Add JSDoc and inline documentation to App.jsx

frontend/src/App.jsx

@@ -1,53 +1,103 @@
+/**
+ * @file App.jsx
+ * @description Main application component for the Superhero Comparison app.
+ * Provides functionality to view superheroes in a table, select them for comparison,
+ * and display a detailed comparison of their power statistics.
+ */
+
 import React, { useEffect, useState } from 'react';
 import './App.css';
 
+/**
+ * Main application component that manages superhero data and comparison functionality.
+ * 
+ * @component
+ * @returns {JSX.Element} The main application interface with table view or comparison view
+ */
 function App() {
+  // State for storing all superheroes fetched from the API
   const [superheroes, setSuperheroes] = useState([]);
+  // State for tracking which heroes are selected for comparison (max 2)
   const [selectedHeroes, setSelectedHeroes] = useState([]);
+  // State for managing which view to display: 'table' for hero list or 'comparison' for head-to-head
   const [currentView, setCurrentView] = useState('table'); // 'table' or 'comparison'
 
+  // Fetch superheroes data from the API when component mounts
   useEffect(() => {
     fetch('/api/superheroes')
       .then((response) => response.json())
       .then((data) => setSuperheroes(data))
       .catch((error) => console.error('Error fetching superheroes:', error));
   }, []);
 
+  /**
+   * Handles the selection and deselection of heroes for comparison.
+   * Implements a maximum selection of 2 heroes with automatic replacement logic.
+   * 
+   * @param {Object} hero - The hero object to select or deselect
+   * @param {number} hero.id - Unique identifier for the hero
+   * @param {string} hero.name - Name of the hero
+   */
   const handleHeroSelection = (hero) => {
     setSelectedHeroes(prev => {
       if (prev.find(h => h.id === hero.id)) {
-        // Remove if already selected
+        // Remove hero if already selected (toggle off)
         return prev.filter(h => h.id !== hero.id);
       } else if (prev.length < 2) {
-        // Add if less than 2 selected
+        // Add hero if less than 2 are currently selected
         return [...prev, hero];
       } else {
-        // Replace first selection if 2 already selected
+        // Replace the oldest selection (first in array) when 2 are already selected
         return [prev[1], hero];
       }
     });
   };
 
+  /**
+   * Checks if a hero is currently selected for comparison.
+   * 
+   * @param {number} heroId - The ID of the hero to check
+   * @returns {boolean} True if the hero is selected, false otherwise
+   */
   const isHeroSelected = (heroId) => {
     return selectedHeroes.some(h => h.id === heroId);
   };
 
+  /**
+   * Switches to the comparison view if exactly 2 heroes are selected.
+   * Triggered when the user clicks the "Compare Heroes" button.
+   */
   const handleCompare = () => {
     if (selectedHeroes.length === 2) {
       setCurrentView('comparison');
     }
   };
 
+  /**
+   * Returns to the table view and clears the hero selections.
+   * Triggered when the user clicks the "Back to Heroes Table" button.
+   */
   const handleBackToTable = () => {
     setCurrentView('table');
     setSelectedHeroes([]);
   };
 
+  /**
+   * Calculates the winner between two heroes by comparing their power statistics.
+   * Each stat category (intelligence, strength, speed, etc.) is scored individually,
+   * and the hero with more winning categories is declared the overall winner.
+   * 
+   * @param {Object} hero1 - The first hero to compare
+   * @param {Object} hero2 - The second hero to compare
+   * @returns {{winner: Object|null, score: string}} Object containing winner (hero object or null for tie) and score string in 'X-Y' format
+   */
   const calculateWinner = (hero1, hero2) => {
+    // All stat categories used for comparison
     const stats = ['intelligence', 'strength', 'speed', 'durability', 'power', 'combat'];
     let hero1Score = 0;
     let hero2Score = 0;
 
+    // Compare each stat category and award points
     stats.forEach(stat => {
       if (hero1.powerstats[stat] > hero2.powerstats[stat]) {
         hero1Score++;
@@ -56,6 +106,7 @@ function App() {
       }
     });
 
+    // Determine overall winner based on total points won
     if (hero1Score > hero2Score) {
       return { winner: hero1, score: `${hero1Score}-${hero2Score}` };
     } else if (hero2Score > hero1Score) {
@@ -65,11 +116,19 @@ function App() {
     }
   };
 
+  /**
+   * Renders the comparison view showing two heroes side-by-side with their stats
+   * and determining a winner based on stat comparisons.
+   * Returns null if not exactly 2 heroes are selected.
+   * 
+   * @returns {JSX.Element|null} The comparison view JSX or null if not exactly 2 heroes selected
+   */
   const renderComparison = () => {
     if (selectedHeroes.length !== 2) return null;
 
     const [hero1, hero2] = selectedHeroes;
     const result = calculateWinner(hero1, hero2);
+    // All stat categories to display in comparison
     const stats = ['intelligence', 'strength', 'speed', 'durability', 'power', 'combat'];
 
     return (
@@ -99,6 +158,7 @@ function App() {
           {stats.map(stat => {
             const stat1 = hero1.powerstats[stat];
             const stat2 = hero2.powerstats[stat];
+            // Determine which hero wins this particular stat, or if it's a tie
             const winner = stat1 > stat2 ? 'hero1' : stat1 < stat2 ? 'hero2' : 'tie';
 
             return (
@@ -135,6 +195,12 @@ function App() {
     );
   };
 
+  /**
+   * Renders the main table view displaying all superheroes with selection checkboxes
+   * and stats. Includes controls for comparing selected heroes.
+   * 
+   * @returns {JSX.Element} The table view JSX with hero data and selection controls
+   */
   const renderTable = () => (
     <div className="table-view">
       <h1>Superheroes</h1>