Random generation of workout plan

App.js

@@ -1,9 +1,14 @@
 document.addEventListener('DOMContentLoaded', function() {
-    fetch('routine.json')
+    fetch('collection.json')
         .then(response => response.json())
-        .then(workout_json => {
-            // Use the JSON workout_json here
+        .then(collection_json => {
+            // Generate Exercise plan
+            const egen = new ExerciseGenerator(collection_json);
+
+            // 2 sets of 4 exercises each, 3 reps per set
+            let workout_json = egen.generate_build_and_burn(2, 4, 3);
             console.log(workout_json);
+
             const wo = new Workout(document.getElementById("content-wrapper"),
                                    workout_json);
             wo.render();

ExerciseGenerator.js

@@ -0,0 +1,132 @@
+class ExerciseGenerator {
+
+// ----------
+constructor(collection) {
+    this.collection = collection;
+
+    // console.log(this.collection);
+    this.used_exercise_ids = new Array;
+
+    this.ex_nxt;
+    this.ex_last = null;
+}
+
+// ----------
+exercise_id_used(ex) {
+    return (this.used_exercise_ids.filter(function(v) { return (v == ex.id) }).length > 0);
+}
+
+// ----------
+exercise_related_to(ex) {
+    let related = false;
+    let gen = this;
+
+    if (gen.ex_last == null) {
+        return related;
+    }
+
+    ex.focus.forEach(function(e) {
+        related |= gen.ex_last.focus.includes(e);
+    });
+
+    return related;
+}
+
+// ----------
+get_next_exercise() {
+    let scope = this.collection.exercises;
+    let gen = this;
+
+    scope = this.collection.exercises.filter(function(e) {
+        let pick = true;
+
+        // Pick if exercise is not already used
+        pick &= (gen.exercise_id_used(e) == false);
+
+        // Pick if nor related to the previous one
+        pick &= (gen.exercise_related_to(e) == false);
+
+        return pick
+    });
+    gen.shuffle_exercise_array(scope);
+    // gen.show_exercise_array(scope);
+
+    return scope[0];
+}
+
+// ----------
+show_exercise_array(arr) {
+    let gen = this;
+
+    arr.map(function(it) {
+        gen.show_exercise(it);
+    });
+}
+
+// ----------
+show_exercise(ex) {
+    console.log(`${ex.id} : ${ex.name} [` + ex.focus.join(", ") + ']');
+}
+
+// ----------
+// From answer on https://stackoverflow.com/questions/2450954/how-to-randomize-shuffle-a-javascript-array
+shuffle_exercise_array(arr) {
+    let currentIndex = arr.length;
+
+    // While there remain elements to shuffle...
+    while (currentIndex != 0) {
+        // Pick a remaining element...
+        let randomIndex = Math.floor(Math.random() * currentIndex);
+        currentIndex--;
+
+        // And swap it with the current element.
+        [arr[currentIndex], arr[randomIndex]] = [
+            arr[randomIndex], arr[currentIndex]];
+    }
+}
+
+// ----------
+generate_set(size) {
+    let set_exercises = Array();
+    let lim = size;
+
+    this.ex_last = null;
+
+    do {
+        this.ex_nxt = this.get_next_exercise();
+        if (this.ex_nxt == null) {
+            break;
+        }
+        this.used_exercise_ids.push(this.ex_nxt.id);
+        set_exercises.push(this.ex_nxt);
+        this.ex_last = this.ex_nxt;
+        lim--;
+    } while ((this.ex_nxt != null) && (lim > 0));
+
+    this.show_exercise_array(set_exercises);
+    console.log(this.used_exercise_ids);
+
+    return set_exercises;
+}
+
+// ----------
+generate_build_and_burn(sets, exercises, reps) {
+    let wo_plan = {
+        "name": "Daily Build and Burn",
+        "set": [
+        ]
+    }
+
+    for (let i = 1; i <= sets; i ++) {
+        let set = {
+            "name": `Set ${i}`,
+            "count": reps,
+            "exercise": this.generate_set(exercises)
+        }
+        wo_plan.set.push(set);
+    }
+
+    return wo_plan;
+}
+
+}

collection.json

@@ -0,0 +1,65 @@
+{
+    "name": "Collection of exercises",
+    "exercises": [
+        {
+          "id": 1,
+          "name": "Leg triads with dumbell",
+          "count": 10,
+          "pattern": "each side",
+          "focus": ["legs"]},
+        {
+          "id": 2,
+          "name": "Forward lunge with dumbell twist",
+          "count": 10,
+          "pattern": "each side",
+          "focus": ["legs"]},
+        {
+          "id": 3,
+          "name": "A and Y core on floor",
+          "count": 10,
+          "pattern": "each end",
+          "focus": ["core"]},
+        {
+          "id": 4,
+          "name": "Bow and arrow pull with bands",
+          "count": 10,
+          "pattern": "each side",
+          "focus": ["arms"]},
+        {
+          "id": 5,
+          "name": "Push ups",
+          "count": 10,
+          "pattern": "",
+          "focus": ["arms", "chest"]},
+        {
+          "id": 6,
+          "name": "Bicep curls",
+          "count": 10,
+          "pattern": "each side",
+          "focus": ["arms"]},
+        {
+          "id": 7,
+          "name": "Russian twists",
+          "count": 10,
+          "pattern": "",
+          "focus": ["core"]},
+        {
+          "id": 8,
+          "name": "Chin up core",
+          "count": 10,
+          "pattern": "",
+          "focus": ["arms", "core"]},
+        {
+          "id": 9,
+          "name": "Tricep curls on the floor",
+          "count": 15,
+          "pattern": "",
+          "focus": ["arms"]},
+        {
+          "id": 10,
+          "name": "Leg curl on floor",
+          "count": 10,
+          "pattern": "each leg",
+          "focus": ["legs"]}
+    ]
+}

index.html

@@ -10,6 +10,7 @@
         <link href="https://fonts.googleapis.com/css2?family=Boldonse&family=Roboto:ital,wght@0,100..900;1,100..900&display=swap" rel="stylesheet">
         <link rel="stylesheet" href="style.css" />
 
+        <script type="text/javascript" src="ExerciseGenerator.js"></script>
         <script type="text/javascript" src="Workout.js"></script>
         <script type="text/javascript" src="App.js"></script>
 

routine.json

@@ -1,39 +0,0 @@
-{
-    "name": "Daily Build and Burn",
-    "set": [
-        { "name": "Build",
-          "count": 3,
-          "exercise": [
-            { "name": "Forward lunge with dumbell twist",
-              "count": 10,
-              "pattern": "each side"},
-            { "name": "A and Y core on floor",
-              "count": 10,
-              "pattern": "each end"},
-            { "name": "Bow and arrow pull with bands",
-              "count": 10,
-              "pattern": "each side"},
-            { "name": "Push ups",
-              "count": 10,
-              "pattern": ""}
-            ]
-        },
-        { "name": "Burn",
-          "count": 3,
-          "exercise": [
-            { "name": "Bicep curls",
-              "count": 10,
-              "pattern": "each side"},
-            { "name": "Russian twists",
-              "count": 10,
-              "pattern": ""},
-            { "name": "Chin up core",
-              "count": 10,
-              "pattern": ""},
-            { "name": "Tricep curls on the floor",
-              "count": 15,
-              "pattern": ""}
-            ]
-        }
-    ]
-}