import Vapor

extension Environment {
    enum Error: Swift.Error, LocalizedError {
        case missing (String)

        var errorDescription: String? {
            switch self {
                case .missing (let variable):
                    return "Missing environment variable: \(variable)"
            }
        }
    }

    static var baseURL: URL {
        get throws {
            guard let baseURL = Environment.get ("BASE_URL"), let url = URL (string: baseURL) else {
                throw Error.missing ("BASE_URL")
            }

            return url
        }
    }

    static func baseURL (_ path: String) throws -> URL {
        return try baseURL.appendingPathComponent (path)
    }

    static var emailSender: String {
        get throws {
            guard let sender = Environment.get ("EMAIL_SENDER") else {
                throw Error.missing ("EMAIL_SENDER")
            }

            return sender
        }
    }
}