import Foundation

public final class DIContainer {

    public static let shared = DIContainer()
    public private(set) var values = InjectionValues()

    private init() {}

    public func register<T>(
        _ keyPath: WritableKeyPath<InjectionValues, T?>,
        value: T
    ) {
        values[keyPath: keyPath] = value
    }

    public func resolve<T>(
        _ keyPath: KeyPath<InjectionValues, T?>
    ) -> T {
        guard let value = values[keyPath: keyPath] else {
            fatalError(
                "DIContainer: No value registered for \(keyPath). "
                    + "Call DIContainer.shared.register(\\.key, value:) during app startup."
            )
        }
        return value
    }

    public func reset() {
        values = InjectionValues()
    }

}