feat(creator): 후원 탭 상태를 추가한다

SodaLive/Sources/V2/CreatorChannel/Donation/CreatorChannelDonationViewModel.swift

@@ -0,0 +1,111 @@
+import Foundation
+import Combine
+
+final class CreatorChannelDonationViewModel: ObservableObject {
+    private let repository = CreatorChannelDonationRepository()
+    private var subscription = Set<AnyCancellable>()
+    private let pageSize = 20
+    private var latestRequestId = 0
+
+    @Published var isLoading = false
+    @Published var isLoadingNextPage = false
+    @Published var response: CreatorChannelDonationTabResponse?
+    @Published var rankings = [MemberDonationRankingResponse]()
+    @Published var donations = [CreatorChannelDonationResponse]()
+    @Published var page = 0
+    @Published var size = 20
+    @Published var hasNext = false
+    @Published var hasLoaded = false
+    @Published var errorMessage = ""
+    @Published var isShowPopup = false
+
+    var donationCount: Int {
+        response?.donationCount ?? 0
+    }
+
+    func fetchFirstPage(creatorId: Int) {
+        fetchDonations(creatorId: creatorId, page: 0, isNextPage: false)
+    }
+
+    func fetchNextPageIfNeeded(creatorId: Int, currentItem: CreatorChannelDonationResponse) {
+        guard let lastDonation = donations.last else { return }
+        guard lastDonation.createdAtUtc == currentItem.createdAtUtc,
+              lastDonation.nickname == currentItem.nickname,
+              lastDonation.can == currentItem.can else { return }
+        guard hasNext, isLoadingNextPage == false, isLoading == false else { return }
+
+        fetchDonations(creatorId: creatorId, page: page + 1, isNextPage: true)
+    }
+
+    private func fetchDonations(creatorId: Int, page requestPage: Int, isNextPage: Bool) {
+        latestRequestId += 1
+        let requestId = latestRequestId
+
+        if isNextPage {
+            isLoadingNextPage = true
+        } else {
+            isLoading = true
+        }
+
+        repository.getDonations(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 jsonDecoder = JSONDecoder()
+                    let decoded = try jsonDecoder.decode(ApiResponse<CreatorChannelDonationTabResponse>.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: CreatorChannelDonationTabResponse, isNextPage: Bool) {
+        response = data
+        rankings = data.rankings
+        page = data.page
+        size = data.size
+        hasNext = data.hasNext
+
+        if isNextPage {
+            donations.append(contentsOf: data.donations)
+        } else {
+            donations = data.donations
+        }
+    }
+
+    private func applyFailureState() {
+        errorMessage = I18n.Common.commonError
+        isShowPopup = true
+        isLoading = false
+        isLoadingNextPage = false
+    }
+}