import Foundation

struct Config: Codable {

    /// The port where the server runs
    let port: Int

    /// The maximum size of the request body
    let maxBodySize: String

    /// The path to the folder where the metric logs are stored
    let logPath: String

    /// Serve files in the Public directory using Vapor
    let serveFiles: Bool

    /// Authentication tokens for remotes allowed to write
    let writers: [String]

    var logURL: URL {
        .init(fileURLWithPath: logPath)
    }
}

extension Config {

    private static func file(in directory: URL) -> URL {
        directory.appendingPathComponent("config.json")
    }

    init(loadFrom directory: URL) {
        let configFileUrl = Config.file(in: directory)

        guard FileManager.default.fileExists(atPath: configFileUrl.path) else {
            print("No configuration found at \(configFileUrl.path)")
            exit(-1)
        }
        self.init(loadAt: configFileUrl)
    }

    private init(loadAt url: URL) {
        do {
            let configData = try Data(contentsOf: url)
            self = try JSONDecoder().decode(Config.self, from: configData)
        } catch {
            print("Failed to load configuration from \(url.path): \(error)")
            exit(-1)
        }
    }
}