Example of very simple API used while learning front-end development

cf-worker.js

addEventListener("fetch", (event) => {
   event.respondWith(handleRequest(event.request));
});

const workouts = [
   {
      week: 1,
      starts: 18383383383,
      workout: [
         {
            workoutNum: 1,
            completed: null,
            exercises: [
               {
                  type: "Warm Up",
                  name: "Treadmill",
                  weight: "",
                  sets: "",
                  reps: "",
                  time: "2.5",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "DB Press",
                  weight: "40",
                  sets: "3",
                  reps: "10",
                  "time(min)": "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "calisthenics",
                  name: "BOSU P/U",
                  weight: "",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Cable Fly Low",
                  weight: "30",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Cable Fly Mid",
                  weight: "35",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Cable Fly High",
                  weight: "40",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Tricep Pushdown",
                  weight: "80",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "calisthenics",
                  name: "Russian Twists",
                  weight: "20",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "calisthenics",
                  name: "Bicycle Crunch",
                  weight: "",
                  sets: "3",
                  reps: "10",
                  notes: "",
                  time: "",
                  accomplished: "0",
               },
               {
                  type: "cool down",
                  name: "Treadmill",
                  weight: "",
                  sets: "",
                  reps: "",
                  time: "5",
                  notes: "",
                  accomplished: "",
               },
            ],
         },
         {
            workoutNum: 2,
            completed: null,
            exercises: [
               {
                  type: "Warm Up",
                  name: "Treadmill",
                  weight: "",
                  sets: "",
                  reps: "",
                  time: "2.5",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "calisthenics",
                  name: "Strict Pull Up",
                  weight: "",
                  sets: "3",
                  reps: "",
                  time: "",
                  notes: "",
                  accomplished: "0",
               },
               {
                  type: "weights",
                  name: "DB Shrug",
                  weight: "80",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "DB Curl",
                  weight: "35",
                  sets: "3",
                  reps: "5",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "DB Bent Row",
                  weight: "45",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "body weight",
                  name: "TRX Inverted Row",
                  weight: "",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "EZ Bar Curl",
                  weight: "70",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Lat Pulldown",
                  weight: "80",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Plank Row",
                  weight: "20",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "calisthenics",
                  name: "Row Machine",
                  weight: "",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "cool down",
                  name: "Treadmill",
                  weight: "",
                  sets: "",
                  reps: "",
                  time: "5",
                  notes: "",
                  accomplished: "",
               },
            ],
         },
         {
            workoutNum: 3,
            completed: null,
            exercises: [
               {
                  type: "Warm Up",
                  name: "Treadmill",
                  weight: "",
                  sets: "",
                  reps: "",
                  time: "2.5",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Smith Machine",
                  weight: "180",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "KB Squat Press",
                  weight: "180",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Leg Curl",
                  weight: "100",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Walking Lunge",
                  weight: "10",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "Plates, DB or Kettle Bell each hand",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Side Lunge to OF Press",
                  weight: "25",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "Plate, DB or Kettle Bell",
                  accomplished: "",
               },
               {
                  type: "weights",
                  name: "Weighted Calf Raises",
                  weight: "150",
                  sets: "3",
                  reps: "10",
                  time: "",
                  notes: "",
                  accomplished: "",
               },
               {
                  type: "calisthenics",
                  name: "Flutter Kicks",
                  weight: "",
                  sets: "3",
                  reps: "10",
                  notes: "",
                  time: "",
                  accomplished: "0",
               },
               {
                  type: "calisthenics",
                  name: "Stair Master",
                  weight: "",
                  sets: "",
                  reps: "",
                  time: "10",
                  notes: "1 min slow (40-50), 30 sec fast (90-100)",
                  accomplished: "671",
               },
               {
                  type: "cool down",
                  name: "Treadmill",
                  weight: "",
                  sets: "",
                  reps: "",
                  time: "5",
                  notes: "",
                  accomplished: "",
               },
            ],
         },
      ],
   },
];

const calories = [
   {
      date: "April 7, 2022",
      totalCalories: 1300,
   },
   {
      date: "April 6, 2022",
      totalCalories: 1100,
   },
   {
      date: "April 5, 2022",
      totalCalories: 1400,
   },
   {
      date: "April 4, 2022",
      totalCalories: 1000,
   },
   {
      date: "April 3, 2022",
      totalCalories: 1450,
   },
   {
      date: "April 2, 2022",
      totalCalories: 1175,
   },
];

const messages = [
   {
      date: "April 7, 2022",
      msg: "message #1",
      direction: "in",
   },
   {
      date: "April 6, 2022",
      msg: "message #2",
      direction: "out",
   },
   {
      date: "April 5, 2022",
      msg: "message #3",
      direction: "in",
   },
   {
      date: "April 4, 2022",
      msg: "message #4",
      direction: "in",
   },
   {
      date: "April 3, 2022",
      msg: "message #5",
      direction: "out",
   },
   {
      date: "April 2, 2022",
      msg: "message #6",
      direction: "out",
   },
];

async function handleRequest(request) {
   const method = request.method.toLowerCase();
   const url = new URL(request.url);

   const headers = {
      "Content-Type": "application/json",
      "Access-Control-Allow-Origin": "*",
      "Access-Control-Allow-Methods": "*",
      "Access-Control-Allow-Headers": "*",
   };

   if (method === "options") {
      return new Response("", { headers });
   }

   if (url.pathname === "/workouts" && method === "get") {
      return new Response(JSON.stringify(workouts), { headers });
   }

   if (url.pathname === "/calories" && method === "get") {
      return new Response(JSON.stringify(calories), { headers });
   }

   if (url.pathname === "/calories" && method === "post") {
      const data = await request.json();
      const newCalories = [...calories, data];
      return new Response(JSON.stringify(newCalories), { headers });
   }

   if (url.pathname === "/messages" && method === "get") {
      return new Response(JSON.stringify(messages), { headers });
   }

   if (url.pathname === "/messages" && method === "post") {
      const data = await request.json();
      const newMessages = [...messages, data];
      return new Response(JSON.stringify(newMessages), { headers });
   }

   // Default to returning workouts until fix routing on the app
   return new Response("Not Found", { status: 404 });
}