Admin can now add attachments to Announcements using Firebase Storage

app/build.gradle

@@ -6,12 +6,12 @@ plugins {
 }
 
 android {
-    compileSdk 32
+    compileSdk 33
 
     defaultConfig {
         applicationId "com.example.cmsclonelite"
         minSdk 21
-        targetSdk 32
+        targetSdk 33
         versionCode 1
         versionName "1.0"
 
@@ -47,11 +47,19 @@ android {
             excludes += '/META-INF/{AL2.0,LGPL2.1}'
         }
     }
+    configurations {
+        all {
+            exclude module: 'httpclient'
+            exclude module: 'commons-logging'
+        }
+    }
 }
 
 dependencies {
     def nav_version = "2.5.2"
 
+    implementation platform('com.google.firebase:firebase-bom:31.1.1')
+    implementation 'com.google.firebase:firebase-storage-ktx'
     implementation 'com.google.firebase:firebase-messaging-ktx:23.0.8'
     implementation 'com.google.firebase:firebase-firestore-ktx:24.3.1'
     implementation 'com.google.firebase:firebase-auth-ktx:21.0.8'

app/src/main/java/com/example/cmsclonelite/Course.kt

@@ -1,6 +1,9 @@
 package com.example.cmsclonelite
 
+import android.net.Uri
 import android.os.Parcelable
+import com.google.firebase.storage.StorageMetadata
+import com.google.firebase.storage.ktx.storageMetadata
 import kotlinx.parcelize.Parcelize
 import kotlinx.parcelize.RawValue
 import java.util.*
@@ -20,5 +23,7 @@ data class Course (
 @Parcelize
 data class Announcement (
     var title: String? = null,
-    var body: String? = null
+    var body: String? = null,
+    var fileName: String = "",
+    var downloadUri: Uri? = null,
 ): Parcelable

app/src/main/java/com/example/cmsclonelite/Screen.kt

@@ -10,4 +10,5 @@ sealed class Screen(val route: String) {
     object EditCourseDetails: Screen(route = "editCourseDetailsScreen")
     object Announcements: Screen(route = "announcementsScreen")
     object AddAnnouncements: Screen(route = "addAnnouncementsScreen")
+    object DetailedAnnouncement: Screen(route = "detailedAnnouncement")
 }

app/src/main/java/com/example/cmsclonelite/graphs/RootNavGraph.kt

@@ -4,6 +4,7 @@ import androidx.compose.runtime.Composable
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
+import com.example.cmsclonelite.Announcement
 import com.example.cmsclonelite.Course
 import com.example.cmsclonelite.Screen
 import com.example.cmsclonelite.screens.*
@@ -65,5 +66,11 @@ fun SetupNavGraph(
                 AddAnnouncementsScreen(navController = navController, course = course, announcementsViewModel = announcementsViewModel)
             }
         }
+        composable(route = Screen.DetailedAnnouncement.route) {
+            val announcement = navController.previousBackStackEntry?.savedStateHandle?.get<Announcement>("announcement")
+            if (announcement != null) {
+                DetailedAnnouncementScreen(navController = navController, announcement = announcement)
+            }
+        }
     }
 }

app/src/main/java/com/example/cmsclonelite/repository/CourseRepository.kt

@@ -3,8 +3,11 @@ package com.example.cmsclonelite.repository
 import android.content.ContentValues
 import android.content.ContentValues.TAG
 import android.content.Context
+import android.net.Uri
 import android.provider.CalendarContract
+import android.provider.OpenableColumns
 import android.util.Log
+import androidx.core.net.toUri
 import com.example.cmsclonelite.Announcement
 import com.example.cmsclonelite.Course
 import com.google.auth.oauth2.AccessToken
@@ -13,7 +16,10 @@ import com.google.firebase.firestore.DocumentSnapshot
 import com.google.firebase.firestore.FieldValue
 import com.google.firebase.firestore.FirebaseFirestore
 import com.google.firebase.firestore.SetOptions
+import com.google.firebase.ktx.Firebase
 import com.google.firebase.messaging.FirebaseMessaging
+import com.google.firebase.storage.StorageMetadata
+import com.google.firebase.storage.ktx.storage
 import kotlinx.coroutines.*
 import kotlinx.coroutines.tasks.await
 import okhttp3.*
@@ -29,6 +35,8 @@ import kotlin.collections.HashMap
 class CourseRepository {
     private val client = OkHttpClient()
     private val ioCoroutineScope = CoroutineScope(Dispatchers.IO)
+    private val storage = Firebase.storage
+    var storageRef = storage.reference
 
     private suspend fun getCourses(db: FirebaseFirestore): List<DocumentSnapshot> {
         val coursesRef = db.collection("courses")
@@ -87,6 +95,8 @@ class CourseRepository {
                 val announcement = Announcement()
                 announcement.title = announcementMap[i]!!.getValue("title")
                 announcement.body = announcementMap[i]!!.getValue("body")
+                announcement.fileName = announcementMap[i]!!.getValue("fileName")
+                announcement.downloadUri = announcementMap[i]!!.getValue("downloadUri").toUri()
                 list.add(announcement)
             }
         }
@@ -219,7 +229,7 @@ class CourseRepository {
                 calName = calCursor.getString(nameCol)
                 calID = calCursor.getString(idCol)
 
-                Log.d(ContentValues.TAG, "Calendar name = $calName Calendar ID = $calID")
+                Log.d(TAG, "Calendar name = $calName Calendar ID = $calID")
 
                 calCursor.close()
                 return calID.toLong()
@@ -233,7 +243,7 @@ class CourseRepository {
             FirebaseMessaging.getInstance().subscribeToTopic(course.id!!)
             db.collection("users").document(uid)
                 .update("enrolled", FieldValue.arrayUnion(course.id))
-                .addOnSuccessListener { Log.d(ContentValues.TAG, "DocumentSnapshot successfully updated!") }
+                .addOnSuccessListener { Log.d(TAG, "DocumentSnapshot successfully updated!") }
                 .addOnFailureListener { e: Exception? -> Log.w(ContentValues.TAG, "Error updating document", e) }
         }
     }
@@ -250,6 +260,12 @@ class CourseRepository {
 
     fun deleteCourse(db: FirebaseFirestore, course: Course) {
         ioCoroutineScope.launch {
+            val fileRef = storageRef.child("files/${course.id}")
+            fileRef.listAll().addOnCompleteListener { dir ->
+                for (item in dir.result.items) {
+                    item.delete()
+                }
+            }
             db.collection("users").whereArrayContains("enrolled", course.id!!)
                 .get()
                 .addOnCompleteListener { task ->
@@ -326,7 +342,9 @@ class CourseRepository {
             for(i in newAnnouncementList) {
                 announcementHashMap["key${count}"] = hashMapOf(
                     "title" to i.title!!,
-                    "body" to i.body!!
+                    "body" to i.body!!,
+                    "fileName" to i.fileName,
+                    "downloadUri" to i.downloadUri.toString()
                 )
                 count -= 1
             }
@@ -335,6 +353,37 @@ class CourseRepository {
         }
     }
 
+    suspend fun uploadFileToFirebase(course: Course, fileUri: Uri, context: Context): Uri? {
+        val returnCursor = context.contentResolver.query(fileUri, null, null, null, null)
+        val nameIndex = returnCursor?.getColumnIndex(OpenableColumns.DISPLAY_NAME)
+        returnCursor?.moveToFirst()
+        val fileName = nameIndex?.let { returnCursor.getString(it) }
+        returnCursor?.close()
+        val fileRef = storageRef.child("files/${course.id}/${fileName}")
+        fileRef.putFile(fileUri).await()
+        return fileRef.downloadUrl.await()
+    }
+
+    suspend fun getFileMetadataFromFirebase(course: Course, fileUri: Uri, context: Context): StorageMetadata {
+        val returnCursor = context.contentResolver.query(fileUri, null, null, null, null)
+        val nameIndex = returnCursor?.getColumnIndex(OpenableColumns.DISPLAY_NAME)
+        returnCursor?.moveToFirst()
+        val fileName = nameIndex?.let { returnCursor.getString(it) }
+        returnCursor?.close()
+        val fileRef = storageRef.child("files/${course.id}/${fileName}")
+        return fileRef.metadata.await()
+    }
+
+    suspend fun deleteFileFromFirebase(course: Course, fileUri: Uri, context: Context) {
+        val returnCursor = context.contentResolver.query(fileUri, null, null, null, null)
+        val nameIndex = returnCursor?.getColumnIndex(OpenableColumns.DISPLAY_NAME)
+        returnCursor?.moveToFirst()
+        val fileName = nameIndex?.let { returnCursor.getString(it) }
+        returnCursor?.close()
+        val fileRef = storageRef.child("files/${course.id}/${fileName}")
+        fileRef.delete().await()
+    }
+
     fun sendPushNotification(course: Course, announcement: Announcement) {
         ioCoroutineScope.launch {
             val url = "https://fcm.googleapis.com/v1/projects/cmsclonelite/messages:send"

app/src/main/java/com/example/cmsclonelite/screens/AboutScreen.kt

@@ -38,7 +38,7 @@ fun AboutScreen(
                     }
                 )
             },
-        ) {
+        ) { padding ->
             Column(
                 modifier = Modifier.fillMaxSize(),
                 verticalArrangement = Arrangement.Top,