import SwiftUI
import MetricsProvider
import OnyxDesign
import OnyxMenuBar

@MainActor
struct NetworkPopoverContent: View {
    let model: NetworkModel

    var body: some View {
        VStack(alignment: .leading, spacing: 12) {
            HStack(alignment: .top) {
                rate(model.snapshot.downloadRate, "network.download", Onyx.Color.download)
                Spacer()
                rate(model.snapshot.uploadRate, "network.upload", Onyx.Color.upload)
            }

            TrafficChart(history: model.history)
                .frame(height: 56)

            HStack {
                peak(model.history.map(\.downloadRate).max() ?? 0, "network.peak.download")
                Spacer()
                peak(model.history.map(\.uploadRate).max() ?? 0, "network.peak.upload")
            }

            Divider()

            Label(connectionName, systemImage: model.snapshot.interfaceKind.symbolName)
                .font(.callout)

            if model.snapshot.interfaceKind == .vpn {
                // Ein VPN verändert, was die Zahlen darüber bedeuten — der
                // Verkehr läuft dann durch den Tunnel, nicht direkt.
                // Über Text statt Label(_:systemImage:): letzteres kennt kein
                // Bundle und zeigt sonst den rohen Schlüssel an.
                Label {
                    Text("network.vpn.active", bundle: .module)
                } icon: {
                    Image(systemName: "lock.shield")
                }
                .font(.caption)
                .foregroundStyle(.secondary)
            }

            section("network.addresses")
            field("network.field.interface", model.snapshot.interfaceName)
            field("network.field.ipv4", model.snapshot.ipv4)
            field("network.field.ipv6", model.snapshot.ipv6)
            field("network.field.router", model.snapshot.router)

            section("network.transferred")
            field("network.total.received", bytes(model.snapshot.totalReceived))
            field("network.total.sent", bytes(model.snapshot.totalSent))

            section("network.public")
            if model.showsPublicAddress {
                HStack {
                    if model.publicAddress.isLoading {
                        ProgressView().controlSize(.small)
                    } else if let address = model.publicAddress.address {
                        Text(address).font(.callout.monospacedDigit()).textSelection(.enabled)
                    } else if model.publicAddress.failed {
                        Text("network.public.failed", bundle: .module)
                            .font(.callout).foregroundStyle(.secondary)
                    }
                    Spacer()
                    Button { model.publicAddress.refresh(force: true) } label: {
                        Image(systemName: "arrow.clockwise")
                    }
                    .buttonStyle(.borderless)
                }
                // Wer die Adresse erfährt, gehört sichtbar dazu.
                Text(verbatim: PublicAddressLookup.serviceName)
                    .font(.caption2).foregroundStyle(.tertiary)
            } else {
                Toggle(isOn: Binding(get: { model.showsPublicAddress },
                                     set: { model.showsPublicAddress = $0 })) {
                    Text("network.public.enable", bundle: .module).font(.callout)
                }
                .toggleStyle(.switch)
                .controlSize(.small)
                Text("network.public.hint", bundle: .module)
                    .font(.caption2).foregroundStyle(.tertiary)
                    .fixedSize(horizontal: false, vertical: true)
            }

            if !model.processes.isEmpty {
                section("network.processes")
                ForEach(model.processes) { process in
                    HStack {
                        Text(process.name).font(.callout).lineLimit(1)
                        Spacer(minLength: 8)
                        Text(Throughput.formatted(process.downloadRate))
                            .font(.caption.monospacedDigit())
                            .foregroundStyle(Onyx.Color.download)
                        Text(Throughput.formatted(process.uploadRate))
                            .font(.caption.monospacedDigit())
                            .foregroundStyle(Onyx.Color.upload)
                    }
                }
            }
        }
        .padding(14)
        .frame(width: 300)
        .onAppear { model.addDetailConsumer() }
        .onDisappear { model.removeDetailConsumer() }
    }

    private var connectionName: String {
        if let ssid = model.snapshot.ssid { return ssid }
        if model.snapshot.isWiFiConnected {
            return String(localized: "network.wifi.connected", bundle: .module)
        }
        return model.snapshot.interfaceName
            ?? String(localized: "network.offline", bundle: .module)
    }

    private func rate(_ value: Double, _ key: LocalizedStringKey, _ tint: Color) -> some View {
        VStack(alignment: .leading, spacing: 1) {
            Text(Throughput.formatted(value))
                .font(.system(size: 18, weight: .medium).monospacedDigit())
            HStack(spacing: 4) {
                Circle().fill(tint).frame(width: 6, height: 6)
                Text(key, bundle: .module).font(.caption).foregroundStyle(.secondary)
            }
        }
    }

    private func peak(_ value: Double, _ key: LocalizedStringKey) -> some View {
        HStack(spacing: 4) {
            Text(key, bundle: .module).font(.caption2).foregroundStyle(.secondary)
            Text(Throughput.formatted(value)).font(.caption2.monospacedDigit())
        }
    }

    private func section(_ key: LocalizedStringKey) -> some View {
        Text(key, bundle: .module)
            .font(.caption.weight(.semibold))
            .foregroundStyle(Onyx.Color.accent)
            .textCase(.uppercase)
    }

    @ViewBuilder
    private func field(_ key: LocalizedStringKey, _ value: String?) -> some View {
        if let value {
            HStack {
                Text(key, bundle: .module).font(.callout).foregroundStyle(.secondary)
                Spacer(minLength: 12)
                Text(value).font(.callout.monospacedDigit()).textSelection(.enabled)
            }
        }
    }

    private func bytes(_ value: UInt64) -> String {
        ByteCountFormatter.string(fromByteCount: Int64(value), countStyle: .binary)
    }
}

/// Verlauf in beide Richtungen: Download nach unten, Upload nach oben.
///
/// Zwei getrennte Kurven übereinander wären platzsparender, aber schwerer zu
/// lesen — hier sieht man sofort, ob gerade geladen oder gesendet wird, und in
/// welchem Verhältnis. Beide Richtungen teilen sich denselben Maßstab, sonst
/// sähe ein Upload von 20 KB/s genauso hoch aus wie ein Download von 20 MB/s.
private struct TrafficChart: View {
    let history: [NetworkSnapshot]

    var body: some View {
        GeometryReader { geometry in
            let points = history.suffix(NetworkModel.historyLength)
            let peak = max(points.map { max($0.downloadRate, $0.uploadRate) }.max() ?? 1, 1)
            // Die Balkenbreite kommt aus der **vollen** Länge des Verlaufs.
            // Vorher war sie `Breite / Anzahl`: bei fünf Messwerten also ein
            // Fünftel je Balken, und mit jedem weiteren wurden sie schmaler.
            // Frisch gestartet sah das Diagramm dadurch aus wie ein Ausschlag.
            let width = GraphLayout.barWidth(capacity: NetworkModel.historyLength,
                                             totalWidth: geometry.size.width, spacing: 1)
            let half = geometry.size.height / 2

            HStack(alignment: .center, spacing: 1) {
                // Fehlende Messwerte bleiben als freie Fläche links stehen; der
                // Verlauf wächst nach links weg, wie bei jedem Zeitdiagramm.
                Spacer(minLength: 0)

                ForEach(Array(points.enumerated()), id: \.offset) { _, snapshot in
                    VStack(spacing: 1) {
                        Rectangle()
                            .fill(Onyx.Color.upload)
                            .frame(height: max(half * CGFloat(snapshot.uploadRate / peak), 0.5))
                            .frame(maxHeight: .infinity, alignment: .bottom)
                        Rectangle()
                            .fill(Onyx.Color.download)
                            .frame(height: max(half * CGFloat(snapshot.downloadRate / peak), 0.5))
                            .frame(maxHeight: .infinity, alignment: .top)
                    }
                    .frame(width: width)
                }
            }
            .frame(width: geometry.size.width, height: geometry.size.height)
        }
    }
}