import Foundation

/// Domain boundary; the concrete server integration will replace the stub.
protocol AuthenticationService: Sendable {
    func signIn(salesCode: String) async throws -> LoginSession
}

struct LoginSession: Equatable, Sendable {
    let salesCode: String
    let displayName: String?

    init(salesCode: String, displayName: String? = nil) {
        self.salesCode = salesCode
        self.displayName = displayName
    }
}

enum LoginError: Error, Equatable {
    case invalidSalesCode
    case rejected
    case unavailable
}