Add messages (#148)

2018-12-06 18:35:02 +01:00 · 2018-12-06 18:35:02 +01:00 · 92baecbd0d
commit 92baecbd0d
parent 48f96b5932
46 changed files with 1356 additions and 41 deletions
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@ -1,4 +1,4 @@
-image: circleci/android:api-27-alpha
+image: circleci/android:api-28-alpha

 before_script:
    - export GRADLE_USER_HOME=`pwd`/.gradle
--- a/.travis.yml
+++ b/.travis.yml
@ -52,6 +52,7 @@ script:
  - ./gradlew createDebugCoverageReport --stacktrace -PdisableCrashlytics --daemon
  - ./gradlew jacocoTestReport --stacktrace --daemon
  - if [ "$TRAVIS_PULL_REQUEST" != "false" ] || [ "$TRAVIS_BRANCH" == "master" ]; then
+      git fetch --unshallow;
      ./gradlew sonarqube -x test -x lint -x fabricGenerateResourcesRelease -Dsonar.host.url=$SONAR_HOST -Dsonar.organization=$SONAR_ORG -Dsonar.login=$SONAR_KEY -Dsonar.branch.name=${TRAVIS_PULL_REQUEST_BRANCH:-$TRAVIS_BRANCH} -PdisableCrashlytics --stacktrace --daemon;
    fi
  - |
--- a/README.md
+++ b/README.md
@ -1,12 +1,13 @@
 # Wulkanowy

 [![CircleCI](https://img.shields.io/circleci/project/github/wulkanowy/wulkanowy/master.svg?style=flat-square)](https://circleci.com/gh/wulkanowy/wulkanowy)
-[![Travis](https://img.shields.io/travis/wulkanowy/wulkanowy/master.svg?style=flat-square)](https://travis-ci.com/wulkanowy/wulkanowy)
+[![Travis](https://img.shields.io/travis/com/wulkanowy/wulkanowy/master.svg?style=flat-square)](https://travis-ci.com/wulkanowy/wulkanowy)
 [![Bitrise](https://img.shields.io/bitrise/daeff1893f3c8128/master.svg?token=Hjm1ACamk86JDeVVJHOeqQ&style=flat-square)](https://www.bitrise.io/app/daeff1893f3c8128)
 [![Codecov](https://img.shields.io/codecov/c/github/wulkanowy/wulkanowy/master.svg?style=flat-square)](https://codecov.io/gh/wulkanowy/wulkanowy)
 [![BCH compliance](https://bettercodehub.com/edge/badge/wulkanowy/wulkanowy?branch=master)](https://bettercodehub.com/)
-[![Discord](https://img.shields.io/discord/390889354199040011.svg?style=flat-square)](https://discord.gg/vccAQBr)
+[![Sonarcloud](https://sonarcloud.io/api/project_badges/measure?project=io.github.wulkanowy%3Aapp&metric=sqale_rating)](https://sonarcloud.io/dashboard?id=io.github.wulkanowy%3Aapp)
 [![FOSSA Status](https://app.fossa.io/api/projects/custom%2B5644%2Fgit%40github.com%3Awulkanowy%2Fwulkanowy.git.svg?type=shield)](https://app.fossa.io/projects/custom%2B5644%2Fgit%40github.com%3Awulkanowy%2Fwulkanowy.git?ref=badge_shield)
+[![Discord](https://img.shields.io/discord/390889354199040011.svg?style=flat-square)](https://discord.gg/vccAQBr)

 [Pobierz wersję beta z Google Play](https://play.google.com/store/apps/details?id=io.github.wulkanowy&amp;utm_source=vcs)

--- a/app/build.gradle
+++ b/app/build.gradle
@ -51,7 +51,7 @@ android {
            signingConfig signingConfigs.release
        }
        debug {
-            buildConfigField "boolean", "FABRIC_ENABLED", fabricApiKey == "null" ? "false" : "true"
+            buildConfigField "boolean", "FABRIC_ENABLED", fabricApiKey != "null" && !project.hasProperty("disableCrashlytics") ? "true" : "false"
            applicationIdSuffix ".dev"
            versionNameSuffix "-dev"
            testCoverageEnabled = true
@ -81,7 +81,7 @@ configurations.all {
 dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
    implementation "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
-    implementation('com.github.wulkanowy:api:0ac961607b') { exclude module: "threetenbp" }
+    implementation('com.github.wulkanowy:api:ba17abc') { exclude module: "threetenbp" }

    implementation "androidx.legacy:legacy-support-v4:1.0.0"
    implementation "androidx.appcompat:appcompat:1.0.2"
--- a/app/src/main/java/io/github/wulkanowy/WulkanowyApp.kt
+++ b/app/src/main/java/io/github/wulkanowy/WulkanowyApp.kt
@ -45,7 +45,7 @@ class WulkanowyApp : DaggerApplication() {

    private fun initializeFabric() {
        Fabric.with(Fabric.Builder(this).kits(
-            Crashlytics.Builder().core(CrashlyticsCore.Builder().disabled(BuildConfig.DEBUG || !BuildConfig.FABRIC_ENABLED).build()).build(),
+            Crashlytics.Builder().core(CrashlyticsCore.Builder().disabled(!BuildConfig.FABRIC_ENABLED).build()).build(),
            Answers()
        ).debuggable(BuildConfig.DEBUG).build())
        Timber.plant(CrashlyticsTree())
--- a/app/src/main/java/io/github/wulkanowy/data/RepositoryModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/RepositoryModule.kt
@ -65,6 +65,10 @@ internal class RepositoryModule {
    @Provides
    fun provideGradeSummaryDao(database: AppDatabase) = database.gradeSummaryDao

+    @Singleton
+    @Provides
+    fun provideMessagesDao(database: AppDatabase) = database.messagesDao
+
    @Singleton
    @Provides
    fun provideExamDao(database: AppDatabase) = database.examsDao
--- a/app/src/main/java/io/github/wulkanowy/data/db/AppDatabase.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/AppDatabase.kt
@ -10,6 +10,7 @@ import io.github.wulkanowy.data.db.dao.AttendanceDao
 import io.github.wulkanowy.data.db.dao.ExamDao
 import io.github.wulkanowy.data.db.dao.GradeDao
 import io.github.wulkanowy.data.db.dao.GradeSummaryDao
+import io.github.wulkanowy.data.db.dao.MessagesDao
 import io.github.wulkanowy.data.db.dao.HomeworkDao
 import io.github.wulkanowy.data.db.dao.NoteDao
 import io.github.wulkanowy.data.db.dao.SemesterDao
@ -19,6 +20,7 @@ import io.github.wulkanowy.data.db.entities.Attendance
 import io.github.wulkanowy.data.db.entities.Exam
 import io.github.wulkanowy.data.db.entities.Grade
 import io.github.wulkanowy.data.db.entities.GradeSummary
+import io.github.wulkanowy.data.db.entities.Message
 import io.github.wulkanowy.data.db.entities.Homework
 import io.github.wulkanowy.data.db.entities.Note
 import io.github.wulkanowy.data.db.entities.Semester
@ -36,6 +38,7 @@ import javax.inject.Singleton
        Attendance::class,
        Grade::class,
        GradeSummary::class,
+        Message::class,
        Note::class,
        Homework::class
    ],
@ -67,6 +70,8 @@ abstract class AppDatabase : RoomDatabase() {

    abstract val gradeSummaryDao: GradeSummaryDao

+    abstract val messagesDao: MessagesDao
+
    abstract val noteDao: NoteDao

    abstract val homeworkDao: HomeworkDao
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/MessagesDao.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/MessagesDao.kt
@ -0,0 +1,37 @@
+package io.github.wulkanowy.data.db.dao
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Insert
+import androidx.room.Query
+import androidx.room.Update
+import io.github.wulkanowy.data.db.entities.Message
+import io.reactivex.Maybe
+
+@Dao
+interface MessagesDao {
+
+    @Insert
+    fun insertAll(messages: List<Message>): List<Long>
+
+    @Delete
+    fun deleteAll(messages: List<Message>)
+
+    @Update
+    fun update(message: Message)
+
+    @Update
+    fun updateAll(messages: List<Message>)
+
+    @Query("SELECT * FROM Messages WHERE student_id = :studentId AND real_id = :id")
+    fun loadOne(studentId: Int, id: Int): Maybe<Message>
+
+    @Query("SELECT * FROM Messages WHERE student_id = :studentId AND folder_id = :folder ORDER BY date DESC")
+    fun load(studentId: Int, folder: Int): Maybe<List<Message>>
+
+    @Query("SELECT * FROM Messages WHERE student_id = :studentId AND removed = 1 ORDER BY date DESC")
+    fun loadDeleted(studentId: Int): Maybe<List<Message>>
+
+    @Query("SELECT * FROM Messages WHERE unread = 1 AND student_id = :studentId")
+    fun loadNewMessages(studentId: Int): Maybe<List<Message>>
+}
--- a/app/src/main/java/io/github/wulkanowy/data/db/entities/Message.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/db/entities/Message.kt
@ -0,0 +1,56 @@
+package io.github.wulkanowy.data.db.entities
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import org.threeten.bp.LocalDateTime
+import java.io.Serializable
+
+@Entity(tableName = "Messages")
+data class Message(
+
+    @ColumnInfo(name = "student_id")
+    var studentId: Int? = null,
+
+    @ColumnInfo(name = "real_id")
+    val realId: Int? = null,
+
+    @ColumnInfo(name = "message_id")
+    val messageId: Int? = null,
+
+    @ColumnInfo(name = "sender_name")
+    val sender: String? = null,
+
+    @ColumnInfo(name = "sender_id")
+    val senderId: Int? = null,
+
+    @ColumnInfo(name = "recipient_id")
+    val recipientId: Int? = null,
+
+    @ColumnInfo(name = "recipient_name")
+    val recipient: String? = "",
+
+    val subject: String = "",
+
+    val date: LocalDateTime? = null,
+
+    @ColumnInfo(name = "folder_id")
+    val folderId: Int = 0,
+
+    var unread: Boolean? = false,
+
+    val unreadBy: Int? = 0,
+
+    val readBy: Int? = 0,
+
+    val removed: Boolean = false
+) : Serializable {
+
+    @PrimaryKey(autoGenerate = true)
+    var id: Long = 0
+
+    @ColumnInfo(name = "is_notified")
+    var isNotified: Boolean = true
+
+    var content: String? = null
+}
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/ExamRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/ExamRepository.kt
@ -16,30 +16,30 @@ import javax.inject.Singleton

@Singleton
 class ExamRepository @Inject constructor(
-        private val settings: InternetObservingSettings,
-        private val local: ExamLocal,
-        private val remote: ExamRemote
+    private val settings: InternetObservingSettings,
+    private val local: ExamLocal,
+    private val remote: ExamRemote
 ) {

    fun getExams(semester: Semester, startDate: LocalDate, endDate: LocalDate, forceRefresh: Boolean = false): Single<List<Exam>> {
        return Single.fromCallable { startDate.monday to endDate.friday }
-                .flatMap { dates ->
-                    local.getExams(semester, dates.first, dates.second).filter { !forceRefresh }
-                            .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
-                                    .flatMap {
-                                        if (it) remote.getExams(semester, dates.first, dates.second)
-                                        else Single.error(UnknownHostException())
-                                    }.flatMap { newExams ->
-                                        local.getExams(semester, dates.first, dates.second)
-                                                .toSingle(emptyList())
-                                                .doOnSuccess { oldExams ->
-                                                    local.deleteExams(oldExams - newExams)
-                                                    local.saveExams(newExams - oldExams)
-                                                }
-                                    }.flatMap {
-                                        local.getExams(semester, dates.first, dates.second)
-                                                .toSingle(emptyList())
-                                    }).map { list -> list.filter { it.date in startDate..endDate } }
-                }
+            .flatMap { dates ->
+                local.getExams(semester, dates.first, dates.second).filter { !forceRefresh }
+                    .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
+                        .flatMap {
+                            if (it) remote.getExams(semester, dates.first, dates.second)
+                            else Single.error(UnknownHostException())
+                        }.flatMap { newExams ->
+                            local.getExams(semester, dates.first, dates.second)
+                                .toSingle(emptyList())
+                                .doOnSuccess { oldExams ->
+                                    local.deleteExams(oldExams - newExams)
+                                    local.saveExams(newExams - oldExams)
+                                }
+                        }.flatMap {
+                            local.getExams(semester, dates.first, dates.second)
+                                .toSingle(emptyList())
+                        }).map { list -> list.filter { it.date in startDate..endDate } }
+            }
    }
 }
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/MessagesRepository.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/MessagesRepository.kt
@ -0,0 +1,79 @@
+package io.github.wulkanowy.data.repositories
+
+import com.github.pwittchen.reactivenetwork.library.rx2.ReactiveNetwork
+import com.github.pwittchen.reactivenetwork.library.rx2.internet.observing.InternetObservingSettings
+import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.local.MessagesLocal
+import io.github.wulkanowy.data.repositories.remote.MessagesRemote
+import io.reactivex.Completable
+import io.reactivex.Single
+import java.net.UnknownHostException
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class MessagesRepository @Inject constructor(
+    private val settings: InternetObservingSettings,
+    private val local: MessagesLocal,
+    private val remote: MessagesRemote
+) {
+
+    enum class MessageFolder(val id: Int = 1) {
+        RECEIVED(1),
+        SENT(2),
+        TRASHED(3)
+    }
+
+    fun getMessages(studentId: Int, folder: MessageFolder, forceRefresh: Boolean = false, notify: Boolean = false): Single<List<Message>> {
+        return local.getMessages(studentId, folder).filter { !forceRefresh }
+            .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
+                .flatMap {
+                    if (it) remote.getMessages(studentId, folder)
+                    else Single.error(UnknownHostException())
+                }.flatMap { new ->
+                    local.getMessages(studentId, folder).toSingle(emptyList())
+                        .doOnSuccess { old ->
+                            local.deleteMessages(old - new)
+                            local.saveMessages((new - old)
+                                .onEach {
+                                    it.isNotified = !notify
+                                })
+                        }
+                }.flatMap { local.getMessages(studentId, folder).toSingle(emptyList()) }
+            )
+    }
+
+    fun getMessage(studentId: Int, messageId: Int, markAsRead: Boolean = false): Single<Message> {
+        return local.getMessage(studentId, messageId)
+            .filter { !it.content.isNullOrEmpty() }
+            .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
+                .flatMap {
+                    if (it) local.getMessage(studentId, messageId).toSingle()
+                    else Single.error(UnknownHostException())
+                }
+                .flatMap { dbMessage ->
+                    remote.getMessagesContent(dbMessage, markAsRead).doOnSuccess {
+                        local.updateMessage(dbMessage.copy(unread = false).apply {
+                            id = dbMessage.id
+                            content = it
+                        })
+                    }
+                }.flatMap {
+                    local.getMessage(studentId, messageId).toSingle()
+                }
+            )
+    }
+
+    fun getNewMessages(student: Student): Single<List<Message>> {
+        return local.getNewMessages(student).toSingle(emptyList())
+    }
+
+    fun updateMessage(message: Message): Completable {
+        return Completable.fromCallable { local.updateMessage(message) }
+    }
+
+    fun updateMessages(messages: List<Message>): Completable {
+        return Completable.fromCallable { local.updateMessages(messages) }
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/local/GradeLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/local/GradeLocal.kt
@ -27,8 +27,8 @@ class GradeLocal @Inject constructor(private val gradeDb: GradeDao) {
        return Completable.fromCallable { gradeDb.update(grade) }
    }

-    fun updateGrades(grade: List<Grade>): Completable {
-        return Completable.fromCallable { gradeDb.updateAll(grade) }
+    fun updateGrades(grades: List<Grade>): Completable {
+        return Completable.fromCallable { gradeDb.updateAll(grades) }
    }

    fun deleteGrades(grades: List<Grade>) {
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/local/MessagesLocal.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/local/MessagesLocal.kt
@ -0,0 +1,44 @@
+package io.github.wulkanowy.data.repositories.local
+
+import io.github.wulkanowy.data.db.dao.MessagesDao
+import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.data.db.entities.Student
+import io.github.wulkanowy.data.repositories.MessagesRepository
+import io.reactivex.Maybe
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class MessagesLocal @Inject constructor(private val messagesDb: MessagesDao) {
+
+    fun getMessage(studentId: Int, id: Int): Maybe<Message> {
+        return messagesDb.loadOne(studentId, id)
+    }
+
+    fun getMessages(studentId: Int, folder: MessagesRepository.MessageFolder): Maybe<List<Message>> {
+        return when (folder) {
+            MessagesRepository.MessageFolder.TRASHED -> messagesDb.loadDeleted(studentId)
+            else -> messagesDb.load(studentId, folder.id)
+        }.filter { !it.isEmpty() }
+    }
+
+    fun getNewMessages(student: Student): Maybe<List<Message>> {
+        return messagesDb.loadNewMessages(student.studentId)
+    }
+
+    fun saveMessages(messages: List<Message>): List<Long> {
+        return messagesDb.insertAll(messages)
+    }
+
+    fun updateMessage(message: Message) {
+        return messagesDb.update(message)
+    }
+
+    fun updateMessages(messages: List<Message>) {
+        return messagesDb.updateAll(messages)
+    }
+
+    fun deleteMessages(messages: List<Message>) {
+        messagesDb.deleteAll(messages)
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/data/repositories/remote/MessagesRemote.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/repositories/remote/MessagesRemote.kt
@ -0,0 +1,40 @@
+package io.github.wulkanowy.data.repositories.remote
+
+import io.github.wulkanowy.api.Api
+import io.github.wulkanowy.api.messages.Folder
+import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.data.repositories.MessagesRepository
+import io.github.wulkanowy.utils.toLocalDateTime
+import io.reactivex.Single
+import javax.inject.Inject
+import io.github.wulkanowy.api.messages.Message as ApiMessage
+
+class MessagesRemote @Inject constructor(private val api: Api) {
+
+    fun getMessages(studentId: Int, folder: MessagesRepository.MessageFolder): Single<List<Message>> {
+        return api.getMessages(Folder.valueOf(folder.name)).map { messages ->
+            messages.map {
+                Message(
+                    studentId = studentId,
+                    realId = it.id,
+                    messageId = it.messageId,
+                    sender = it.sender,
+                    senderId = it.senderId,
+                    recipient = it.recipient,
+                    recipientId = it.recipientId,
+                    subject = it.subject.trim(),
+                    date = it.date?.toLocalDateTime(),
+                    folderId = it.folderId,
+                    unread = it.unread,
+                    unreadBy = it.unreadBy,
+                    readBy = it.readBy,
+                    removed = it.removed
+                )
+            }
+        }
+    }
+
+    fun getMessagesContent(message: Message, markAsRead: Boolean = false): Single<String> {
+        return api.getMessageContent(message.messageId ?: 0, message.folderId, markAsRead, message.realId ?: 0)
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/services/job/SyncWorker.kt
+++ b/app/src/main/java/io/github/wulkanowy/services/job/SyncWorker.kt
@ -8,12 +8,15 @@ import io.github.wulkanowy.data.repositories.ExamRepository
 import io.github.wulkanowy.data.repositories.GradeRepository
 import io.github.wulkanowy.data.repositories.GradeSummaryRepository
 import io.github.wulkanowy.data.repositories.HomeworkRepository
+import io.github.wulkanowy.data.repositories.MessagesRepository
+import io.github.wulkanowy.data.repositories.MessagesRepository.MessageFolder.RECEIVED
 import io.github.wulkanowy.data.repositories.NoteRepository
 import io.github.wulkanowy.data.repositories.PreferencesRepository
 import io.github.wulkanowy.data.repositories.SemesterRepository
 import io.github.wulkanowy.data.repositories.StudentRepository
 import io.github.wulkanowy.data.repositories.TimetableRepository
 import io.github.wulkanowy.services.notification.GradeNotification
+import io.github.wulkanowy.services.notification.MessageNotification
 import io.github.wulkanowy.services.notification.NoteNotification
 import io.github.wulkanowy.utils.friday
 import io.github.wulkanowy.utils.isHolidays
@ -47,6 +50,9 @@ class SyncWorker : SimpleJobService() {
    @Inject
    lateinit var timetable: TimetableRepository

+    @Inject
+    lateinit var message: MessagesRepository
+
    @Inject
    lateinit var note: NoteRepository

@ -87,6 +93,7 @@ class SyncWorker : SimpleJobService() {
                        attendance.getAttendance(it, start, end, true),
                        exam.getExams(it, start, end, true),
                        timetable.getTimetable(it, start, end, true),
+                        message.getMessages(it.studentId, RECEIVED, true, true),
                        note.getNotes(it, true, true),
                        homework.getHomework(it, LocalDate.now(), true),
                        homework.getHomework(it, LocalDate.now().plusDays(1), true)
@ -107,35 +114,57 @@ class SyncWorker : SimpleJobService() {

    private fun sendNotifications() {
        sendGradeNotifications()
+        sendMessageNotification()
        sendNoteNotification()
    }

    private fun sendGradeNotifications() {
        disposable.add(student.getCurrentStudent()
-            .flatMap { semester.getCurrentSemester(it, true) }
+            .flatMap { semester.getCurrentSemester(it) }
            .flatMap { gradesDetails.getNewGrades(it) }
            .map { it.filter { grade -> !grade.isNotified } }
-            .subscribe({
+            .doOnSuccess {
                if (it.isNotEmpty()) {
                    Timber.d("Found ${it.size} unread grades")
                    GradeNotification(applicationContext).sendNotification(it)
-                    gradesDetails.updateGrades(it.map { grade -> grade.apply { isNotified = true } }).subscribe()
                }
-            }) { Timber.e("Notifications sending failed") })
+            }
+            .map { it.map { grade -> grade.apply { isNotified = true } } }
+            .flatMapCompletable { gradesDetails.updateGrades(it) }
+            .subscribe({}, { Timber.e(it, "Grade notifications sending failed") }))
+    }
+
+    private fun sendMessageNotification() {
+        disposable.add(student.getCurrentStudent()
+            .flatMap { message.getNewMessages(it) }
+            .map { it.filter { message -> !message.isNotified } }
+            .doOnSuccess{
+                if (it.isNotEmpty()) {
+                    Timber.d("Found ${it.size} unread messages")
+                    MessageNotification(applicationContext).sendNotification(it)
+                }
+            }
+            .map { it.map { message -> message.apply { isNotified = true } } }
+            .flatMapCompletable { message.updateMessages(it) }
+            .subscribe({}, { Timber.e(it, "Message notifications sending failed") })
+        )
    }

    private fun sendNoteNotification() {
        disposable.add(student.getCurrentStudent()
-            .flatMap { semester.getCurrentSemester(it, true) }
+            .flatMap { semester.getCurrentSemester(it) }
            .flatMap { note.getNewNotes(it) }
            .map { it.filter { note -> !note.isNotified } }
-            .subscribe({
+            .doOnSuccess {
                if (it.isNotEmpty()) {
                    Timber.d("Found ${it.size} unread notes")
                    NoteNotification(applicationContext).sendNotification(it)
-                    note.updateNotes(it.map { note -> note.apply { isNotified = true } }).subscribe()
                }
-            }) { Timber.e("Notifications sending failed") })
+            }
+            .map { it.map { note -> note.apply { isNotified = true } } }
+            .flatMapCompletable { note.updateNotes(it) }
+            .subscribe({}, { Timber.e("Notifications sending failed") })
+        )
    }

    override fun onDestroy() {
--- a/app/src/main/java/io/github/wulkanowy/services/notification/MessageNotification.kt
+++ b/app/src/main/java/io/github/wulkanowy/services/notification/MessageNotification.kt
@ -0,0 +1,58 @@
+package io.github.wulkanowy.services.notification
+
+import android.annotation.TargetApi
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import androidx.core.app.NotificationCompat
+import androidx.core.content.ContextCompat
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.ui.modules.main.MainActivity
+import timber.log.Timber
+
+class MessageNotification(context: Context) : BaseNotification(context) {
+
+    private val channelId = "Message_Notify"
+
+    @TargetApi(26)
+    override fun createChannel(channelId: String) {
+        notificationManager.createNotificationChannel(NotificationChannel(
+            channelId, context.getString(R.string.notify_message_channel), NotificationManager.IMPORTANCE_HIGH
+        ).apply {
+            enableLights(true)
+            enableVibration(true)
+            lockscreenVisibility = Notification.VISIBILITY_PUBLIC
+        })
+    }
+
+    fun sendNotification(items: List<Message>) {
+        notify(notificationBuilder(channelId)
+            .setContentTitle(context.resources.getQuantityString(R.plurals.message_new_items, items.size, items.size))
+            .setContentText(context.resources.getQuantityString(R.plurals.notify_message_new_items, items.size, items.size))
+            .setSmallIcon(R.drawable.ic_stat_notify_message)
+            .setAutoCancel(true)
+            .setDefaults(NotificationCompat.DEFAULT_ALL)
+            .setPriority(NotificationCompat.PRIORITY_HIGH)
+            .setColor(ContextCompat.getColor(context, R.color.colorPrimary))
+            .setContentIntent(
+                PendingIntent.getActivity(context, 0,
+                    MainActivity.getStartIntent(context).putExtra(MainActivity.EXTRA_START_MENU_INDEX, 4),
+                    PendingIntent.FLAG_UPDATE_CURRENT
+                )
+            )
+            .setStyle(NotificationCompat.InboxStyle().run {
+                setSummaryText(context.resources.getQuantityString(R.plurals.message_number_item, items.size, items.size))
+                items.forEach {
+                    addLine("${it.sender}: ${it.subject}")
+                }
+                this
+            })
+            .build()
+        )
+
+        Timber.d("Notification sent")
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeModule.kt
@ -22,7 +22,7 @@ abstract class GradeModule {
    }

    @PerChildFragment
-    @ContributesAndroidInjector()
+    @ContributesAndroidInjector
    abstract fun bindGradeDetailsFragment(): GradeDetailsFragment

    @PerChildFragment
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/main/MainModule.kt
@ -15,6 +15,9 @@ import io.github.wulkanowy.ui.modules.exam.ExamFragment
 import io.github.wulkanowy.ui.modules.grade.GradeFragment
 import io.github.wulkanowy.ui.modules.grade.GradeModule
 import io.github.wulkanowy.ui.modules.homework.HomeworkFragment
+import io.github.wulkanowy.ui.modules.message.MessageFragment
+import io.github.wulkanowy.ui.modules.message.MessageModule
+import io.github.wulkanowy.ui.modules.message.preview.MessagePreviewFragment
 import io.github.wulkanowy.ui.modules.more.MoreFragment
 import io.github.wulkanowy.ui.modules.note.NoteFragment
 import io.github.wulkanowy.ui.modules.settings.SettingsFragment
@ -46,6 +49,14 @@ abstract class MainModule {
    @ContributesAndroidInjector(modules = [GradeModule::class])
    abstract fun bindGradeFragment(): GradeFragment

+    @PerFragment
+    @ContributesAndroidInjector(modules = [MessageModule::class])
+    abstract fun bindMessagesFragment(): MessageFragment
+
+    @PerFragment
+    @ContributesAndroidInjector
+    abstract fun bindMessagePreviewFragment(): MessagePreviewFragment
+
    @PerFragment
    @ContributesAndroidInjector
    abstract fun bindMoreFragment(): MoreFragment
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageFragment.kt
@ -0,0 +1,83 @@
+package io.github.wulkanowy.ui.modules.message
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.View.INVISIBLE
+import android.view.View.VISIBLE
+import android.view.ViewGroup
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.repositories.MessagesRepository.MessageFolder.RECEIVED
+import io.github.wulkanowy.data.repositories.MessagesRepository.MessageFolder.SENT
+import io.github.wulkanowy.data.repositories.MessagesRepository.MessageFolder.TRASHED
+import io.github.wulkanowy.ui.base.BaseFragment
+import io.github.wulkanowy.ui.base.BasePagerAdapter
+import io.github.wulkanowy.ui.modules.main.MainView
+import io.github.wulkanowy.ui.modules.message.tab.MessageTabFragment
+import io.github.wulkanowy.utils.setOnSelectPageListener
+import kotlinx.android.synthetic.main.fragment_message.*
+import javax.inject.Inject
+
+class MessageFragment : BaseFragment(), MessageView, MainView.TitledView {
+
+    @Inject
+    lateinit var presenter: MessagePresenter
+
+    @Inject
+    lateinit var pagerAdapter: BasePagerAdapter
+
+    companion object {
+        fun newInstance() = MessageFragment()
+    }
+
+    override val titleStringId: Int
+        get() = R.string.message_title
+
+    override val currentPageIndex: Int
+        get() = messageViewPager.currentItem
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        return inflater.inflate(R.layout.fragment_message, container, false)
+    }
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        presenter.onAttachView(this)
+    }
+
+    override fun initView() {
+        pagerAdapter.fragments.putAll(mapOf(
+            getString(R.string.message_inbox) to MessageTabFragment.newInstance(RECEIVED),
+            getString(R.string.message_sent) to MessageTabFragment.newInstance(SENT),
+            getString(R.string.message_trash) to MessageTabFragment.newInstance(TRASHED)
+        ))
+        messageViewPager.run {
+            adapter = pagerAdapter
+            offscreenPageLimit = 2
+            setOnSelectPageListener { presenter.onPageSelected(it) }
+        }
+        messageTabLayout.setupWithViewPager(messageViewPager)
+    }
+
+    override fun showContent(show: Boolean) {
+        messageViewPager.visibility = if (show) VISIBLE else INVISIBLE
+        messageTabLayout.visibility = if (show) VISIBLE else INVISIBLE
+    }
+
+    override fun showProgress(show: Boolean) {
+        messageProgress.visibility = if (show) VISIBLE else INVISIBLE
+    }
+
+    fun onChildFragmentLoaded() {
+        presenter.onChildViewLoaded()
+    }
+
+    override fun notifyChildLoadData(index: Int, forceRefresh: Boolean) {
+        (childFragmentManager.fragments[index] as MessageView.MessageChildView).onParentLoadData(forceRefresh)
+    }
+
+    override fun onDestroyView() {
+        presenter.onDetachView()
+        super.onDestroyView()
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageItem.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageItem.kt
@ -0,0 +1,67 @@
+package io.github.wulkanowy.ui.modules.message
+
+import android.graphics.Typeface.BOLD
+import android.graphics.Typeface.NORMAL
+import android.view.View
+import eu.davidea.flexibleadapter.FlexibleAdapter
+import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
+import eu.davidea.flexibleadapter.items.IFlexible
+import eu.davidea.viewholders.FlexibleViewHolder
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.utils.toFormattedString
+import kotlinx.android.extensions.LayoutContainer
+import kotlinx.android.synthetic.main.item_message.*
+
+class MessageItem(val message: Message, private val noSubjectString: String) :
+    AbstractFlexibleItem<MessageItem.ViewHolder>() {
+
+    override fun createViewHolder(view: View, adapter: FlexibleAdapter<IFlexible<*>>): ViewHolder {
+        return ViewHolder(view, adapter)
+    }
+
+    override fun getLayoutRes(): Int = R.layout.item_message
+
+    override fun bindViewHolder(
+        adapter: FlexibleAdapter<IFlexible<*>>, holder: ViewHolder,
+        position: Int, payloads: MutableList<Any>?
+    ) {
+        holder.apply {
+            val style = if (message.unread == true) BOLD else NORMAL
+
+            messageItemAuthor.run {
+                text = if (message.recipient?.isNotBlank() == true) message.recipient else message.sender
+                setTypeface(null, style)
+            }
+            messageItemSubject.run {
+                text = if (message.subject.isNotBlank()) message.subject else noSubjectString
+                setTypeface(null, style)
+            }
+            messageItemDate.run {
+                text = message.date?.toFormattedString()
+                setTypeface(null, style)
+            }
+        }
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (javaClass != other?.javaClass) return false
+
+        other as MessageItem
+
+        if (message != other.message) return false
+        return true
+    }
+
+    override fun hashCode(): Int {
+        return message.hashCode()
+    }
+
+    class ViewHolder(val view: View, adapter: FlexibleAdapter<*>) : FlexibleViewHolder(view, adapter),
+        LayoutContainer {
+
+        override val containerView: View
+            get() = contentView
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageModule.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageModule.kt
@ -0,0 +1,26 @@
+package io.github.wulkanowy.ui.modules.message
+
+import dagger.Module
+import dagger.Provides
+import dagger.android.ContributesAndroidInjector
+import io.github.wulkanowy.di.scopes.PerChildFragment
+import io.github.wulkanowy.di.scopes.PerFragment
+import io.github.wulkanowy.ui.base.BasePagerAdapter
+import io.github.wulkanowy.ui.modules.message.tab.MessageTabFragment
+
+@Module
+abstract class MessageModule {
+
+    @Module
+    companion object {
+
+        @JvmStatic
+        @PerFragment
+        @Provides
+        fun provideGradePagerAdapter(fragment: MessageFragment) = BasePagerAdapter(fragment.childFragmentManager)
+    }
+
+    @PerChildFragment
+    @ContributesAndroidInjector
+    abstract fun bindMessageTabFragment(): MessageTabFragment
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessagePresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessagePresenter.kt
@ -0,0 +1,42 @@
+package io.github.wulkanowy.ui.modules.message
+
+import io.github.wulkanowy.data.ErrorHandler
+import io.github.wulkanowy.ui.base.BasePresenter
+import io.github.wulkanowy.utils.SchedulersProvider
+import io.reactivex.Completable
+import java.util.concurrent.TimeUnit.MILLISECONDS
+import javax.inject.Inject
+
+class MessagePresenter @Inject constructor(
+    errorHandler: ErrorHandler,
+    private val schedulers: SchedulersProvider
+) : BasePresenter<MessageView>(errorHandler) {
+
+    override fun onAttachView(view: MessageView) {
+        super.onAttachView(view)
+        disposable.add(Completable.timer(150, MILLISECONDS, schedulers.mainThread)
+            .subscribe {
+                view.initView()
+                loadData()
+            })
+    }
+
+    fun onPageSelected(index: Int) {
+        loadChild(index)
+    }
+
+    private fun loadData() {
+        view?.run { loadChild(currentPageIndex) }
+    }
+
+    private fun loadChild(index: Int, forceRefresh: Boolean = false) {
+        view?.notifyChildLoadData(index, forceRefresh)
+    }
+
+    fun onChildViewLoaded() {
+        view?.apply {
+            showContent(true)
+            showProgress(false)
+        }
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageView.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/MessageView.kt
@ -0,0 +1,21 @@
+package io.github.wulkanowy.ui.modules.message
+
+import io.github.wulkanowy.ui.base.BaseView
+
+interface MessageView : BaseView {
+
+    val currentPageIndex: Int
+
+    fun initView()
+
+    fun showContent(show: Boolean)
+
+    fun showProgress(show: Boolean)
+
+    fun notifyChildLoadData(index: Int, forceRefresh: Boolean)
+
+    interface MessageChildView {
+
+        fun onParentLoadData(forceRefresh: Boolean)
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewFragment.kt
@ -0,0 +1,81 @@
+package io.github.wulkanowy.ui.modules.message.preview
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import io.github.wulkanowy.R
+import io.github.wulkanowy.ui.base.BaseFragment
+import io.github.wulkanowy.ui.modules.main.MainView
+import kotlinx.android.synthetic.main.fragment_message_preview.*
+import javax.inject.Inject
+
+class MessagePreviewFragment : BaseFragment(), MessagePreviewView, MainView.TitledView {
+
+    @Inject
+    lateinit var presenter: MessagePreviewPresenter
+
+    override val titleStringId: Int
+        get() = R.string.message_title
+
+    override val noSubjectString: String
+        get() = getString(R.string.message_no_subject)
+
+    companion object {
+        const val MESSAGE_ID_KEY = "message_id"
+
+        fun newInstance(messageId: Int?): MessagePreviewFragment {
+            return MessagePreviewFragment().apply {
+                arguments = Bundle().apply { putInt(MESSAGE_ID_KEY, messageId ?: 0) }
+            }
+        }
+    }
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        return inflater.inflate(R.layout.fragment_message_preview, container, false)
+    }
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        messageContainer = message
+        presenter.onAttachView(this, (savedInstanceState ?: arguments)?.getInt(MESSAGE_ID_KEY) ?: 0)
+    }
+
+    override fun setSubject(subject: String) {
+        messageSubject.text = subject
+    }
+
+    override fun setRecipient(recipient: String?) {
+        messageAuthor.text = getString(R.string.message_to, recipient)
+    }
+
+    override fun setSender(sender: String?) {
+        messageAuthor.text = getString(R.string.message_from, sender)
+    }
+
+    override fun setDate(date: String?) {
+        messageDate.text = getString(R.string.message_date, date)
+    }
+
+    override fun setContent(content: String?) {
+        messageContent.text = content
+    }
+
+    override fun showProgress(show: Boolean) {
+        messageProgress.visibility = if (show) View.VISIBLE else View.GONE
+    }
+
+    override fun showMessageError() {
+        messageError.visibility = View.VISIBLE
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        outState.putInt(MESSAGE_ID_KEY, presenter.messageId)
+    }
+
+    override fun onDestroyView() {
+        presenter.onDetachView()
+        super.onDestroyView()
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewPresenter.kt
@ -0,0 +1,53 @@
+package io.github.wulkanowy.ui.modules.message.preview
+
+import io.github.wulkanowy.data.ErrorHandler
+import io.github.wulkanowy.data.repositories.MessagesRepository
+import io.github.wulkanowy.data.repositories.StudentRepository
+import io.github.wulkanowy.ui.base.BasePresenter
+import io.github.wulkanowy.utils.SchedulersProvider
+import io.github.wulkanowy.utils.logEvent
+import io.github.wulkanowy.utils.toFormattedString
+import javax.inject.Inject
+
+class MessagePreviewPresenter @Inject constructor(
+    private val errorHandler: ErrorHandler,
+    private val schedulers: SchedulersProvider,
+    private val messagesRepository: MessagesRepository,
+    private val studentRepository: StudentRepository
+) : BasePresenter<MessagePreviewView>(errorHandler) {
+
+    var messageId: Int = 0
+
+    fun onAttachView(view: MessagePreviewView, id: Int) {
+        super.onAttachView(view)
+        loadData(id)
+    }
+
+    private fun loadData(id: Int) {
+        messageId = id
+        disposable.apply {
+            clear()
+            add(studentRepository.getCurrentStudent()
+                .flatMap { messagesRepository.getMessage(it.studentId, messageId, true) }
+                .subscribeOn(schedulers.backgroundThread)
+                .observeOn(schedulers.mainThread)
+                .doFinally { view?.showProgress(false) }
+                .subscribe({ messages ->
+                    view?.run {
+                        messages.let {
+                            setSubject(if (it.subject.isNotBlank()) it.subject else noSubjectString)
+                            setDate(it.date?.toFormattedString("yyyy-MM-dd HH:mm:ss"))
+                            setContent(it.content)
+
+                            if (it.recipient?.isNotBlank() == true) setRecipient(it.recipient)
+                            else setSender(it.sender)
+                        }
+                    }
+                    logEvent("Message load", mapOf("length" to messages.content?.length))
+                }) {
+                    view?.showMessageError()
+                    errorHandler.dispatch(it)
+                })
+        }
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewView.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/preview/MessagePreviewView.kt
@ -0,0 +1,22 @@
+package io.github.wulkanowy.ui.modules.message.preview
+
+import io.github.wulkanowy.ui.base.BaseView
+
+interface MessagePreviewView : BaseView {
+
+    val noSubjectString: String
+
+    fun setSubject(subject: String)
+
+    fun setRecipient(recipient: String?)
+
+    fun setSender(sender: String?)
+
+    fun setDate(date: String?)
+
+    fun setContent(content: String?)
+
+    fun showProgress(show: Boolean)
+
+    fun showMessageError()
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabFragment.kt
@ -0,0 +1,122 @@
+package io.github.wulkanowy.ui.modules.message.tab
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.View.GONE
+import android.view.View.INVISIBLE
+import android.view.View.VISIBLE
+import android.view.ViewGroup
+import eu.davidea.flexibleadapter.FlexibleAdapter
+import eu.davidea.flexibleadapter.common.SmoothScrollLinearLayoutManager
+import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.repositories.MessagesRepository
+import io.github.wulkanowy.ui.base.BaseFragment
+import io.github.wulkanowy.ui.modules.main.MainActivity
+import io.github.wulkanowy.ui.modules.message.MessageFragment
+import io.github.wulkanowy.ui.modules.message.MessageItem
+import io.github.wulkanowy.ui.modules.message.MessageView
+import io.github.wulkanowy.ui.modules.message.preview.MessagePreviewFragment
+import io.github.wulkanowy.utils.setOnItemClickListener
+import kotlinx.android.synthetic.main.fragment_message_tab.*
+import javax.inject.Inject
+
+class MessageTabFragment : BaseFragment(), MessageTabView, MessageView.MessageChildView {
+
+    @Inject
+    lateinit var presenter: MessageTabPresenter
+
+    @Inject
+    lateinit var tabAdapter: FlexibleAdapter<AbstractFlexibleItem<*>>
+
+    companion object {
+        const val MESSAGE_TAB_FOLDER_ID = "message_tab_folder_id"
+
+        fun newInstance(folder: MessagesRepository.MessageFolder): MessageTabFragment {
+            return MessageTabFragment().apply {
+                arguments = Bundle().apply {
+                    putString(MESSAGE_TAB_FOLDER_ID, folder.name)
+                }
+            }
+        }
+    }
+
+    override val noSubjectString: String
+        get() = getString(R.string.message_no_subject)
+
+    override val isViewEmpty
+        get() = tabAdapter.isEmpty
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        return inflater.inflate(R.layout.fragment_message_tab, container, false)
+    }
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        messageContainer = messageTabRecycler
+        presenter.onAttachView(this, MessagesRepository.MessageFolder.valueOf(
+            (savedInstanceState ?: arguments)?.getString(MessageTabFragment.MESSAGE_TAB_FOLDER_ID) ?: ""
+        ))
+    }
+
+    override fun initView() {
+        tabAdapter.setOnItemClickListener { presenter.onMessageItemSelected(it) }
+
+        messageTabRecycler.run {
+            layoutManager = SmoothScrollLinearLayoutManager(context)
+            adapter = tabAdapter
+        }
+        messageTabSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+    }
+
+    override fun updateData(data: List<MessageItem>) {
+        tabAdapter.updateDataSet(data, true)
+    }
+
+    override fun updateItem(item: AbstractFlexibleItem<*>) {
+        tabAdapter.updateItem(item)
+    }
+
+    override fun clearView() {
+        tabAdapter.clear()
+    }
+
+    override fun showProgress(show: Boolean) {
+        messageTabProgress.visibility = if (show) VISIBLE else GONE
+    }
+
+    override fun showContent(show: Boolean) {
+        messageTabRecycler.visibility = if (show) VISIBLE else INVISIBLE
+    }
+
+    override fun showEmpty(show: Boolean) {
+        messageTabEmpty.visibility = if (show) VISIBLE else INVISIBLE
+    }
+
+    override fun showRefresh(show: Boolean) {
+        messageTabSwipe.isRefreshing = show
+    }
+
+    override fun openMessage(messageId: Int?) {
+        (activity as? MainActivity)?.pushView(MessagePreviewFragment.newInstance(messageId))
+    }
+
+    override fun notifyParentDataLoaded() {
+        (parentFragment as? MessageFragment)?.onChildFragmentLoaded()
+    }
+
+    override fun onParentLoadData(forceRefresh: Boolean) {
+        presenter.onParentViewLoadData(forceRefresh)
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        outState.putString(MessageTabFragment.MESSAGE_TAB_FOLDER_ID, presenter.folder.name)
+    }
+
+    override fun onDestroyView() {
+        presenter.onDetachView()
+        super.onDestroyView()
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabPresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabPresenter.kt
@ -0,0 +1,85 @@
+package io.github.wulkanowy.ui.modules.message.tab
+
+import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
+import io.github.wulkanowy.data.ErrorHandler
+import io.github.wulkanowy.data.db.entities.Message
+import io.github.wulkanowy.data.repositories.MessagesRepository
+import io.github.wulkanowy.data.repositories.StudentRepository
+import io.github.wulkanowy.ui.base.BasePresenter
+import io.github.wulkanowy.ui.modules.message.MessageItem
+import io.github.wulkanowy.utils.SchedulersProvider
+import io.github.wulkanowy.utils.logEvent
+import timber.log.Timber
+import javax.inject.Inject
+
+class MessageTabPresenter @Inject constructor(
+    private val errorHandler: ErrorHandler,
+    private val schedulers: SchedulersProvider,
+    private val messagesRepository: MessagesRepository,
+    private val studentRepository: StudentRepository
+) : BasePresenter<MessageTabView>(errorHandler) {
+
+    lateinit var folder: MessagesRepository.MessageFolder
+
+    fun onAttachView(view: MessageTabView, folder: MessagesRepository.MessageFolder) {
+        super.onAttachView(view)
+        view.initView()
+        this.folder = folder
+    }
+
+    fun onSwipeRefresh() {
+        onParentViewLoadData(true)
+    }
+
+    fun onParentViewLoadData(forceRefresh: Boolean) {
+        disposable.apply {
+            clear()
+            add(studentRepository.getCurrentStudent()
+                .flatMap { messagesRepository.getMessages(it.studentId, folder, forceRefresh) }
+                .map { items -> items.map { MessageItem(it, view?.noSubjectString.orEmpty()) } }
+                .subscribeOn(schedulers.backgroundThread)
+                .observeOn(schedulers.mainThread)
+                .doFinally {
+                    view?.run {
+                        showRefresh(false)
+                        showProgress(false)
+                        notifyParentDataLoaded()
+                    }
+                }
+                .subscribe({
+                    view?.run {
+                        showEmpty(it.isEmpty())
+                        showContent(it.isNotEmpty())
+                        updateData(it)
+                    }
+                    logEvent("Message tab load", mapOf("items" to it.size, "forceRefresh" to forceRefresh))
+                }) {
+                    view?.run { showEmpty(isViewEmpty) }
+                    errorHandler.dispatch(it)
+                })
+        }
+    }
+
+    fun onMessageItemSelected(item: AbstractFlexibleItem<*>) {
+        if (item is MessageItem) {
+            view?.run {
+                openMessage(item.message.realId)
+                if (item.message.unread == true) {
+                    item.message.unread = false
+                    updateItem(item)
+                    updateMessage(item.message)
+                }
+            }
+        }
+    }
+
+    private fun updateMessage(message: Message) {
+        disposable.add(messagesRepository.updateMessage(message)
+            .subscribeOn(schedulers.backgroundThread)
+            .observeOn(schedulers.mainThread)
+            .subscribe({
+                Timber.d("Message ${message.realId} updated")
+            }) { error -> errorHandler.dispatch(error) }
+        )
+    }
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabView.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/message/tab/MessageTabView.kt
@ -0,0 +1,32 @@
+package io.github.wulkanowy.ui.modules.message.tab
+
+import eu.davidea.flexibleadapter.items.AbstractFlexibleItem
+import io.github.wulkanowy.ui.base.BaseView
+import io.github.wulkanowy.ui.modules.message.MessageItem
+
+interface MessageTabView : BaseView {
+
+    val noSubjectString: String
+
+    val isViewEmpty: Boolean
+
+    fun initView()
+
+    fun updateData(data: List<MessageItem>)
+
+    fun updateItem(item: AbstractFlexibleItem<*>)
+
+    fun clearView()
+
+    fun showProgress(show: Boolean)
+
+    fun showContent(show: Boolean)
+
+    fun showEmpty(show: Boolean)
+
+    fun showRefresh(show: Boolean)
+
+    fun openMessage(messageId: Int?)
+
+    fun notifyParentDataLoaded()
+}
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreFragment.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreFragment.kt
@ -15,6 +15,7 @@ import io.github.wulkanowy.ui.modules.about.AboutFragment
 import io.github.wulkanowy.ui.modules.homework.HomeworkFragment
 import io.github.wulkanowy.ui.modules.main.MainActivity
 import io.github.wulkanowy.ui.modules.main.MainView
+import io.github.wulkanowy.ui.modules.message.MessageFragment
 import io.github.wulkanowy.ui.modules.note.NoteFragment
 import io.github.wulkanowy.ui.modules.settings.SettingsFragment
 import io.github.wulkanowy.utils.setOnItemClickListener
@ -36,6 +37,15 @@ class MoreFragment : BaseFragment(), MoreView, MainView.TitledView, MainView.Mai
    override val titleStringId: Int
        get() = R.string.more_title

+
+    override val messagesRes: Pair<String, Drawable?>?
+        get() {
+            return context?.run {
+                getString(R.string.message_title) to
+                    ContextCompat.getDrawable(this, R.drawable.ic_more_messages_24dp)
+            }
+        }
+
    override val homeworkRes: Pair<String, Drawable?>?
        get() {
            return context?.run {
@ -92,6 +102,10 @@ class MoreFragment : BaseFragment(), MoreView, MainView.TitledView, MainView.Mai
        moreAdapter.updateDataSet(data)
    }

+    override fun openMessagesView() {
+        (activity as? MainActivity)?.pushView(MessageFragment.newInstance())
+    }
+
    override fun openHomeworkView() {
        (activity as? MainActivity)?.pushView(HomeworkFragment.newInstance())
    }
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/more/MorePresenter.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/more/MorePresenter.kt
@ -17,6 +17,7 @@ class MorePresenter @Inject constructor(errorHandler: ErrorHandler) : BasePresen
        if (item is MoreItem) {
            view?.run {
                when (item.title) {
+                    messagesRes?.first -> openMessagesView()
                    homeworkRes?.first -> openHomeworkView()
                    noteRes?.first -> openNoteView()
                    settingsRes?.first -> openSettingsView()
@ -33,6 +34,7 @@ class MorePresenter @Inject constructor(errorHandler: ErrorHandler) : BasePresen
    private fun loadData() {
        view?.run {
            updateData(listOfNotNull(
+                messagesRes?.let { MoreItem(it.first, it.second) },
                homeworkRes?.let { MoreItem(it.first, it.second) },
                noteRes?.let { MoreItem(it.first, it.second) },
                settingsRes?.let { MoreItem(it.first, it.second) },
--- a/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreView.kt
+++ b/app/src/main/java/io/github/wulkanowy/ui/modules/more/MoreView.kt
@ -5,6 +5,8 @@ import io.github.wulkanowy.ui.base.BaseView

 interface MoreView : BaseView {

+    val messagesRes: Pair<String, Drawable?>?
+
    val homeworkRes: Pair<String, Drawable?>?

    val noteRes: Pair<String, Drawable?>?
@ -23,6 +25,8 @@ interface MoreView : BaseView {

    fun popView()

+    fun openMessagesView()
+
    fun openHomeworkView()

    fun openNoteView()
--- a/app/src/main/java/io/github/wulkanowy/utils/TimeExtension.kt
+++ b/app/src/main/java/io/github/wulkanowy/utils/TimeExtension.kt
@ -1,5 +1,6 @@
 package io.github.wulkanowy.utils

+import org.threeten.bp.DateTimeUtils
 import org.threeten.bp.DayOfWeek.*
 import org.threeten.bp.Instant
 import org.threeten.bp.LocalDate
--- a/app/src/main/res/drawable-hdpi/ic_stat_notify_message.png
+++ b/app/src/main/res/drawable-hdpi/ic_stat_notify_message.png
--- a/app/src/main/res/drawable-mdpi/ic_stat_notify_message.png
+++ b/app/src/main/res/drawable-mdpi/ic_stat_notify_message.png
--- a/app/src/main/res/drawable-xhdpi/ic_stat_notify_message.png
+++ b/app/src/main/res/drawable-xhdpi/ic_stat_notify_message.png
--- a/app/src/main/res/drawable-xxhdpi/ic_stat_notify_message.png
+++ b/app/src/main/res/drawable-xxhdpi/ic_stat_notify_message.png
--- a/app/src/main/res/drawable-xxxhdpi/ic_stat_notify_message.png
+++ b/app/src/main/res/drawable-xxxhdpi/ic_stat_notify_message.png
--- a/app/src/main/res/drawable/ic_more_messages_24dp.xml
+++ b/app/src/main/res/drawable/ic_more_messages_24dp.xml
@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24.0"
+    android:viewportHeight="24.0">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M20,4L4,4c-1.1,0 -1.99,0.9 -1.99,2L2,18c0,1.1 0.9,2 2,2h16c1.1,0 2,-0.9 2,-2L22,6c0,-1.1 -0.9,-2 -2,-2zM20,8l-8,5 -8,-5L4,6l8,5 8,-5v2z" />
+</vector>
--- a/app/src/main/res/layout/fragment_grade.xml
+++ b/app/src/main/res/layout/fragment_grade.xml
@ -57,4 +57,4 @@
            android:text="@string/grade_no_items"
            android:textSize="20sp" />
    </LinearLayout>
-</androidx.coordinatorlayout.widget.CoordinatorLayout>
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
--- a/app/src/main/res/layout/fragment_message.xml
+++ b/app/src/main/res/layout/fragment_message.xml
@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.google.android.material.tabs.TabLayout
+        android:id="@+id/messageTabLayout"
+        android:layout_width="match_parent"
+        android:layout_height="48dp"
+        android:background="@color/colorPrimary"
+        android:elevation="5dp"
+        android:visibility="invisible"
+        app:tabGravity="fill"
+        app:tabIndicatorColor="@android:color/white"
+        app:tabMaxWidth="0dp"
+        app:tabMode="fixed"
+        app:tabTextColor="@android:color/white" />
+
+    <androidx.viewpager.widget.ViewPager
+        android:id="@+id/messageViewPager"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:layout_marginTop="48dp"
+        android:visibility="invisible" />
+
+    <ProgressBar
+        android:id="@+id/messageProgress"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:indeterminate="true" />
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
--- a/app/src/main/res/layout/fragment_message_preview.xml
+++ b/app/src/main/res/layout/fragment_message_preview.xml
@ -0,0 +1,90 @@
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <ScrollView
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <LinearLayout
+            android:id="@+id/message"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical"
+            android:padding="16dp">
+
+            <TextView
+                android:id="@+id/messageSubject"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="15dp"
+                android:lineSpacingMultiplier="1.2"
+                android:textSize="22sp"
+                tools:text="@tools:sample/lorem" />
+
+            <TextView
+                android:id="@+id/messageAuthor"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="4dp"
+                android:textColor="?android:attr/textColorSecondary"
+                android:textSize="15sp"
+                tools:text="@tools:sample/full_names" />
+
+            <TextView
+                android:id="@+id/messageDate"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginBottom="15dp"
+                android:textColor="?android:attr/textColorSecondary"
+                android:textSize="15sp"
+                tools:text="@tools:sample/date/ddmmyy" />
+
+            <TextView
+                android:id="@+id/messageContent"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:autoLink="web"
+                android:lineSpacingMultiplier="1.2"
+                android:textIsSelectable="true"
+                tools:text="@tools:sample/lorem" />
+        </LinearLayout>
+
+    </ScrollView>
+
+    <LinearLayout
+        android:id="@+id/messageError"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:padding="10dp"
+        android:visibility="invisible">
+
+        <androidx.appcompat.widget.AppCompatImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:minWidth="100dp"
+            android:minHeight="100dp"
+            app:srcCompat="@drawable/ic_more_messages_24dp"
+            app:tint="?android:attr/textColorPrimary"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:text="@string/message_preview_error"
+            android:textSize="20sp" />
+    </LinearLayout>
+
+    <ProgressBar
+        android:id="@+id/messageProgress"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:indeterminate="true" />
+</FrameLayout>
--- a/app/src/main/res/layout/fragment_message_tab.xml
+++ b/app/src/main/res/layout/fragment_message_tab.xml
@ -0,0 +1,50 @@
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+        android:id="@+id/messageTabSwipe"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <androidx.recyclerview.widget.RecyclerView
+            android:id="@+id/messageTabRecycler"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent" />
+    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+
+    <ProgressBar
+        android:id="@+id/messageTabProgress"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center"
+        android:indeterminate="true" />
+
+    <LinearLayout
+        android:id="@+id/messageTabEmpty"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:visibility="invisible">
+
+        <androidx.appcompat.widget.AppCompatImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:minWidth="100dp"
+            android:minHeight="100dp"
+            app:srcCompat="@drawable/ic_more_messages_24dp"
+            app:tint="?android:attr/textColorPrimary"
+            tools:ignore="contentDescription" />
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="20dp"
+            android:gravity="center"
+            android:text="@string/message_no_items"
+            android:textSize="20sp" />
+    </LinearLayout>
+</FrameLayout>
--- a/app/src/main/res/layout/item_message.xml
+++ b/app/src/main/res/layout/item_message.xml
@ -0,0 +1,52 @@
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tool="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="@drawable/ic_all_divider"
+    android:foreground="?attr/selectableItemBackgroundBorderless"
+    android:paddingLeft="16dp"
+    android:paddingTop="10dp"
+    android:paddingRight="16dp"
+    android:paddingBottom="10dp">
+
+    <TextView
+        android:id="@+id/messageItemAuthor"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_alignParentTop="true"
+        android:layout_marginEnd="40dp"
+        android:layout_marginRight="40dp"
+        android:ellipsize="end"
+        android:maxLines="1"
+        android:textSize="15sp"
+        tool:text="@tools:sample/full_names" />
+
+    <TextView
+        android:id="@+id/messageItemDate"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_alignParentEnd="true"
+        android:layout_alignParentRight="true"
+        android:layout_marginStart="10dp"
+        android:layout_marginLeft="10dp"
+        android:layout_toEndOf="@id/messageItemAuthor"
+        android:layout_toRightOf="@id/messageItemAuthor"
+        android:gravity="end"
+        android:textSize="13sp"
+        tool:text="@tools:sample/date/mmddyy" />
+
+    <TextView
+        android:id="@+id/messageItemSubject"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_below="@+id/messageItemAuthor"
+        android:layout_alignStart="@id/messageItemAuthor"
+        android:layout_alignLeft="@id/messageItemAuthor"
+        android:layout_marginTop="5dp"
+        android:ellipsize="end"
+        android:maxLines="1"
+        android:textColor="?android:attr/android:textColorSecondary"
+        android:textSize="12sp"
+        tool:text="@tools:sample/lorem" />
+
+</RelativeLayout>
--- a/app/src/main/res/values-pl/strings.xml
+++ b/app/src/main/res/values-pl/strings.xml
@ -11,6 +11,7 @@
    <string name="settings_title">Ustawienia</string>
    <string name="more_title">Więcej</string>
    <string name="about_title">O aplikacji</string>
+    <string name="message_title">Wiadomości</string>
    <string name="note_title">Uwagi i osiągnięcia</string>
    <string name="homework_title">Zadania domowe</string>
    <string name="account_title">Wybierz konto</string>
@ -68,8 +69,7 @@
    <plurals name="grade_new_items">
        <item quantity="one">Nowa ocena</item>
        <item quantity="few">Nowe oceny</item>
-        <item quantity="many">Nowych ocen</item>
-        <item quantity="other">Nowych ocen</item>
+        <item quantity="many">Nowe oceny</item>
    </plurals>


@ -124,6 +124,38 @@
    <string name="exam_type">Typ</string>
    <string name="exam_entry_date">Data wpisu</string>

+
+    <!--Message-->
+    <string name="message_inbox">Odebrane</string>
+    <string name="message_sent">Wysłane</string>
+    <string name="message_trash">Kosz</string>
+    <string name="message_no_subject">(brak tematu)</string>
+    <string name="message_no_items">Brak wiadomości</string>
+    <string name="message_preview_error">Wystąpił błąd podczas pobierania treści wiadomości</string>
+    <string name="message_from">Od: %s</string>
+    <string name="message_to">Do: %s</string>
+    <string name="message_date">Data: %s</string>
+    <plurals name="message_number_item">
+        <item quantity="one">%d wiadomość</item>
+        <item quantity="few">%d wiadomości</item>
+        <item quantity="many">%d wiadomości</item>
+    </plurals>
+
+    <plurals name="message_new_items">
+        <item quantity="one">Nowa wiadomość</item>
+        <item quantity="few">Nowe wiadomości</item>
+        <item quantity="many">Nowe wiadomości</item>
+    </plurals>
+
+
+    <!--Message notify-->
+    <string name="notify_message_channel">Nowe wiadomości</string>
+    <plurals name="notify_message_new_items">
+        <item quantity="one">Dostałeś %1$d wiadomość</item>
+        <item quantity="few">"Dostałeś %1$d wiadomości</item>
+        <item quantity="many">Dostałeś %1$d wiadomości</item>
+    </plurals>
+
    <!--About-->
    <string name="about_source_code">Kod źródłowy</string>
    <string name="about_feedback">Zgłoś błąd</string>
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@ -11,6 +11,7 @@
    <string name="settings_title">Settings</string>
    <string name="more_title">More</string>
    <string name="about_title">About</string>
+    <string name="message_title">Messages</string>
    <string name="note_title">Notes and achievements</string>
    <string name="homework_title">Homework</string>
    <string name="account_title">Choose account</string>
@ -113,6 +114,34 @@
    <string name="exam_type">Type</string>
    <string name="exam_entry_date">Entry date</string>

+
+    <!--Message-->
+    <string name="message_inbox">Inbox</string>
+    <string name="message_sent">Sent</string>
+    <string name="message_trash">Trash</string>
+    <string name="message_no_subject">(no subject)</string>
+    <string name="message_no_items">No messages</string>
+    <string name="message_preview_error">An error occurred while downloading message content</string>
+    <string name="message_from">From: %s</string>
+    <string name="message_to">To: %s</string>
+    <string name="message_date">Date: %s</string>
+    <plurals name="message_number_item">
+        <item quantity="one">%d message</item>
+        <item quantity="other">%d messages</item>
+    </plurals>
+
+    <plurals name="message_new_items">
+        <item quantity="one">New message</item>
+        <item quantity="other">New messages</item>
+    </plurals>
+
+    <!--Message notify-->
+    <string name="notify_message_channel">New messages</string>
+    <plurals name="notify_message_new_items">
+        <item quantity="one">You received %1$d message</item>
+        <item quantity="other">You received %1$d messages</item>
+    </plurals>
+
    <!--About-->
    <string name="about_source_code">Source code</string>
    <string name="about_feedback">Report a bug</string>