diff --git a/app/src/main/java/com/faraphel/tasks_valider/connectivity/task/TaskClient.kt b/app/src/main/java/com/faraphel/tasks_valider/connectivity/task/TaskClient.kt
index 2ca14f3..b6696d7 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/connectivity/task/TaskClient.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/connectivity/task/TaskClient.kt
@@ -3,8 +3,8 @@ 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
+import okhttp3.logging.HttpLoggingInterceptor
 
 
 /**
@@ -19,19 +19,21 @@ class TaskClient(
     private val baseCookies: List<okhttp3.Cookie> = listOf()
 ) {
     private val baseUrl = "http://$address:$port"
-    private val client = OkHttpClient().newBuilder().cookieJar(
-        // TODO(Faraphel): should be moved into another object
-        object : okhttp3.CookieJar {
-            private val cookies = baseCookies.toMutableList()  ///< list of cookies
+    private val client = OkHttpClient().newBuilder()
+        .cookieJar(
+            // TODO(Faraphel): should be moved into another object
+            object : okhttp3.CookieJar {
+                private val cookies = baseCookies.toMutableList()  ///< list of cookies
 
-            override fun loadForRequest(url: HttpUrl): List<okhttp3.Cookie> {
-                return this.cookies
+                override fun loadForRequest(url: HttpUrl): List<okhttp3.Cookie> {
+                    return this.cookies
+                }
+                override fun saveFromResponse(url: HttpUrl, cookies: List<okhttp3.Cookie>) {
+                    this.cookies.addAll(cookies)
+                }
             }
-            override fun saveFromResponse(url: HttpUrl, cookies: List<okhttp3.Cookie>) {
-                this.cookies.addAll(cookies)
-            }
-        }
-    ).build()
+        )
+    .build()
 
     // TODO(Faraphel): automatically convert content to the correct type ?
 
@@ -83,7 +85,7 @@ class TaskClient(
         this.client.newCall(
             this.baseRequestBuilder(endpoint)
                 .patch(content.toRequestBody(type.toMediaType()))
-                .build()
+            .build()
         ).execute()
 
     /**
@@ -96,6 +98,6 @@ class TaskClient(
         this.client.newCall(
             this.baseRequestBuilder(endpoint)
                 .delete(content.toRequestBody(type.toMediaType()))
-                .build()
+            .build()
         ).execute()
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ClassApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ClassApi.kt
index bbfe608..386b757 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ClassApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ClassApi.kt
@@ -4,6 +4,11 @@ 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.ClassEntity
 import com.faraphel.tasks_valider.database.entities.SessionEntity
+import com.google.gson.reflect.TypeToken
 
 class ClassApi(dao: BaseTaskDao<ClassEntity>, session: SessionEntity) :
-    BaseTaskApi<ClassEntity>(dao, session)
+    BaseTaskApi<ClassEntity>(
+        dao,
+        object: TypeToken<ClassEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/PersonApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/PersonApi.kt
index eb8a8b8..a7c9410 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/PersonApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/PersonApi.kt
@@ -4,6 +4,11 @@ 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.PersonEntity
 import com.faraphel.tasks_valider.database.entities.SessionEntity
+import com.google.gson.reflect.TypeToken
 
 class PersonApi(dao: BaseTaskDao<PersonEntity>, session: SessionEntity) :
-    BaseTaskApi<PersonEntity>(dao, session)
+    BaseTaskApi<PersonEntity>(
+        dao,
+        object: TypeToken<PersonEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationClassPersonApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationClassPersonApi.kt
index e2395e9..308e7e5 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationClassPersonApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationClassPersonApi.kt
@@ -4,7 +4,12 @@ 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.RelationClassPersonEntity
 import com.faraphel.tasks_valider.database.entities.SessionEntity
+import com.google.gson.reflect.TypeToken
 
 
 class RelationClassPersonApi(dao: BaseTaskDao<RelationClassPersonEntity>, session: SessionEntity) :
-    BaseTaskApi<RelationClassPersonEntity>(dao, session)
+    BaseTaskApi<RelationClassPersonEntity>(
+        dao,
+        object: TypeToken<RelationClassPersonEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationPersonSessionSubjectApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationPersonSessionSubjectApi.kt
index 5b2983b..d5bcb99 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationPersonSessionSubjectApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/RelationPersonSessionSubjectApi.kt
@@ -4,7 +4,12 @@ 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
+import com.google.gson.reflect.TypeToken
 
 
 class RelationPersonSessionSubjectApi(dao: BaseTaskDao<RelationPersonSessionSubjectEntity>, session: SessionEntity) :
-    BaseTaskApi<RelationPersonSessionSubjectEntity>(dao, session)
+    BaseTaskApi<RelationPersonSessionSubjectEntity>(
+        dao,
+        object: TypeToken<RelationPersonSessionSubjectEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SessionApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SessionApi.kt
index cfad134..eafbc25 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SessionApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SessionApi.kt
@@ -3,6 +3,11 @@ 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.SessionEntity
+import com.google.gson.reflect.TypeToken
 
 class SessionApi(dao: BaseTaskDao<SessionEntity>, session: SessionEntity) :
-    BaseTaskApi<SessionEntity>(dao, session)
+    BaseTaskApi<SessionEntity>(
+        dao,
+        object: TypeToken<SessionEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SubjectApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SubjectApi.kt
index 383e3ed..fbbed53 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SubjectApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/SubjectApi.kt
@@ -4,7 +4,12 @@ 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.SessionEntity
 import com.faraphel.tasks_valider.database.entities.SubjectEntity
+import com.google.gson.reflect.TypeToken
 
 
 class SubjectApi(dao: BaseTaskDao<SubjectEntity>, session: SessionEntity) :
-    BaseTaskApi<SubjectEntity>(dao, session)
+    BaseTaskApi<SubjectEntity>(
+        dao,
+        object: TypeToken<SubjectEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/TaskApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/TaskApi.kt
index f56a317..6f5351e 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/TaskApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/TaskApi.kt
@@ -4,7 +4,12 @@ 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.SessionEntity
 import com.faraphel.tasks_valider.database.entities.TaskEntity
+import com.google.gson.reflect.TypeToken
 
 
 class TaskApi(dao: BaseTaskDao<TaskEntity>, session: SessionEntity) :
-    BaseTaskApi<TaskEntity>(dao, session)
+    BaseTaskApi<TaskEntity>(
+        dao,
+        object: TypeToken<TaskEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ValidationApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ValidationApi.kt
index 4326afc..46132b6 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ValidationApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/ValidationApi.kt
@@ -4,7 +4,12 @@ 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.SessionEntity
 import com.faraphel.tasks_valider.database.entities.ValidationEntity
+import com.google.gson.reflect.TypeToken
 
 
 class ValidationApi(dao: BaseTaskDao<ValidationEntity>, session: SessionEntity) :
-    BaseTaskApi<ValidationEntity>(dao, session)
+    BaseTaskApi<ValidationEntity>(
+        dao,
+        object: TypeToken<ValidationEntity>() {},
+        session
+    )
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseJsonApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseJsonApi.kt
index 70bfa15..71441f7 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseJsonApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseJsonApi.kt
@@ -1,5 +1,6 @@
 package com.faraphel.tasks_valider.database.api.entities.base
 
+import android.util.Log
 import com.faraphel.tasks_valider.database.dao.base.BaseCronDao
 import com.faraphel.tasks_valider.database.entities.base.BaseEntity
 import com.google.gson.Gson
@@ -11,13 +12,14 @@ 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: BaseCronDao<Entity>) : BaseApi {
+abstract class BaseJsonApi<Entity: BaseEntity>(
+    private val dao: BaseCronDao<Entity>,
+    private val entityTypeToken: TypeToken<Entity>,
+) : BaseApi {
     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 {
@@ -43,10 +45,16 @@ abstract class BaseJsonApi<Entity: BaseEntity>(private val dao: BaseCronDao<Enti
     }
 
     override fun post(httpSession: NanoHTTPD.IHTTPSession): NanoHTTPD.Response {
+        val data = httpSession.inputStream.bufferedReader().readText()
+        Log.i("post data", "data raw : $data")
+
         val obj = parser.fromJson<Entity>(
-            httpSession.inputStream.bufferedReader().readText(),
+            data,
             this.entityTypeToken.type
         )
+
+        Log.i("post data", "data parsed : $obj")
+
         val id = this.dao.insert(obj)
 
         return NanoHTTPD.newFixedLengthResponse(
diff --git a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseTaskApi.kt b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseTaskApi.kt
index 5e29abb..b22ca9f 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseTaskApi.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/database/api/entities/base/BaseTaskApi.kt
@@ -14,14 +14,16 @@ import fi.iki.elonen.NanoHTTPD
  */
 abstract class BaseTaskApi<Entity: BaseEntity>(
     private val dao: BaseTaskDao<Entity>,
+    private val entityTypeToken: TypeToken<Entity>,
     private val session: SessionEntity,
-) : BaseJsonApi<Entity>(dao) {
+) : BaseJsonApi<Entity>(
+    dao,
+    entityTypeToken,
+) {
     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 {
diff --git a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/client.kt b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/client.kt
index 5c0e98f..b89ae26 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/client.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/client.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.foundation.text.KeyboardOptions
 import androidx.compose.material3.Button
@@ -19,12 +21,14 @@ import com.faraphel.tasks_valider.ui.screen.communication.RANGE_SERVER_PORT
 import com.faraphel.tasks_valider.ui.screen.task.TaskSessionScreen
 
 
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
 fun CommunicationInternetClientScreen(activity: Activity) {
     val client = remember { mutableStateOf<TaskClient?>(null) }
 
-    if (client.value == null) CommunicationInternetClientContent(client)
-    else TaskSessionScreen(activity, client.value!!)
+    // TODO(Faraphel): fix and get a user
+    // if (client.value == null) CommunicationInternetClientContent(client)
+    // else TaskSessionScreen(activity, client.value!!, user)
 }
 
 
diff --git a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/server.kt b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/server.kt
index fdf598e..626fae9 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/server.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/internet/server.kt
@@ -28,6 +28,7 @@ import com.faraphel.tasks_valider.ui.screen.authentification.AuthentificationSer
 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 kotlinx.coroutines.flow.MutableStateFlow
 import java.time.Instant
 
 
@@ -42,26 +43,32 @@ fun CommunicationInternetServerScreen(
 ) {
     val controller = rememberNavController()
 
+    val adminPersonEntityRaw = remember { mutableStateOf<PersonEntity?>(null) }
     val adminPersonEntity = remember { mutableStateOf<PersonEntity?>(null) }
     val client = remember { mutableStateOf<TaskClient?>(null) }
 
     NavHost(navController = controller, startDestination = "authentication") {
         composable("authentication") {
             // if the admin person is not created, prompt the user for the admin information
-            if (adminPersonEntity.value == null) AuthentificationServerScreen(adminPersonEntity)
+            if (adminPersonEntityRaw.value == null) AuthentificationServerScreen(adminPersonEntityRaw)
             else controller.navigate("configuration")
         }
         composable("configuration") {
             if (client.value == null)
                 CommunicationInternetServerContent(
                     database,
-                    adminPersonEntity.value!!,
-                    client
+                    adminPersonEntityRaw,
+                    adminPersonEntity,
+                    client,
                 )
             else controller.navigate("session")
         }
         composable("session") {
-            TaskSessionScreen(activity, client.value!!)
+            TaskSessionScreen(
+                activity,
+                client.value!!,
+                adminPersonEntity.value!!
+            )
         }
     }
 }
@@ -71,7 +78,8 @@ fun CommunicationInternetServerScreen(
 @Composable
 fun CommunicationInternetServerContent(
     database: TaskDatabase,
-    adminPersonEntity: PersonEntity,
+    adminPersonEntityRaw: MutableState<PersonEntity?>,
+    adminPersonEntity: MutableState<PersonEntity?>,
     client: MutableState<TaskClient?>
 ) {
     val classes = remember { mutableStateOf<List<ClassEntity>?>(null) }
@@ -129,16 +137,17 @@ fun CommunicationInternetServerContent(
             Button(onClick = {
                 Thread {  // a thread is used for networking
 
-                    // Insert the admin in the database
-                    database.personDao().insert(adminPersonEntity)
+                    // Insert the admin in the database and get its id
+                    val (adminPersonEntityId) = database.personDao().insert(adminPersonEntityRaw.value!!)
+                    adminPersonEntity.value = database.personDao().getById(adminPersonEntityId)!!
 
                     // Create a new session
                     // TODO(Faraphel): name
                     val (sessionId) = database.sessionDao().insert(
                         SessionEntity(
-                        name="NOM",
-                        start=Instant.now(),
-                        classId=selectedClass.value!!.id,
+                            name="NOM",
+                            start=Instant.now(),
+                            classId=selectedClass.value!!.id,
                         )
                     )
                     val session = database.sessionDao().getById(sessionId)!!
@@ -157,7 +166,7 @@ fun CommunicationInternetServerContent(
                         serverPort.intValue,
                         database,
                         session,
-                        adminPersonEntity,
+                        adminPersonEntity.value!!,
                     )
                     server.start()
 
diff --git a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/wifiP2p/server/screen.kt b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/wifiP2p/server/screen.kt
index 1415230..11fb145 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/wifiP2p/server/screen.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/communication/wifiP2p/server/screen.kt
@@ -30,10 +30,11 @@ import com.faraphel.tasks_valider.ui.screen.task.TaskSessionScreen
 fun CommunicationWifiP2pServerScreen(activity: Activity, bwfManager: BwfManager) {
     val client = remember { mutableStateOf<TaskClient?>(null) }
 
+    // TODO(Faraphel): fix and get a user
     // if the server is not created, prompt the user for the server configuration
-    if (client.value == null) CommunicationWifiP2pServerContent(activity, bwfManager, client)
+    // if (client.value == null) CommunicationWifiP2pServerContent(activity, bwfManager, client)
     // else, go to the base tasks screen
-    else TaskSessionScreen(activity, client.value!!)
+    // else TaskSessionScreen(activity, client.value!!)
 }
 
 
diff --git a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/session.kt b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/session.kt
index 2d1335a..d9dea02 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/session.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/session.kt
@@ -1,7 +1,9 @@
 package com.faraphel.tasks_valider.ui.screen.task
 
 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.Text
@@ -20,8 +22,13 @@ import com.google.gson.reflect.TypeToken
  * @param activity the android activity
  * @param client an HTTP client that can communicate with the server
  */
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
-fun TaskSessionScreen(activity: Activity, client: TaskClient) {
+fun TaskSessionScreen(
+    activity: Activity,
+    client: TaskClient,
+    user: PersonEntity,
+) {
     val students = remember { mutableStateOf<List<PersonEntity>?>(null) }
     val selectedStudent = remember { mutableStateOf<PersonEntity?>(null) }
 
@@ -30,7 +37,12 @@ fun TaskSessionScreen(activity: Activity, client: TaskClient) {
         return Thread { refreshStudents(activity, client, students) }.start()
 
     if (selectedStudent.value != null)
-        return TaskStudentScreen(activity, client, selectedStudent.value!!)
+        return TaskStudentScreen(
+            activity,
+            client,
+            user,
+            selectedStudent.value!!
+        )
 
     Column {
         // if the groups have already been defined, display them
@@ -44,7 +56,11 @@ fun TaskSessionScreen(activity: Activity, client: TaskClient) {
 
 
 // TODO(Faraphel): template this function ?
-fun refreshStudents(activity: Activity, client: TaskClient, students: MutableState<List<PersonEntity>?>) {
+fun refreshStudents(
+    activity: Activity,
+    client: TaskClient,
+    students: MutableState<List<PersonEntity>?>
+) {
     // TODO(Faraphel): global variable ?
     val jsonParser = Gson()
 
diff --git a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/student.kt b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/student.kt
index 20acbb8..e5c0005 100644
--- a/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/student.kt
+++ b/app/src/main/java/com/faraphel/tasks_valider/ui/screen/task/student.kt
@@ -1,49 +1,103 @@
 package com.faraphel.tasks_valider.ui.screen.task
 
 import android.app.Activity
+import android.os.Build
+import android.util.Log
 import android.widget.Toast
+import androidx.annotation.RequiresApi
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.material3.Button
+import androidx.compose.material3.Checkbox
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 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.connectivity.task.session.TaskPermission
 import com.faraphel.tasks_valider.database.entities.*
 import com.google.gson.Gson
 import com.google.gson.reflect.TypeToken
+import java.time.Instant
 
 /**
  * This screen represent a student
  * @param student the student object
  */
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
-fun TaskStudentScreen(activity: Activity, client: TaskClient, student: PersonEntity) {
+fun TaskStudentScreen(
+    activity: Activity,
+    client: TaskClient,
+    user: PersonEntity,
+    student: PersonEntity,
+) {
     val tasks = remember { mutableStateOf<List<TaskEntity>?>(null) }
+    val validations = remember { mutableStateOf<List<ValidationEntity>?>(null) }
 
-    if (tasks.value == null)
-        Thread { refreshTasks(activity, client, student, tasks) }.start()
+    if (tasks.value == null || validations.value == null)
+        Thread {
+            refreshTasksValidations(
+                activity,
+                client,
+                student,
+                tasks,
+                validations
+            )
+        }.start()
 
     Column {
         Text(text = student.fullName())
 
-        tasks.value?.forEach { task ->
-            Button(onClick = {}) {
-                Column {
-                    Text(task.title)
-                    task.description?.let { description -> Text(description) }
+        // if both the list of tasks and validations are loaded
+        if (!(tasks.value == null || validations.value == null)) {
+            tasks.value?.forEach { task ->
+                // get the validation
+                val validation = validations.value!!.firstOrNull { validation -> validation.taskId == task.id }
+
+                Button(onClick = {}) {
+                    Row {
+                        Column {
+                            // task title
+                            Text(task.title)
+                            // task description
+                            task.description?.let { description -> Text(description) }
+                            // if the task have been validated, show the date
+                            if (validation != null) Text(validation.date.toString())
+                        }
+                        // the validation state
+                        Checkbox(
+                            checked = validation != null,
+                            enabled = user.role.permissions.contains(TaskPermission.WRITE),
+                            onCheckedChange = { state ->
+                                Thread {
+                                    updateValidation(
+                                        client,
+                                        state,
+                                        validation ?: ValidationEntity(
+                                            Instant.now(),
+                                            user.id,
+                                            student.id,
+                                            task.id,
+                                        )
+                                    )
+                                }.start()
+                            }
+                        )
+                    }
                 }
             }
         }
     }
 }
 
-fun refreshTasks(
+fun refreshTasksValidations(
     activity: Activity,
     client: TaskClient,
     student: PersonEntity,
-    tasks: MutableState<List<TaskEntity>?>
+    tasks: MutableState<List<TaskEntity>?>,
+    validations: MutableState<List<ValidationEntity>?>,
 ) {
     val jsonParser = Gson()
 
@@ -86,4 +140,45 @@ fun refreshTasks(
     }.sortedBy { task ->
         task.order
     }
+
+    // try to obtain the list of validations
+    val responseValidations = client.get("entities/" + ValidationEntity.TABLE_NAME)
+
+    // in case of error, notify it
+    if (!responseValidations.isSuccessful)
+        return activity.runOnUiThread { Toast.makeText(activity, responseTasks.message, Toast.LENGTH_LONG).show() }
+
+    // parse the list of validations
+    val allValidations = jsonParser.fromJson<List<ValidationEntity>>(
+        responseValidations.body.string(),
+        object : TypeToken<List<ValidationEntity>>(){}.type
+    )
+
+    // filter only the interesting validations
+    validations.value = allValidations.filter { validation ->
+        validation.studentId == student.id &&
+        validation.taskId in allTasks.map { task -> task.id }
+    }
 }
+
+
+fun updateValidation(client: TaskClient, checked: Boolean, validation: ValidationEntity) {
+    val jsonParser = Gson()
+
+    if (checked) {
+        // if the validation is not set, create it
+        client.post(
+            "entities/" + ValidationEntity.TABLE_NAME,
+            jsonParser.toJson(validation),
+            "application/json"
+        )
+    }
+    else {
+        // if the validation is set, delete it
+        client.delete(
+            "entities/" + ValidationEntity.TABLE_NAME,
+            jsonParser.toJson(validation),
+            "application/json"
+        )
+    }
+}
\ No newline at end of file