Improvements for working with conversations

core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt

@@ -815,3 +815,14 @@ class Plaintext private constructor(
 
     }
 }
+
+data class Conversation(val id: UUID, val subject: String, val messages: List<Plaintext>) {
+    val participants = messages
+        .map { it.from }
+        .filter { it.privateKey == null || it.isChan }
+        .distinct()
+
+    val extract: String by lazy { messages.lastOrNull()?.text ?: "" }
+
+    fun hasUnread() = messages.any { it.isUnread() }
+}

core/src/main/kotlin/ch/dissem/bitmessage/ports/MessageRepository.kt

@@ -41,7 +41,7 @@ interface MessageRepository {
      * *
      * @return a distinct list of all conversations that have at least one message with the given label.
      */
-    fun findConversations(label: Label?): List<UUID>
+    fun findConversations(label: Label?, offset: Int = 0, limit: Int = 0): List<UUID>
 
     fun findMessages(label: Label?): List<Plaintext>
 

core/src/main/kotlin/ch/dissem/bitmessage/utils/ConversationService.kt

@@ -16,10 +16,11 @@
 
 package ch.dissem.bitmessage.utils
 
+import ch.dissem.bitmessage.entity.Conversation
 import ch.dissem.bitmessage.entity.Plaintext
 import ch.dissem.bitmessage.entity.valueobject.InventoryVector
+import ch.dissem.bitmessage.entity.valueobject.Label
 import ch.dissem.bitmessage.ports.MessageRepository
-import org.slf4j.LoggerFactory
 import java.util.*
 import java.util.Collections
 import java.util.regex.Pattern
@@ -30,7 +31,10 @@ import java.util.regex.Pattern.CASE_INSENSITIVE
  */
 class ConversationService(private val messageRepository: MessageRepository) {
 
-    private val SUBJECT_PREFIX = Pattern.compile("^(re|fwd?):", CASE_INSENSITIVE)
+    private val SUBJECT_PREFIX = Pattern.compile("^(re|fwd?):\\s*", CASE_INSENSITIVE)
+
+    fun findConversations(label: Label?, offset: Int = 0, limit: Int = 0) = messageRepository.findConversations(label, offset, limit)
+        .map { getConversation(it) }
 
     /**
      * Retrieve the whole conversation from one single message. If the message isn't part
@@ -41,7 +45,7 @@ class ConversationService(private val messageRepository: MessageRepository) {
      * *
      * @return a list of messages that belong to the same conversation.
      */
-    fun getConversation(message: Plaintext): List<Plaintext> {
+    fun getConversation(message: Plaintext): Conversation {
         return getConversation(message.conversationId)
     }
 
@@ -58,7 +62,7 @@ class ConversationService(private val messageRepository: MessageRepository) {
         return result
     }
 
-    fun getConversation(conversationId: UUID): List<Plaintext> {
+    fun getConversation(conversationId: UUID): Conversation {
         val messages = sorted(messageRepository.getConversation(conversationId))
         val map = HashMap<InventoryVector, Plaintext>(messages.size)
         for (message in messages) {
@@ -74,7 +78,7 @@ class ConversationService(private val messageRepository: MessageRepository) {
             result.add(pos, last)
             addAncestors(last, result, messages, map)
         }
-        return result
+        return Conversation(conversationId, getSubject(result) ?: "", result)
     }
 
     fun getSubject(conversation: List<Plaintext>): String? {
@@ -109,7 +113,12 @@ class ConversationService(private val messageRepository: MessageRepository) {
         return child.parents.firstOrNull { it == item.inventoryVector } != null
     }
 
-    private fun addAncestors(message: Plaintext, result: LinkedList<Plaintext>, messages: LinkedList<Plaintext>, map: MutableMap<InventoryVector, Plaintext>) {
+    private fun addAncestors(
+        message: Plaintext,
+        result: LinkedList<Plaintext>,
+        messages: LinkedList<Plaintext>,
+        map: MutableMap<InventoryVector, Plaintext>
+    ) {
         for (parentKey in message.parents) {
             map.remove(parentKey)?.let {
                 messages.remove(it)

repositories/src/main/kotlin/ch/dissem/bitmessage/repository/JdbcMessageRepository.kt

@@ -257,18 +257,19 @@ class JdbcMessageRepository(private val config: JdbcConfig) : AbstractMessageRep
         }
     }
 
-    override fun findConversations(label: Label?): List<UUID> {
+    override fun findConversations(label: Label?, offset: Int, limit: Int): List<UUID> {
         val where = if (label == null) {
             "id NOT IN (SELECT message_id FROM Message_Label)"
         } else {
             "id IN (SELECT message_id FROM Message_Label WHERE label_id=${label.id})"
         }
+        val limit = if (limit == 0) "" else "LIMIT $limit OFFSET $offset"
         val result = LinkedList<UUID>()
         try {
             config.getConnection().use { connection ->
                 connection.createStatement().use { stmt ->
                     stmt.executeQuery(
-                        "SELECT DISTINCT conversation FROM Message WHERE $where").use { rs ->
+                        "SELECT DISTINCT conversation FROM Message WHERE $where $limit").use { rs ->
                         while (rs.next()) {
                             result.add(rs.getObject(1) as UUID)
                         }