onyx/Packages/OnyxKit/Sources/NetworkProvider/NetworkMenuBarModule.swift

import AppKit
import SwiftUI
import OnyxMenuBar
import MetricsProvider

/// Das Netzwerk in der Menüleiste.
///
/// Anders als die Hardwaregrößen hat es **zwei** Werte, die beide interessieren.
/// Sie untereinander zu setzen ist der einzige Weg, beide in der Höhe einer
/// Menüleiste unterzubringen — nebeneinander bräuchte es die doppelte Breite,
/// und die hat man dort nicht.
@MainActor
public final class NetworkMenuBarModule: MenuBarModule {

    public let id = "network"
    public var displayName: String { String(localized: "network.name", bundle: .module) }

    private let model: NetworkModel
    private var token: UUID?
    private var view: NetworkStatusView?

    public init(model: NetworkModel) { self.model = model }

    public var shortLabel: String { String(localized: "menubar.short.network", bundle: .module) }

    public func makeStatusView(presentation: MenuBarPresentation) -> NSView {
        let view = NetworkStatusView(presentation: presentation)
        view.update(model.snapshot, history: model.series(download: true))
        self.view = view
        return view
    }

    public func makePopoverView() -> AnyView {
        AnyView(NetworkPopoverContent(model: model))
    }

    public func activate() {
        guard token == nil else { return }
        token = model.addConsumer(interval: 2)
        startObserving()
    }

    public func deactivate() {
        if let token { model.removeConsumer(token) }
        token = nil
        view = nil
    }

    private func startObserving() {
        withObservationTracking {
            _ = model.snapshot
        } onChange: {
            Task { @MainActor [weak self] in
                guard let self, token != nil else { return }
                view?.update(model.snapshot, history: model.series(download: true))
                startObserving()
            }
        }
    }
}

final class NetworkStatusView: NSView, WidthReporting {

    private let presentation: MenuBarPresentation
    private var snapshot = NetworkSnapshot()
    private var history: [Double] = []

    init(presentation: MenuBarPresentation) {
        self.presentation = presentation
        super.init(frame: NSRect(x: 0, y: 0, width: MenuBarText.minimumWidth, height: 22))
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) { fatalError() }

    /// Breiter als die Hardwaremodule: „↓ 2,4 MB/s" braucht schlicht mehr Platz
    /// als „46 %".
    /// Der Platz für die **aktuellen** Raten.
    ///
    /// Auf „↓ 999,9 MB/s" zu dimensionieren hieße, neben „↓ 13 KB/s" dauerhaft
    /// die halbe Breite leer zu lassen — und genau so sah es aus. Gemessen wird
    /// deshalb, was gerade dasteht; `AdaptiveWidth` sorgt dafür, dass die
    /// Leiste dabei nicht zappelt.
    private static func ratesWidth(_ snapshot: NetworkSnapshot) -> CGFloat {
        let font = NSFont.monospacedDigitSystemFont(ofSize: 9, weight: .regular)
        let lines = ["↓ " + Throughput.formatted(snapshot.downloadRate),
                     "↑ " + Throughput.formatted(snapshot.uploadRate)]
        let widest = lines
            .map { NSAttributedString(string: $0, attributes: [.font: font]).size().width }
            .max() ?? 0
        return ceil(widest) + 2 * MenuBarText.sidePadding
    }

    private func neededWidth() -> CGFloat {
        switch presentation {
        case .symbol:
            max(MenuBarText.minimumWidth,
                MenuBarText.symbolWidth(snapshot.interfaceKind.symbolName, height: 15) + 4)
        case .graph, .bars: 28
        case .value: Self.ratesWidth(snapshot)
        case .valueAndGraph: Self.ratesWidth(snapshot) + 26
        // Die Raten tragen mit ↓ und ↑ ihre Beschriftung schon in sich; ein
        // Kürzel davor wäre doppelt gemoppelt, ein Symbol dagegen nützlich —
        // es zeigt WLAN, Ethernet oder VPN.
        case .labelAndValue, .symbolAndValue:
            Self.ratesWidth(snapshot) + symbolSlot + MenuBarText.innerGap
        }
    }

    private var symbolSlot: CGFloat {
        MenuBarText.symbolWidth(snapshot.interfaceKind.symbolName, height: 13)
    }

    private var adaptive = AdaptiveWidth(minimum: MenuBarText.minimumWidth)
    private var width: CGFloat = MenuBarText.minimumWidth
    var onWidthChange: ((CGFloat) -> Void)?

    override var intrinsicContentSize: NSSize {
        NSSize(width: width, height: 22)
    }

    func update(_ snapshot: NetworkSnapshot, history: [Double]) {
        self.snapshot = snapshot
        self.history = history
        needsDisplay = true

        let next = adaptive.update(needed: neededWidth())
        guard next != width else { return }
        width = next
        invalidateIntrinsicContentSize()
        onWidthChange?(next)
    }

    override func draw(_ dirtyRect: NSRect) {
        let color = NSColor.labelColor

        switch presentation {
        case .symbol:
            MenuBarText.drawSymbol(snapshot.interfaceKind.symbolName, color: color,
                                   in: NSRect(x: bounds.midX - 7.5, y: bounds.midY - 7.5,
                                              width: 15, height: 15))

        case .graph, .bars:
            drawGraph(color: color, in: bounds.insetBy(dx: 2, dy: 5))

        case .labelAndValue, .symbolAndValue:
            let glyph = symbolSlot
            MenuBarText.drawSymbol(snapshot.interfaceKind.symbolName, color: color,
                                   in: NSRect(x: 0, y: bounds.midY - 6.5,
                                              width: glyph, height: 13))
            drawRates(color: color,
                      in: NSRect(x: glyph + MenuBarText.innerGap, y: 0,
                                 width: bounds.width - glyph - MenuBarText.innerGap,
                                 height: bounds.height))

        case .value, .valueAndGraph:
            drawRates(color: color,
                      in: presentation == .value ? bounds
                          : NSRect(x: 0, y: 0, width: bounds.width - 26, height: bounds.height))
            if presentation == .valueAndGraph {
                drawGraph(color: color,
                          in: NSRect(x: bounds.width - 24, y: 5, width: 22, height: 12))
            }
        }
    }

    /// Zwei Zeilen à 9 pt — die einzige Art, Hoch und Runter in 22 pt Höhe
    /// unterzubringen.
    private func drawRates(color: NSColor, in rect: NSRect) {
        let attributes: [NSAttributedString.Key: Any] = [
            .font: NSFont.monospacedDigitSystemFont(ofSize: 9, weight: .regular),
            .foregroundColor: color,
        ]
        let down = NSAttributedString(string: "↓ " + Throughput.formatted(snapshot.downloadRate),
                                      attributes: attributes)
        let up = NSAttributedString(string: "↑ " + Throughput.formatted(snapshot.uploadRate),
                                    attributes: attributes)
        down.draw(at: NSPoint(x: rect.minX + 2, y: rect.midY - 0.5))
        up.draw(at: NSPoint(x: rect.minX + 2, y: rect.midY - 10.5))
    }

    private func drawGraph(color: NSColor, in rect: NSRect) {
        guard history.count > 1, let context = NSGraphicsContext.current?.cgContext else { return }
        let step = rect.width / CGFloat(history.count - 1)
        context.setStrokeColor(color.withAlphaComponent(0.85).cgColor)
        context.setLineWidth(1)
        for (index, value) in history.enumerated() {
            let point = CGPoint(x: rect.minX + CGFloat(index) * step,
                                y: rect.minY + rect.height * CGFloat(min(max(value, 0), 1)))
            index == 0 ? context.move(to: point) : context.addLine(to: point)
        }
        context.strokePath()
    }
}