rewrote the database, added the entire session system, updated the api with it, continued the UI

app/build.gradle.kts

@@ -76,4 +76,5 @@ dependencies {
     debugImplementation("androidx.compose.ui:ui-tooling")
     debugImplementation("androidx.compose.ui:ui-test-manifest")
     ksp("androidx.room:room-compiler:2.6.1")
+    implementation(kotlin("reflect"))
 }

app/src/main/java/com/faraphel/tasks_valider/MainActivity.kt

@@ -6,24 +6,42 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.annotation.RequiresApi
+import androidx.room.Room
 import com.faraphel.tasks_valider.connectivity.bwf.BwfManager
 import com.faraphel.tasks_valider.database.TaskDatabase
+import com.faraphel.tasks_valider.database.populateTaskDatabaseTest
 import com.faraphel.tasks_valider.ui.screen.communication.CommunicationModeSelectionScreen
 
 
 class MainActivity : ComponentActivity() {
     private var bwfManager: BwfManager? = null  ///< the WiFi-Direct helper
-
-    companion object {
     private lateinit var database: TaskDatabase  ///< the database manager
-    }
 
     @RequiresApi(Build.VERSION_CODES.O)
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
+        // Reset the database | TODO(Faraphel): only for testing purpose
+        this.deleteDatabase("local")
+
+        // Create the database
+        this.database = Room.databaseBuilder(
+            this,
+            TaskDatabase::class.java,
+            "local"
+        ).build()
+
+        // Populate the database with test data
+        // TODO(Faraphel): remove test data
+        Thread {
+            populateTaskDatabaseTest(database)
+        }.let { thread ->
+            thread.start()
+            thread.join()
+        }
+
         this.setContent {
-            CommunicationModeSelectionScreen(this)
+            CommunicationModeSelectionScreen(this, database)
         }
     }
 

app/src/main/java/com/faraphel/tasks_valider/connectivity/task/TaskClient.kt

@@ -3,6 +3,7 @@ package com.faraphel.tasks_valider.connectivity.task
 import okhttp3.HttpUrl
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
+import okhttp3.RequestBody
 import okhttp3.RequestBody.Companion.toRequestBody
 
 

app/src/main/java/com/faraphel/tasks_valider/connectivity/task/TaskServer.kt

@@ -5,21 +5,25 @@ import com.faraphel.tasks_valider.connectivity.task.session.TaskSessionManager
 import com.faraphel.tasks_valider.database.TaskDatabase
 import com.faraphel.tasks_valider.database.api.TaskDatabaseApi
 import com.faraphel.tasks_valider.database.entities.PersonEntity
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 import fi.iki.elonen.NanoHTTPD
 
 
 /**
  * A server to handle the task API to allow clients to interact with the database.
- * @param port the port of the server
+ * @param port the port of the server.
- * @param database the database to interact with
+ * @param database the database to interact with.
+ * @param session the current session.
+ * @param adminPersonEntity the person that represent the host of the session.
  */
 class TaskServer(
     private val port: Int,
     private val database: TaskDatabase,
-    adminPersonEntity: PersonEntity,
+    private val session: SessionEntity,
+    private val adminPersonEntity: PersonEntity,
 ) : NanoHTTPD(port) {
     private val sessionManager = TaskSessionManager(adminPersonEntity)  ///< the session manager
-    private val databaseApi = TaskDatabaseApi(this.database)  ///< the api of the database
+    private val databaseApi = TaskDatabaseApi(this.database, session)  ///< the api of the database
     private val sessionManagerApi = TaskSessionManagerApi(this.sessionManager, this.database)  ///< the api of the session manager
 
     /**

app/src/main/java/com/faraphel/tasks_valider/database/TaskDatabase.kt

@@ -22,6 +22,7 @@ import com.faraphel.tasks_valider.database.entities.*
         ValidationEntity::class,
 
         RelationClassPersonEntity::class,
+        RelationPersonSessionSubjectEntity::class,
     ],
     version = 1
 )
@@ -37,4 +38,5 @@ abstract class TaskDatabase: RoomDatabase() {
     abstract fun validationDao(): ValidationDao
 
     abstract fun relationClassPersonDao(): RelationClassPersonDao
+    abstract fun relationPersonSessionSubjectDao(): RelationPersonSessionSubjectDao
 }

app/src/main/java/com/faraphel/tasks_valider/database/api/TaskDatabaseApi.kt

@@ -8,16 +8,20 @@ import com.faraphel.tasks_valider.database.api.entities.base.BaseApi
 import com.faraphel.tasks_valider.database.entities.*
 import fi.iki.elonen.NanoHTTPD
 
-class TaskDatabaseApi(private val database: TaskDatabase) {
+class TaskDatabaseApi(
+    private val database: TaskDatabase,
+    private val session: SessionEntity,
+) {
     private val api: Map<String, BaseApi> = mapOf(
-        ClassEntity.TABLE_NAME to ClassApi(this.database.classDao()),
+        ClassEntity.TABLE_NAME to ClassApi(this.database.classDao(), session),
-        PersonEntity.TABLE_NAME to PersonApi(this.database.personDao()),
+        PersonEntity.TABLE_NAME to PersonApi(this.database.personDao(), session),
-        SessionEntity.TABLE_NAME to SessionApi(this.database.sessionDao()),
+        SessionEntity.TABLE_NAME to SessionApi(this.database.sessionDao(), session),
-        SubjectEntity.TABLE_NAME to SubjectApi(this.database.subjectDao()),
+        SubjectEntity.TABLE_NAME to SubjectApi(this.database.subjectDao(), session),
-        TaskEntity.TABLE_NAME to TaskApi(this.database.taskDao()),
+        TaskEntity.TABLE_NAME to TaskApi(this.database.taskDao(), session),
-        ValidationEntity.TABLE_NAME to ValidationApi(this.database.validationDao()),
+        ValidationEntity.TABLE_NAME to ValidationApi(this.database.validationDao(), session),
 
-        RelationClassPersonEntity.TABLE_NAME to RelationClassPersonApi(this.database.relationClassPersonDao()),
+        RelationClassPersonEntity.TABLE_NAME to RelationClassPersonApi(this.database.relationClassPersonDao(), session),
+        RelationPersonSessionSubjectEntity.TABLE_NAME to RelationPersonSessionSubjectApi(this.database.relationPersonSessionSubjectDao(), session),
     )
 
     /**

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ClassApi.kt

@@ -1,7 +1,9 @@
 package com.faraphel.tasks_valider.database.api.entities
 
-import com.faraphel.tasks_valider.database.api.entities.base.BaseJsonApi
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
 import com.faraphel.tasks_valider.database.entities.ClassEntity
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 
-class ClassApi(dao: BaseDao<ClassEntity>) : BaseJsonApi<ClassEntity>(dao)
+class ClassApi(dao: BaseTaskDao<ClassEntity>, session: SessionEntity) :
+    BaseTaskApi<ClassEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/PersonApi.kt

@@ -1,7 +1,9 @@
 package com.faraphel.tasks_valider.database.api.entities
 
-import com.faraphel.tasks_valider.database.api.entities.base.BaseJsonApi
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
 import com.faraphel.tasks_valider.database.entities.PersonEntity
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 
-class PersonApi(dao: BaseDao<PersonEntity>) : BaseJsonApi<PersonEntity>(dao)
+class PersonApi(dao: BaseTaskDao<PersonEntity>, session: SessionEntity) :
+    BaseTaskApi<PersonEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationClassPersonApi.kt

@@ -1,7 +1,10 @@
 package com.faraphel.tasks_valider.database.api.entities
 
-import com.faraphel.tasks_valider.database.api.entities.base.BaseJsonApi
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
 import com.faraphel.tasks_valider.database.entities.RelationClassPersonEntity
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 
-class RelationClassPersonApi(dao: BaseDao<RelationClassPersonEntity>) : BaseJsonApi<RelationClassPersonEntity>(dao)
+
+class RelationClassPersonApi(dao: BaseTaskDao<RelationClassPersonEntity>, session: SessionEntity) :
+    BaseTaskApi<RelationClassPersonEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationPersonSessionSubjectApi.kt

@@ -0,0 +1,10 @@
+package com.faraphel.tasks_valider.database.api.entities
+
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.RelationPersonSessionSubjectEntity
+import com.faraphel.tasks_valider.database.entities.SessionEntity
+
+
+class RelationPersonSessionSubjectApi(dao: BaseTaskDao<RelationPersonSessionSubjectEntity>, session: SessionEntity) :
+    BaseTaskApi<RelationPersonSessionSubjectEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SessionApi.kt

@@ -1,7 +1,8 @@
 package com.faraphel.tasks_valider.database.api.entities
 
-import com.faraphel.tasks_valider.database.api.entities.base.BaseJsonApi
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
 import com.faraphel.tasks_valider.database.entities.SessionEntity
 
-class SessionApi(dao: BaseDao<SessionEntity>) : BaseJsonApi<SessionEntity>(dao)
+class SessionApi(dao: BaseTaskDao<SessionEntity>, session: SessionEntity) :
+    BaseTaskApi<SessionEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SubjectApi.kt

@@ -1,7 +1,10 @@
 package com.faraphel.tasks_valider.database.api.entities
 
-import com.faraphel.tasks_valider.database.api.entities.base.BaseJsonApi
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 import com.faraphel.tasks_valider.database.entities.SubjectEntity
 
-class SubjectApi(dao: BaseDao<SubjectEntity>) : BaseJsonApi<SubjectEntity>(dao)
+
+class SubjectApi(dao: BaseTaskDao<SubjectEntity>, session: SessionEntity) :
+    BaseTaskApi<SubjectEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/TaskApi.kt

@@ -1,7 +1,10 @@
 package com.faraphel.tasks_valider.database.api.entities
 
-import com.faraphel.tasks_valider.database.api.entities.base.BaseJsonApi
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 import com.faraphel.tasks_valider.database.entities.TaskEntity
 
-class TaskApi(dao: BaseDao<TaskEntity>) : BaseJsonApi<TaskEntity>(dao)
+
+class TaskApi(dao: BaseTaskDao<TaskEntity>, session: SessionEntity) :
+    BaseTaskApi<TaskEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ValidationApi.kt

@@ -1,7 +1,10 @@
 package com.faraphel.tasks_valider.database.api.entities
 
-import com.faraphel.tasks_valider.database.api.entities.base.BaseJsonApi
+import com.faraphel.tasks_valider.database.api.entities.base.BaseTaskApi
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 import com.faraphel.tasks_valider.database.entities.ValidationEntity
 
-class ValidationApi(dao: BaseDao<ValidationEntity>) : BaseJsonApi<ValidationEntity>(dao)
+
+class ValidationApi(dao: BaseTaskDao<ValidationEntity>, session: SessionEntity) :
+    BaseTaskApi<ValidationEntity>(dao, session)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseApi.kt

@@ -10,23 +10,23 @@ interface BaseApi {
      * Handle the HEAD request
      * This is used to check if a data exists in the database
      */
-    fun head(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
+    fun head(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
 
     /**
      * Handle the GET request
-     * This is used to get data from the database
+     * This is used to get all the data of a table from the database
      */
-    fun get(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
+    fun get(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
 
     /**
      * Handle the POST request
      * This is used to insert data into the database
      */
-    fun post(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
+    fun post(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
 
     /**
      * Handle the PUT request
      * This is used to delete data from the database
      */
-    fun delete(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
+    fun delete(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response
 }

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseJsonApi.kt

@@ -1,6 +1,6 @@
 package com.faraphel.tasks_valider.database.api.entities.base
 
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
 import com.faraphel.tasks_valider.database.entities.base.BaseEntity
 import com.google.gson.Gson
 import com.google.gson.reflect.TypeToken
@@ -11,7 +11,7 @@ import fi.iki.elonen.NanoHTTPD
  * This is preconfigured to handle JSON data.
  * @param Entity the entity type to handle
  */
-abstract class BaseJsonApi<Entity: BaseEntity>(private val dao: BaseDao<Entity>) : BaseApi {
+abstract class BaseJsonApi<Entity: BaseEntity>(private val dao: BaseCronDao<Entity>) : BaseApi {
     companion object {
         private val parser = Gson()  ///< The JSON parser
     }
@@ -20,9 +20,9 @@ abstract class BaseJsonApi<Entity: BaseEntity>(private val dao: BaseDao<Entity>)
 
     // Requests
 
-    override fun head(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
+    override fun head(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
         val obj = parser.fromJson<Entity>(
-            session.inputStream.bufferedReader().readText(),
+            httpSession.inputStream.bufferedReader().readText(),
             this.entityTypeToken.type
         )
         val exists = this.dao.exists(obj)
@@ -34,7 +34,7 @@ abstract class BaseJsonApi<Entity: BaseEntity>(private val dao: BaseDao<Entity>)
         )
     }
 
-    override fun get(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
+    override fun get(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
         return NanoHTTPD.newFixedLengthResponse(
             NanoHTTPD.Response.Status.OK,
             "application/json",
@@ -42,9 +42,9 @@ abstract class BaseJsonApi<Entity: BaseEntity>(private val dao: BaseDao<Entity>)
         )
     }
 
-    override fun post(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
+    override fun post(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
         val obj = parser.fromJson<Entity>(
-            session.inputStream.bufferedReader().readText(),
+            httpSession.inputStream.bufferedReader().readText(),
             this.entityTypeToken.type
         )
         val id = this.dao.insert(obj)
@@ -56,9 +56,9 @@ abstract class BaseJsonApi<Entity: BaseEntity>(private val dao: BaseDao<Entity>)
         )
     }
 
-    override fun delete(session: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
+    override fun delete(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
         val obj = parser.fromJson<Entity>(
-            session.inputStream.bufferedReader().readText(),
+            httpSession.inputStream.bufferedReader().readText(),
             this.entityTypeToken.type
         )
         val count = this.dao.delete(obj)

app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseTaskApi.kt

@@ -0,0 +1,49 @@
+package com.faraphel.tasks_valider.database.api.entities.base
+
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.SessionEntity
+import com.faraphel.tasks_valider.database.entities.base.BaseEntity
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import fi.iki.elonen.NanoHTTPD
+
+/**
+ * A base for the API to handle the database operations.
+ * This is preconfigured to handle data for Task objects.
+ * @param Entity the entity type to handle
+ */
+abstract class BaseTaskApi<Entity: BaseEntity>(
+    private val dao: BaseTaskDao<Entity>,
+    private val session: SessionEntity,
+) : BaseJsonApi<Entity>(dao) {
+    companion object {
+        private val parser = Gson()  ///< The JSON parser
+    }
+
+    private val entityTypeToken: TypeToken<Entity> = object: TypeToken<Entity>() {}  ///< the type of the managed entity
+
+    // Requests
+
+    override fun head(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
+        val obj = parser.fromJson<Entity>(
+            httpSession.inputStream.bufferedReader().readText(),
+            this.entityTypeToken.type
+        )
+        // check if the object is in the object accessible from the session
+        val exists = this.dao.getAllBySession(session.id).contains(obj)
+
+        return NanoHTTPD.newFixedLengthResponse(
+            if (exists) NanoHTTPD.Response.Status.OK else NanoHTTPD.Response.Status.NOT_FOUND,
+            "text/plain",
+            if (exists) "Exists" else "Not found"
+        )
+    }
+
+    override fun get(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
+        return NanoHTTPD.newFixedLengthResponse(
+            NanoHTTPD.Response.Status.OK,
+            "application/json",
+            parser.toJson(this.dao.getAllBySession(session.id))
+        )
+    }
+}

app/src/main/java/com/faraphel/tasks_valider/database/dao/ClassDao.kt

@@ -2,17 +2,27 @@ package com.faraphel.tasks_valider.database.dao
 
 import androidx.room.Dao
 import androidx.room.Query
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
 import com.faraphel.tasks_valider.database.entities.ClassEntity
 import com.faraphel.tasks_valider.database.entities.PersonEntity
 import com.faraphel.tasks_valider.database.entities.RelationClassPersonEntity
 import com.faraphel.tasks_valider.database.entities.SessionEntity
 
 @Dao
-interface ClassDao : BaseDao<ClassEntity> {
+interface ClassDao : BaseTaskDao<ClassEntity> {
     @Query("SELECT * FROM ${ClassEntity.TABLE_NAME}")
     override fun getAll(): List<ClassEntity>
 
+    @Query(
+        "SELECT * FROM ${ClassEntity.TABLE_NAME} " +
+        "JOIN ${SessionEntity.TABLE_NAME} " +
+        "ON ${SessionEntity.TABLE_NAME}.class_id = ${ClassEntity.TABLE_NAME}.id " +
+        "WHERE ${SessionEntity.TABLE_NAME}.id = :sessionId"
+    )
+    override fun getAllBySession(sessionId: Long): List<ClassEntity>
+
     /**
      * Get the object from its identifier
      */
@@ -31,7 +41,7 @@ interface ClassDao : BaseDao<ClassEntity> {
      * @param id the id of the class
      */
     @Query(
-        "SELECT * FROM ${PersonEntity.TABLE_NAME} " +
+        "SELECT ${PersonEntity.TABLE_NAME}.* FROM ${PersonEntity.TABLE_NAME} " +
         "JOIN ${RelationClassPersonEntity.TABLE_NAME} " +
         "ON ${PersonEntity.TABLE_NAME}.id = ${RelationClassPersonEntity.TABLE_NAME}.student_id " +
         "WHERE ${RelationClassPersonEntity.TABLE_NAME}.class_id = :id"

app/src/main/java/com/faraphel/tasks_valider/database/dao/PersonDao.kt

@@ -2,11 +2,13 @@ package com.faraphel.tasks_valider.database.dao
 
 import androidx.room.Dao
 import androidx.room.Query
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
 import com.faraphel.tasks_valider.database.entities.*
 
 @Dao
-interface PersonDao : BaseDao<PersonEntity> {
+interface PersonDao : BaseTaskDao<PersonEntity> {
     @Query("SELECT * FROM ${PersonEntity.TABLE_NAME}")
     override fun getAll(): List<PersonEntity>
 
@@ -16,6 +18,19 @@ interface PersonDao : BaseDao<PersonEntity> {
     @Query("SELECT * FROM ${PersonEntity.TABLE_NAME} WHERE id = :id")
     fun getById(id: Long): PersonEntity?
 
+    @Query(
+        "SELECT * FROM ${PersonEntity.TABLE_NAME} " +
+        "WHERE id IN (" +
+            "SELECT student_id FROM ${RelationClassPersonEntity.TABLE_NAME} " +
+            "JOIN ${ClassEntity.TABLE_NAME} " +
+            "ON ${RelationClassPersonEntity.TABLE_NAME}.class_id = ${ClassEntity.TABLE_NAME}.id " +
+            "JOIN ${SessionEntity.TABLE_NAME} " +
+            "ON ${SessionEntity.TABLE_NAME}.class_id = ${ClassEntity.TABLE_NAME}.id " +
+            "WHERE ${SessionEntity.TABLE_NAME}.id = :sessionId" +
+        ")"
+    )
+    override fun getAllBySession(sessionId: Long): List<PersonEntity>
+
     /**
      * Allow to get all the classes the person is attending as a student
      */

app/src/main/java/com/faraphel/tasks_valider/database/dao/RelationClassPersonDao.kt

@@ -2,22 +2,35 @@ package com.faraphel.tasks_valider.database.dao
 
 import androidx.room.Dao
 import androidx.room.Query
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.ClassEntity
 import com.faraphel.tasks_valider.database.entities.RelationClassPersonEntity
+import com.faraphel.tasks_valider.database.entities.SessionEntity
 
 @Dao
-interface RelationClassPersonDao : BaseDao<RelationClassPersonEntity> {
+interface RelationClassPersonDao : BaseTaskDao<RelationClassPersonEntity> {
     @Query("SELECT * FROM ${RelationClassPersonEntity.TABLE_NAME}")
     override fun getAll(): List<RelationClassPersonEntity>
 
+    @Query(
+        "SELECT ${RelationClassPersonEntity.TABLE_NAME}.* FROM ${RelationClassPersonEntity.TABLE_NAME} " +
+        "JOIN ${ClassEntity.TABLE_NAME} " +
+        "ON ${RelationClassPersonEntity.TABLE_NAME}.class_id = ${ClassEntity.TABLE_NAME}.id " +
+        "JOIN ${SessionEntity.TABLE_NAME} " +
+        "ON ${SessionEntity.TABLE_NAME}.class_id = ${ClassEntity.TABLE_NAME}.id " +
+        "WHERE ${SessionEntity.TABLE_NAME}.id = :sessionId"
+    )
+    override fun getAllBySession(sessionId: Long): List<RelationClassPersonEntity>
+
     /**
      * Get the object from its identifiers
      */
     @Query(
         "SELECT * FROM ${RelationClassPersonEntity.TABLE_NAME} " +
-        "WHERE " +
+        "WHERE class_id = :classId " +
-        "class_id = :classId AND " +
+        "AND student_id = :studentId"
-        "student_id = :studentId"
     )
     fun getById(classId: Long, studentId: Long): RelationClassPersonEntity?
 }

app/src/main/java/com/faraphel/tasks_valider/database/dao/RelationPersonSessionSubjectDao.kt

@@ -0,0 +1,32 @@
+package com.faraphel.tasks_valider.database.dao
+
+import androidx.room.Dao
+import androidx.room.Query
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.RelationPersonSessionSubjectEntity
+
+
+@Dao
+interface RelationPersonSessionSubjectDao : BaseTaskDao<RelationPersonSessionSubjectEntity> {
+    @Query("SELECT * FROM ${RelationPersonSessionSubjectEntity.TABLE_NAME}")
+    override fun getAll(): List<RelationPersonSessionSubjectEntity>
+
+    @Query(
+        "SELECT * FROM ${RelationPersonSessionSubjectEntity.TABLE_NAME} " +
+        "WHERE session_id = :sessionId"
+    )
+    override fun getAllBySession(sessionId: Long): List<RelationPersonSessionSubjectEntity>
+
+    /**
+     * Get the object from its identifiers
+     */
+    @Query(
+        "SELECT * FROM ${RelationPersonSessionSubjectEntity.TABLE_NAME} " +
+        "WHERE student_id = :studentId " +
+        "AND session_id = :sessionId " +
+        "AND subject_id = :subjectId"
+    )
+    fun getById(studentId: Long, sessionId: Long, subjectId: Long): RelationPersonSessionSubjectEntity?
+}

app/src/main/java/com/faraphel/tasks_valider/database/dao/SessionDao.kt

@@ -2,14 +2,20 @@ package com.faraphel.tasks_valider.database.dao
 
 import androidx.room.Dao
 import androidx.room.Query
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.ClassEntity
 import com.faraphel.tasks_valider.database.entities.SessionEntity
 
 @Dao
-interface SessionDao : BaseDao<SessionEntity> {
+interface SessionDao : BaseTaskDao<SessionEntity> {
     @Query("SELECT * FROM ${SessionEntity.TABLE_NAME}")
     override fun getAll(): List<SessionEntity>
 
+    @Query("SELECT * FROM ${SessionEntity.TABLE_NAME} WHERE id = :sessionId")
+    override fun getAllBySession(sessionId: Long): List<SessionEntity>
+
     /**
      * Get the object from its identifier
      */

app/src/main/java/com/faraphel/tasks_valider/database/dao/SubjectDao.kt

@@ -2,15 +2,28 @@ package com.faraphel.tasks_valider.database.dao
 
 import androidx.room.Dao
 import androidx.room.Query
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.ClassEntity
+import com.faraphel.tasks_valider.database.entities.RelationPersonSessionSubjectEntity
 import com.faraphel.tasks_valider.database.entities.SubjectEntity
 import com.faraphel.tasks_valider.database.entities.TaskEntity
 
 @Dao
-interface SubjectDao : BaseDao<SubjectEntity> {
+interface SubjectDao : BaseTaskDao<SubjectEntity> {
     @Query("SELECT * FROM ${SubjectEntity.TABLE_NAME}")
     override fun getAll(): List<SubjectEntity>
 
+    @Query(
+        "SELECT * FROM ${SubjectEntity.TABLE_NAME} " +
+        "WHERE id IN (" +
+            "SELECT subject_id FROM ${RelationPersonSessionSubjectEntity.TABLE_NAME} " +
+            "WHERE session_id = :sessionId" +
+        ")"
+    )
+    override fun getAllBySession(sessionId: Long): List<SubjectEntity>
+
     /**
      * Get the object from its identifier
      */

app/src/main/java/com/faraphel/tasks_valider/database/dao/TaskDao.kt

@@ -2,15 +2,27 @@ package com.faraphel.tasks_valider.database.dao
 
 import androidx.room.Dao
 import androidx.room.Query
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.RelationPersonSessionSubjectEntity
 import com.faraphel.tasks_valider.database.entities.TaskEntity
 import com.faraphel.tasks_valider.database.entities.ValidationEntity
 
 @Dao
-interface TaskDao : BaseDao<TaskEntity> {
+interface TaskDao : BaseTaskDao<TaskEntity> {
     @Query("SELECT * FROM ${TaskEntity.TABLE_NAME}")
     override fun getAll(): List<TaskEntity>
 
+    @Query(
+        "SELECT * FROM ${TaskEntity.TABLE_NAME} " +
+        "WHERE subject_id IN (" +
+            "SELECT subject_id FROM ${RelationPersonSessionSubjectEntity.TABLE_NAME} " +
+            "WHERE session_id = :sessionId" +
+        ")"
+    )
+    override fun getAllBySession(sessionId: Long): List<TaskEntity>
+
     /**
      * Get the object from its identifier
      */

app/src/main/java/com/faraphel/tasks_valider/database/dao/ValidationDao.kt

@@ -2,14 +2,29 @@ package com.faraphel.tasks_valider.database.dao
 
 import androidx.room.Dao
 import androidx.room.Query
-import com.faraphel.tasks_valider.database.dao.base.BaseDao
+import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
+import com.faraphel.tasks_valider.database.dao.base.BaseSessionDao
+import com.faraphel.tasks_valider.database.dao.base.BaseTaskDao
+import com.faraphel.tasks_valider.database.entities.RelationPersonSessionSubjectEntity
+import com.faraphel.tasks_valider.database.entities.TaskEntity
 import com.faraphel.tasks_valider.database.entities.ValidationEntity
 
 @Dao
-interface ValidationDao : BaseDao<ValidationEntity> {
+interface ValidationDao : BaseTaskDao<ValidationEntity> {
     @Query("SELECT * FROM ${ValidationEntity.TABLE_NAME}")
     override fun getAll(): List<ValidationEntity>
 
+    @Query(
+        "SELECT * FROM ${ValidationEntity.TABLE_NAME} " +
+        "JOIN ${TaskEntity.TABLE_NAME} " +
+        "ON ${ValidationEntity.TABLE_NAME}.task_id = ${TaskEntity.TABLE_NAME}.id " +
+        "WHERE ${TaskEntity.TABLE_NAME}.subject_id IN (" +
+            "SELECT subject_id FROM ${RelationPersonSessionSubjectEntity.TABLE_NAME} " +
+            "WHERE session_id = :sessionId" +
+        ")"
+    )
+    override fun getAllBySession(sessionId: Long): List<ValidationEntity>
+
     /**
      * Get the object from its identifiers
      */

app/src/main/java/com/faraphel/tasks_valider/database/dao/base/BaseCronDao.kt

@@ -3,17 +3,13 @@ package com.faraphel.tasks_valider.database.dao.base
 import androidx.room.Delete
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
-import androidx.room.Update
-import com.google.gson.Gson
-import com.google.gson.reflect.TypeToken
-
 
 
 /**
- * A base DAO to handle the database operations.
+ * A base DAO to handle the database operations (CRON).
  * @param Entity the entity to handle
  */
-interface BaseDao<Entity> {
+interface BaseCronDao<Entity> {
     /**
      * Check if the entities exists in the database.
      */

app/src/main/java/com/faraphel/tasks_valider/database/dao/base/BaseSessionDao.kt

@@ -0,0 +1,11 @@
+package com.faraphel.tasks_valider.database.dao.base
+
+/**
+ * The base for a DAO that is inside a session scope.
+ */
+interface BaseSessionDao<Entity> {
+    /**
+     * Return all the objects concerned by a session.
+     */
+    fun getAllBySession(sessionId: Long): List<Entity>
+}

app/src/main/java/com/faraphel/tasks_valider/database/dao/base/BaseTaskDao.kt

@@ -0,0 +1,6 @@
+package com.faraphel.tasks_valider.database.dao.base
+
+/**
+ * The base for a DAO for the task project.
+ */
+interface BaseTaskDao<Entity>: BaseCronDao<Entity>, BaseSessionDao<Entity>

app/src/main/java/com/faraphel/tasks_valider/database/entities/RelationPersonSessionSubjectEntity.kt

@@ -0,0 +1,48 @@
+package com.faraphel.tasks_valider.database.entities
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.ForeignKey
+import com.faraphel.tasks_valider.database.entities.base.BaseEntity
+
+
+/**
+ * Represent the relation that associate a subject to a person for a specific session.
+ */
+@Entity(
+    tableName = RelationPersonSessionSubjectEntity.TABLE_NAME,
+    primaryKeys = [
+        "student_id",
+        "session_id",
+        "subject_id"
+    ],
+    foreignKeys = [
+        ForeignKey(
+            entity = PersonEntity::class,
+            parentColumns = ["id"],
+            childColumns = ["student_id"],
+            onDelete = ForeignKey.CASCADE
+        ),
+        ForeignKey(
+            entity = SessionEntity::class,
+            parentColumns = ["id"],
+            childColumns = ["session_id"],
+            onDelete = ForeignKey.CASCADE
+        ),
+        ForeignKey(
+            entity = SubjectEntity::class,
+            parentColumns = ["id"],
+            childColumns = ["subject_id"],
+            onDelete = ForeignKey.CASCADE
+        ),
+    ]
+)
+data class RelationPersonSessionSubjectEntity (
+    @ColumnInfo("student_id", index = true) val studentId: Long,
+    @ColumnInfo("session_id", index = true) val sessionId: Long,
+    @ColumnInfo("subject_id", index = true) val subjectId: Long,
+) : BaseEntity() {
+    companion object {
+        const val TABLE_NAME = "relation_person_session_subject"
+    }
+}

app/src/main/java/com/faraphel/tasks_valider/database/test.kt

@@ -115,3 +115,19 @@ fun populateTaskDatabaseTest(database: TaskDatabase) {
     val taskB1 = database.taskDao().getById(taskB1Id)!!
     val taskB2 = database.taskDao().getById(taskB2Id)!!
 }
+
+
+fun populateSubjectSessionPersonTest(database: TaskDatabase, session: SessionEntity) {
+    // get the list of available subjects
+    val subjects = database.subjectDao().getAll()
+
+    // give a random subject to everyone in the session
+    database.personDao().getAllBySession(session.id).forEach { person ->
+        // get a random subject
+        val subject = subjects.random()
+        // insert a new subject for a person for a specific session
+        database.relationPersonSessionSubjectDao().insert(
+            RelationPersonSessionSubjectEntity(person.id, session.id, subject.id)
+        )
+    }
+}

app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/selection.kt

@@ -1,6 +1,8 @@
 package com.faraphel.tasks_valider.ui.screen.communication.internet
 
 import android.app.Activity
+import android.os.Build
+import androidx.annotation.RequiresApi
 import androidx.compose.foundation.layout.Column
 import androidx.compose.material3.Button
 import androidx.compose.material3.Text
@@ -9,16 +11,18 @@ import androidx.navigation.NavController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
+import com.faraphel.tasks_valider.database.TaskDatabase
 
 
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
-fun CommunicationInternetSelectScreen(activity: Activity) {
+fun CommunicationInternetSelectScreen(activity: Activity, database: TaskDatabase) {
     val controller = rememberNavController()
 
     NavHost(navController = controller, startDestination = "mode") {
         composable("mode") { CommunicationInternetSelectContent(controller) }
         composable("client") { CommunicationInternetClientScreen(activity) }
-        composable("server") { CommunicationInternetServerScreen(activity) }
+        composable("server") { CommunicationInternetServerScreen(activity, database) }
     }
 }
 

app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/server.kt

@@ -1,89 +1,115 @@
 package com.faraphel.tasks_valider.ui.screen.communication.internet
 
 import android.app.Activity
+import android.os.Build
 import android.util.Log
+import androidx.annotation.RequiresApi
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material3.Button
 import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextField
-import androidx.compose.runtime.Composable
+import androidx.compose.runtime.*
-import androidx.compose.runtime.MutableState
-import androidx.compose.runtime.mutableIntStateOf
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
 import androidx.compose.ui.text.input.KeyboardType
-import androidx.room.Room
+import androidx.navigation.compose.NavHost
+import androidx.navigation.compose.composable
+import androidx.navigation.compose.rememberNavController
 import com.faraphel.tasks_valider.connectivity.task.TaskClient
 import com.faraphel.tasks_valider.connectivity.task.TaskServer
 import com.faraphel.tasks_valider.database.TaskDatabase
 import com.faraphel.tasks_valider.database.entities.ClassEntity
 import com.faraphel.tasks_valider.database.entities.PersonEntity
-import com.faraphel.tasks_valider.database.populateTaskDatabaseTest
+import com.faraphel.tasks_valider.database.entities.SessionEntity
+import com.faraphel.tasks_valider.database.populateSubjectSessionPersonTest
 import com.faraphel.tasks_valider.ui.screen.authentification.AuthentificationServerScreen
 import com.faraphel.tasks_valider.ui.screen.communication.DEFAULT_SERVER_PORT
 import com.faraphel.tasks_valider.ui.screen.communication.RANGE_SERVER_PORT
 import com.faraphel.tasks_valider.ui.screen.task.TaskSessionScreen
+import java.time.Instant
 
 
 /**
  * Screen for the host to configure the server
  */
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
-fun CommunicationInternetServerScreen(activity: Activity) {
+fun CommunicationInternetServerScreen(
+    activity: Activity,
+    database: TaskDatabase,
+) {
+    val controller = rememberNavController()
+
     val adminPersonEntity = remember { mutableStateOf<PersonEntity?>(null) }
-
-    // if the admin person is not created, prompt the user for the admin information
-    if (adminPersonEntity.value == null) {
-        return AuthentificationServerScreen(adminPersonEntity)
-    }
-
     val client = remember { mutableStateOf<TaskClient?>(null) }
 
-    // if the client to the server is not created, prompt the user for the server configuration
+    NavHost(navController = controller, startDestination = "authentication") {
-    if (client.value == null) {
+        composable("authentication") {
-        return CommunicationInternetServerContent(
+            // if the admin person is not created, prompt the user for the admin information
-            activity,
+            if (adminPersonEntity.value == null) AuthentificationServerScreen(adminPersonEntity)
+            else controller.navigate("configuration")
+        }
+        composable("configuration") {
+            if (client.value == null)
+                CommunicationInternetServerContent(
+                    database,
                     adminPersonEntity.value!!,
                     client
                 )
+            else controller.navigate("session")
+        }
+        composable("session") {
+            TaskSessionScreen(activity, client.value!!)
+        }
     }
-
-    // otherwise, go to the base tasks screen
-    return TaskSessionScreen(activity, client.value!!)
 }
 
 
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
 fun CommunicationInternetServerContent(
-    activity: Activity,
+    database: TaskDatabase,
     adminPersonEntity: PersonEntity,
     client: MutableState<TaskClient?>
 ) {
-    val expandedStudentList = remember { mutableStateOf(false) }
+    val classes = remember { mutableStateOf<List<ClassEntity>?>(null) }
+    val selectedClass = remember { mutableStateOf<ClassEntity?>(null) }
+    val areClassesExpanded = remember { mutableStateOf(false) }
+
     val serverPort = remember { mutableIntStateOf(DEFAULT_SERVER_PORT) }
 
+    LaunchedEffect(true) {
+        // refresh the list of classes
+        Thread { refreshClasses(database, classes) }.start()
+    }
+
     Column {
-        // student list
+        // classes
-        Button(onClick = { expandedStudentList.value = !expandedStudentList.value }) {
+        Button(onClick = { areClassesExpanded.value = !areClassesExpanded.value }) {
-            Text(text = "Select Students List")
+            Row {
+                Text(text = "Class")
+                // display the selected class, if selected
+                if (selectedClass.value != null)
+                    Text(text = selectedClass.value!!.name)
+            }
         }
         DropdownMenu(
-            expanded = expandedStudentList.value,
+            expanded = areClassesExpanded.value,
-            onDismissRequest = { expandedStudentList.value = false }
+            onDismissRequest = { areClassesExpanded.value = false }
         ) {
             // TODO(Faraphel): student lists should be loaded from the database or a file
+            classes.value?.forEach { class_ ->
                 DropdownMenuItem(
-                text = { Text("ISRI") },
+                    text = { Text(class_.name) },
-                onClick = {}
+                    onClick = {
-            )
+                        selectedClass.value = class_
-            DropdownMenuItem(
+                        areClassesExpanded.value = false
-                text = { Text("MIAGE") },
+                    }
-                onClick = {}
                 )
             }
+        }
 
         // server port
         TextField(
@@ -97,28 +123,42 @@ fun CommunicationInternetServerContent(
             }
         )
 
+        // check if a class is selected
+        if (selectedClass.value != null)
+            // button to create the server
             Button(onClick = {
                 Thread {  // a thread is used for networking
-                // Reset the database | TODO(Faraphel): only for testing purpose
-                activity.deleteDatabase("local")
-
-                // Create the database
-                val database = Room.databaseBuilder(
-                    activity,
-                    TaskDatabase::class.java,
-                    "local"
-                ).build()
-
-                // Populate the database with test data
-                // TODO(Faraphel): remove test data
-                populateTaskDatabaseTest(database)
 
                     // Insert the admin in the database
                     database.personDao().insert(adminPersonEntity)
 
+                    // Create a new session
+                    // TODO(Faraphel): name
+                    val (sessionId) = database.sessionDao().insert(
+                        SessionEntity(
+                        name="NOM",
+                        start=Instant.now(),
+                        classId=selectedClass.value!!.id,
+                        )
+                    )
+                    val session = database.sessionDao().getById(sessionId)!!
+
+                    // TODO(Faraphel): remove, this is a test function
+                    Thread {
+                        populateSubjectSessionPersonTest(database, session)
+                    }.let { thread ->
+                        thread.start()
+                        thread.join()
+                    }
+
                     // Create the server
                     Log.i("room-server", "creating the server")
-                val server = TaskServer(serverPort.intValue, database, adminPersonEntity)
+                    val server = TaskServer(
+                        serverPort.intValue,
+                        database,
+                        session,
+                        adminPersonEntity,
+                    )
                     server.start()
 
                     // Get the client from the server
@@ -129,3 +169,11 @@ fun CommunicationInternetServerContent(
             }
     }
 }
+
+
+/**
+ * Refresh the list of classes
+ */
+fun refreshClasses(database: TaskDatabase, classes: MutableState<List<ClassEntity>?>) {
+    classes.value = database.classDao().getAll()
+}

app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/selection.kt

@@ -1,7 +1,9 @@
 package com.faraphel.tasks_valider.ui.screen.communication
 
 import android.app.Activity
+import android.os.Build
 import android.widget.Toast
+import androidx.annotation.RequiresApi
 import androidx.compose.foundation.layout.Column
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
@@ -13,6 +15,7 @@ import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
 import com.faraphel.tasks_valider.connectivity.bwf.BwfManager
+import com.faraphel.tasks_valider.database.TaskDatabase
 import com.faraphel.tasks_valider.ui.screen.communication.internet.CommunicationInternetSelectScreen
 import com.faraphel.tasks_valider.ui.screen.communication.wifiP2p.CommunicationWifiP2pScreen
 
@@ -21,10 +24,13 @@ import com.faraphel.tasks_valider.ui.screen.communication.wifiP2p.CommunicationW
  * CommunicationController is the main controller for the communication screen.
  * It is responsible for handling the navigation between the different communication methods.
  * It is also responsible for initializing the communication methods.
+ *
  * @param activity: The activity that hosts the communication screen.
+ * @param database: the database.
  */
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
-fun CommunicationModeSelectionScreen(activity: Activity) {
+fun CommunicationModeSelectionScreen(activity: Activity, database: TaskDatabase) {
     val controller = rememberNavController()
 
     NavHost(
@@ -35,7 +41,7 @@ fun CommunicationModeSelectionScreen(activity: Activity) {
             CommunicationSelectContent(controller, activity)
         }
         composable("internet") {
-            CommunicationInternetSelectScreen(activity)
+            CommunicationInternetSelectScreen(activity, database)
         }
         composable("wifi-p2p") {
             val bwfManager = BwfManager.fromActivity(activity)

app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/session.kt

@@ -23,19 +23,19 @@ import com.google.gson.reflect.TypeToken
 @Composable
 fun TaskSessionScreen(activity: Activity, client: TaskClient) {
     val students = remember { mutableStateOf<List<PersonEntity>?>(null) }
-    val selected_student = remember { mutableStateOf<PersonEntity?>(null) }
+    val selectedStudent = remember { mutableStateOf<PersonEntity?>(null) }
 
     // if the groups are not yet defined, refresh the list
     if (students.value == null)
         return Thread { refreshStudents(activity, client, students) }.start()
 
-    if (selected_student.value != null)
+    if (selectedStudent.value != null)
-        return TaskStudentScreen(selected_student.value!!)
+        return TaskStudentScreen(activity, client, selectedStudent.value!!)
 
     Column {
         // if the groups have already been defined, display them
         for (student in students.value!!) {
-            Button(onClick = { selected_student.value = student }) {
+            Button(onClick = { selectedStudent.value = student }) {
                 Text(text = student.fullName())
             }
         }

app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/student.kt

@@ -1,14 +1,89 @@
 package com.faraphel.tasks_valider.ui.screen.task
 
+import android.app.Activity
+import android.widget.Toast
+import androidx.compose.foundation.layout.Column
+import androidx.compose.material3.Button
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import com.faraphel.tasks_valider.database.entities.PersonEntity
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import com.faraphel.tasks_valider.connectivity.task.TaskClient
+import com.faraphel.tasks_valider.database.entities.*
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
 
 /**
  * This screen represent a student
  * @param student the student object
  */
 @Composable
-fun TaskStudentScreen(student: PersonEntity) {
+fun TaskStudentScreen(activity: Activity, client: TaskClient, student: PersonEntity) {
+    val tasks = remember { mutableStateOf<List<TaskEntity>?>(null) }
+
+    if (tasks.value == null)
+        Thread { refreshTasks(activity, client, student, tasks) }.start()
+
+    Column {
         Text(text = student.fullName())
+
+        tasks.value?.forEach { task ->
+            Button(onClick = {}) {
+                Column {
+                    Text(task.title)
+                    task.description?.let { description -> Text(description) }
+                }
+            }
+        }
+    }
+}
+
+fun refreshTasks(
+    activity: Activity,
+    client: TaskClient,
+    student: PersonEntity,
+    tasks: MutableState<List<TaskEntity>?>
+) {
+    val jsonParser = Gson()
+
+    // try to obtain the list of subject
+    val responseSubjects = client.get("entities/" + RelationPersonSessionSubjectEntity.TABLE_NAME)
+
+    // in case of error, notify it
+    if (!responseSubjects.isSuccessful)
+        return activity.runOnUiThread { Toast.makeText(activity, responseSubjects.message, Toast.LENGTH_LONG).show() }
+
+    // parse the list of subjects
+    val allPersonSessionSubjects = jsonParser.fromJson<List<RelationPersonSessionSubjectEntity>>(
+        responseSubjects.body.string(),
+        object : TypeToken<List<RelationPersonSessionSubjectEntity>>(){}.type
+    )
+
+    // get the subject that the student is using
+    val relationPersonSessionSubjects = allPersonSessionSubjects.firstOrNull { relation -> relation.studentId == student.id }
+
+    if (relationPersonSessionSubjects == null)
+        // TODO(Faraphel): should be able to assign a subject ?
+        return activity.runOnUiThread { Toast.makeText(activity, "No subject assigned", Toast.LENGTH_LONG).show() }
+
+    // try to obtain the list of tasks
+    val responseTasks = client.get("entities/" + TaskEntity.TABLE_NAME)
+
+    // in case of error, notify it
+    if (!responseTasks.isSuccessful)
+        return activity.runOnUiThread { Toast.makeText(activity, responseTasks.message, Toast.LENGTH_LONG).show() }
+
+    // parse the list of subjects
+    val allTasks = jsonParser.fromJson<List<TaskEntity>>(
+        responseTasks.body.string(),
+        object : TypeToken<List<TaskEntity>>(){}.type
+    )
+
+    // get the tasks that are linked to this subject
+    tasks.value = allTasks.filter { task ->
+        task.subjectId == relationPersonSessionSubjects.subjectId
+    }.sortedBy { task ->
+        task.order
+    }
 }