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

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() }
                )
            }
        }

    }
}