add publisher

posts/src/commonMain/kotlin/sending/PostPublisher.kt

@@ -0,0 +1,60 @@
+package dev.inmo.plaguposter.posts.sending
+
+import dev.inmo.kslog.common.logger
+import dev.inmo.kslog.common.w
+import dev.inmo.plaguposter.posts.models.PostId
+import dev.inmo.plaguposter.posts.repo.PostsRepo
+import dev.inmo.tgbotapi.bot.TelegramBot
+import dev.inmo.tgbotapi.extensions.api.forwardMessage
+import dev.inmo.tgbotapi.extensions.api.send.copyMessage
+import dev.inmo.tgbotapi.extensions.api.send.send
+import dev.inmo.tgbotapi.extensions.utils.*
+import dev.inmo.tgbotapi.types.*
+import dev.inmo.tgbotapi.types.message.content.MediaGroupContent
+
+class PostPublisher(
+    private val bot: TelegramBot,
+    private val repo: PostsRepo,
+    private val cachingChatId: ChatId,
+    private val targetChatId: ChatId
+) {
+    suspend fun publish(postId: PostId) {
+        val messagesInfo = repo.getById(postId) ?: let {
+            logger.w { "Unable to get post with id $postId for publishing" }
+            return
+        }
+        val sortedMessagesContents = messagesInfo.content.groupBy { it.group }.flatMap { (group, list) ->
+            if (group == null) {
+                list.map {
+                    it.order to listOf(it)
+                }
+            } else {
+                listOf(list.first().order to list)
+            }
+        }.sortedBy { it.first }
+
+        sortedMessagesContents.forEach { (_, contents) ->
+            contents.singleOrNull() ?.also {
+                bot.copyMessage(targetChatId, it.chatId, it.messageId)
+                return@forEach
+            }
+            val resultContents = contents.mapNotNull {
+                it.order to (bot.forwardMessage(cachingChatId, it.chatId, it.messageId).contentMessageOrNull() ?: return@mapNotNull null)
+            }.sortedBy { it.first }.mapNotNull { (_, it) ->
+                it.withContentOrNull<MediaGroupContent>() ?: null.also { _ ->
+                    bot.copyMessage(targetChatId, it)
+                }
+            }
+            resultContents.singleOrNull() ?.also {
+                bot.copyMessage(targetChatId, it)
+                return@forEach
+            } ?: resultContents.chunked(mediaCountInMediaGroup.last).forEach {
+                bot.send(
+                    targetChatId,
+                    it.map { it.content.toMediaGroupMemberTelegramMedia() }
+                )
+            }
+        }
+
+    }
+}