  }
+  },
+  "1" : {
+    "id": 1,
+    "difficulty": 1,
+    "title": "Reverse Integer",
+    "description": "Given a 32-bit signed integer, reverse digits of an integer.",
+    "test_cases": {
+		  "123" : "321",
+		  "1"   : "1",
+		  "22"  : "22"
+	  }
+  }
+};
+
+export async function fetchQuestion(questionId: string): Promise<Question|ErrorBody> {
+  // remove this when services are up
+  if (process.env.DEV_ENV === "dev") {
+    return questions[questionId] === undefined
+        ? {error: "Question not found", status: 404}
+        : questions[questionId];
+  }
+  try {
+    const response = await fetch(`${process.env.QUESTION_SERVICE}/questions/solve/${questionId}`);
+    if (!response.ok) {
+      return {
+        ...(await response.json()),
+        status: response.status
+      };
+    }
+    return await response.json() as Question;
+  } catch (err: any) {
+    return { error: err.message, status: 0};
+  }
+}

peerprep/api/structs.ts

@@ -0,0 +1,24 @@
+export enum Difficulty {
+  Easy = 1,
+  Medium,
+  Hard
+}
+
+export interface Question {
+  id: number;
+  difficulty: Difficulty;
+  title: string;
+  description: string;
+  test_cases: {
+    [key: string]: string;
+  };
+}
+
+export interface ErrorBody {
+  error: string;
+  status: number;
+}
+
+export function isError(obj: Question | ErrorBody): obj is ErrorBody {
+  return (obj as ErrorBody).error !== undefined;
+}