import Combine
import Foundation

final class ArchivedMessagesMiddleware {
    static let shared = ArchivedMessagesMiddleware()

    func middleware(state _: AppState, action: AppAction) -> AnyPublisher<AppAction, Never> {
        switch action {
        // case .conversationAction(.messagesUpdated(let messages)):
        //     if state.conversationsState.archivedMessagesRequested {
        //         return Empty().eraseToAnyPublisher()
        //     } else {
        //         guard let chat = state.conversationsState.currentChat else {
        //             return Empty().eraseToAnyPublisher()
        //         }
        //         return Deferred {
        //             Future<AppAction, Never> { promise in
        //                 if let currentClient = state.accountsState.accounts.first(where: { $0.bareJid == chat.account }) {
        //                     let features = state.accountsState.discoFeatures[currentClient.bareJid] ?? []
        //                     if features.map({ $0.xep }).contains("XEP-0313") {
        //                         let roster = state.conversationsState.currentRoster
        //                         let date = self.archivesRequestDate(from: messages)
        //                         promise(.success(.xmppAction(.xmppLoadArchivedMessages(jid: currentClient.bareJid, to: roster?.bareJid, fromDate: date))))
        //                     } else {
        //                         promise(.success(.info("MessageMiddleware: XEP-0313 not supported for client \(currentClient.bareJid)")))
        //                     }
        //                 } else {
        //                     promise(.success(.info("MessageMiddleware: No client found for account \(chat.account), probably some error here")))
        //                 }
        //             }
        //         }
        //         .eraseToAnyPublisher()
        //     }

        default:
            return Empty().eraseToAnyPublisher()
        }
    }
}

private extension ArchivedMessagesMiddleware {
    func archivesRequestDate(from messages: [Message]) -> Date {
        if let lastDate = messages.first?.date {
            return lastDate
        } else {
            return Calendar.current.date(byAdding: .day, value: -Const.mamRequestDaysLength, to: Date()) ?? Date()
        }
    }
}