feat(content): 랭킹 탭을 추가한다

SodaLive/Sources/V2/Main/Content/Ranking/MainContentRankingViewModel.swift

@@ -0,0 +1,80 @@
+import Foundation
+import Combine
+
+final class MainContentRankingViewModel: ObservableObject {
+    private let repository = MainContentRankingRepository()
+    private var subscription = Set<AnyCancellable>()
+
+    @Published var isLoading = false
+    @Published var isShowPopup = false
+    @Published var errorMessage = ""
+    @Published var items = [AudioRankingItemResponse]()
+    @Published var showRankChange = false
+    @Published var hasLoaded = false
+
+    var emptyStateMessage: String {
+        if !errorMessage.isEmpty {
+            return errorMessage
+        }
+
+        return I18n.MainContentRanking.emptyStateMessage
+    }
+
+    var shouldShowEmptyState: Bool {
+        hasLoaded && !isLoading && items.isEmpty
+    }
+
+    func fetchRankings() {
+        guard !isLoading else { return }
+
+        isLoading = true
+
+        repository.getAudioRankings()
+            .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.items = []
+                    self.showRankChange = false
+                    self.errorMessage = I18n.MainContentRanking.loadFailedMessage
+                    self.isShowPopup = true
+                    self.isLoading = false
+                    self.hasLoaded = true
+                }
+            } receiveValue: { [weak self] response in
+                guard let self else { return }
+
+                let responseData = response.data
+
+                do {
+                    let jsonDecoder = JSONDecoder()
+                    let decoded = try jsonDecoder.decode(ApiResponse<AudioRankingResponse>.self, from: responseData)
+
+                    if let data = decoded.data, decoded.success, !data.items.isEmpty {
+                        self.errorMessage = ""
+                        self.items = Array(data.items.prefix(20))
+                        self.showRankChange = data.showRankChange
+                    } else {
+                        self.items = []
+                        self.showRankChange = false
+                        self.errorMessage = decoded.success ? "" : I18n.MainContentRanking.loadFailedMessage
+                        self.isShowPopup = !decoded.success
+                    }
+                } catch {
+                    ERROR_LOG(error.localizedDescription)
+                    self.items = []
+                    self.showRankChange = false
+                    self.errorMessage = I18n.MainContentRanking.loadFailedMessage
+                    self.isShowPopup = true
+                }
+
+                self.isLoading = false
+                self.hasLoaded = true
+            }
+            .store(in: &subscription)
+    }
+}