fun setFiltersUiState(dialogView: View, prefs: SharedPreferences, context: Context){
            val discoursesCheck = dialogView.findViewById<CheckBox>(R.id.filter_discourses)
            val exercisesCheck = dialogView.findViewById<CheckBox>(R.id.filter_exercises)
            val lecturesCheck = dialogView.findViewById<CheckBox>(R.id.filter_lectures)
            discoursesCheck.isChecked = prefs.getBoolean(context.getString(R.string.PREFS_DISCOURSES_VISIBLE), true)
            exercisesCheck.isChecked = prefs.getBoolean(context.getString(R.string.PREFS_EXERCISES_VISIBLE), true)
            lecturesCheck.isChecked = prefs.getBoolean(context.getString(R.string.PREFS_LECTURES_VISIBLE), true)
        }

        fun setFilters(dialogView: View, prefs:SharedPreferences, context: Context){
            val discoursesCheck = dialogView.findViewById<CheckBox>(R.id.filter_discourses)
            val exercisesCheck = dialogView.findViewById<CheckBox>(R.id.filter_exercises)
            val lecturesCheck = dialogView.findViewById<CheckBox>(R.id.filter_lectures)
            prefs.edit()
                    .putBoolean(context.getString(R.string.PREFS_DISCOURSES_VISIBLE), discoursesCheck.isChecked)
                    .putBoolean(context.getString(R.string.PREFS_EXERCISES_VISIBLE), exercisesCheck.isChecked)
                    .putBoolean(context.getString(R.string.PREFS_LECTURES_VISIBLE), lecturesCheck.isChecked)
                    .apply()
        }

        fun addLessonToFilteredLessons(context: Context, scheduleItem: ScheduleItem){
            val dbHelper = ScheduleDbHelper(context)
            val db = dbHelper.writableDatabase
            val calendar = Calendar.getInstance()
            calendar.time = scheduleItem.startDate

            val values = ContentValues().apply{
                put(ScheduleContract.FilteredLessonEntry.LESSON_SUBJECT, scheduleItem.subject)
                put(ScheduleContract.FilteredLessonEntry.LESSON_TYPE, scheduleItem.type)
                put(ScheduleContract.FilteredLessonEntry.LESSON_TEACHER, scheduleItem.teacher)
                put(ScheduleContract.FilteredLessonEntry.LESSON_TEACHER_ID, scheduleItem.teacherId)
                put(ScheduleContract.FilteredLessonEntry.LESSON_DAY_OF_WEEK, scheduleItem.dayOfTheWeekStr)
                put(ScheduleContract.FilteredLessonEntry.LESSON_START_HOUR, "${calendar.get(Calendar.HOUR_OF_DAY)}:${calendar.get(Calendar.MINUTE)}")
            }

            db.insert(ScheduleContract.FilteredLessonEntry.TABLE_NAME, null, values)

            val prefs = PreferenceManager.getDefaultSharedPreferences(context)
            prefs.edit().putBoolean(context.getString(R.string.PREFS_REFRESH_SCHEDULE), true).apply()
        }

        fun getFilteredLessons(context: Context): List<FilteredLesson>{
            val dbHelper = ScheduleDbHelper(context)
            val db = dbHelper.readableDatabase

            val cursor = db.query(
                    ScheduleContract.FilteredLessonEntry.TABLE_NAME,
                    arrayOf(
                            ScheduleContract.FilteredLessonEntry._ID,
                            ScheduleContract.FilteredLessonEntry.LESSON_SUBJECT,
                            ScheduleContract.FilteredLessonEntry.LESSON_TYPE,
                            ScheduleContract.FilteredLessonEntry.LESSON_TEACHER,
                            ScheduleContract.FilteredLessonEntry.LESSON_TEACHER_ID,
                            ScheduleContract.FilteredLessonEntry.LESSON_DAY_OF_WEEK,
                            ScheduleContract.FilteredLessonEntry.LESSON_START_HOUR
                    ),
                    null,
                    null,
                    null,
                    null,
                    null
            )

            val filteredLessonsList = mutableListOf<FilteredLesson>()

            try{
                cursor.moveToFirst()
                do{
                    val filteredLesson = FilteredLesson(
                            cursor.getInt(cursor.getColumnIndex(ScheduleContract.FilteredLessonEntry._ID)),
                            cursor.getString(cursor.getColumnIndex(ScheduleContract.FilteredLessonEntry.LESSON_SUBJECT)),
                            cursor.getString(cursor.getColumnIndex(ScheduleContract.FilteredLessonEntry.LESSON_TYPE)),
                            cursor.getString(cursor.getColumnIndex(ScheduleContract.FilteredLessonEntry.LESSON_TEACHER)),
                            cursor.getInt(cursor.getColumnIndex(ScheduleContract.FilteredLessonEntry.LESSON_TEACHER_ID)),
                            cursor.getString(cursor.getColumnIndex(ScheduleContract.FilteredLessonEntry.LESSON_DAY_OF_WEEK)),
                            cursor.getString(cursor.getColumnIndex(ScheduleContract.FilteredLessonEntry.LESSON_START_HOUR))
                    )
                    filteredLessonsList.add(filteredLesson)
                }while(cursor.moveToNext())

                cursor.close()
                return filteredLessonsList
            }catch(e: CursorIndexOutOfBoundsException){
                return emptyList()
            }

        }

        fun removeFilteredLesson(id: Int, context: Context){
            val db = ScheduleDbHelper(context).readableDatabase
            db.delete(
                    ScheduleContract.FilteredLessonEntry.TABLE_NAME,
                    "${ScheduleContract.FilteredLessonEntry._ID}=?",
                    arrayOf("$id")
            )

            val prefs = PreferenceManager.getDefaultSharedPreferences(context)
            prefs.edit().putBoolean(context.getString(R.string.PREFS_REFRESH_SCHEDULE), true).apply()
        }

        private fun isInFilteredLessons(scheduleItem: ScheduleItem, filteredLessons: List<FilteredLesson>): Boolean{
            val calendar = Calendar.getInstance()
            calendar.time = scheduleItem.startDate
            val startHour = "${calendar.get(Calendar.HOUR_OF_DAY)}:${calendar.get(Calendar.MINUTE)}"

            for(lesson in filteredLessons){
                if(lesson.subject == scheduleItem.subject
                && lesson.type == scheduleItem.type
                && lesson.teacher == scheduleItem.teacher
                && lesson.teacherId == scheduleItem.teacherId
                && lesson.dayOfWeek == scheduleItem.dayOfTheWeekStr
                && lesson.startHour == startHour){
                    return true
                }
            }
            return false
        }