Add grade statistics (#251)

app/build.gradle

@@ -97,6 +97,9 @@ dependencies {
     implementation "com.aurelhubert:ahbottomnavigation:2.3.4"
     implementation 'com.ncapdevi:frag-nav:3.1.0'
 
+    implementation "com.hootsuite.android:nachos:1.1.1"
+    implementation 'com.github.PhilJay:MPAndroidChart:971640b29d'
+
     implementation 'com.github.pwittchen:reactivenetwork-rx2:3.0.2'
     implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
     implementation "io.reactivex.rxjava2:rxjava:2.2.5"
@@ -125,8 +128,6 @@ dependencies {
     androidTestImplementation 'androidx.test.ext:junit:1.1.0'
     androidTestImplementation 'org.mockito:mockito-android:2.23.4'
     androidTestImplementation "org.jetbrains.kotlin:kotlin-test:$kotlin_version"
-
-    implementation "com.hootsuite.android:nachos:1.1.1"
 }
 
 apply plugin: 'com.google.gms.google-services'

app/proguard-rules.pro

@@ -32,5 +32,8 @@
 -dontwarn rx.internal.util.**
 -dontwarn sun.misc.Unsafe
 
+#Config for MPAndroidChart
+-keep class com.github.mikephil.charting.** { *; }
+
 #Config for API
 -keep class io.github.wulkanowy.api.** {*;}

app/src/androidTest/java/io/github/wulkanowy/data/repositories/grade/GradeStatisticsLocalTest.kt

@@ -0,0 +1,69 @@
+package io.github.wulkanowy.data.repositories.grade
+
+import androidx.room.Room
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import io.github.wulkanowy.data.db.AppDatabase
+import io.github.wulkanowy.data.db.entities.GradeStatistics
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.repositories.gradestatistics.GradeStatisticsLocal
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import kotlin.test.assertEquals
+
+@RunWith(AndroidJUnit4::class)
+class GradeStatisticsLocalTest {
+
+    private lateinit var gradeStatisticsLocal: GradeStatisticsLocal
+
+    private lateinit var testDb: AppDatabase
+
+    @Before
+    fun createDb() {
+        testDb = Room.inMemoryDatabaseBuilder(ApplicationProvider.getApplicationContext(), AppDatabase::class.java)
+            .build()
+        gradeStatisticsLocal = GradeStatisticsLocal(testDb.gradeStatistics)
+    }
+
+    @After
+    fun closeDb() {
+        testDb.close()
+    }
+
+    @Test
+    fun saveAndRead_subject() {
+        gradeStatisticsLocal.saveGradesStatistics(listOf(
+            getGradeStatistics("Matematyka", 2, 1),
+            getGradeStatistics("Fizyka", 1, 2)
+        ))
+
+        val stats = gradeStatisticsLocal.getGradesStatistics(
+            Semester(2, 2, "", 1, 2, true, 1 ,1), false,
+            "Matematyka"
+        ).blockingGet()
+        assertEquals(1, stats.size)
+        assertEquals(stats[0].subject, "Matematyka")
+    }
+
+    @Test
+    fun saveAndRead_all() {
+        gradeStatisticsLocal.saveGradesStatistics(listOf(
+            getGradeStatistics("Matematyka", 2, 1),
+            getGradeStatistics("Chemia", 2, 1),
+            getGradeStatistics("Fizyka", 1, 2)
+        ))
+
+        val stats = gradeStatisticsLocal.getGradesStatistics(
+            Semester(2, 2, "", 1, 2, true, 1, 1), false,
+            "Wszystkie"
+        ).blockingGet()
+        assertEquals(1, stats.size)
+        assertEquals(stats[0].subject, "Wszystkie")
+    }
+
+    private fun getGradeStatistics(subject: String, studentId: Int, semesterId: Int): GradeStatistics {
+        return GradeStatistics(studentId, semesterId, subject, 5, 5, false)
+    }
+}

app/src/main/AndroidManifest.xml

@@ -4,7 +4,7 @@
     package="io.github.wulkanowy"
     android:installLocation="internalOnly">
 
-    <uses-sdk tools:overrideLibrary="com.readystatesoftware.chuck"/>
+    <uses-sdk tools:overrideLibrary="com.readystatesoftware.chuck" />
 
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
@@ -20,7 +20,7 @@
         android:supportsRtl="false"
         android:theme="@style/WulkanowyTheme"
         android:usesCleartextTraffic="true"
-        tools:ignore="GoogleAppIndexingWarning">
+        tools:ignore="GoogleAppIndexingWarning,UnusedAttribute">
         <activity
             android:name=".ui.modules.splash.SplashActivity"
             android:screenOrientation="portrait"

app/src/main/java/io/github/wulkanowy/data/RepositoryModule.kt

@@ -82,6 +82,10 @@ internal class RepositoryModule {
     @Provides
     fun provideGradeSummaryDao(database: AppDatabase) = database.gradeSummaryDao
 
+    @Singleton
+    @Provides
+    fun provideGradeStatisticsDao(database: AppDatabase) = database.gradeStatistics
+
     @Singleton
     @Provides
     fun provideMessagesDao(database: AppDatabase) = database.messagesDao

app/src/main/java/io/github/wulkanowy/data/db/AppDatabase.kt

@@ -11,6 +11,7 @@ import io.github.wulkanowy.data.db.dao.AttendanceSummaryDao
 import io.github.wulkanowy.data.db.dao.CompletedLessonsDao
 import io.github.wulkanowy.data.db.dao.ExamDao
 import io.github.wulkanowy.data.db.dao.GradeDao
+import io.github.wulkanowy.data.db.dao.GradeStatisticsDao
 import io.github.wulkanowy.data.db.dao.GradeSummaryDao
 import io.github.wulkanowy.data.db.dao.HomeworkDao
 import io.github.wulkanowy.data.db.dao.LuckyNumberDao
@@ -27,6 +28,7 @@ import io.github.wulkanowy.data.db.entities.AttendanceSummary
 import io.github.wulkanowy.data.db.entities.CompletedLesson
 import io.github.wulkanowy.data.db.entities.Exam
 import io.github.wulkanowy.data.db.entities.Grade
+import io.github.wulkanowy.data.db.entities.GradeStatistics
 import io.github.wulkanowy.data.db.entities.GradeSummary
 import io.github.wulkanowy.data.db.entities.Homework
 import io.github.wulkanowy.data.db.entities.LuckyNumber
@@ -43,6 +45,7 @@ import io.github.wulkanowy.data.db.migrations.Migration3
 import io.github.wulkanowy.data.db.migrations.Migration4
 import io.github.wulkanowy.data.db.migrations.Migration5
 import io.github.wulkanowy.data.db.migrations.Migration6
+import io.github.wulkanowy.data.db.migrations.Migration7
 import javax.inject.Singleton
 
 @Singleton
@@ -56,6 +59,7 @@ import javax.inject.Singleton
         AttendanceSummary::class,
         Grade::class,
         GradeSummary::class,
+        GradeStatistics::class,
         Message::class,
         Note::class,
         Homework::class,
@@ -72,7 +76,7 @@ import javax.inject.Singleton
 abstract class AppDatabase : RoomDatabase() {
 
     companion object {
-        const val VERSION_SCHEMA = 6
+        const val VERSION_SCHEMA = 7
 
         fun newInstance(context: Context): AppDatabase {
             return Room.databaseBuilder(context, AppDatabase::class.java, "wulkanowy_database")
@@ -84,7 +88,8 @@ abstract class AppDatabase : RoomDatabase() {
                     Migration3(),
                     Migration4(),
                     Migration5(),
-                    Migration6()
+                    Migration6(),
+                    Migration7()
                 )
                 .build()
         }
@@ -106,6 +111,8 @@ abstract class AppDatabase : RoomDatabase() {
 
     abstract val gradeSummaryDao: GradeSummaryDao
 
+    abstract val gradeStatistics: GradeStatisticsDao
+
     abstract val messagesDao: MessagesDao
 
     abstract val noteDao: NoteDao

app/src/main/java/io/github/wulkanowy/data/db/dao/GradeStatisticsDao.kt

@@ -0,0 +1,26 @@
+package io.github.wulkanowy.data.db.dao
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Insert
+import androidx.room.Query
+import io.github.wulkanowy.data.db.entities.GradeStatistics
+import io.reactivex.Maybe
+import javax.inject.Singleton
+
+@Singleton
+@Dao
+interface GradeStatisticsDao {
+
+    @Insert
+    fun insertAll(gradesStatistics: List<GradeStatistics>)
+
+    @Delete
+    fun deleteAll(gradesStatistics: List<GradeStatistics>)
+
+    @Query("SELECT * FROM GradesStatistics WHERE student_id = :studentId AND semester_id = :semesterId AND subject = :subjectName AND is_semester = :isSemester")
+    fun loadSubject(semesterId: Int, studentId: Int, subjectName: String, isSemester: Boolean): Maybe<List<GradeStatistics>>
+
+    @Query("SELECT * FROM GradesStatistics WHERE student_id = :studentId AND semester_id = :semesterId AND is_semester = :isSemester")
+    fun loadAll(semesterId: Int, studentId: Int, isSemester: Boolean): Maybe<List<GradeStatistics>>
+}

app/src/main/java/io/github/wulkanowy/data/db/entities/GradeStatistics.kt

@@ -0,0 +1,27 @@
+package io.github.wulkanowy.data.db.entities
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity(tableName = "GradesStatistics")
+data class GradeStatistics(
+
+    @ColumnInfo(name = "student_id")
+    val studentId: Int,
+
+    @ColumnInfo(name = "semester_id")
+    val semesterId: Int,
+
+    val subject: String,
+
+    val grade: Int,
+
+    val amount: Int,
+
+    @ColumnInfo(name = "is_semester")
+    val semester: Boolean
+) {
+    @PrimaryKey(autoGenerate = true)
+    var id: Long = 0
+}

app/src/main/java/io/github/wulkanowy/data/db/migrations/Migration7.kt

@@ -0,0 +1,18 @@
+package io.github.wulkanowy.data.db.migrations
+
+import androidx.room.migration.Migration
+import androidx.sqlite.db.SupportSQLiteDatabase
+
+class Migration7 : Migration(6, 7) {
+
+    override fun migrate(database: SupportSQLiteDatabase) {
+        database.execSQL("CREATE TABLE IF NOT EXISTS `GradesStatistics` (" +
+            "`id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL," +
+            "`student_id` INTEGER NOT NULL," +
+            "`semester_id` INTEGER NOT NULL," +
+            "`subject` TEXT NOT NULL," +
+            "`grade` INTEGER NOT NULL," +
+            "`amount` INTEGER NOT NULL," +
+            "`is_semester` INTEGER NOT NULL)")
+    }
+}

app/src/main/java/io/github/wulkanowy/data/repositories/gradestatistics/GradeStatisticsLocal.kt

@@ -0,0 +1,34 @@
+package io.github.wulkanowy.data.repositories.gradestatistics
+
+import io.github.wulkanowy.data.db.dao.GradeStatisticsDao
+import io.github.wulkanowy.data.db.entities.GradeStatistics
+import io.github.wulkanowy.data.db.entities.Semester
+import io.reactivex.Maybe
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class GradeStatisticsLocal @Inject constructor(private val gradeStatisticsDb: GradeStatisticsDao) {
+
+    fun getGradesStatistics(semester: Semester, isSemester: Boolean): Maybe<List<GradeStatistics>> {
+        return gradeStatisticsDb.loadAll(semester.semesterId, semester.studentId, isSemester)
+            .filter { !it.isEmpty() }
+    }
+
+    fun getGradesStatistics(semester: Semester, isSemester: Boolean, subjectName: String): Maybe<List<GradeStatistics>> {
+        return (if ("Wszystkie" == subjectName) gradeStatisticsDb.loadAll(semester.semesterId, semester.studentId, isSemester).map { list ->
+            list.groupBy { it.grade }.map {
+                GradeStatistics(semester.studentId, semester.semesterId, subjectName, it.key, it.value.fold(0) { acc, e -> acc + e.amount }, false)
+            }
+        }
+        else gradeStatisticsDb.loadSubject(semester.semesterId, semester.studentId, subjectName, isSemester)).filter { !it.isEmpty() }
+    }
+
+    fun saveGradesStatistics(gradesStatistics: List<GradeStatistics>) {
+        gradeStatisticsDb.insertAll(gradesStatistics)
+    }
+
+    fun deleteGradesStatistics(gradesStatistics: List<GradeStatistics>) {
+        gradeStatisticsDb.deleteAll(gradesStatistics)
+    }
+}

app/src/main/java/io/github/wulkanowy/data/repositories/gradestatistics/GradeStatisticsRemote.kt

@@ -0,0 +1,29 @@
+package io.github.wulkanowy.data.repositories.gradestatistics
+
+import io.github.wulkanowy.api.Api
+import io.github.wulkanowy.data.db.entities.GradeStatistics
+import io.github.wulkanowy.data.db.entities.Semester
+import io.reactivex.Single
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class GradeStatisticsRemote @Inject constructor(private val api: Api) {
+
+    fun getGradeStatistics(semester: Semester, isSemester: Boolean): Single<List<GradeStatistics>> {
+        return Single.just(api.apply { diaryId = semester.diaryId })
+            .flatMap { it.getGradesStatistics(semester.semesterId, isSemester) }
+            .map { gradeStatistics ->
+                gradeStatistics.map {
+                    GradeStatistics(
+                        semesterId = semester.semesterId,
+                        studentId = semester.studentId,
+                        subject = it.subject,
+                        grade = it.gradeValue,
+                        amount = it.amount ?: 0,
+                        semester = isSemester
+                    )
+                }
+            }
+    }
+}

app/src/main/java/io/github/wulkanowy/data/repositories/gradestatistics/GradeStatisticsRepository.kt

@@ -0,0 +1,33 @@
+package io.github.wulkanowy.data.repositories.gradestatistics
+
+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.GradeStatistics
+import io.github.wulkanowy.data.db.entities.Semester
+import io.reactivex.Single
+import java.net.UnknownHostException
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class GradeStatisticsRepository @Inject constructor(
+    private val settings: InternetObservingSettings,
+    private val local: GradeStatisticsLocal,
+    private val remote: GradeStatisticsRemote
+) {
+
+    fun getGradesStatistics(semester: Semester, subjectName: String, isSemester: Boolean, forceRefresh: Boolean = false): Single<List<GradeStatistics>> {
+        return local.getGradesStatistics(semester, isSemester, subjectName).filter { !forceRefresh }
+            .switchIfEmpty(ReactiveNetwork.checkInternetConnectivity(settings)
+                .flatMap {
+                    if (it) remote.getGradeStatistics(semester, isSemester)
+                    else Single.error(UnknownHostException())
+                }.flatMap { newGradesStats ->
+                    local.getGradesStatistics(semester, isSemester).toSingle(emptyList())
+                        .doOnSuccess { oldGradesStats ->
+                            local.deleteGradesStatistics(oldGradesStats - newGradesStats)
+                            local.saveGradesStatistics(newGradesStats - oldGradesStats)
+                        }
+                }.flatMap { local.getGradesStatistics(semester, isSemester, subjectName).toSingle(emptyList()) })
+    }
+}

app/src/main/java/io/github/wulkanowy/data/repositories/subject/SubjectRepository.kt

@@ -10,7 +10,7 @@ import javax.inject.Inject
 import javax.inject.Singleton
 
 @Singleton
-class SubjectRepostory @Inject constructor(
+class SubjectRepository @Inject constructor(
     private val settings: InternetObservingSettings,
     private val local: SubjectLocal,
     private val remote: SubjectRemote

app/src/main/java/io/github/wulkanowy/ui/modules/attendance/summary/AttendanceSummaryPresenter.kt

@@ -5,7 +5,7 @@ import io.github.wulkanowy.data.db.entities.Subject
 import io.github.wulkanowy.data.repositories.attendancesummary.AttendanceSummaryRepository
 import io.github.wulkanowy.data.repositories.semester.SemesterRepository
 import io.github.wulkanowy.data.repositories.student.StudentRepository
-import io.github.wulkanowy.data.repositories.subject.SubjectRepostory
+import io.github.wulkanowy.data.repositories.subject.SubjectRepository
 import io.github.wulkanowy.ui.base.session.BaseSessionPresenter
 import io.github.wulkanowy.ui.base.session.SessionErrorHandler
 import io.github.wulkanowy.utils.FirebaseAnalyticsHelper
@@ -21,7 +21,7 @@ import javax.inject.Inject
 class AttendanceSummaryPresenter @Inject constructor(
     private val errorHandler: SessionErrorHandler,
     private val attendanceSummaryRepository: AttendanceSummaryRepository,
-    private val subjectRepository: SubjectRepostory,
+    private val subjectRepository: SubjectRepository,
     private val studentRepository: StudentRepository,
     private val semesterRepository: SemesterRepository,
     private val schedulers: SchedulersProvider,

app/src/main/java/io/github/wulkanowy/ui/modules/grade/CustomTabLayout.kt

@@ -0,0 +1,34 @@
+package io.github.wulkanowy.ui.modules.grade
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.ViewGroup
+import com.google.android.material.tabs.TabLayout
+
+/**
+ * @see <a href="https://stackoverflow.com/a/50382854">Tabs don't fit to screen with tabmode=scrollable, Even with a Custom Tab Layout</a>
+ */
+class CustomTabLayout : TabLayout {
+
+    constructor(context: Context) : super(context)
+
+    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
+
+    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
+
+    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+        setMeasuredDimension(widthMeasureSpec, heightMeasureSpec)
+        val tabLayout = getChildAt(0) as ViewGroup
+        val childCount = tabLayout.childCount
+
+        if (childCount == 0) return
+
+        val tabMinWidth = context.resources.displayMetrics.widthPixels / childCount
+
+        for (i in 0 until childCount) {
+            tabLayout.getChildAt(i).minimumWidth = tabMinWidth
+        }
+
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
+    }
+}

app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeFragment.kt

@@ -14,6 +14,7 @@ import io.github.wulkanowy.R
 import io.github.wulkanowy.ui.base.BaseFragmentPagerAdapter
 import io.github.wulkanowy.ui.base.session.BaseSessionFragment
 import io.github.wulkanowy.ui.modules.grade.details.GradeDetailsFragment
+import io.github.wulkanowy.ui.modules.grade.statistics.GradeStatisticsFragment
 import io.github.wulkanowy.ui.modules.grade.summary.GradeSummaryFragment
 import io.github.wulkanowy.ui.modules.main.MainView
 import io.github.wulkanowy.utils.setOnSelectPageListener
@@ -63,12 +64,14 @@ class GradeFragment : BaseSessionFragment(), GradeView, MainView.MainChildView,
             containerId = gradeViewPager.id
             addFragmentsWithTitle(mapOf(
                 GradeDetailsFragment.newInstance() to getString(R.string.all_details),
-                GradeSummaryFragment.newInstance() to getString(R.string.grade_menu_summary)
+                GradeSummaryFragment.newInstance() to getString(R.string.grade_menu_summary),
+                GradeStatisticsFragment.newInstance() to getString(R.string.grade_menu_statistics)
             ))
         }
 
         gradeViewPager.run {
             adapter = pagerAdapter
+            offscreenPageLimit = 3
             setOnSelectPageListener { presenter.onPageSelected(it) }
         }
         gradeTabLayout.setupWithViewPager(gradeViewPager)

app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradeModule.kt

@@ -7,6 +7,7 @@ import io.github.wulkanowy.di.scopes.PerChildFragment
 import io.github.wulkanowy.di.scopes.PerFragment
 import io.github.wulkanowy.ui.base.BaseFragmentPagerAdapter
 import io.github.wulkanowy.ui.modules.grade.details.GradeDetailsFragment
+import io.github.wulkanowy.ui.modules.grade.statistics.GradeStatisticsFragment
 import io.github.wulkanowy.ui.modules.grade.summary.GradeSummaryFragment
 
 @Module
@@ -28,4 +29,8 @@ abstract class GradeModule {
     @PerChildFragment
     @ContributesAndroidInjector
     abstract fun binGradeSummaryFragment(): GradeSummaryFragment
+
+    @PerChildFragment
+    @ContributesAndroidInjector
+    abstract fun binGradeStatisticsFragment(): GradeStatisticsFragment
 }

app/src/main/java/io/github/wulkanowy/ui/modules/grade/GradePresenter.kt

@@ -114,6 +114,6 @@ class GradePresenter @Inject constructor(
     }
 
     private fun notifyChildrenSemesterChange() {
-        for (i in 0..1) view?.notifyChildSemesterChange(i)
+        for (i in 0..2) view?.notifyChildSemesterChange(i)
     }
 }

app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsFragment.kt

@@ -0,0 +1,191 @@
+package io.github.wulkanowy.ui.modules.grade.statistics
+
+import android.graphics.Color.WHITE
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.ArrayAdapter
+import android.widget.TextView
+import androidx.core.content.ContextCompat
+import com.github.mikephil.charting.components.Legend
+import com.github.mikephil.charting.components.LegendEntry
+import com.github.mikephil.charting.data.PieData
+import com.github.mikephil.charting.data.PieDataSet
+import com.github.mikephil.charting.data.PieEntry
+import com.github.mikephil.charting.formatter.ValueFormatter
+import io.github.wulkanowy.R
+import io.github.wulkanowy.data.db.entities.GradeStatistics
+import io.github.wulkanowy.ui.base.session.BaseSessionFragment
+import io.github.wulkanowy.ui.modules.grade.GradeFragment
+import io.github.wulkanowy.ui.modules.grade.GradeView
+import io.github.wulkanowy.utils.getThemeAttrColor
+import io.github.wulkanowy.utils.setOnItemSelectedListener
+import kotlinx.android.synthetic.main.fragment_grade_statistics.*
+import javax.inject.Inject
+
+class GradeStatisticsFragment : BaseSessionFragment(), GradeStatisticsView, GradeView.GradeChildView {
+
+    @Inject
+    lateinit var presenter: GradeStatisticsPresenter
+
+    private lateinit var subjectsAdapter: ArrayAdapter<String>
+
+    companion object {
+        private const val SAVED_CHART_TYPE = "CURRENT_TYPE"
+
+        fun newInstance() = GradeStatisticsFragment()
+    }
+
+    override val isViewEmpty
+        get() = gradeStatisticsChart.isEmpty
+
+    private val gradeColors = listOf(
+        6 to R.color.grade_material_six,
+        5 to R.color.grade_material_five,
+        4 to R.color.grade_material_four,
+        3 to R.color.grade_material_three,
+        2 to R.color.grade_material_two,
+        1 to R.color.grade_material_one
+    )
+
+    private val gradeLabels = listOf(
+        "6, 6-", "5, 5-, 5+", "4, 4-, 4+", "3, 3-, 3+", "2, 2-, 2+", "1, 1+"
+    )
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        return inflater.inflate(R.layout.fragment_grade_statistics, container, false)
+    }
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        messageContainer = gradeStatisticsChart
+        presenter.onAttachView(this, savedInstanceState?.getBoolean(SAVED_CHART_TYPE))
+    }
+
+    override fun initView() {
+        gradeStatisticsChart.run {
+            description.isEnabled = false
+            setHoleColor(context.getThemeAttrColor(android.R.attr.windowBackground))
+            setCenterTextColor(context.getThemeAttrColor(android.R.attr.textColorPrimary))
+            animateXY(1000, 1000)
+            minAngleForSlices = 25f
+            legend.apply {
+                textColor = context.getThemeAttrColor(android.R.attr.textColorPrimary)
+                setCustom(gradeLabels.mapIndexed { i, it ->
+                    LegendEntry().apply {
+                        label = it
+                        formColor = ContextCompat.getColor(context, gradeColors[i].second)
+                        form = Legend.LegendForm.SQUARE
+                    }
+                })
+            }
+        }
+
+        context?.let {
+            subjectsAdapter = ArrayAdapter(it, android.R.layout.simple_spinner_item, ArrayList<String>())
+            subjectsAdapter.setDropDownViewResource(R.layout.item_attendance_summary_subject)
+        }
+
+        gradeStatisticsSubjects.run {
+            adapter = subjectsAdapter
+            setOnItemSelectedListener { presenter.onSubjectSelected((it as TextView).text.toString()) }
+        }
+
+        gradeStatisticsSwipe.setOnRefreshListener { presenter.onSwipeRefresh() }
+    }
+
+    override fun updateSubjects(data: ArrayList<String>) {
+        subjectsAdapter.run {
+            clear()
+            addAll(data)
+            notifyDataSetChanged()
+        }
+    }
+
+    override fun updateData(items: List<GradeStatistics>) {
+        gradeStatisticsChart.run {
+            data = PieData(PieDataSet(items.map {
+                PieEntry(it.amount.toFloat(), it.grade.toString())
+            }, "Legenda").apply {
+                valueTextSize = 12f
+                sliceSpace = 1f
+                valueTextColor = WHITE
+                setColors(items.map {
+                    gradeColors.single { color -> color.first == it.grade }.second
+                }.toIntArray(), context)
+            }).apply {
+                setTouchEnabled(false)
+                setValueFormatter(object : ValueFormatter() {
+                    override fun getPieLabel(value: Float, pieEntry: PieEntry): String {
+                        return resources.getQuantityString(R.plurals.grade_number_item, value.toInt(), value.toInt())
+                    }
+                })
+                centerText = items.fold(0) { acc, it -> acc + it.amount }
+                    .let { resources.getQuantityString(R.plurals.grade_number_item, it, it) }
+            }
+            invalidate()
+        }
+    }
+
+    override fun showSubjects(show: Boolean) {
+        gradeStatisticsSubjectsContainer.visibility = if (show) View.VISIBLE else View.INVISIBLE
+    }
+
+    override fun clearView() {
+        gradeStatisticsChart.clear()
+    }
+
+    override fun showContent(show: Boolean) {
+        gradeStatisticsChart.visibility = if (show) View.VISIBLE else View.GONE
+    }
+
+    override fun showEmpty(show: Boolean) {
+        gradeStatisticsEmpty.visibility = if (show) View.VISIBLE else View.INVISIBLE
+    }
+
+    override fun showProgress(show: Boolean) {
+        gradeStatisticsProgress.visibility = if (show) View.VISIBLE else View.GONE
+    }
+
+    override fun showRefresh(show: Boolean) {
+        gradeStatisticsSwipe.isRefreshing = show
+    }
+
+    override fun onParentLoadData(semesterId: Int, forceRefresh: Boolean) {
+        presenter.onParentViewLoadData(semesterId, forceRefresh)
+    }
+
+    override fun onParentReselected() {
+        //
+    }
+
+    override fun onParentChangeSemester() {
+        presenter.onParentViewChangeSemester()
+    }
+
+    override fun notifyParentDataLoaded(semesterId: Int) {
+        (parentFragment as? GradeFragment)?.onChildFragmentLoaded(semesterId)
+    }
+
+    override fun notifyParentRefresh() {
+        (parentFragment as? GradeFragment)?.onChildRefresh()
+    }
+
+    override fun onResume() {
+        super.onResume()
+        gradeStatisticsTypeSwitch.setOnCheckedChangeListener { _, checkedId ->
+            presenter.onTypeChange(checkedId == R.id.gradeStatisticsTypeSemester)
+        }
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        outState.putBoolean(GradeStatisticsFragment.SAVED_CHART_TYPE, presenter.currentIsSemester)
+    }
+
+    override fun onDestroyView() {
+        super.onDestroyView()
+        presenter.onDetachView()
+    }
+}

app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsPresenter.kt

@@ -0,0 +1,140 @@
+package io.github.wulkanowy.ui.modules.grade.statistics
+
+import io.github.wulkanowy.data.db.entities.Subject
+import io.github.wulkanowy.data.repositories.gradestatistics.GradeStatisticsRepository
+import io.github.wulkanowy.data.repositories.semester.SemesterRepository
+import io.github.wulkanowy.data.repositories.student.StudentRepository
+import io.github.wulkanowy.data.repositories.subject.SubjectRepository
+import io.github.wulkanowy.ui.base.session.BaseSessionPresenter
+import io.github.wulkanowy.ui.base.session.SessionErrorHandler
+import io.github.wulkanowy.utils.FirebaseAnalyticsHelper
+import io.github.wulkanowy.utils.SchedulersProvider
+import timber.log.Timber
+import javax.inject.Inject
+
+class GradeStatisticsPresenter @Inject constructor(
+    private val errorHandler: SessionErrorHandler,
+    private val gradeStatisticsRepository: GradeStatisticsRepository,
+    private val subjectRepository: SubjectRepository,
+    private val studentRepository: StudentRepository,
+    private val semesterRepository: SemesterRepository,
+    private val schedulers: SchedulersProvider,
+    private val analytics: FirebaseAnalyticsHelper
+) : BaseSessionPresenter<GradeStatisticsView>(errorHandler) {
+
+    private var subjects = emptyList<Subject>()
+
+    private var currentSemesterId = 0
+
+    private var currentSubjectName: String = "Wszystkie"
+
+    var currentIsSemester = false
+        private set
+
+    fun onAttachView(view: GradeStatisticsView, isSemester: Boolean?) {
+        super.onAttachView(view)
+        currentIsSemester = isSemester ?: false
+        view.initView()
+    }
+
+    fun onParentViewLoadData(semesterId: Int, forceRefresh: Boolean) {
+        currentSemesterId = semesterId
+        loadSubjects()
+        loadData(semesterId, currentSubjectName, currentIsSemester, forceRefresh)
+    }
+
+    fun onParentViewChangeSemester() {
+        view?.run {
+            showProgress(true)
+            showRefresh(false)
+            showContent(false)
+            showEmpty(false)
+            clearView()
+        }
+        disposable.clear()
+    }
+
+    fun onSwipeRefresh() {
+        Timber.i("Force refreshing the grade stats")
+        view?.notifyParentRefresh()
+    }
+
+    fun onSubjectSelected(name: String) {
+        Timber.i("Select attendance stats subject $name")
+        view?.run {
+            showContent(false)
+            showProgress(true)
+            showEmpty(false)
+            clearView()
+        }
+        (subjects.singleOrNull { it.name == name }?.name).let {
+            if (it != currentSubjectName) loadData(currentSemesterId, name, currentIsSemester)
+        }
+    }
+
+    fun onTypeChange(isSemester: Boolean) {
+        Timber.i("Select attendance stats semester: $isSemester")
+        view?.run {
+            showContent(false)
+            showProgress(true)
+            showEmpty(false)
+            clearView()
+        }
+        loadData(currentSemesterId, currentSubjectName, isSemester)
+    }
+
+    private fun loadSubjects() {
+        Timber.i("Loading grade stats subjects started")
+        disposable.add(studentRepository.getCurrentStudent()
+            .flatMap { semesterRepository.getCurrentSemester(it) }
+            .flatMap { subjectRepository.getSubjects(it) }
+            .doOnSuccess { subjects = it }
+            .map { ArrayList(it.map { subject -> subject.name }) }
+            .subscribeOn(schedulers.backgroundThread)
+            .observeOn(schedulers.mainThread)
+            .subscribe({
+                Timber.i("Loading grade stats subjects result: Success")
+                view?.run {
+                    updateSubjects(it)
+                    showSubjects(true)
+                }
+            }, {
+                Timber.e("Loading grade stats subjects result: An exception occurred")
+                errorHandler.dispatch(it)
+            })
+        )
+    }
+
+    private fun loadData(semesterId: Int, subjectName: String, isSemester: Boolean, forceRefresh: Boolean = false) {
+        Timber.i("Loading grade stats data started")
+        currentSubjectName = subjectName
+        currentIsSemester = isSemester
+        disposable.add(studentRepository.getCurrentStudent()
+            .flatMap { semesterRepository.getSemesters(it) }
+            .flatMap { gradeStatisticsRepository.getGradesStatistics(it.first { item -> item.semesterId == semesterId }, subjectName, isSemester, forceRefresh) }
+            .map { list -> list.sortedByDescending { it.grade } }
+            .map { list -> list.filter { it.amount != 0 } }
+            .subscribeOn(schedulers.backgroundThread)
+            .observeOn(schedulers.mainThread)
+            .doFinally {
+                view?.run {
+                    showRefresh(false)
+                    showProgress(false)
+                    notifyParentDataLoaded(semesterId)
+                }
+            }
+            .subscribe({
+                Timber.i("Loading grade stats result: Success")
+                view?.run {
+                    showEmpty(it.isEmpty())
+                    showContent(it.isNotEmpty())
+                    updateData(it)
+                }
+                analytics.logEvent("load_grade_statistics", "items" to it.size, "force_refresh" to forceRefresh)
+            }) {
+                Timber.e("Loading grade stats result: An exception occurred")
+                view?.run { showEmpty(isViewEmpty) }
+                errorHandler.dispatch(it)
+            })
+    }
+}

app/src/main/java/io/github/wulkanowy/ui/modules/grade/statistics/GradeStatisticsView.kt

@@ -0,0 +1,31 @@
+package io.github.wulkanowy.ui.modules.grade.statistics
+
+import io.github.wulkanowy.data.db.entities.GradeStatistics
+import io.github.wulkanowy.ui.base.session.BaseSessionView
+
+interface GradeStatisticsView : BaseSessionView {
+
+    val isViewEmpty: Boolean
+
+    fun initView()
+
+    fun updateSubjects(data: ArrayList<String>)
+
+    fun updateData(items: List<GradeStatistics>)
+
+    fun showSubjects(show: Boolean)
+
+    fun notifyParentDataLoaded(semesterId: Int)
+
+    fun notifyParentRefresh()
+
+    fun clearView()
+
+    fun showContent(show: Boolean)
+
+    fun showEmpty(show: Boolean)
+
+    fun showProgress(show: Boolean)
+
+    fun showRefresh(show: Boolean)
+}

app/src/main/java/io/github/wulkanowy/utils/SpinnerExtension.kt

@@ -4,11 +4,19 @@ import android.view.View
 import android.widget.AdapterView
 import android.widget.Spinner
 
+/**
+ * @see <a href="https://stackoverflow.com/a/29602298">How to keep onItemSelected from firing off on a newly instantiated Spinner?</a>
+ */
 inline fun Spinner.setOnItemSelectedListener(crossinline listener: (view: View?) -> Unit) {
+    onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
+        override fun onNothingSelected(parent: AdapterView<*>?) {}
+        override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
             onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
                 override fun onNothingSelected(parent: AdapterView<*>?) {}
                 override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
                     listener(view)
                 }
             }
+        }
+    }
 }

app/src/main/res/layout/fragment_grade.xml

@@ -5,32 +5,33 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
-    <com.google.android.material.tabs.TabLayout
+    <io.github.wulkanowy.ui.modules.grade.CustomTabLayout
         android:id="@+id/gradeTabLayout"
         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="scrollable"
-        app:tabMode="fixed"
+        app:tabTextColor="@android:color/white"
-        app:tabTextColor="@android:color/white" />
+        tools:visibility="visible" />
 
     <androidx.viewpager.widget.ViewPager
         android:id="@+id/gradeViewPager"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:layout_marginTop="48dp"
-        android:visibility="invisible" />
+        android:visibility="invisible"
+        tools:visibility="visible" />
 
     <ProgressBar
         android:id="@+id/gradeProgress"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
-        android:indeterminate="true" />
+        android:indeterminate="true"
+        tools:visibility="invisible" />
 
     <LinearLayout
         android:id="@+id/gradeEmpty"
@@ -38,7 +39,8 @@
         android:layout_height="match_parent"
         android:gravity="center"
         android:orientation="vertical"
-        android:visibility="invisible">
+        android:visibility="invisible"
+        tools:visibility="visible">
 
         <androidx.appcompat.widget.AppCompatImageView
             android:layout_width="wrap_content"

app/src/main/res/layout/fragment_grade_details.xml

@@ -2,7 +2,8 @@
     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">
+    android:layout_height="match_parent"
+    tools:context=".ui.modules.grade.details.GradeDetailsFragment">
 
     <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
         android:id="@+id/gradeDetailsSwipe"
@@ -20,7 +21,8 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
-        android:indeterminate="true" />
+        android:indeterminate="true"
+        tools:visibility="gone" />
 
     <LinearLayout
         android:id="@+id/gradeDetailsEmpty"

app/src/main/res/layout/fragment_grade_statistics.xml

@@ -0,0 +1,128 @@
+<LinearLayout 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"
+    android:orientation="vertical"
+    tools:context=".ui.modules.grade.statistics.GradeStatisticsFragment">
+
+    <LinearLayout
+        android:id="@+id/gradeStatisticsSubjectsContainer"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:background="?android:attr/windowBackground"
+        android:elevation="5dp"
+        android:padding="5dp"
+        android:visibility="invisible"
+        tools:listitem="@layout/item_attendance_summary"
+        tools:targetApi="lollipop"
+        tools:visibility="visible">
+
+        <androidx.appcompat.widget.AppCompatSpinner
+            android:id="@+id/gradeStatisticsSubjects"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:ellipsize="middle"
+            android:entries="@array/endpoints_keys"
+            android:paddingStart="10dp"
+            android:paddingLeft="10dp"
+            android:paddingTop="10dp"
+            android:paddingEnd="30dp"
+            android:paddingRight="30dp"
+            android:paddingBottom="10dp"
+            android:spinnerMode="dialog" />
+    </LinearLayout>
+
+
+    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+        android:id="@+id/gradeStatisticsSwipe"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <ScrollView
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:fillViewport="true">
+
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:orientation="vertical">
+
+                <RadioGroup
+                    android:id="@+id/gradeStatisticsTypeSwitch"
+                    android:layout_width="fill_parent"
+                    android:layout_height="wrap_content"
+                    android:layout_gravity="center"
+                    android:gravity="center"
+                    android:orientation="horizontal"
+                    android:paddingTop="5dp">
+
+                    <RadioButton
+                        android:id="@+id/gradeStatisticsTypePartial"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:checked="true"
+                        android:tag="partial"
+                        android:text="@string/grade_statistics_partial" />
+
+                    <RadioButton
+                        android:id="@+id/gradeStatisticsTypeSemester"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:tag="annual"
+                        android:text="@string/grade_statistics_semester" />
+                </RadioGroup>
+
+                <FrameLayout
+                    android:layout_width="match_parent"
+                    android:layout_height="match_parent">
+
+                    <com.github.mikephil.charting.charts.PieChart
+                        android:id="@+id/gradeStatisticsChart"
+                        android:layout_width="match_parent"
+                        android:layout_height="match_parent"
+                        android:background="?android:attr/windowBackground"
+                        android:minHeight="400dp"
+                        android:visibility="gone"
+                        android:layout_margin="10dp"
+                        tools:visibility="visible" />
+
+                    <ProgressBar
+                        android:id="@+id/gradeStatisticsProgress"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:layout_gravity="center"
+                        android:indeterminate="true"
+                        tools:visibility="gone" />
+
+                    <LinearLayout
+                        android:id="@+id/gradeStatisticsEmpty"
+                        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_menu_main_grade_26dp"
+                            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/grade_no_items"
+                            android:textSize="20sp" />
+                    </LinearLayout>
+                </FrameLayout>
+            </LinearLayout>
+        </ScrollView>
+    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+</LinearLayout>

app/src/main/res/layout/fragment_grade_summary.xml

@@ -2,7 +2,8 @@
     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">
+    android:layout_height="match_parent"
+    tools:context=".ui.modules.grade.summary.GradeSummaryFragment">
 
     <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
         android:id="@+id/gradeSummarySwipe"
@@ -20,7 +21,8 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
-        android:indeterminate="true" />
+        android:indeterminate="true"
+        tools:visibility="gone" />
 
     <LinearLayout
         android:id="@+id/gradeSummaryEmpty"

app/src/main/res/layout/item_login_options.xml

@@ -16,7 +16,7 @@
         android:layout_height="40dp"
         android:layout_marginEnd="16dp"
         android:layout_marginRight="16dp"
-        android:tint="?android:attr/textColorPrimary"
+        android:tint="@android:color/black"
         app:srcCompat="@drawable/ic_all_account_24dp" />
 
     <TextView

app/src/main/res/values-pl/strings.xml

@@ -60,7 +60,10 @@
     <string name="grade_summary_calculated_average">Obliczona średnia</string>
     <string name="grade_summary_final_average">Końcowa średnia</string>
     <string name="grade_menu_summary">Podsumowanie</string>
+    <string name="grade_menu_statistics">Oceny klasy</string>
     <string name="grade_menu_read">Oznacz jako przeczytane</string>
+    <string name="grade_statistics_partial">Oceny cząstkowe</string>
+    <string name="grade_statistics_semester">Oceny semestralne</string>
     <plurals name="grade_number_item">
         <item quantity="one">%d ocena</item>
         <item quantity="few">%d oceny</item>

app/src/main/res/values/strings.xml

@@ -60,7 +60,10 @@
     <string name="grade_summary_calculated_average">Calculated average</string>
     <string name="grade_summary_final_average">Final average</string>
     <string name="grade_menu_summary">Summary</string>
+    <string name="grade_menu_statistics">Class grades</string>
     <string name="grade_menu_read">Mark as read</string>
+    <string name="grade_statistics_partial">Partial grades</string>
+    <string name="grade_statistics_semester">Semester grades</string>
     <plurals name="grade_number_item">
         <item quantity="one">%d grade</item>
         <item quantity="other">%d grades</item>

app/src/test/java/io/github/wulkanowy/data/repositories/remote/GradeStatisticsRemoteTest.kt

@@ -0,0 +1,53 @@
+package io.github.wulkanowy.data.repositories.remote
+
+import io.github.wulkanowy.api.Api
+import io.github.wulkanowy.api.grades.GradeStatistics
+import io.github.wulkanowy.data.db.entities.Semester
+import io.github.wulkanowy.data.repositories.gradestatistics.GradeStatisticsRemote
+import io.mockk.MockKAnnotations
+import io.mockk.every
+import io.mockk.impl.annotations.MockK
+import io.mockk.impl.annotations.SpyK
+import io.reactivex.Single
+import org.junit.Assert
+import org.junit.Before
+import org.junit.Test
+
+class GradeStatisticsRemoteTest {
+
+    @SpyK
+    private var mockApi = Api()
+
+    @MockK
+    private lateinit var semesterMock: Semester
+
+    @Before
+    fun initApi() {
+        MockKAnnotations.init(this)
+    }
+
+    @Test
+    fun getGradeStatisticsTest() {
+        every { mockApi.getGradesStatistics(1, any()) } returns Single.just(listOf(
+            getGradeStatistics("Fizyka"),
+            getGradeStatistics("Matematyka")
+        ))
+
+        every { mockApi.diaryId } returns 1
+        every { semesterMock.studentId } returns 1
+        every { semesterMock.semesterId } returns 1
+        every { semesterMock.semesterName } returns 2
+        every { semesterMock.diaryId } returns 1
+
+        val stats = GradeStatisticsRemote(mockApi).getGradeStatistics(semesterMock, false).blockingGet()
+        Assert.assertEquals(2, stats.size)
+    }
+
+    private fun getGradeStatistics(subjectName: String): GradeStatistics {
+        return GradeStatistics().apply {
+            subject = subjectName
+            gradeValue = 5
+            amount = 10
+        }
+    }
+}