import Combine
import Foundation
import Swinject

protocol Provider {
    init(resolver: Resolver)
    var user: CurrentValueSubject<User?, Never> { get }
}

class BaseProvider: Provider, Injectable {
    let user = CurrentValueSubject<User?, Never>(nil)
    var lifetime = Set<AnyCancellable>()
    @Injected() var authorizationManager: AuthorizationManager!

    required init(resolver: Resolver) {
        injectServices(resolver)
        subscribe()
    }

    private func subscribe() {
        authorizationManager.credentials
            .map { credentials -> User? in
                guard let credentials = credentials else { return nil }
                return User(id: credentials.id)
            }
            .sink { user in
                self.user.send(user)
            }
            .store(in: &lifetime)
    }

    func defaults(for file: String) -> RawJSON {
        guard let url = Foundation.Bundle.main.url(forResource: "json/defaults/\(file)", withExtension: "") else {
            return ""
        }
        return (try? String(contentsOf: url)) ?? ""
    }
}