src/main/kotlin/net/pterodactylus/sone/core/SoneChangeCollector.kt

   1 package net.pterodactylus.sone.core
   2
   3 import net.pterodactylus.sone.data.Post
   4 import net.pterodactylus.sone.data.PostReply
   5 import net.pterodactylus.sone.data.Sone
   6
   7 /**
   8  * Wrapper around a [SoneChangeDetector] that can turn changed elements into
   9  * different elements which are then being returned. This can be used to turn
  10  * changed elements into events for further processing.
  11  */
  12 class SoneChangeCollector(private val oldSone: Sone) {
  13
  14         private val newPostEventCreators = mutableListOf<(Post) -> Any?>()
  15         private val removedPostEventCreators = mutableListOf<(Post) -> Any?>()
  16         private val newPostReplyEventCreators = mutableListOf<(PostReply) -> Any?>()
  17         private val removedPostReplyEventCreators = mutableListOf<(PostReply) -> Any?>()
  18
  19         fun onNewPost(postProcessor: (Post) -> Unit) =
  20                         newPostEventCreators.add { postProcessor(it).let { null } }.let { this }
  21
  22         fun newPostEvent(postEventCreator: (Post) -> Any?) =
  23                         newPostEventCreators.add(postEventCreator).let { this }
  24
  25         fun onNewPostReply(postReplyProcessor: (PostReply) -> Unit) =
  26                         newPostReplyEventCreators.add { postReplyProcessor(it).let { null } }.let { this }
  27
  28         fun newPostReplyEvent(postReplyEventCreator: (PostReply) -> Any?) =
  29                         newPostReplyEventCreators.add(postReplyEventCreator).let { this }
  30
  31         fun removedPostEvent(postEventCreator: (Post) -> Any?) =
  32                         removedPostEventCreators.add(postEventCreator).let { this }
  33
  34         fun onRemovedPostReply(postReplyEventCreator: (PostReply) -> Any?) =
  35                         removedPostReplyEventCreators.add(postReplyEventCreator).let { this }
  36
  37         fun detectChanges(newSone: Sone): List<Any> {
  38                 val events = mutableListOf<Any>()
  39                 SoneChangeDetector(oldSone).apply {
  40                         onNewPosts { post -> newPostEventCreators.mapNotNull { it(post) }.forEach { events.add(it) } }
  41                         onRemovedPosts { post -> removedPostEventCreators.mapNotNull { it(post) }.forEach { events.add(it) } }
  42                         onNewPostReplies { reply -> newPostReplyEventCreators.mapNotNull { it(reply) }.forEach { events.add(it) } }
  43                         onRemovedPostReplies { reply -> removedPostReplyEventCreators.mapNotNull { it(reply) }.forEach { events.add(it) } }
  44                         detectChanges(newSone)
  45                 }
  46                 return events
  47         }
  48
  49 }