Camper-Monitor/CamperMonitor/Views/DeviceDetailView.swift

import Charts
import SwiftUI

struct DeviceDetailView: View {
    let device: ConfiguredDevice

    @Environment(DeviceStore.self) private var store
    @Environment(BluetoothManager.self) private var bluetooth
    @Environment(\.dismiss) private var dismiss

    @State private var editedName = ""
    @State private var keyInput = ""
    @State private var showDeleteConfirmation = false

    private var snapshot: DeviceSnapshot? { bluetooth.snapshots[device.id] }
    private var linkState: DeviceLinkState { bluetooth.linkStates[device.id] ?? .searching }
    private var samples: [HistorySample] { bluetooth.history[device.id] ?? [] }

    var body: some View {
        List {
            statusSection

            if device.role == .fridge, let fridge = bluetooth.fridgeStates[device.id], fridge.hasStatus {
                FridgeControls(device: device, state: fridge)
            }

            if let snapshot, !snapshot.metrics.isEmpty {
                Section("Messwerte") {
                    ForEach(snapshot.metrics) { metric in
                        LabeledContent(metric.label) {
                            Text(metric.formattedWithUnit)
                                .monospacedDigit()
                                .foregroundStyle(metric.value == nil ? .secondary : .primary)
                        }
                    }
                }
            }

            if samples.count > 1, let primary = snapshot?.primaryMetric {
                Section("Verlauf – \(primary.label)") {
                    Chart(samples) { sample in
                        AreaMark(x: .value("Zeit", sample.time),
                                 y: .value(primary.label, sample.value))
                        .foregroundStyle(.tint.opacity(0.15))
                        LineMark(x: .value("Zeit", sample.time),
                                 y: .value(primary.label, sample.value))
                        .foregroundStyle(.tint)
                        .interpolationMethod(.monotone)
                    }
                    .chartYAxisLabel(primary.unit)
                    .frame(height: 180)
                    .padding(.vertical, 8)
                }
            }

            if let snapshot, !snapshot.cellVoltages.isEmpty {
                cellSection(snapshot.cellVoltages)
            }

            if let snapshot, !snapshot.info.isEmpty {
                Section("Gerät") {
                    ForEach(snapshot.info) { item in
                        LabeledContent(item.label, value: item.value)
                    }
                }
            }

            if let snapshot, snapshot.temperatures.count > 1 {
                Section("Temperaturen") {
                    ForEach(Array(snapshot.temperatures.enumerated()), id: \.offset) { index, value in
                        LabeledContent("Fühler \(index + 1)") {
                            Text(String(format: "%.0f °C", value)).monospacedDigit()
                        }
                    }
                }
            }

            if device.role.transport == .advertisement {
                keySection
                diagnosticsSection
            } else {
                bmsDiagnosticsSection
            }

            settingsSection
        }
        .navigationTitle(device.name)
        .navigationBarTitleDisplayMode(.inline)
        .onAppear {
            editedName = device.name
            keyInput = store.victronKeyText(for: device.id) ?? ""
        }
        .confirmationDialog("Gerät entfernen?",
                            isPresented: $showDeleteConfirmation,
                            titleVisibility: .visible) {
            Button("Entfernen", role: .destructive) {
                store.remove(device)
                bluetooth.refreshConfiguration()
                dismiss()
            }
        } message: {
            Text("Die Einstellungen und der hinterlegte Schlüssel werden gelöscht.")
        }
    }

    // MARK: - Abschnitte

    private var statusSection: some View {
        Section {
            LabeledContent("Verbindung") {
                StatusDot(linkState: linkState, isStale: snapshot?.isStale ?? true)
            }
            if let state = snapshot?.state {
                LabeledContent("Zustand", value: state)
            }
            if let fault = snapshot?.fault {
                Label(fault, systemImage: "exclamationmark.triangle.fill")
                    .foregroundStyle(.red)
            }
            ForEach(snapshot?.offReasons ?? [], id: \.self) { reason in
                Label(reason, systemImage: "pause.circle")
                    .foregroundStyle(.orange)
            }
            if let snapshot {
                LabeledContent("Aktualisiert vor") {
                    Text(snapshot.timestamp, style: .relative)
                }
                .foregroundStyle(.secondary)
            }
            if let rssi = snapshot?.rssi {
                LabeledContent("Signal", value: "\(rssi) dBm")
                    .foregroundStyle(.secondary)
            }
        }
    }

    private func cellSection(_ voltages: [Double]) -> some View {
        let minimum = voltages.min() ?? 0
        let maximum = voltages.max() ?? 0
        return Section("Zellspannungen") {
            Chart(Array(voltages.enumerated()), id: \.offset) { index, voltage in
                // Kategoriale x-Achse: sonst stehen die Balken zwischen den
                // Beschriftungen statt darüber.
                BarMark(
                    x: .value("Zelle", "\(index + 1)"),
                    y: .value("Spannung", voltage)
                )
                .foregroundStyle(voltage == maximum ? Color.orange
                                 : voltage == minimum ? Color.blue : Color.accentColor)
                // Die Zellnummer als Beschriftung am Balken statt über die
                // x-Achse – die blendet Swift Charts in der Liste aus.
                // Ab neun Zellen wird es zu eng, dann ordnet die Liste zu.
                .annotation(position: .bottom, alignment: .center) {
                    if voltages.count <= 8 {
                        Text("\(index + 1)")
                            .font(.caption2)
                            .foregroundStyle(.secondary)
                    }
                }
            }
            .chartXAxis(.hidden)
            // Der interessante Bereich sind die letzten Millivolt, nicht die
            // absolute Spannung – deshalb eng um die Messwerte zoomen.
            .chartYScale(domain: (minimum - 0.05)...(maximum + 0.05))
            .chartYAxisLabel("V")
            .frame(height: 160)
            .padding(.vertical, 8)

            ForEach(Array(voltages.enumerated()), id: \.offset) { index, voltage in
                LabeledContent("Zelle \(index + 1)") {
                    Text(String(format: "%.3f V", voltage)).monospacedDigit()
                }
            }
        }
    }

    private var keySection: some View {
        Section {
            TextField("32 Hex-Zeichen", text: $keyInput)
                .font(.system(.body, design: .monospaced))
                .textInputAutocapitalization(.never)
                .autocorrectionDisabled()
                .onSubmit(saveKey)
            Button("Schlüssel speichern", action: saveKey)
                .disabled(keyInput.hexBytes?.count != 16)
        } header: {
            Text("Verschlüsselungsschlüssel")
        } footer: {
            Text("In VictronConnect: Gerät öffnen → Zahnrad → ⋮ → Produkt-Info → "
                 + "„Instant Readout“ einschalten → Verschlüsselungsdaten anzeigen. "
                 + "Der Schlüssel ist 16 Byte lang (32 Hex-Zeichen).")
        }
    }

    /// Zeigt, was das Gerät unverschlüsselt sendet. Wichtigster Wert ist das
    /// erste Schlüsselbyte: stimmt es nicht mit der Eingabe überein, gehört der
    /// Schlüssel zu einem anderen Victron-Gerät.
    @ViewBuilder
    private var diagnosticsSection: some View {
        if let info = bluetooth.diagnostics[device.id] {
            Section {
                LabeledContent("Gerät sendet als erstes Schlüsselbyte") {
                    Text(info.expectedKeyText)
                        .font(.body.monospaced())
                        .foregroundStyle(keyBytesAgree == false ? .red : .primary)
                }
                LabeledContent("Eingetragener Schlüssel beginnt mit") {
                    Text(enteredKeyText)
                        .font(.body.monospaced())
                        .foregroundStyle(keyBytesAgree == false ? .red : .secondary)
                }
                LabeledContent("Datensatz", value: info.recordName)
                LabeledContent("Produkt-ID") {
                    Text(info.productIDText).font(.body.monospaced())
                }
                VStack(alignment: .leading, spacing: 4) {
                    Text("Rohdaten")
                    Text(info.rawHex)
                        .font(.caption.monospaced())
                        .foregroundStyle(.secondary)
                        .textSelection(.enabled)
                }
            } header: {
                Text("Diagnose")
            } footer: {
                if keyBytesAgree == false {
                    Text("Die beiden Bytes müssen übereinstimmen. Tun sie das nicht, "
                         + "stammt der Schlüssel von einem anderen Victron-Gerät – in "
                         + "VictronConnect prüfen, ob wirklich dieses Gerät geöffnet war.")
                } else {
                    Text("Diese Werte sendet das Gerät unverschlüsselt mit.")
                }
            }
        }
    }

    /// nil, solange kein vollständiger Schlüssel eingetragen ist.
    private var keyBytesAgree: Bool? {
        guard let expected = bluetooth.diagnostics[device.id]?.expectedKeyFirstByte,
              let entered = keyInput.hexBytes?.first else { return nil }
        return expected == entered
    }

    private var enteredKeyText: String {
        guard let byte = keyInput.hexBytes?.first else { return "–" }
        return String(format: "0x%02X", byte)
    }

    /// Welches Protokoll das BMS spricht und was zuletzt ankam.
    @ViewBuilder
    private var bmsDiagnosticsSection: some View {
        if let info = bluetooth.bmsDiagnostics[device.id] {
            Section {
                LabeledContent("Erkanntes Protokoll", value: info.dialect)
                if let position = info.endpointPosition {
                    LabeledContent("Verbindungsweg",
                                   value: "\(position.index) von \(position.total)")
                }
                if let endpoint = info.endpointLabel {
                    VStack(alignment: .leading, spacing: 4) {
                        Text("Aktueller Weg")
                        Text(endpoint)
                            .font(.caption.monospaced())
                            .foregroundStyle(.secondary)
                    }
                }
                LabeledContent("Verbunden") {
                    Label(info.isConnected ? "ja" : "nein",
                          systemImage: info.isConnected ? "checkmark.circle" : "xmark.circle")
                        .foregroundStyle(info.isConnected ? .green : .red)
                }
                LabeledContent("Empfang abonniert") {
                    Label(info.isNotifyActive ? "ja" : "nein",
                          systemImage: info.isNotifyActive ? "checkmark.circle" : "xmark.circle")
                        .foregroundStyle(info.isNotifyActive ? .green : .orange)
                }
                LabeledContent("Gesendet / empfangen",
                               value: "\(info.sentFrames) Anfragen / \(info.receivedBytes) Byte")
                if let lastSendAt = info.lastSendAt {
                    LabeledContent("Zuletzt gesendet vor") {
                        Text(lastSendAt, style: .relative)
                    }
                    .foregroundStyle(.secondary)
                }
                if let command = info.lastCommandHex {
                    VStack(alignment: .leading, spacing: 4) {
                        HStack {
                            Text("Letzter Stellbefehl")
                            Spacer()
                            if let at = info.lastCommandAt {
                                Text(at, style: .relative).foregroundStyle(.secondary)
                            }
                        }
                        Text(command)
                            .font(.caption.monospaced())
                            .foregroundStyle(.secondary)
                            .textSelection(.enabled)
                    }
                }
                if let hex = info.lastResponseHex {
                    VStack(alignment: .leading, spacing: 4) {
                        Text("Letzte Antwort")
                        Text(hex)
                            .font(.caption.monospaced())
                            .foregroundStyle(.secondary)
                            .textSelection(.enabled)
                    }
                }
            } header: {
                Text("Diagnose")
            } footer: {
                Text("Die App probiert alle Schreib-/Empfangs-Kombinationen des Geräts "
                     + "durch und fragt auf jeder Daly (klassisch und Modbus) sowie "
                     + "JBD/Xiaoxiang an. Der „Verbindungsweg“ zählt dabei hoch. "
                     + "Bleibt „empfangen“ am Ende bei 0 Byte, nimmt das BMS auf keinem "
                     + "Weg Kommandos an; kommen Bytes an, ohne dass ein Protokoll "
                     + "erkannt wird, spricht es ein noch unbekanntes.")
            }

            if !info.gattSummary.isEmpty {
                Section {
                    Text(info.gattSummary.joined(separator: "\n"))
                        .font(.caption2.monospaced())
                        .foregroundStyle(.secondary)
                        .textSelection(.enabled)
                } header: {
                    Text("Bluetooth-Merkmale des Geräts")
                }
            }
        }
    }

    private var settingsSection: some View {
        Section("Einstellungen") {
            TextField("Name", text: $editedName)
                .onSubmit(saveName)
            Button("Namen übernehmen", action: saveName)
                .disabled(editedName.trimmingCharacters(in: .whitespaces).isEmpty
                          || editedName == device.name)
            LabeledContent("Typ", value: device.role.title)
            if device.role == .fridge {
                Picker("Kühlzonen", selection: Binding(
                    get: { device.fridgeZoneMode },
                    set: { mode in
                        var updated = device
                        updated.fridgeZoneMode = mode
                        store.update(updated)
                        bluetooth.updateFridgeZoneMode(for: updated)
                    }
                )) {
                    ForEach(FridgeZoneMode.allCases) { mode in
                        Text(mode.title).tag(mode)
                    }
                }
            }
            LabeledContent("Bluetooth-ID") {
                Text(device.peripheralID.uuidString.prefix(8) + "…")
                    .font(.caption.monospaced())
                    .foregroundStyle(.secondary)
            }
            Button("Gerät entfernen", role: .destructive) {
                showDeleteConfirmation = true
            }
        }
    }

    // MARK: - Aktionen

    private func saveKey() {
        store.setVictronKey(keyInput, for: device.id)
        bluetooth.refreshConfiguration()
    }

    private func saveName() {
        var updated = device
        updated.name = editedName.trimmingCharacters(in: .whitespaces)
        store.update(updated)
    }
}