sodalive-ios/SodaLive/Sources/V2/CreatorChannel/FanTalk/CreatorChannelFanTalkViewModel.swift

import Foundation
import Combine

final class CreatorChannelFanTalkViewModel: ObservableObject {
    private let repository = CreatorChannelFanTalkRepository()
    private let reportRepository = ReportRepository()
    private let explorerRepository = ExplorerRepository()
    private var subscription = Set<AnyCancellable>()
    private let pageSize = 20
    private var latestRequestId = 0

    @Published var isLoading = false
    @Published var isLoadingNextPage = false
    @Published var response: CreatorChannelFanTalkTabResponse?
    @Published var fanTalks = [CreatorChannelFanTalkItemResponse]()
    @Published var page = 0
    @Published var size = 20
    @Published var hasNext = false
    @Published var hasLoaded = false
    @Published var errorMessage = ""
    @Published var isShowPopup = false
    @Published var isShowReportDialog = false
    @Published var isShowDeleteDialog = false
    @Published var selectedFanTalkId = 0

    var fanTalkCount: Int {
        response?.fanTalkCount ?? 0
    }

    func fetchFirstPage(creatorId: Int) {
        fetchFanTalks(creatorId: creatorId, page: 0, isNextPage: false)
    }

    func fetchNextPageIfNeeded(creatorId: Int, currentItem: CreatorChannelFanTalkItemResponse) {
        guard let lastFanTalk = fanTalks.last else { return }
        guard lastFanTalk.fanTalkId == currentItem.fanTalkId else { return }
        guard hasNext, isLoadingNextPage == false, isLoading == false else { return }

        fetchFanTalks(creatorId: creatorId, page: page + 1, isNextPage: true)
    }

    func presentReportDialog(fanTalkId: Int) {
        selectedFanTalkId = fanTalkId
        isShowReportDialog = true
    }

    func presentDeleteDialog(fanTalkId: Int) {
        selectedFanTalkId = fanTalkId
        isShowDeleteDialog = true
    }

    func report(reason: String) {
        guard selectedFanTalkId > 0 else { return }

        isLoading = true
        let request = ReportRequest(type: .CHEERS, reason: reason, reportedMemberId: nil, cheersId: selectedFanTalkId, audioContentId: nil)

        reportRepository.report(request: request)
            .sink { [weak self] result in
                guard let self else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }

                self.isLoading = false
                self.selectedFanTalkId = 0

                do {
                    let decoded = try JSONDecoder().decode(ApiResponseWithoutData.self, from: response.data)
                    self.errorMessage = decoded.message ?? I18n.Common.commonError
                    self.isShowPopup = true
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.errorMessage = I18n.Common.commonError
                    self.isShowPopup = true
                }
            }
            .store(in: &subscription)
    }

    func deleteSelectedFanTalk(creatorId: Int) {
        guard selectedFanTalkId > 0 else { return }

        isLoading = true
        explorerRepository.modifyCheers(cheersId: selectedFanTalkId, content: nil, isActive: false)
            .sink { [weak self] result in
                guard let self else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }

                self.isLoading = false
                self.selectedFanTalkId = 0

                do {
                    let decoded = try JSONDecoder().decode(ApiResponseWithoutData.self, from: response.data)

                    if decoded.success {
                        self.fetchFirstPage(creatorId: creatorId)
                    } else {
                        self.errorMessage = decoded.message ?? I18n.Common.commonError
                        self.isShowPopup = true
                    }
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.errorMessage = I18n.Common.commonError
                    self.isShowPopup = true
                }
            }
            .store(in: &subscription)
    }

    private func fetchFanTalks(creatorId: Int, page requestPage: Int, isNextPage: Bool) {
        latestRequestId += 1
        let requestId = latestRequestId

        if isNextPage {
            isLoadingNextPage = true
        } else {
            isLoading = true
        }

        repository.getFanTalks(creatorId: creatorId, page: requestPage, size: pageSize)
            .sink { [weak self] result in
                guard let self else { return }
                guard requestId == self.latestRequestId else { return }

                switch result {
                case .finished:
                    DEBUG_LOG("finish")
                    self.isLoading = false
                    self.isLoadingNextPage = false
                case .failure(let error):
                    ERROR_LOG(error.localizedDescription)
                    self.applyFailureState()
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }
                guard requestId == self.latestRequestId else { return }

                do {
                    let decoded = try JSONDecoder().decode(ApiResponse<CreatorChannelFanTalkTabResponse>.self, from: response.data)

                    if let data = decoded.data, decoded.success {
                        self.applySuccessState(data, isNextPage: isNextPage)
                        self.hasLoaded = true
                    } else {
                        self.errorMessage = decoded.message ?? I18n.Common.commonError
                        self.isShowPopup = true
                    }
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.errorMessage = I18n.Common.commonError
                    self.isShowPopup = true
                }

                self.isLoading = false
                self.isLoadingNextPage = false
            }
            .store(in: &subscription)
    }

    private func applySuccessState(_ data: CreatorChannelFanTalkTabResponse, isNextPage: Bool) {
        response = data
        page = data.page
        size = data.size
        hasNext = data.hasNext

        if isNextPage {
            fanTalks.append(contentsOf: data.fanTalks)
        } else {
            fanTalks = data.fanTalks
        }
    }

    private func applyFailureState() {
        errorMessage = I18n.Common.commonError
        isShowPopup = true
        isLoading = false
        isLoadingNextPage = false
    }
}