import Foundation

public enum Environment: String {

    // A plist should exist for each of the environments
    // below. For example `case production = "Prod"` will
    // have a corresponding `Prod.plist`.

    case production
    case staging
    case development

    // Below represents a key found in each/every plist
    // file mentioned above

    public enum Key: String {

        case baseUrl = "BASE_URL"
        case socialToken = "SOCIAL_TOKEN"
    }

    fileprivate class EnvBundleClass { }

    private static var bundle: Bundle? = {

        return Bundle(for: EnvBundleClass.self)
    }()

    public static var versionNumber: String? {

        guard let version = bundle?.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String else {

            return nil
        }

        return version
    }

    public static var buildNumber: String? {

        guard let build = bundle?.object(forInfoDictionaryKey: kCFBundleVersionKey as String) as? String else {

            return nil
        }

        return build
    }

    public static var current: Environment = {

        var raw: String?

        if let currentConfig = bundle?.object(forInfoDictionaryKey: "Config") as? String {

            raw = currentConfig
                .replacingOccurrences(of: "Debug", with: "")
                .replacingOccurrences(of: "Release", with: "")
                .replacingOccurrences(of: "-", with: "")
        }

        if let raw = raw, let environment = Environment(rawValue: raw) {

            return environment
        }

        return .production
    }()

    public static var plistPath: String? {

        return Environment.bundle?.path(forResource: current.rawValue, ofType: "plist")
    }

    public static var plist: Dictionary<String, Any>? = {

        guard let plistPath = plistPath else {

            return nil
        }

        return NSDictionary(contentsOfFile: plistPath) as? Dictionary<String, Any>
    }()

    // MARK: - Convenience

    public static func value<T>(for key: Environment.Key) -> T? {

        return plist?[key.rawValue] as? T
    }

    public static func int(for key: Environment.Key) -> Int? {

        return plist?[key.rawValue] as? Int
    }

    public static func string(for key: Environment.Key) -> String? {

        return plist?[key.rawValue] as? String
    }
}