Make ids unique across both habits and groups

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/database/Repository.kt

@@ -22,8 +22,6 @@ import org.apache.commons.lang3.StringUtils
 import org.apache.commons.lang3.tuple.ImmutablePair
 import org.apache.commons.lang3.tuple.Pair
 import java.lang.reflect.Field
-import java.util.ArrayList
-import java.util.HashMap
 import java.util.LinkedList
 
 class Repository<T>(
@@ -130,6 +128,26 @@ class Repository<T>(
         }
     }
 
+    /**
+     * Gets the shared id for tables that need to maintain unique ids across tables
+     * like habits and habit groups
+     */
+
+    fun getNextAvailableId(name: String): Long {
+        val query = "SELECT next_id FROM SharedIds WHERE name = ?"
+        val cursor = db.query(query, name)
+        val nextId: Long
+        cursor.use { c ->
+            if (cursor.moveToNext()) {
+                nextId = cursor.getLong(0) ?: throw IllegalStateException("Cannot fetch shared ID for $name")
+                execSQL("UPDATE SharedIds SET next_id = next_id + 1 WHERE name = ?", name)
+            } else {
+                throw IllegalStateException("Cannot fetch shared ID for $name")
+            }
+        }
+        return nextId
+    }
+
     private fun cursorToMultipleRecords(c: Cursor): List<T> {
         val records: MutableList<T> = LinkedList()
         while (c.moveToNext()) records.add(cursorToSingleRecord(c))

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/models/sqlite/SQLiteHabitGroupList.kt

@@ -36,10 +36,10 @@ class SQLiteHabitGroupList @Inject constructor(private val modelFactory: ModelFa
     override fun add(habitGroup: HabitGroup) {
         loadRecords()
         habitGroup.position = size()
+        habitGroup.id = repository.getNextAvailableId("habitandgroup")
         val record = HabitGroupRecord()
         record.copyFrom(habitGroup)
         repository.save(record)
-        habitGroup.id = record.id
         habitGroup.habitList.groupID = record.id
         list.add(habitGroup)
         observable.notifyListeners()

uhabits-core/src/jvmMain/java/org/isoron/uhabits/core/models/sqlite/SQLiteHabitList.kt

@@ -52,10 +52,10 @@ class SQLiteHabitList @Inject constructor(private val modelFactory: ModelFactory
     override fun add(habit: Habit) {
         loadRecords()
         habit.position = size()
+        habit.id = repository.getNextAvailableId("habitandgroup")
         val record = HabitRecord()
         record.copyFrom(habit)
         repository.save(record)
-        habit.id = record.id
         (habit.originalEntries as SQLiteEntryList).habitId = record.id
         list.add(habit)
         observable.notifyListeners()

uhabits-core/src/jvmMain/resources/migrations/26.sql

@@ -1,5 +1,41 @@
+create table SharedIds (
+    name text primary key,
+    next_id integer not null
+);
+
+insert into SharedIds (name, next_id) values ('habitandgroup', (select coalesce(max(id),0) from Habits) + 1 );
+
+alter table Habits rename to HabitsOld;
+
+create table Habits (
+    id integer primary key,
+    archived integer,
+    color integer,
+    description text,
+    freq_den integer,
+    freq_num integer,
+    highlight integer,
+    name text,
+    position integer,
+    reminder_hour integer,
+    reminder_min integer,
+    reminder_days integer not null default 127,
+    type integer not null default 0,
+    target_type integer not null default 0,
+    target_value real not null default 0,
+    unit text not null default "",
+    question text,
+    uuid text
+);
+
+insert into Habits (id, archived, color, description, freq_den, freq_num, highlight, name, position, reminder_min, reminder_days, type, target_type, target_value, unit, question, uuid)
+select id, archived, color, description, freq_den, freq_num, highlight, name, position, reminder_min, reminder_days, type, target_type, target_value, unit, question, uuid
+from HabitsOld;
+
+drop table HabitsOld;
+
 create table HabitGroups (
-    id integer primary key autoincrement,
+    id integer primary key,
     archived integer,
     color integer,
     description text not null default "",