import SwiftUI
import CoreBluetooth

/// Main provisioning screen (matches Android ScanActivity)
/// Flow: Select/create service point → Scan for beacons → Connect → Provision → Verify
struct ScanView: View {
    @EnvironmentObject var appState: AppState

    let business: Business

    @StateObject private var bleManager = BLEManager()

    // MARK: - State

    @State private var servicePoints: [ServicePoint] = []
    @State private var selectedServicePoint: ServicePoint?
    @State private var showCreateServicePoint = false
    @State private var newServicePointName = ""

    @State private var namespace: (uuid: String, major: Int)?
    @State private var isLoadingNamespace = false

    // Provisioning flow
    @State private var selectedBeacon: DiscoveredBeacon?
    @State private var provisioningState: ProvisioningState = .idle
    @State private var statusMessage = ""
    @State private var errorMessage: String?
    @State private var showQRScanner = false
    @State private var scannedMAC: String?
    @StateObject private var provisionLog = ProvisionLog()

    enum ProvisioningState {
        case idle
        case scanning
        case connecting
        case connected     // DXSmart: beacon flashing, waiting for user to tap "Write"
        case writing
        case verifying
        case done
        case failed
    }

    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                // Service Point Picker
                servicePointSection

                Divider()

                // Beacon Scanner / Provisioning
                if selectedServicePoint != nil {
                    if namespace != nil {
                        beaconSection
                    } else {
                        namespaceLoadingView
                    }
                } else {
                    selectServicePointPrompt
                }
            }
            .navigationTitle(business.name)
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .topBarLeading) {
                    Button("Back") {
                        appState.backToBusinessList()
                    }
                }
            }
            .sheet(isPresented: $showCreateServicePoint) {
                createServicePointSheet
            }
            .sheet(isPresented: $showQRScanner) {
                QRScannerView { code in
                    handleQRScan(code)
                }
            }
        }
        .task {
            await loadServicePoints()
            await loadNamespace()
        }
    }

    // MARK: - Service Point Section

    private var servicePointSection: some View {
        VStack(spacing: 12) {
            HStack {
                Text("Service Point")
                    .font(.headline)
                Spacer()
                Button {
                    suggestServicePointName()
                    showCreateServicePoint = true
                } label: {
                    Label("Add", systemImage: "plus")
                        .font(.subheadline)
                }
            }

            if servicePoints.isEmpty {
                Text("No service points — create one to get started")
                    .font(.caption)
                    .foregroundStyle(.secondary)
            } else {
                ScrollView(.horizontal, showsIndicators: false) {
                    HStack(spacing: 8) {
                        ForEach(servicePoints) { sp in
                            Button {
                                selectedServicePoint = sp
                                resetProvisioningState()
                            } label: {
                                Text(sp.name)
                                    .font(.subheadline.weight(selectedServicePoint?.id == sp.id ? .semibold : .regular))
                                    .padding(.horizontal, 14)
                                    .padding(.vertical, 8)
                                    .background(
                                        selectedServicePoint?.id == sp.id ? Color.payfritGreen : Color(.systemGray5),
                                        in: Capsule()
                                    )
                                    .foregroundStyle(selectedServicePoint?.id == sp.id ? .white : .primary)
                            }
                        }
                    }
                }
            }
        }
        .padding()
    }

    @ViewBuilder
    private var selectServicePointPrompt: some View {
        if #available(iOS 17.0, *) {
            ContentUnavailableView(
                "Select a Service Point",
                systemImage: "mappin.and.ellipse",
                description: Text("Choose or create a service point (table) to provision a beacon for.")
            )
        } else {
            VStack(spacing: 12) {
                Image(systemName: "mappin.and.ellipse")
                    .font(.system(size: 48))
                    .foregroundStyle(.secondary)
                Text("Select a Service Point")
                    .font(.headline)
                Text("Choose or create a service point (table) to provision a beacon for.")
                    .font(.subheadline)
                    .foregroundStyle(.secondary)
                    .multilineTextAlignment(.center)
            }
            .frame(maxHeight: .infinity)
            .padding()
        }
    }

    // MARK: - Namespace Loading

    @ViewBuilder
    private var namespaceLoadingView: some View {
        VStack(spacing: 16) {
            if isLoadingNamespace {
                ProgressView("Allocating beacon namespace…")
            } else {
                if #available(iOS 17.0, *) {
                    ContentUnavailableView {
                        Label("Namespace Error", systemImage: "exclamationmark.triangle")
                    } description: {
                        Text(errorMessage ?? "Failed to allocate beacon namespace")
                    } actions: {
                        Button("Retry") { Task { await loadNamespace() } }
                    }
                } else {
                    VStack(spacing: 12) {
                        Image(systemName: "exclamationmark.triangle")
                            .font(.system(size: 48))
                            .foregroundStyle(Color.warningOrange)
                        Text("Namespace Error")
                            .font(.headline)
                        Text(errorMessage ?? "Failed to allocate beacon namespace")
                            .font(.subheadline)
                            .foregroundStyle(.secondary)
                            .multilineTextAlignment(.center)
                        Button("Retry") { Task { await loadNamespace() } }
                            .buttonStyle(.borderedProminent)
                    }
                    .padding()
                }
            }
        }
        .frame(maxHeight: .infinity)
    }

    // MARK: - Beacon Scanner Section

    private var beaconSection: some View {
        VStack(spacing: 0) {
            // Status bar
            statusBar

            // Beacon list or provisioning progress
            switch provisioningState {
            case .idle, .scanning:
                beaconList

            case .connecting:
                progressView(title: "Connecting…", message: statusMessage)

            case .connected:
                // DXSmart: beacon is flashing, show write button
                dxsmartConnectedView

            case .writing:
                progressView(title: "Writing Config…", message: statusMessage)

            case .verifying:
                progressView(title: "Verifying…", message: statusMessage)

            case .done:
                successView

            case .failed:
                failedView
            }
        }
    }

    private var statusBar: some View {
        HStack {
            if let ns = namespace {
                VStack(alignment: .leading, spacing: 2) {
                    Text("Shard: \(ns.uuid.prefix(8))… / Major: \(ns.major)")
                        .font(.caption2.monospaced())
                        .foregroundStyle(.secondary)
                }
            }

            Spacer()

            if bleManager.bluetoothState != .poweredOn {
                Label("Bluetooth Off", systemImage: "bluetooth.slash")
                    .font(.caption)
                    .foregroundStyle(Color.errorRed)
            }
        }
        .padding(.horizontal)
        .padding(.vertical, 8)
        .background(.ultraThinMaterial)
    }

    // MARK: - Beacon List

    private var beaconList: some View {
        VStack(spacing: 0) {
            // Scan buttons
            HStack(spacing: 12) {
                Button {
                    Task { await startScan() }
                } label: {
                    HStack {
                        Image(systemName: bleManager.isScanning ? "antenna.radiowaves.left.and.right" : "magnifyingglass")
                        Text(bleManager.isScanning ? "Scanning…" : "BLE Scan")
                    }
                    .frame(maxWidth: .infinity)
                }
                .buttonStyle(.borderedProminent)
                .disabled(bleManager.isScanning || bleManager.bluetoothState != .poweredOn)

                Button {
                    showQRScanner = true
                } label: {
                    HStack {
                        Image(systemName: "qrcode.viewfinder")
                        Text("QR Scan")
                    }
                    .frame(maxWidth: .infinity)
                }
                .buttonStyle(.bordered)
            }
            .padding()

            if bleManager.discoveredBeacons.isEmpty && !bleManager.isScanning {
                if #available(iOS 17.0, *) {
                    ContentUnavailableView(
                        "No Beacons Found",
                        systemImage: "antenna.radiowaves.left.and.right.slash",
                        description: Text("Tap Scan to search for nearby beacons")
                    )
                } else {
                    VStack(spacing: 12) {
                        Image(systemName: "antenna.radiowaves.left.and.right.slash")
                            .font(.system(size: 48))
                            .foregroundStyle(.secondary)
                        Text("No Beacons Found")
                            .font(.headline)
                        Text("Tap Scan to search for nearby beacons")
                            .font(.subheadline)
                            .foregroundStyle(.secondary)
                    }
                    .frame(maxHeight: .infinity)
                    .padding()
                }
            } else {
                List(bleManager.discoveredBeacons.sorted { $0.rssi > $1.rssi }) { beacon in
                    Button {
                        selectedBeacon = beacon
                        Task { await startProvisioning(beacon) }
                    } label: {
                        BeaconRow(beacon: beacon)
                    }
                    .disabled(provisioningState != .idle)
                }
                .listStyle(.plain)
            }
        }
    }

    // MARK: - DXSmart Connected View

    private var dxsmartConnectedView: some View {
        VStack(spacing: 24) {
            Spacer()

            Image(systemName: "light.beacon.max")
                .font(.system(size: 64))
                .foregroundStyle(Color.payfritGreen)
                .modifier(PulseEffectModifier())

            Text("Connected — Beacon is Flashing")
                .font(.title2.bold())

            Text("Confirm the beacon LED is flashing, then tap Write Config to program it.\n\nThe beacon will timeout if you wait too long.")
                .font(.subheadline)
                .foregroundStyle(.secondary)
                .multilineTextAlignment(.center)
                .padding(.horizontal, 32)

            Button {
                Task { await writeConfigToConnectedBeacon() }
            } label: {
                HStack {
                    Image(systemName: "arrow.down.doc")
                    Text("Write Config")
                }
                .frame(maxWidth: .infinity)
            }
            .buttonStyle(.borderedProminent)
            .tint(Color.payfritGreen)
            .controlSize(.large)
            .padding(.horizontal, 32)

            Button("Cancel") {
                cancelProvisioning()
            }
            .foregroundStyle(.secondary)

            // Show diagnostic log
            if !provisionLog.entries.isEmpty {
                diagnosticLogView
            }

            Spacer()
        }
    }

    // MARK: - Progress / Success / Failed Views

    private func progressView(title: String, message: String) -> some View {
        VStack(spacing: 16) {
            Spacer()
            ProgressView()
                .scaleEffect(1.5)
            Text(title)
                .font(.headline)
            Text(message)
                .font(.subheadline)
                .foregroundStyle(.secondary)

            // Show live diagnostic log during connecting/writing
            if !provisionLog.entries.isEmpty {
                diagnosticLogView
            }

            Spacer()

            Button("Cancel") {
                cancelProvisioning()
            }
            .foregroundStyle(.secondary)
            .padding(.bottom, 16)
        }
    }

    /// Reusable diagnostic log view
    private var diagnosticLogView: some View {
        VStack(alignment: .leading, spacing: 4) {
            HStack {
                Text("Log (\(provisionLog.elapsed))")
                    .font(.caption.bold())
                Spacer()
                ShareLink(item: provisionLog.fullText) {
                    Label("Share", systemImage: "square.and.arrow.up")
                        .font(.caption)
                }
            }
            .padding(.horizontal, 16)

            ScrollViewReader { proxy in
                ScrollView {
                    LazyVStack(alignment: .leading, spacing: 2) {
                        ForEach(provisionLog.entries) { entry in
                            Text(entry.formatted)
                                .font(.system(.caption2, design: .monospaced))
                                .foregroundStyle(entry.isError ? Color.errorRed : .primary)
                                .id(entry.id)
                        }
                    }
                    .padding(.horizontal, 16)
                }
                .onChange(of: provisionLog.entries.count) { _ in
                    if let last = provisionLog.entries.last {
                        proxy.scrollTo(last.id, anchor: .bottom)
                    }
                }
            }
            .frame(maxHeight: 160)
            .background(Color(.systemGray6))
            .clipShape(RoundedRectangle(cornerRadius: 8))
            .padding(.horizontal, 16)
        }
    }

    private var successView: some View {
        VStack(spacing: 24) {
            Spacer()
            Image(systemName: "checkmark.circle.fill")
                .font(.system(size: 64))
                .foregroundStyle(Color.successGreen)
            Text("Beacon Provisioned!")
                .font(.title2.bold())
            Text(statusMessage)
                .font(.subheadline)
                .foregroundStyle(.secondary)
                .multilineTextAlignment(.center)
                .padding(.horizontal, 32)
            Button("Provision Another") {
                resetProvisioningState()
            }
            .buttonStyle(.borderedProminent)
            Spacer()
        }
    }

    private var failedView: some View {
        VStack(spacing: 16) {
            Image(systemName: "xmark.circle.fill")
                .font(.system(size: 48))
                .foregroundStyle(Color.errorRed)
            Text("Provisioning Failed")
                .font(.title2.bold())
            Text(errorMessage ?? "Unknown error")
                .font(.subheadline)
                .foregroundStyle(.secondary)
                .multilineTextAlignment(.center)
                .padding(.horizontal, 32)

            // Diagnostic log
            if !provisionLog.entries.isEmpty {
                diagnosticLogView
            }

            HStack(spacing: 16) {
                Button("Try Again") {
                    if let beacon = selectedBeacon {
                        Task { await startProvisioning(beacon) }
                    }
                }
                .buttonStyle(.borderedProminent)

                Button("Register Anyway") {
                    Task { await registerAnywayAfterFailure() }
                }
                .buttonStyle(.bordered)
            }

            Button("Cancel") {
                resetProvisioningState()
            }
            .foregroundStyle(.secondary)
        }
        .padding(.vertical, 8)
    }

    // MARK: - Create Service Point Sheet

    private var createServicePointSheet: some View {
        NavigationStack {
            Form {
                TextField("Name (e.g. Table 1)", text: $newServicePointName)
            }
            .navigationTitle("New Service Point")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") { showCreateServicePoint = false }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("Create") {
                        Task { await createServicePoint() }
                    }
                    .disabled(newServicePointName.trimmingCharacters(in: .whitespaces).isEmpty)
                }
            }
        }
        .presentationDetents([.medium])
    }

    // MARK: - Actions

    private func loadServicePoints() async {
        guard let token = appState.token else { return }
        do {
            servicePoints = try await APIClient.shared.listServicePoints(
                businessId: business.id, token: token
            )
        } catch {
            errorMessage = error.localizedDescription
        }
    }

    private func loadNamespace() async {
        guard let token = appState.token else { return }
        isLoadingNamespace = true
        do {
            let ns = try await APIClient.shared.allocateBusinessNamespace(
                businessId: business.id, token: token
            )
            namespace = ns
        } catch {
            errorMessage = error.localizedDescription
        }
        isLoadingNamespace = false
    }

    private func createServicePoint() async {
        guard let token = appState.token else { return }
        let name = newServicePointName.trimmingCharacters(in: .whitespaces)
        guard !name.isEmpty else { return }

        do {
            let sp = try await APIClient.shared.createServicePoint(
                name: name, businessId: business.id, token: token
            )
            servicePoints.append(sp)
            selectedServicePoint = sp
            showCreateServicePoint = false
            newServicePointName = ""
        } catch {
            errorMessage = error.localizedDescription
        }
    }

    /// Smart-increment: parse existing names, suggest "Table N+1"
    private func suggestServicePointName() {
        let numbers = servicePoints.compactMap { sp -> Int? in
            let parts = sp.name.split(separator: " ")
            guard parts.count >= 2, parts[0].lowercased() == "table" else { return nil }
            return Int(parts[1])
        }
        let next = (numbers.max() ?? 0) + 1
        newServicePointName = "Table \(next)"
    }

    private func startScan() async {
        provisioningState = .scanning
        let _ = await bleManager.scan()
        if provisioningState == .scanning {
            provisioningState = .idle
        }
    }

    private func startProvisioning(_ beacon: DiscoveredBeacon) async {
        guard let sp = selectedServicePoint,
              let ns = namespace,
              let token = appState.token else { return }

        provisioningState = .connecting
        statusMessage = "Allocating beacon config…"
        errorMessage = nil
        provisionLog.reset()
        provisionLog.log("init", "Starting provisioning: \(beacon.displayName) (\(beacon.type.rawValue)) RSSI:\(beacon.rssi)")
        provisionLog.log("init", "Service point: \(sp.name), Business: \(business.name)")

        do {
            // Allocate minor for this service point
            provisionLog.log("api", "Allocating minor for service point \(sp.id)…")
            let minor = try await APIClient.shared.allocateMinor(
                businessId: business.id, servicePointId: sp.id, token: token
            )
            provisionLog.log("api", "Minor allocated: \(minor)")

            let config = BeaconConfig(
                uuid: ns.uuid.normalizedUUID,
                major: UInt16(ns.major),
                minor: UInt16(minor),
                measuredPower: BeaconConfig.defaultMeasuredPower,
                advInterval: BeaconConfig.defaultAdvInterval,
                txPower: BeaconConfig.defaultTxPower,
                servicePointName: sp.name,
                businessName: business.name
            )

            // Create appropriate provisioner
            let provisioner = makeProvisioner(for: beacon)

            // Wire up real-time status updates from provisioner
            if let dxProvisioner = provisioner as? DXSmartProvisioner {
                dxProvisioner.onStatusUpdate = { [weak self] status in
                    self?.statusMessage = status
                }
            }

            statusMessage = "Connecting to \(beacon.displayName)…"
            provisionLog.log("connect", "Connecting to \(beacon.type.rawValue) provisioner…")

            // Monitor for unexpected disconnects during provisioning
            bleManager.onPeripheralDisconnected = { [weak provisionLog] peripheral, error in
                if peripheral.identifier == beacon.peripheral.identifier {
                    DispatchQueue.main.async { [weak self] in
                        let reason = error?.localizedDescription ?? "beacon timed out"
                        provisionLog?.log("disconnect", "Unexpected disconnect: \(reason)", isError: true)
                        guard let self = self else { return }
                        // CP-28: disconnect during .connected is expected — beacon keeps
                        // flashing after BLE drops. We'll reconnect when user taps Write Config.
                        if self.provisioningState == .connected {
                            provisionLog?.log("disconnect", "CP-28 idle disconnect — beacon still flashing, ignoring")
                            return
                        }
                        // For all other active states, treat disconnect as failure
                        if self.provisioningState == .connecting || self.provisioningState == .connected ||
                           self.provisioningState == .writing || self.provisioningState == .verifying {
                            self.provisioningState = .failed
                            self.errorMessage = "Beacon disconnected: \(reason)"
                        }
                    }
                }
            }

            try await provisioner.connect()
            provisionLog.log("connect", "Connected and authenticated successfully")

            // CP-28: stop at connected state, wait for user to confirm flashing
            provisioningState = .connected
            pendingConfig = config
            pendingProvisioner = provisioner

        } catch {
            provisionLog.log("error", "Provisioning failed after \(provisionLog.elapsed): \(error.localizedDescription)", isError: true)
            provisioningState = .failed
            errorMessage = error.localizedDescription
        }
    }

    // Store for DXSmart two-phase flow
    @State private var pendingConfig: BeaconConfig?
    @State private var pendingProvisioner: (any BeaconProvisioner)?

    private func writeConfigToConnectedBeacon() async {
        guard let config = pendingConfig,
              let provisioner = pendingProvisioner,
              let sp = selectedServicePoint,
              let ns = namespace,
              let token = appState.token else { return }

        provisioningState = .writing
        statusMessage = "Writing config to DX-Smart…"

        do {
            // Reconnect if the beacon dropped BLE during the "confirm flashing" wait
            if !provisioner.isConnected {
                provisionLog.log("write", "Beacon disconnected while waiting — reconnecting…")
                statusMessage = "Reconnecting to beacon…"
                try await provisioner.connect()
                provisionLog.log("write", "Reconnected — writing config…")
                statusMessage = "Writing config to DX-Smart…"
            }

            try await provisioner.writeConfig(config)
            provisioner.disconnect()

            try await APIClient.shared.registerBeaconHardware(
                businessId: business.id,
                servicePointId: sp.id,
                uuid: ns.uuid,
                major: ns.major,
                minor: Int(config.minor),
                macAddress: nil,
                beaconType: BeaconType.dxsmart.rawValue,
                token: token
            )

            provisioningState = .done
            statusMessage = "\(sp.name) — DX-Smart\nUUID: \(config.formattedUUID.prefix(13))…\nMajor: \(config.major) Minor: \(config.minor)"

        } catch {
            provisioningState = .failed
            errorMessage = error.localizedDescription
        }

        pendingConfig = nil
        pendingProvisioner = nil
    }

    private func registerAnywayAfterFailure() async {
        guard let sp = selectedServicePoint,
              let ns = namespace,
              let config = pendingConfig ?? makeCurrentConfig(),
              let token = appState.token else {
            resetProvisioningState()
            return
        }

        do {
            try await APIClient.shared.registerBeaconHardware(
                businessId: business.id,
                servicePointId: sp.id,
                uuid: ns.uuid,
                major: ns.major,
                minor: Int(config.minor),
                macAddress: nil,
                beaconType: selectedBeacon?.type.rawValue ?? "Unknown",
                token: token
            )
            provisioningState = .done
            statusMessage = "Registered (broadcast unverified)\n\(sp.name) — Minor: \(config.minor)"
        } catch {
            errorMessage = "Registration failed: \(error.localizedDescription)"
        }
    }

    private func makeCurrentConfig() -> BeaconConfig? {
        // Only used for "Register Anyway" fallback
        return nil
    }

    private func cancelProvisioning() {
        pendingProvisioner?.disconnect()
        pendingProvisioner = nil
        pendingConfig = nil
        resetProvisioningState()
    }

    /// Handle QR/barcode scan result — could be MAC address, UUID, or other identifier
    private func handleQRScan(_ code: String) {
        let cleaned = code.trimmingCharacters(in: .whitespacesAndNewlines)

        // Check if it looks like a MAC address (AA:BB:CC:DD:EE:FF or AABBCCDDEEFF)
        let macPattern = #"^([0-9A-Fa-f]{2}[:-]?){5}[0-9A-Fa-f]{2}$"#
        if cleaned.range(of: macPattern, options: .regularExpression) != nil {
            scannedMAC = cleaned.replacingOccurrences(of: "-", with: ":").uppercased()
            statusMessage = "Scanned MAC: \(scannedMAC ?? cleaned)"
            // Look up the beacon by MAC
            Task { await lookupScannedMAC() }
            return
        }

        // Check if it looks like a UUID
        let uuidPattern = #"^[0-9A-Fa-f]{8}-?[0-9A-Fa-f]{4}-?[0-9A-Fa-f]{4}-?[0-9A-Fa-f]{4}-?[0-9A-Fa-f]{12}$"#
        if cleaned.range(of: uuidPattern, options: .regularExpression) != nil {
            statusMessage = "Scanned UUID: \(cleaned)"
            return
        }

        // Generic code — just show it
        statusMessage = "Scanned: \(cleaned)"
    }

    private func lookupScannedMAC() async {
        guard let mac = scannedMAC, let token = appState.token else { return }
        do {
            if let existing = try await APIClient.shared.lookupByMac(macAddress: mac, token: token) {
                let beaconType = existing.beaconType ?? existing.BeaconType ?? "Unknown"
                statusMessage = "MAC \(mac) — already registered as \(beaconType)"
            } else {
                statusMessage = "MAC \(mac) — not yet registered. Scan BLE to find and provision."
            }
        } catch {
            statusMessage = "MAC \(mac) — lookup failed: \(error.localizedDescription)"
        }
    }

    private func resetProvisioningState() {
        provisioningState = .idle
        statusMessage = ""
        errorMessage = nil
        selectedBeacon = nil
        pendingConfig = nil
        pendingProvisioner = nil
        scannedMAC = nil
    }

    private func makeProvisioner(for beacon: DiscoveredBeacon) -> any BeaconProvisioner {
        var provisioner: any BeaconProvisioner = DXSmartProvisioner(
            peripheral: beacon.peripheral,
            centralManager: bleManager.centralManager
        )
        provisioner.bleManager = bleManager
        provisioner.diagnosticLog = provisionLog
        return provisioner
    }
}

// MARK: - Beacon Row

struct BeaconRow: View {
    let beacon: DiscoveredBeacon

    var body: some View {
        HStack(spacing: 12) {
            // Signal strength indicator
            Image(systemName: signalIcon)
                .font(.title2)
                .foregroundStyle(signalColor)
                .frame(width: 32)

            VStack(alignment: .leading, spacing: 4) {
                Text(beacon.displayName)
                    .font(.headline)

                HStack(spacing: 8) {
                    Text(beacon.type.rawValue)
                        .font(.caption.bold())
                        .padding(.horizontal, 6)
                        .padding(.vertical, 2)
                        .background(typeColor.opacity(0.15), in: Capsule())
                        .foregroundStyle(typeColor)

                    Text("\(beacon.rssi) dBm")
                        .font(.caption)
                        .foregroundStyle(.secondary)

                    Text(beacon.signalDescription)
                        .font(.caption)
                        .foregroundStyle(.secondary)
                }
            }

            Spacer()

            Image(systemName: "chevron.right")
                .foregroundStyle(.tertiary)
        }
        .padding(.vertical, 4)
    }

    private var signalIcon: String {
        switch beacon.rssi {
        case -50...0:    return "wifi"
        case -65 ... -51: return "wifi"
        case -80 ... -66: return "wifi.exclamationmark"
        default:          return "wifi.slash"
        }
    }

    private var signalColor: Color {
        switch beacon.rssi {
        case -50...0:    return .signalStrong
        case -65 ... -51: return .payfritGreen
        case -80 ... -66: return .signalMedium
        default:          return .signalWeak
        }
    }

    private var typeColor: Color {
        return .payfritGreen
    }
}

// MARK: - iOS 16/17 Compatibility

/// Applies `.symbolEffect(.pulse)` on iOS 17+, no-op on iOS 16
private struct PulseEffectModifier: ViewModifier {
    func body(content: Content) -> some View {
        if #available(iOS 17.0, *) {
            content.symbolEffect(.pulse)
        } else {
            content
        }
    }
}