#74 added FeedDAO and firebase implementation

app/src/main/java/be/ugent/sel/studeez/domain/FeedDAO.kt

@@ -1,4 +1,10 @@
 package be.ugent.sel.studeez.domain
 
+import be.ugent.sel.studeez.data.local.models.FeedEntry
+import kotlinx.coroutines.flow.Flow
+
 interface FeedDAO {
+
+    fun getFeedEntries(): Flow<List<FeedEntry>>
+
 }

app/src/main/java/be/ugent/sel/studeez/domain/implementation/FirebaseFeedDAO.kt

@@ -1,4 +1,51 @@
 package be.ugent.sel.studeez.domain.implementation
 
-class FirebaseFeedDAO {
+import be.ugent.sel.studeez.data.local.models.FeedEntry
+import be.ugent.sel.studeez.data.local.models.SessionReport
+import be.ugent.sel.studeez.data.local.models.task.Subject
+import be.ugent.sel.studeez.data.local.models.task.Task
+import be.ugent.sel.studeez.domain.FeedDAO
+import be.ugent.sel.studeez.domain.SessionDAO
+import be.ugent.sel.studeez.domain.TaskDAO
+import kotlinx.coroutines.flow.*
+import javax.inject.Inject
+
+class FirebaseFeedDAO @Inject constructor(
+    private val sessionDAO: SessionDAO,
+    private val taskDAO: TaskDAO,
+    private val subjectDAO: FireBaseSubjectDAO
+) : FeedDAO {
+
+    override fun getFeedEntries(): Flow<List<FeedEntry>> {
+        return sessionDAO.getSessions().map {sessionReports ->
+            sessionReports
+                .map { sessionReport ->  sessionToFeedEntry(sessionReport) }
+                .groupBy { it.taskId }
+                .map { fuseFeedEntries(it.component2()) }
+        }
+    }
+
+    private fun fuseFeedEntries(entries: List<FeedEntry>): FeedEntry =
+        entries.fold(entries[0]) { accEntry, newEntry ->
+            val newStudyTime = accEntry.totalStudyTime + newEntry.totalStudyTime
+            accEntry.copy(totalStudyTime = newStudyTime)
+        }
+
+
+    private suspend fun sessionToFeedEntry(sessionReport: SessionReport): FeedEntry {
+        val subjectId: String = sessionReport.subjectId
+        val taskId: String = sessionReport.taskId
+
+        val task: Task = taskDAO.getTask(subjectId, taskId)
+        val subject: Subject = subjectDAO.getSubject(subjectId)!!
+
+        return FeedEntry(
+            argb_color = subject.argb_color,
+            subJectName = subject.name,
+            taskName = task.name,
+            taskId = task.id,
+            subjectId = subject.id,
+            totalStudyTime = sessionReport.studyTime
+        )
+    }
 }