import Foundation

public struct OpenFoodFactsConfig: Sendable {
	public let baseURL: URL
	public let userAgent: UserAgent
	public let apiURL: URL
	public let searchURL: URL

	public struct UserAgent: CustomStringConvertible, Sendable {
		public let appName: String
		public let version: String
		public let contactInfo: String

		/// AppName/Version (Contact info)
		public var description: String {
			"\(appName)/\(version) (\(contactInfo))"
		}

		public init(appName: String, version: String, contactInfo: String) {
			self.appName = appName
			self.version = version
			self.contactInfo = contactInfo
		}

		public init?(from userAgent: String) {
			guard userAgent.count > 0 else {
				return nil
			}
			let splitted = userAgent.split(separator: " ")
			guard splitted.count == 2 else {
				return nil
			}

			let appNameVersion = splitted[0].split(separator: "/")
			guard appNameVersion.count == 2 else {
				return nil
			}

			self.appName = String(appNameVersion[0])
			self.version = String(appNameVersion[1])
			self.contactInfo = String(splitted[1])
		}

	}

	public enum Environment: Sendable {
		case production
		case staging

		var url: URL {
			switch self {
			case .production:
				return URL(string: "https://world.openfoodfacts.org")!
			case .staging:
				return URL(string: "https://world.openfoodfacts.net")!
			}
		}
	}

	/// - Parameters:
	///   - userAgent: Crucial for OFF. Format: "AppName/Version (Contact info)"
	public init(environment: Environment = .production, userAgent: UserAgent) {
		self.baseURL = environment.url
		self.userAgent = userAgent
		self.apiURL = self.baseURL.appendingPathComponent("/api/v2")
		self.searchURL = URL(string: "https://search.openfoodfacts.org/search")!
	}
}