Resolve conflicts

src/main/java/teammates/common/util/HibernateUtil.java

@@ -6,10 +6,12 @@
 import org.hibernate.boot.model.naming.CamelCaseToUnderscoresNamingStrategy;
 import org.hibernate.cfg.Configuration;
 
+import teammates.storage.sqlentity.Account;
 import teammates.storage.sqlentity.BaseEntity;
 import teammates.storage.sqlentity.Course;
 import teammates.storage.sqlentity.FeedbackSession;
 import teammates.storage.sqlentity.Notification;
+import teammates.storage.sqlentity.ReadNotification;
 
 /**
  * Class containing utils for setting up the Hibernate session factory.
@@ -18,7 +20,7 @@ public final class HibernateUtil {
     private static SessionFactory sessionFactory;
 
     private static final List<Class<? extends BaseEntity>> ANNOTATED_CLASSES = List.of(Course.class,
-            FeedbackSession.class, Notification.class);
+            FeedbackSession.class, Account.class, Notification.class, ReadNotification.class);
 
     private HibernateUtil() {
         // Utility class

src/main/java/teammates/storage/sqlapi/UsageStatisticsDb.java

@@ -0,0 +1,47 @@
+package teammates.storage.sqlapi;
+
+import java.time.Instant;
+import java.util.List;
+
+import org.hibernate.Session;
+
+import teammates.common.util.HibernateUtil;
+import teammates.storage.sqlentity.UsageStatistics;
+
+import jakarta.persistence.criteria.CriteriaBuilder;
+import jakarta.persistence.criteria.CriteriaQuery;
+import jakarta.persistence.criteria.Root;
+
+/**
+ * Handles CRUD operations for usage statistics.
+ *
+ * @see UsageStatistics
+ */
+public final class UsageStatisticsDb extends EntitiesDb<UsageStatistics> {
+
+    private static final UsageStatisticsDb instance = new UsageStatisticsDb();
+
+    private UsageStatisticsDb() {
+        // prevent initialization
+    }
+
+    public static UsageStatisticsDb inst() {
+        return instance;
+    }
+
+    /**
+     * Gets a list of statistics objects between start time and end time.
+     */
+    public List<UsageStatistics> getUsageStatisticsForTimeRange(Instant startTime, Instant endTime) {
+        Session session = HibernateUtil.getSessionFactory().getCurrentSession();
+        CriteriaBuilder cb = session.getCriteriaBuilder();
+        CriteriaQuery<UsageStatistics> cr = cb.createQuery(UsageStatistics.class);
+        Root<UsageStatistics> root = cr.from(UsageStatistics.class);
+
+        cr.select(root).where(cb.and(
+                cb.greaterThanOrEqualTo(root.get("startTime"), startTime),
+                cb.lessThan(root.get("startTime"), endTime)));
+
+        return session.createQuery(cr).getResultList();
+    }
+}

src/main/java/teammates/storage/sqlentity/Account.java

@@ -0,0 +1,164 @@
+package teammates.storage.sqlentity;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+import org.hibernate.annotations.CreationTimestamp;
+import org.hibernate.annotations.UpdateTimestamp;
+
+import teammates.common.util.FieldValidator;
+import teammates.common.util.SanitizationHelper;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+
+/**
+ * Represents a unique account in the system.
+ */
+@Entity
+@Table(name = "Accounts")
+public class Account extends BaseEntity {
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @Column(nullable = false)
+    private String googleId;
+
+    @Column(nullable = false)
+    private String name;
+
+    @Column(nullable = false)
+    private String email;
+
+    @OneToMany(mappedBy = "account")
+    private List<ReadNotification> readNotifications;
+
+    @CreationTimestamp
+    @Column(updatable = false)
+    private Instant createdAt;
+
+    @UpdateTimestamp
+    @Column
+    private Instant updatedAt;
+
+    protected Account() {
+        // required by Hibernate
+    }
+
+    public Account(String googleId, String name, String email) {
+        this.googleId = googleId;
+        this.name = name;
+        this.email = email;
+        this.readNotifications = new ArrayList<>();
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getGoogleId() {
+        return googleId;
+    }
+
+    public void setGoogleId(String googleId) {
+        this.googleId = googleId;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public List<ReadNotification> getReadNotifications() {
+        return readNotifications;
+    }
+
+    public void setReadNotifications(List<ReadNotification> readNotifications) {
+        this.readNotifications = readNotifications;
+    }
+
+    public Instant getCreatedAt() {
+        return createdAt;
+    }
+
+    public void setCreatedAt(Instant createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public Instant getUpdatedAt() {
+        return updatedAt;
+    }
+
+    public void setUpdatedAt(Instant updatedAt) {
+        this.updatedAt = updatedAt;
+    }
+
+    @Override
+    public List<String> getInvalidityInfo() {
+        List<String> errors = new ArrayList<>();
+
+        addNonEmptyError(FieldValidator.getInvalidityInfoForGoogleId(googleId), errors);
+        addNonEmptyError(FieldValidator.getInvalidityInfoForPersonName(name), errors);
+        addNonEmptyError(FieldValidator.getInvalidityInfoForEmail(email), errors);
+
+        return errors;
+    }
+
+    @Override
+    public void sanitizeForSaving() {
+        this.googleId = SanitizationHelper.sanitizeGoogleId(googleId);
+        this.name = SanitizationHelper.sanitizeName(name);
+        this.email = SanitizationHelper.sanitizeEmail(email);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == null) {
+            return false;
+        } else if (this == other) {
+            return true;
+        } else if (this.getClass() == other.getClass()) {
+            Account otherAccount = (Account) other;
+            return Objects.equals(this.email, otherAccount.email)
+                    && Objects.equals(this.name, otherAccount.name)
+                    && Objects.equals(this.googleId, otherAccount.googleId)
+                    && Objects.equals(this.id, otherAccount.id);
+        } else {
+            return false;
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        return this.getId().hashCode();
+    }
+
+    @Override
+    public String toString() {
+        return "Account [id=" + id + ", googleId=" + googleId + ", name=" + name + ", email=" + email
+                + ", readNotifications=" + readNotifications + ", createdAt=" + createdAt + ", updatedAt=" + updatedAt
+                + "]";
+    }
+}

src/main/java/teammates/storage/sqlentity/Notification.java

@@ -20,6 +20,7 @@
 import jakarta.persistence.Enumerated;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
 import jakarta.persistence.Table;
 
 /**
@@ -56,6 +57,9 @@ public class Notification extends BaseEntity {
     @Column(nullable = false)
     private boolean shown;
 
+    @OneToMany(mappedBy = "notification")
+    private List<ReadNotification> readNotifications;
+
     @CreationTimestamp
     @Column(nullable = false, updatable = false)
     private Instant createdAt;
@@ -164,6 +168,14 @@ public boolean isShown() {
         return shown;
     }
 
+    public List<ReadNotification> getReadNotifications() {
+        return readNotifications;
+    }
+
+    public void setReadNotifications(List<ReadNotification> readNotifications) {
+        this.readNotifications = readNotifications;
+    }
+
     /**
      * Sets the notification as shown to the user.
      * Only allowed to change value from false to true.
@@ -190,8 +202,9 @@ public void setUpdatedAt(Instant updatedAt) {
 
     @Override
     public String toString() {
-        return "Notification [id=" + notificationId + ", startTime=" + startTime + ", endTime=" + endTime
-                + ", style=" + style + ", targetUser=" + targetUser + ", shown=" + shown + ", createdAt=" + createdAt
+        return "Notification [notificationId=" + notificationId + ", startTime=" + startTime + ", endTime=" + endTime
+                + ", style=" + style + ", targetUser=" + targetUser + ", title=" + title + ", message=" + message
+                + ", shown=" + shown + ", readNotifications=" + readNotifications + ", createdAt=" + createdAt
                 + ", updatedAt=" + updatedAt + "]";
     }
 
@@ -209,7 +222,15 @@ public boolean equals(Object other) {
             return true;
         } else if (this.getClass() == other.getClass()) {
             Notification otherNotification = (Notification) other;
-            return Objects.equals(this.notificationId, otherNotification.getNotificationId());
+            return Objects.equals(this.notificationId, otherNotification.getNotificationId())
+                && Objects.equals(this.startTime, otherNotification.startTime)
+                && Objects.equals(this.endTime, otherNotification.endTime)
+                && Objects.equals(this.style, otherNotification.style)
+                && Objects.equals(this.targetUser, otherNotification.targetUser)
+                && Objects.equals(this.title, otherNotification.title)
+                && Objects.equals(this.message, otherNotification.message)
+                && Objects.equals(this.shown, otherNotification.shown)
+                && Objects.equals(this.readNotifications, otherNotification.readNotifications);
         } else {
             return false;
         }