- all user interface unrelated data is now kept in baresip service

allowing proper recovery in case Android kills other activities
- many other improvements and bug fixes

app/src/main/kotlin/com/tutpro/baresip/CallHistory.kt

@@ -1,6 +1,8 @@
 package com.tutpro.baresip
 
-import java.io.Serializable
+import android.util.Log
+import java.io.*
+import java.util.ArrayList
 import java.util.GregorianCalendar
 
 class CallHistory(val aor: String, val peerURI: String, val direction: String,
@@ -10,29 +12,72 @@ class CallHistory(val aor: String, val peerURI: String, val direction: String,
 
     companion object {
 
-        fun aorHistory(history: ArrayList<CallHistory>, aor: String): Int {
+        const val CALL_HISTORY_SIZE = 100
+
+        fun history(): ArrayList<CallHistory> {
+            return BaresipService.history
+        }
+
+        fun historySet(history: ArrayList<CallHistory>) {
+            BaresipService.history = history
+        }
+
+        fun add(history: CallHistory) {
+            BaresipService.history.add(history)
+            if (aorHistorySize(history.aor) > CALL_HISTORY_SIZE) {
+                var i = 0
+                for (h in BaresipService.history)
+                    if (h.aor == history.aor)
+                        break
+                    else
+                        i++
+                BaresipService.history.removeAt(i)
+            }
+        }
+
+        fun aorHistorySize(aor: String): Int {
             var size = 0;
-            for (h in history) {
+            for (h in BaresipService.history) {
                 if (h.aor == aor) size++
             }
             return size
         }
 
-        fun aorRemoveHistory(history: ArrayList<CallHistory>, aor: String) {
-            for (h in history) {
-                if (h.aor == aor) {
-                    history.remove(h)
-                    return
-                }
-            }
-        }
-
-        fun aorLatestHistory(history: ArrayList<CallHistory>, aor: String): CallHistory? {
-            for (h in history.reversed())
+        fun aorLatestHistory(aor: String): CallHistory? {
+            for (h in BaresipService.history.reversed())
                 if (h.aor == aor) return h
             return null
         }
 
+        fun save(path: String) {
+            val file = File(path, "history")
+            try {
+                val fos = FileOutputStream(file)
+                val oos = ObjectOutputStream(fos)
+                oos.writeObject(history())
+                oos.close()
+                fos.close()
+            } catch (e: IOException) {
+                Log.w("Baresip", "OutputStream exception: " + e.toString())
+                e.printStackTrace()
+            }
+        }
+
+        fun restore(path: String) {
+            val file = File(path + "/history")
+            if (file.exists()) {
+                try {
+                    val fis = FileInputStream(file)
+                    val ois = ObjectInputStream(fis)
+                    historySet(ois.readObject() as ArrayList<CallHistory>)
+                    ois.close()
+                    fis.close()
+                } catch (e: Exception) {
+                    Log.w("Baresip", "InputStream exception: - " + e.toString())
+                }
+            }
+
+        }
     }
 
 }