avoid importing the same event twice from ics file

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/DBHelper.kt

@@ -118,6 +118,7 @@ class DBHelper(context: Context) : SQLiteOpenHelper(context, DB_NAME, null, DB_V
             put(COL_TITLE, event.title)
             put(COL_DESCRIPTION, event.description)
             put(COL_REMINDER_MINUTES, event.reminderMinutes)
+            put(COL_IMPORT_ID, event.importId)
         }
     }
 
@@ -152,6 +153,25 @@ class DBHelper(context: Context) : SQLiteOpenHelper(context, DB_NAME, null, DB_V
         mEventsListener?.eventsDeleted(ids.size)
     }
 
+    fun getImportIds(): ArrayList<String> {
+        val ids = ArrayList<String>()
+        val columns = arrayOf(COL_IMPORT_ID)
+        val selection = "$COL_IMPORT_ID IS NOT NULL"
+        var cursor: Cursor? = null
+        try {
+            cursor = mDb.query(MAIN_TABLE_NAME, columns, selection, null, null, null, null)
+            if (cursor != null && cursor.moveToFirst()) {
+                do {
+                    val id = cursor.getStringValue(COL_IMPORT_ID)
+                    ids.add(id)
+                } while (cursor.moveToNext())
+            }
+        } finally {
+            cursor?.close()
+        }
+        return ids
+    }
+
     fun getEvent(id: Int): Event? {
         val selection = "$MAIN_TABLE_NAME.$COL_ID = ?"
         val selectionArgs = arrayOf(id.toString())

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/IcsParser.kt

@@ -21,11 +21,13 @@ class IcsParser {
     private val DTEND = "DTEND:"
     private val SUMMARY = "SUMMARY:"
     private val DESCRIPTION = "DESCRIPTION:"
+    private val UID = "UID:"
 
     var curStart = -1
     var curEnd = -1
     var curTitle = ""
     var curDescription = ""
+    var curImportId = ""
 
     var eventsImported = 0
     var eventsFailed = 0
@@ -33,6 +35,7 @@ class IcsParser {
     fun parseIcs(context: Context, reminderMinutes: Int, path: String): ImportResult {
         try {
             val dbHelper = DBHelper(context)
+            val importIDs = dbHelper.getImportIds()
 
             File(path).inputStream().bufferedReader().use {
                 while (true) {
@@ -47,11 +50,13 @@ class IcsParser {
                         curTitle = line.substring(SUMMARY.length)
                     } else if (line.startsWith(DESCRIPTION)) {
                         curDescription = line.substring(DESCRIPTION.length)
+                    } else if (line.startsWith(UID)) {
+                        curImportId = line.substring(UID.length)
                     } else if (line == END || line == BEGIN_ALARM) {
-                        if (curTitle.isEmpty() || curStart == -1 || curEnd == -1)
+                        if (curTitle.isEmpty() || curStart == -1 || curEnd == -1 || importIDs.contains(curImportId))
                             continue
 
-                        val event = Event(0, curStart, curEnd, curTitle, curDescription, reminderMinutes)
+                        val event = Event(0, curStart, curEnd, curTitle, curDescription, reminderMinutes, importId = curImportId)
                         dbHelper.insert(event) {
                             context.scheduleNotification(event)
                         }
@@ -89,5 +94,6 @@ class IcsParser {
         curEnd = -1
         curTitle = ""
         curDescription = ""
+        curImportId = ""
     }
 }

app/src/main/kotlin/com/simplemobiletools/calendar/models/Event.kt

@@ -6,7 +6,7 @@ import org.joda.time.DateTime
 import java.io.Serializable
 
 data class Event(var id: Int = 0, var startTS: Int = 0, var endTS: Int = 0, var title: String = "", var description: String = "",
-                 var reminderMinutes: Int = 0, var repeatInterval: Int = 0) : Serializable {
+                 var reminderMinutes: Int = 0, var repeatInterval: Int = 0, var importId: String = "") : Serializable {
 
     companion object {
         private val serialVersionUID = -32456795132344616L