Added custom sorting algorithm to restore the old sorting system of the school's substitution plan that ordered by group first, then time, instead of the other way around

app/src/main/java/com/denizd/substitutionplan/data/DataFetcher.kt

@@ -50,7 +50,6 @@ internal class DataFetcher(isPlan: Boolean, isMenu: Boolean, isJobService: Boole
     private var mContext = WeakReference(context)
     private var mApplication = application
     private var mView = WeakReference(parentView)
-    private var priority = 200
     private var notificationText = ""
     private var informational = ""
     private val prefs = PreferenceManager.getDefaultSharedPreferences(mContext.get())
@@ -91,6 +90,7 @@ internal class DataFetcher(isPlan: Boolean, isMenu: Boolean, isJobService: Boole
                 }
             }
         } catch (e: Exception) {
+            e.printStackTrace()
             mView.get()?.let { v: View ->
                 val snackBarView = v.findViewById<View>(R.id.coordination)
                 Snackbar.make(snackBarView, mContext.get()?.getString(R.string.no_internet_connection) ?: "", Snackbar.LENGTH_LONG).setBackgroundTint(ContextCompat.getColor(mContext.get()!!,
@@ -169,20 +169,22 @@ internal class DataFetcher(isPlan: Boolean, isMenu: Boolean, isJobService: Boole
                 val row = rows[i]
                 val cols = row.select("th")
 
+                val group = cols[0].text()
+                val date = cols[1].text()
                 val subst = Substitution(
-                    group = cols[0].text(),
-                    date = cols[1].text(),
+                    group = group,
+                    date = date,
                     time = cols[2].text(),
                     course = cols[3].text(),
                     room = cols[4].text(),
                     additional = cols[5].text(),
                     teacher = cols[6].text(),
                     type = cols[7].text(),
-                    priority = priority
+                    priority = HelperFunctions.assignRanking(group, date.substring(0, 3) == "psa"),
+                    date_priority = HelperFunctions.assignDatePriority(date)
                 )
                 substArray.add(subst)
                 substRepo.insert(subst)
-                priority--
             }
             var countOfNotificationItems = 0
             var countOfMoreNotificationItems = 0

app/src/main/java/com/denizd/substitutionplan/data/HelperFunctions.kt

@@ -25,6 +25,7 @@ import java.util.*
 import java.io.File
 import java.io.FileOutputStream
 import java.io.OutputStreamWriter
+import java.lang.NumberFormatException
 import javax.xml.parsers.DocumentBuilderFactory
 
 /**
@@ -309,6 +310,52 @@ internal object HelperFunctions {
         return false
     }
 
+    /**
+     * Assigns an integer to a given group used to sort the substitution plan in SQL.
+     * The ranking is stored as 'priority' in the database
+     *
+     * @param group     the group string that should be assigned a ranking
+     * @param isPSA     used to determine a PSA, assigns lowest value if true, therefore putting
+     *                  the PSA at the top
+     *
+     * @return the ranking as an integer
+     */
+    fun assignRanking(group: String, isPSA: Boolean): Int {
+        val juniors = arrayOf("5", "6", "7", "8", "9")
+        if (isPSA) return -31
+        return try {
+            when {
+                checkStringForArray(group.substring(0, 1), juniors) -> -30
+                group.substring(0, 1) == "1" || group.substring(0, 1) == "2" -> {
+                    val a = group.substring(1, 2).toInt()
+                    a - (a * 2)
+                }
+                else -> -29
+            }
+        } catch (e: StringIndexOutOfBoundsException) {
+            0
+        }
+    }
+
+    /**
+     * Assigns a date priority to circumvent the event of the 1.12. being shown before the
+     * 31.11., essentially
+     *
+     * @param date      the date to be analysed
+     *
+     * @return an integer value to determine the ranking in the database
+     */
+    fun assignDatePriority(date: String): Int {
+        val periodIndex = date.indexOf('.', 0, true)
+        return try {
+            date.substring(periodIndex + 1, date.length - 1).toInt()
+        } catch (e: StringIndexOutOfBoundsException) {
+            0
+        } catch (n: NumberFormatException) {
+            -1
+        }
+    }
+
     /**
      * The code below is used for saving and restoring user settings. However, it is currently
      * inaccessible to the end user without entering a code in the hidden settings menu,

app/src/main/java/com/denizd/substitutionplan/database/SubstDao.kt

@@ -8,8 +8,7 @@ import com.denizd.substitutionplan.models.Substitution
 @Dao
 internal interface SubstDao {
 
-//    @get:Query("SELECT * FROM subst_table ORDER BY date ASC, `group` ASC, time ASC, priority DESC")
-    @get:Query("SELECT * FROM subst_table ORDER BY priority DESC")
+    @get:Query("SELECT * FROM subst_table ORDER BY date_priority ASC, priority ASC, `group` ASC, time ASC")
     val allSubstitutions: LiveData<List<Substitution>>
 
     @Insert

app/src/main/java/com/denizd/substitutionplan/database/SubstDatabase.kt

@@ -9,7 +9,7 @@ import androidx.sqlite.db.SupportSQLiteDatabase
 import com.denizd.substitutionplan.models.Food
 import com.denizd.substitutionplan.models.Substitution
 
-@Database(entities = [Substitution::class, Food::class], version = 7, exportSchema = false)
+@Database(entities = [Substitution::class, Food::class], version = 8, exportSchema = false)
 internal abstract class SubstDatabase : RoomDatabase() {
 
     abstract fun substDao(): SubstDao
@@ -27,6 +27,11 @@ internal abstract class SubstDatabase : RoomDatabase() {
                 database.execSQL("ALTER TABLE subst_table ADD COLUMN type TEXT NOT NULL DEFAULT ''")
             }
         }
+        private val addDatePriorityColumn = object : Migration(7, 8) {
+            override fun migrate(database: SupportSQLiteDatabase) {
+                database.execSQL("ALTER TABLE subst_table ADD COLUMN date_priority INTEGER NOT NULL DEFAULT 0")
+            }
+        }
 
         fun getInstance(context: Context): SubstDatabase? {
             if (instance == null) {
@@ -34,7 +39,7 @@ internal abstract class SubstDatabase : RoomDatabase() {
                     instance = Room.databaseBuilder(context.applicationContext,
                         SubstDatabase::class.java,
                         "subst_database")
-                        .addMigrations(addTeacherColumn, addTypeColumn)
+                        .addMigrations(addTeacherColumn, addTypeColumn, addDatePriorityColumn)
                         .fallbackToDestructiveMigration()
                         .build()
                 }

app/src/main/java/com/denizd/substitutionplan/models/Substitution.kt

@@ -13,7 +13,8 @@ internal data class Substitution(
     val additional: String,
     val teacher: String,
     val type: String,
-    val priority: Int
+    val priority: Int,
+    val date_priority: Int
 ) {
 
     @PrimaryKey(autoGenerate = true)