import Foundation
import Combine

final class MainHomeRankingViewModel: ObservableObject {
    private let repository = MainHomeRankingRepository()
    private var subscription = Set<AnyCancellable>()

    @Published var isLoading = false
    @Published var items = [MainHomeCreatorRankingItem]()
    @Published var showRankChange = false
    @Published var emptyMessage = ""
    @Published var hasLoaded = false

    func fetchRankings() {
        isLoading = true
        emptyMessage = ""

        repository.getCreatorRankings()
            .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.emptyMessage = I18n.HomeRanking.emptyStateMessage
                    self.hasLoaded = true
                    self.isLoading = false
                }
            } receiveValue: { [weak self] response in
                guard let self else { return }

                let responseData = response.data

                do {
                    let jsonDecoder = JSONDecoder()
                    let decoded = try jsonDecoder.decode(ApiResponse<MainHomeCreatorRankingResponse>.self, from: responseData)

                    if let data = decoded.data, decoded.success, !data.items.isEmpty {
                        self.items = Array(data.items.prefix(20))
                        self.showRankChange = data.showRankChange
                        self.emptyMessage = ""
                    } else {
                        self.items = []
                        self.showRankChange = false
                        self.emptyMessage = I18n.HomeRanking.emptyStateMessage
                    }
                } catch {
                    ERROR_LOG(error.localizedDescription)
                    self.items = []
                    self.showRankChange = false
                    self.emptyMessage = I18n.HomeRanking.emptyStateMessage
                }

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