import Hummingbird
import Localization

/// A request context that carries the language negotiated for the request.
///
/// ``LocalizationMiddleware`` resolves the visitor's preferred language from the `Accept-Language`
/// header and stores it here, so downstream controllers and middleware can serve the matching
/// localization without re-reading the header.
public protocol LocalizedRequestContext: RequestContext {

    // MARK: Properties

    /// The language identifier negotiated for the request.
    var language: String { get set }

}

// MARK: - Context

/// The website's request context.
///
/// Extends the core request storage with the negotiated language, defaulting to the default
/// supported language until ``LocalizationMiddleware`` resolves it from the request.
public struct WebsiteRequestContext: LocalizedRequestContext {

    // MARK: Properties

    /// The core request context storage Hummingbird requires.
    public var coreContext: CoreRequestContextStorage
    /// The language identifier negotiated for the request.
    public var language: String

    // MARK: Initializers

    /// Creates a request context for the given source.
    /// - Parameter source: the source the context is initialized from.
    public init(source: Source) {
        self.coreContext = .init(source: source)
        self.language = LanguageList(bundle: .module).default
    }

}