import Vapor
import Foundation
import Clairvoyant
import ClairvoyantVapor
import ClairvoyantBinaryCodable

private var provider: VaporMetricProvider!
private var serverStatus: Metric<ServerStatus>!

private let asyncScheduler = MultiThreadedEventLoopGroup(numberOfThreads: 2)

private var server: CapServer!

func configure(_ app: Application) async throws {

    let resourceDirectory = URL(fileURLWithPath: app.directory.resourcesDirectory)
    let publicDirectory = app.directory.publicDirectory

    let config = Config(loadFrom: resourceDirectory)
    let authenticator = Authenticator(writers: config.writers)

    let logURL = config.logURL(possiblyRelativeTo: resourceDirectory)
    let monitor = MetricObserver(logFileFolder: logURL, logMetricId: "caps.log")
    MetricObserver.standard = monitor

    serverStatus = Metric<ServerStatus>("caps.status",
                                      name: "Status",
                                      description: "The general status of the service")
    try await serverStatus.update(.initializing)

    app.http.server.configuration.port = config.port
    app.routes.defaultMaxBodySize = .init(stringLiteral: config.maxBodySize)

    let dataDirectory = config.customDataDirectory(or: publicDirectory)
    server = CapServer(in: dataDirectory)

    provider = .init(observer: monitor, accessManager: config.writers)
    provider.asyncScheduler = asyncScheduler
    provider.registerRoutes(app)

    if config.serveFiles {
        let middleware = FileMiddleware(publicDirectory: publicDirectory)
        app.middleware.use(middleware)
    }

    // Register routes to the router
    server.registerRoutes(with: app, authenticator: authenticator)

    // Initialize the server data
    do {
        try server.loadData()
    } catch {
        try await serverStatus.update(.initializationFailure)
        print("[\(df.string(from: Date()))] Server failed to start: \(error)")
        return
    }
    if server.canResizeImages {
        try await serverStatus.update(.nominal)
    } else {
        try await serverStatus.update(.reducedFunctionality)
    }
    print("[\(df.string(from: Date()))] Server started (\(app.environment.name), \(server.capCount) caps)")
}

func shutdown() {
    Task {
        print("[\(df.string(from: Date()))] Server shutdown")
        do {
            try await asyncScheduler.shutdownGracefully()
        } catch {
            print("Failed to shut down MultiThreadedEventLoopGroup: \(error)")
        }
    }
}

func log(_ message: String) {
    guard let observer = MetricObserver.standard else {
        print(message)
        return
    }
    asyncScheduler.schedule {
        await observer.log(message)
    }
}

private let df: DateFormatter = {
    let df = DateFormatter()
    df.dateStyle = .short
    df.timeStyle = .short
    return df
}()