import Combine
import Foundation

@MainActor
final class PaywallConfigService: ObservableObject {
    static let shared = PaywallConfigService()

    private static let remoteConfigURL = URL(
        string: "https://git.mqldevelopment.com/MQL-Development/app_for_reddit/-/raw/main/App%20AI%20for%20Reddit/paywall.json"
    )!

    @Published private(set) var config: PaywallConfig
    private var hasStarted = false

    private init() {
        config = PaywallConfig.loadBundled()
    }

    func start() {
        guard !hasStarted else { return }
        hasStarted = true
        Task { await refreshFromRemote() }
    }

    func refreshFromRemote() async {
        var request = URLRequest(url: Self.remoteConfigURL)
        request.cachePolicy = .reloadIgnoringLocalCacheData
        request.timeoutInterval = 15

        do {
            let (data, response) = try await URLSession.shared.data(for: request)
            guard let http = response as? HTTPURLResponse, (200 ... 299).contains(http.statusCode) else {
                return
            }
            let remoteConfig = try JSONDecoder().decode(PaywallConfig.self, from: data)
            apply(remoteConfig)
        } catch {
            #if DEBUG
            print("Failed to refresh paywall config: \(error.localizedDescription)")
            #endif
        }
    }

    private func apply(_ remoteConfig: PaywallConfig) {
        let bundledConfig = PaywallConfig.loadBundled()
        let mergedConfig = bundledConfig.mergingMarketing(from: remoteConfig)
        guard mergedConfig != config else { return }
        config = mergedConfig
        NotificationCenter.default.post(name: .paywallConfigDidUpdate, object: nil)
    }
}