Merge pull request #29 from SwEnt-Group8/feat/mvvm-for-users

Feat/MVVM for users

app/src/main/java/com/android/streetworkapp/model/user/User.kt

@@ -0,0 +1,9 @@
+package com.android.streetworkapp.model.user
+
+data class User(
+    val uid: String,
+    val username: String,
+    val email: String,
+    val score: Int,
+    val friends: List<String>
+)

app/src/main/java/com/android/streetworkapp/model/user/UserRepository.kt

@@ -0,0 +1,26 @@
+package com.android.streetworkapp.model.user
+/** A repository interface for user data. */
+interface UserRepository {
+
+  fun getNewUid(): String
+
+  suspend fun getUserByUid(uid: String): User?
+
+  suspend fun getUserByEmail(email: String): User?
+
+  suspend fun getUserByUserName(userName: String): User?
+
+  suspend fun getFriendsByUid(uid: String): List<User>?
+
+  suspend fun addUser(user: User)
+
+  suspend fun updateUserScore(uid: String, newScore: Int)
+
+  suspend fun increaseUserScore(uid: String, points: Int)
+
+  suspend fun addFriend(uid: String, friendUid: String)
+
+  suspend fun removeFriend(uid: String, friendUid: String)
+
+  suspend fun deleteUserByUid(uid: String)
+}

app/src/main/java/com/android/streetworkapp/model/user/UserRepositoryFirestore.kt

@@ -0,0 +1,265 @@
+package com.android.streetworkapp.model.user
+
+import android.util.Log
+import com.google.firebase.firestore.DocumentSnapshot
+import com.google.firebase.firestore.FieldPath
+import com.google.firebase.firestore.FieldValue
+import com.google.firebase.firestore.FirebaseFirestore
+import kotlinx.coroutines.tasks.await
+
+private const val UID_EMPTY = "UID must not be empty"
+
+class UserRepositoryFirestore(private val db: FirebaseFirestore) : UserRepository {
+  // Setup the collection path
+  companion object {
+    private const val COLLECTION_PATH = "users"
+  }
+
+  /**
+   * Generates a new unique ID for a user.
+   *
+   * @return A new unique ID (document ID) generated by Firestore.
+   */
+  override fun getNewUid(): String {
+    return db.collection(COLLECTION_PATH).document().id
+  }
+
+  /**
+   * Retrieves a user from Firestore based on the provided ID.
+   *
+   * @param uid The unique ID of the user to retrieve.
+   * @return The User object if found, or null if the user doesn't exist or an error occurs.
+   */
+  override suspend fun getUserByUid(uid: String): User? {
+    require(uid.isNotEmpty()) { UID_EMPTY }
+    return try {
+      val document = db.collection("users").document(uid).get().await()
+      documentToUser(document)
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error getting user with ID: $uid. Reason: ${e.message}")
+      null
+    }
+  }
+
+  /**
+   * Retrieves a user from Firestore based on the provided email.
+   *
+   * @param email The email of the user to retrieve.
+   * @return The User object if found, or null if the user doesn't exist or an error occurs.
+   */
+  override suspend fun getUserByEmail(email: String): User? {
+    require(email.isNotEmpty()) { "Email must not be empty" }
+    return try {
+      val querySnapshot = db.collection(COLLECTION_PATH).whereEqualTo("email", email).get().await()
+
+      if (querySnapshot.documents.isNotEmpty()) {
+        documentToUser(querySnapshot.documents[0]) // Return the first match
+      } else {
+        null // No user with that email found
+      }
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error getting user by email: $email. Reason: ${e.message}")
+      null
+    }
+  }
+
+  /**
+   * Retrieves a user from Firestore based on the provided username.
+   *
+   * @param userName The username of the user to retrieve.
+   * @return The User object if found, or null if the user doesn't exist or an error occurs.
+   */
+  override suspend fun getUserByUserName(userName: String): User? {
+    require(userName.isNotEmpty()) { "Username must not be empty" }
+    return try {
+      val querySnapshot =
+          db.collection(COLLECTION_PATH).whereEqualTo("username", userName).get().await()
+
+      if (querySnapshot.documents.isNotEmpty()) {
+        documentToUser(querySnapshot.documents[0])
+      } else {
+        null
+      }
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error getting user by username: $userName. Reason: ${e.message}")
+      null
+    }
+  }
+
+  /**
+   * Retrieves the friends of a user from Firestore based on the provided user ID (uid).
+   *
+   * @param uid The unique ID of the user whose friends are being retrieved.
+   * @return A list of User objects representing the user's friends, or null if an error occurs.
+   */
+  override suspend fun getFriendsByUid(uid: String): List<User>? {
+    require(uid.isNotEmpty()) { UID_EMPTY }
+    return try {
+      // Get the user's document first to retrieve the list of friend UIDs
+      val document = db.collection(COLLECTION_PATH).document(uid).get().await()
+      val friendIds = document["friends"] as? List<*> ?: emptyList<String>()
+
+      if (friendIds.isNotEmpty()) {
+        // Now fetch all the friends' user documents
+        val friendsQuery =
+            db.collection(COLLECTION_PATH).whereIn(FieldPath.documentId(), friendIds).get().await()
+
+        friendsQuery.documents.mapNotNull {
+          documentToUser(it)
+        } // Convert documents to User objects
+      } else {
+        emptyList() // No friends found
+      }
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error getting friends for user ID: $uid. Reason: ${e.message}")
+      null
+    }
+  }
+
+  /**
+   * Adds a new user to Firestore.
+   *
+   * @param user The User object to add to Firestore.
+   */
+  override suspend fun addUser(user: User) {
+    require(user.uid.isNotEmpty()) { UID_EMPTY }
+    try {
+      db.collection("users").document(user.uid).set(user).await()
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error adding user: ${e.message}")
+    }
+  }
+
+  /**
+   * Updates the user's score in Firestore.
+   *
+   * @param uid The unique ID of the user whose score is being updated.
+   * @param newScore The new score to set for the user.
+   */
+  override suspend fun updateUserScore(uid: String, newScore: Int) {
+    require(uid.isNotEmpty()) { UID_EMPTY }
+    require(newScore >= 0) { "Score must be a non-negative integer" }
+    try {
+      db.collection("users").document(uid).update("score", newScore).await()
+    } catch (e: Exception) {
+      Log.e(
+          "FirestoreError", "Error updating score of the user with ID: $uid. Reason: ${e.message}")
+    }
+  }
+
+  /**
+   * Increases the user's score in Firestore by a specified number of points.
+   *
+   * @param uid The unique ID of the user whose score is being increased.
+   * @param points The number of points to add to the user's score.
+   */
+  override suspend fun increaseUserScore(uid: String, points: Int) {
+    require(uid.isNotEmpty()) { UID_EMPTY }
+    require(points >= 0) { "Points must be a non-negative integer" }
+    try {
+      db.collection("users")
+          .document(uid)
+          .update("score", FieldValue.increment(points.toLong()))
+          .await()
+    } catch (e: Exception) {
+      Log.e(
+          "FirestoreError",
+          "Error increasing score of the user with ID: $uid. Reason: ${e.message}")
+    }
+  }
+
+  /**
+   * Adds a friend to both the user's and friend's friend lists in Firestore.
+   *
+   * @param uid The unique ID of the user.
+   * @param friendUid The ID of the friend to add to the user's friend list.
+   */
+  override suspend fun addFriend(uid: String, friendUid: String) {
+    require(uid.isNotEmpty()) { UID_EMPTY }
+    require(friendUid.isNotEmpty()) { "Friend UID must not be empty" }
+    try {
+      // Start a Firestore batch operation for both updates
+      val batch = db.batch()
+
+      // Add friendId to the user's friends list
+      val userRef = db.collection("users").document(uid)
+      batch.update(userRef, "friends", FieldValue.arrayUnion(friendUid))
+
+      // Add uid to the friend's friends list and commit the batch
+      val friendRef = db.collection("users").document(friendUid)
+      batch.update(friendRef, "friends", FieldValue.arrayUnion(uid))
+      batch.commit().await()
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error adding friend: ${e.message}")
+    }
+  }
+
+  /**
+   * Removes a friend from the user's friend list in Firestore.
+   *
+   * @param uid The unique ID of the user.
+   * @param friendUid The ID of the friend to remove from the user's friend list.
+   */
+  override suspend fun removeFriend(uid: String, friendUid: String) {
+    require(uid.isNotEmpty()) { UID_EMPTY }
+    require(friendUid.isNotEmpty()) { "Friend UID must not be empty" }
+    try {
+      // Start a Firestore batch operation for both removals
+      val batch = db.batch()
+
+      // Remove friendId from the user's friends list
+      val userRef = db.collection("users").document(uid)
+      batch.update(userRef, "friends", FieldValue.arrayRemove(friendUid))
+
+      // Remove uid from the friend's friends list and commit the batch
+      val friendRef = db.collection("users").document(friendUid)
+      batch.update(friendRef, "friends", FieldValue.arrayRemove(uid))
+      batch.commit().await()
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error removing friend: ${e.message}")
+    }
+  }
+
+  /**
+   * Deletes a user from Firestore based on the provided UID.
+   *
+   * @param uid The unique UID of the user to delete.
+   */
+  override suspend fun deleteUserByUid(uid: String) {
+    require(uid.isNotEmpty()) { UID_EMPTY }
+    try {
+      db.collection("users").document(uid).delete().await()
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error deleting user: ${e.message}")
+    }
+  }
+
+  /**
+   * Converts a Firestore DocumentSnapshot into a User object.
+   *
+   * @param document The Firestore DocumentSnapshot containing user data.
+   * @return A User object if the document is valid, or null if the document cannot be converted.
+   */
+  internal fun documentToUser(document: DocumentSnapshot): User? {
+    return try {
+      val uid = document.id
+      val username = document.getString("username") ?: return null
+      val email = document.getString("email") ?: return null
+      val score = document.getLong("score")?.toInt() ?: 0
+      // Safely handle the 'friends' field
+      val friends =
+          try {
+            document["friends"] as? List<*> ?: emptyList<String>()
+          } catch (e: Exception) {
+            Log.e("FirestoreError", "Error retrieving friends list", e)
+            emptyList<String>() // Return an empty list in case of an exception
+          }
+
+      val validFriends = friends.filterIsInstance<String>()
+      User(uid = uid, username = username, email = email, score = score, friends = validFriends)
+    } catch (e: Exception) {
+      Log.e("FirestoreError", "Error converting document to User", e)
+      null
+    }
+  }
+}