Add support for archiving conversations

Archiving messages currently acts like recycle bin in
Simple Gallery, meaning that after 30 days, conversations
will be deleted permanently. Any updates to the conversation
(new messages) removes it from archive.

This closes #177

app/src/main/kotlin/com/simplemobiletools/smsmessenger/extensions/Context.kt

@@ -581,6 +581,35 @@ fun Context.insertNewSMS(address: String, subject: String, body: String, date: L
     }
 }
 
+fun Context.checkAndDeleteOldArchivedConversations(callback: (() -> Unit)? = null) {
+    if (config.useArchive && config.lastArchiveCheck < System.currentTimeMillis() - DAY_SECONDS * 1000) {
+        config.lastArchiveCheck = System.currentTimeMillis()
+        ensureBackgroundThread {
+            try {
+                for (conversation in conversationsDB.getOldArchived(System.currentTimeMillis() - MONTH_SECONDS * 1000L)) {
+                    deleteConversation(conversation.threadId)
+                }
+                callback?.invoke()
+            } catch (e: Exception) {
+            }
+        }
+    }
+}
+
+fun Context.removeAllArchivedConversations(callback: (() -> Unit)? = null) {
+    ensureBackgroundThread {
+        try {
+            for (conversation in conversationsDB.getAllArchived()) {
+                deleteConversation(conversation.threadId)
+            }
+            toast(R.string.recycle_bin_emptied)
+            callback?.invoke()
+        } catch (e: Exception) {
+            toast(R.string.unknown_error_occurred)
+        }
+    }
+}
+
 fun Context.deleteConversation(threadId: Long) {
     var uri = Sms.CONTENT_URI
     val selection = "${Sms.THREAD_ID} = ?"
@@ -602,6 +631,15 @@ fun Context.deleteConversation(threadId: Long) {
     messagesDB.deleteThreadMessages(threadId)
 }
 
+fun Context.moveConversationToRecycleBin(threadId: Long) {
+    conversationsDB.archiveConversation(
+        ArchivedConversation(
+            threadId = threadId,
+            deletedTs = System.currentTimeMillis()
+        )
+    )
+}
+
 fun Context.deleteMessage(id: Long, isMMS: Boolean) {
     val uri = if (isMMS) Mms.CONTENT_URI else Sms.CONTENT_URI
     val selection = "${Sms._ID} = ?"