refactor: mail to kotlin - part 1

mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/ImapCommandSplitter.kt

@@ -0,0 +1,71 @@
+package com.fsck.k9.mail.store.imap
+
+internal object ImapCommandSplitter {
+    fun splitCommand(prefix: String, suffix: String, groupedIds: GroupedIds, lengthLimit: Int): List<String> {
+        val commands = mutableListOf<String>()
+        val workingIdSet = sortedSetOf<Long>().apply { addAll(groupedIds.ids) }
+        val workingIdGroups = groupedIds.idGroups.toMutableList()
+        val suffixLength = suffix.length
+        val staticCommandLength = prefix.length + suffixLength + 2
+        while (workingIdSet.isNotEmpty() || workingIdGroups.isNotEmpty()) {
+            val commandBuilder = StringBuilder(prefix).append(' ')
+            var length = staticCommandLength
+            while (length < lengthLimit) {
+                val (appended, newLength) = appendNextItem(
+                    commandBuilder,
+                    workingIdSet,
+                    workingIdGroups,
+                    length,
+                    lengthLimit,
+                )
+                length = newLength
+                if (!appended) break
+            }
+            if (suffixLength != 0) {
+                // Replace the last comma with a space
+                commandBuilder.setCharAt(commandBuilder.length - 1, ' ')
+                commandBuilder.append(suffix)
+            } else {
+                // Remove last comma
+                commandBuilder.setLength(commandBuilder.length - 1)
+            }
+            commands.add(commandBuilder.toString())
+        }
+        return commands
+    }
+    private fun appendNextItem(
+        commandBuilder: StringBuilder,
+        workingIdSet: MutableSet<Long>,
+        workingIdGroups: MutableList<ContiguousIdGroup>,
+        currentLength: Int,
+        lengthLimit: Int,
+    ): Pair<Boolean, Int> {
+        return when {
+            workingIdSet.isNotEmpty() -> {
+                val id = workingIdSet.first()
+                val idString = id.toString()
+                val newLength = currentLength + idString.length + 1
+                if (newLength >= lengthLimit) {
+                    false to currentLength
+                } else {
+                    commandBuilder.append(idString).append(',')
+                    workingIdSet.remove(id)
+                    true to newLength
+                }
+            }
+            workingIdGroups.isNotEmpty() -> {
+                val idGroup = workingIdGroups.first()
+                val idGroupString = idGroup.toString()
+                val newLength = currentLength + idGroupString.length + 1
+                if (newLength >= lengthLimit) {
+                    false to currentLength
+                } else {
+                    commandBuilder.append(idGroupString).append(',')
+                    workingIdGroups.remove(idGroup)
+                    true to newLength
+                }
+            }
+            else -> false to currentLength
+        }
+    }
+}

mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/ImapResponseCallback.java → mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/ImapResponseCallback.kt

@@ -1,8 +1,8 @@
-package com.fsck.k9.mail.store.imap;
+package com.fsck.k9.mail.store.imap
 
-import com.fsck.k9.mail.filter.FixedLengthInputStream;
+import com.fsck.k9.mail.filter.FixedLengthInputStream
 
-public interface ImapResponseCallback {
+internal fun interface ImapResponseCallback {
     /**
      * Callback method that is called by the parser when a literal string
      * is found in an IMAP response.
@@ -20,5 +20,6 @@ public interface ImapResponseCallback {
      *                   and the exception will be thrown after the
      *                   complete IMAP response has been parsed.
      */
-    Object foundLiteral(ImapResponse response, FixedLengthInputStream literal) throws Exception;
+    @Throws(Exception::class)
+    fun foundLiteral(response: ImapResponse, literal: FixedLengthInputStream): Any?
 }