📝 Add docstrings to moonMissionDb

src/main/java/com/example/AccountRepository.java

@@ -3,8 +3,42 @@
 import java.sql.SQLException;
 
 public interface AccountRepository {
-    boolean findByNameAndPassword(String username, String password) throws SQLException;
-    int create(String firstName, String lastName, String ssn, String password, String username) throws SQLException;
-    int updatePassword(long userId, String newPassword) throws SQLException;
-    int delete(long userId) throws SQLException;
-}
+    /**
+ * Checks whether an account exists that matches the given username and password.
+ *
+ * @param username the account's username to look up
+ * @param password the account's password to validate
+ * @return `true` if an account with the provided username and password exists, `false` otherwise
+ * @throws SQLException if a database access error occurs
+ */
+boolean findByNameAndPassword(String username, String password) throws SQLException;
+    /**
+ * Creates a new account record using the provided personal and credential details.
+ *
+ * @param firstName the account holder's given name
+ * @param lastName  the account holder's family name
+ * @param ssn       the account holder's social security number
+ * @param password  the account password
+ * @param username  the desired account username
+ * @return the generated primary key for the new account when available; otherwise an implementation-specific integer status or affected-row count
+ * @throws SQLException if a database access error occurs
+ */
+int create(String firstName, String lastName, String ssn, String password, String username) throws SQLException;
+    /**
+ * Update the password for the account identified by the given user ID.
+ *
+ * @param userId     identifier of the user whose password will be changed
+ * @param newPassword the new password to set for the account
+ * @return           an integer result representing the outcome of the update (for example, number of rows affected or a status code)
+ * @throws SQLException if a database access error occurs while performing the update
+ */
+int updatePassword(long userId, String newPassword) throws SQLException;
+    /**
+ * Delete the account associated with the given user identifier.
+ *
+ * @param userId the identifier of the user to delete
+ * @return an integer result code (for example, the number of rows deleted or a status code)
+ * @throws SQLException if a database access error occurs
+ */
+int delete(long userId) throws SQLException;
+}

src/main/java/com/example/DataSource.java

@@ -4,5 +4,11 @@
 import java.sql.SQLException;
 
 public interface DataSource {
-    Connection getConnection() throws SQLException;
-}
+    /**
+ * Obtain a database connection.
+ *
+ * @return a {@link java.sql.Connection} instance
+ * @throws SQLException if a database access error occurs
+ */
+Connection getConnection() throws SQLException;
+}

src/main/java/com/example/JdbcAccountRepository.java

@@ -9,10 +9,21 @@ public class JdbcAccountRepository implements AccountRepository {
 
     private final DataSource dataSource;
 
+    /**
+     * Creates a JdbcAccountRepository backed by the provided DataSource.
+     */
     public JdbcAccountRepository(DataSource dataSource) {
         this.dataSource = dataSource;
     }
 
+    /**
+     * Checks whether an account exists for the given username and password.
+     *
+     * @param username the account name to authenticate
+     * @param password the password to match for the account
+     * @return `true` if an account with the specified credentials exists, `false` otherwise
+     * @throws SQLException if a database access error occurs
+     */
     @Override
     public boolean findByNameAndPassword(String username, String password) throws SQLException {
         String sql = "SELECT user_id FROM account WHERE name = ? AND password = ?";
@@ -27,6 +38,17 @@ public boolean findByNameAndPassword(String username, String password) throws SQ
         }
     }
 
+    /**
+     * Inserts a new account record with the provided personal and credential fields.
+     *
+     * @param firstName the account holder's first name
+     * @param lastName  the account holder's last name
+     * @param ssn       the account holder's social security number
+     * @param password  the account password to store
+     * @param username  the account username
+     * @return          the number of rows inserted (1 if the account was created, 0 otherwise)
+     * @throws SQLException if a database access error occurs
+     */
     @Override
     public int create(String firstName, String lastName, String ssn, String password, String username) throws SQLException {
         String sql = "INSERT INTO account (first_name, last_name, ssn, password, name) VALUES (?, ?, ?, ?, ?)";
@@ -42,6 +64,14 @@ public int create(String firstName, String lastName, String ssn, String password
         }
     }
 
+    /**
+     * Update the password for the account with the given user ID.
+     *
+     * @param userId the ID of the user whose password will be updated
+     * @param newPassword the new password value to set
+     * @return the number of rows affected by the update
+     * @throws SQLException if a database access error occurs
+     */
     @Override
     public int updatePassword(long userId, String newPassword) throws SQLException {
         String sql = "UPDATE account SET password = ? WHERE user_id = ?";
@@ -54,6 +84,13 @@ public int updatePassword(long userId, String newPassword) throws SQLException {
         }
     }
 
+    /**
+     * Deletes the account with the given user ID.
+     *
+     * @param userId the identifier of the account to delete
+     * @return the number of rows deleted (0 if no matching account was found)
+     * @throws SQLException if a database access error occurs
+     */
     @Override
     public int delete(long userId) throws SQLException {
         String sql = "DELETE FROM account WHERE user_id = ?";
@@ -64,4 +101,4 @@ public int delete(long userId) throws SQLException {
             return stmt.executeUpdate();
         }
     }
-}
+}

src/main/java/com/example/JdbcMoonMissionRepository.java

@@ -12,10 +12,21 @@ public class JdbcMoonMissionRepository implements MoonMissionRepository {
 
     private final DataSource dataSource;
 
+    /**
+     * Creates a repository backed by the given DataSource.
+     *
+     * @param dataSource the DataSource used to obtain database connections for repository operations
+     */
     public JdbcMoonMissionRepository(DataSource dataSource) {
         this.dataSource = dataSource;
     }
 
+    /**
+     * Retrieve all spacecraft names stored in the `moon_mission` table.
+     *
+     * @return a list of spacecraft names from the `moon_mission` table; the list is empty if no rows are found
+     * @throws SQLException if a database access error occurs
+     */
     @Override
     public List<String> findAllSpacecraftNames() throws SQLException {
         List<String> names = new ArrayList<>();
@@ -31,6 +42,16 @@ public List<String> findAllSpacecraftNames() throws SQLException {
     }
 
 
+    /**
+     * Fetches the database row for the mission with the specified mission ID.
+     *
+     * @param missionId the primary key of the mission to retrieve
+     * @param connection JDBC connection used to create and execute the query; this method does not close it
+     * @return a ResultSet positioned before the first row containing the matching mission (empty if no match)
+     * @throws SQLException if a database access error occurs
+     * 
+     * Note: the returned ResultSet is produced by a PreparedStatement created inside this method; the caller is responsible for closing both the ResultSet and its originating PreparedStatement.
+     */
     @Override
     public ResultSet findMissionById(long missionId, Connection connection) throws SQLException {
         String sql = "SELECT * FROM moon_mission WHERE mission_id = ?";
@@ -39,6 +60,13 @@ public ResultSet findMissionById(long missionId, Connection connection) throws S
         return stmt.executeQuery();
     }
 
+    /**
+     * Count moon missions whose launch_date falls in the specified year.
+     *
+     * @param year the launch year to count missions for
+     * @return the number of missions launched in the specified year
+     * @throws SQLException if a database access error occurs
+     */
     @Override
     public int countMissionsByYear(int year) throws SQLException {
         String sql = "SELECT COUNT(*) FROM moon_mission WHERE YEAR(launch_date) = ?";
@@ -53,4 +81,4 @@ public int countMissionsByYear(int year) throws SQLException {
             }
         }
     }
-}
+}

src/main/java/com/example/Main.java

@@ -11,7 +11,11 @@ public class Main {
     private final Scanner scanner = new Scanner(System.in);
     private AccountRepository accountRepository;
     private MoonMissionRepository moonMissionRepository;
-    private DataSource dataSource; // Behålls för att hantera anslutning i getMoonMissionById
+    private DataSource dataSource; /**
+     * Starts the application: initializes a development database when dev mode is detected and runs the interactive Main flow.
+     *
+     * Uses system properties, environment variables, and command-line arguments to determine dev mode before constructing and running the Main instance.
+     */
 
     public static void main(String[] args) {
         if (isDevMode(args)) {
@@ -20,6 +24,11 @@ public static void main(String[] args) {
         new Main().run();
     }
 
+    /**
+     * Initializes application resources, verifies database configuration and connectivity, then starts the interactive login and main menu flow.
+     *
+     * <p>Specifically, this method resolves JDBC configuration, initializes the data source and repositories, tests a database connection, and proceeds to prompt for user login. If login succeeds it enters the main menu loop; otherwise it handles an invalid login. If required configuration is missing the method prints an error and exits early.</p>
+     */
     public void run() {
 
         String JDBC_URL = resolveConfig("APP_JDBC_URL", "APP_JDBC_URL");
@@ -58,7 +67,12 @@ public void run() {
         // eftersom varje Repository-metod hanterar sin egen Connection.
     }
 
-    // --- Inloggning ---
+    /**
+     * Prompts the user for a username and password and authenticates them using the account repository.
+     *
+     * @return `true` if authentication succeeds, `false` otherwise.
+     * @throws SQLException if a database access error occurs while validating credentials.
+     */
 
     private boolean login() throws SQLException {
         System.out.print("Username: ");
@@ -71,6 +85,11 @@ private boolean login() throws SQLException {
     }
 
 
+    /**
+     * Shows an invalid-credentials message and waits for the user to confirm exit by entering "0".
+     *
+     * Prints a prompt and consumes input lines until the user types exactly "0".
+     */
     private void handleInvalidLogin() {
         System.out.println("Invalid username or password. Press 0 to exit.");
         while (true) {
@@ -82,7 +101,15 @@ private void handleInvalidLogin() {
         }
     }
 
-    // --- Menyhantering ---
+    /**
+     * Present the interactive main menu, read user choices, and invoke the corresponding actions.
+     *
+     * Repeatedly displays the menu and processes selections until the user chooses 0 to exit.
+     * Supported choices:
+     * 1 — list moon missions; 2 — get moon mission by ID; 3 — count missions by year;
+     * 4 — create an account; 5 — update an account password; 6 — delete an account.
+     * Handles non-numeric input by prompting the user and reports database operation errors to stderr.
+     */
 
     private void mainMenu() {
         // ... (mainMenu och printMenu förblir oförändrade, förutom anropen nedan) ...
@@ -128,6 +155,11 @@ private void mainMenu() {
         }
     }
 
+    /**
+     * Displays the main interactive menu options to the user.
+     *
+     * The menu lists available numeric commands used by the application's main loop.
+     */
     private void printMenu() {
         System.out.println("\n--- Menu ---");
         System.out.println("1) List moon missions (spacecraft names)");
@@ -141,7 +173,14 @@ private void printMenu() {
     }
 
 
-    // 1) List moon missions
+    /**
+     * Prints the spacecraft names of all moon missions to standard output.
+     *
+     * Prints a header line ("--- Moon Missions ---") followed by each spacecraft name
+     * on its own line, prefixed with " - ".
+     *
+     * @throws SQLException if a database access error occurs while retrieving missions
+     */
     private void listMoonMissions() throws SQLException {
         // Använder MoonMissionRepository
         List<String> spacecrafts = moonMissionRepository.findAllSpacecraftNames();
@@ -151,7 +190,14 @@ private void listMoonMissions() throws SQLException {
         }
     }
 
-    // 2) Get a moon mission by mission_id
+    /**
+     * Prompts the user for a mission ID and displays that mission's details if a record exists.
+     *
+     * If the entered mission ID is not a valid number, the method prints a warning and returns
+     * without querying the database.
+     *
+     * @throws SQLException if a database access error occurs while retrieving the mission
+     */
     private void getMoonMissionById() throws SQLException {
         System.out.print("Enter mission_id: ");
         long missionId;
@@ -177,7 +223,11 @@ private void getMoonMissionById() throws SQLException {
         }
     }
 
-    // 3) Count missions for a given year
+    /**
+     * Prompts for a year, queries the repository for the number of moon missions launched that year, and prints the result.
+     *
+     * @throws SQLException if a database error occurs while counting missions
+     */
     private void countMissionsByYear() throws SQLException {
         System.out.print("Enter year: ");
         int year = scanner.nextInt();
@@ -188,7 +238,16 @@ private void countMissionsByYear() throws SQLException {
         System.out.println("Found " + count + " missions launched in " + year + ".");
     }
 
-    // 4) Create an account
+    /**
+     * Creates a new account by prompting the user for first name, last name, SSN and password,
+     * generates a username from up to the first three characters of the first and last names,
+     * and persists the account via the AccountRepository.
+     *
+     * If the generated username is empty (both names empty) the method prints an error and returns
+     * without creating an account.
+     *
+     * @throws SQLException if the repository fails to perform the database operation
+     */
     private void createAccount() throws SQLException {
         System.out.print("Enter first name: ");
         String firstName = scanner.nextLine();
@@ -217,7 +276,11 @@ private void createAccount() throws SQLException {
         }
     }
 
-    // 5) Update an account password
+    /**
+     * Prompts for a user ID and a new password, updates that account's password, and reports success or absence.
+     *
+     * @throws SQLException if the database update fails
+     */
     private void updateAccountPassword() throws SQLException {
         System.out.print("Enter user_id to update: ");
         long userId = scanner.nextLong();
@@ -234,7 +297,12 @@ private void updateAccountPassword() throws SQLException {
         }
     }
 
-    // 6) Delete an account
+    /**
+     * Prompts for a user ID, deletes the corresponding account via the account repository,
+     * and prints whether the deletion succeeded or no matching account was found.
+     *
+     * @throws SQLException if a database access error occurs during the delete operation
+     */
     private void deleteAccount() throws SQLException {
         System.out.print("Enter user_id to delete: ");
         long userId = scanner.nextLong();
@@ -251,6 +319,14 @@ private void deleteAccount() throws SQLException {
     }
 
 
+    /**
+     * Detects whether the application should run in development mode.
+     *
+     * @param args the command-line arguments; the presence of the `--dev` flag enables dev mode
+     * @return `true` if development mode is enabled via the `devMode` JVM system property (e.g. `-DdevMode=true`),
+     *         the `DEV_MODE` environment variable (case-insensitive), or the `--dev` command-line flag;
+     *         `false` otherwise
+     */
     private static boolean isDevMode(String[] args) {
         if (Boolean.getBoolean("devMode"))  //Add VM option -DdevMode=true
             return true;