import SwiftUI
import NetworkExtension

struct ContentView: View {
    @EnvironmentObject private var model: AppModel

    var body: some View {
        NavigationStack {
            VStack(spacing: 0) {
                header
                controls
                Divider()
                profileList
                footer
            }
            .background(Color(uiColor: .systemGroupedBackground))
            .navigationTitle("Navis")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .topBarTrailing) {
                    Text(
                        Bundle.main.infoDictionary?["CFBundleVersion"] as? String
                            ?? Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String
                            ?? "3.8.2"
                    )
                        .font(.caption.monospaced())
                        .foregroundStyle(.secondary)
                }
            }
        }
    }

    private var header: some View {
        VStack(alignment: .leading, spacing: 8) {
            TextField("URL подписки", text: $model.subURL)
                .textInputAutocapitalization(.never)
                .autocorrectionDisabled()
                .textFieldStyle(.roundedBorder)
            TextField("Или вставьте vless/hy2/… ссылки", text: $model.importText, axis: .vertical)
                .lineLimit(2...4)
                .textInputAutocapitalization(.never)
                .autocorrectionDisabled()
                .textFieldStyle(.roundedBorder)
        }
        .padding()
    }

    private var controls: some View {
        VStack(spacing: 10) {
            HStack(spacing: 8) {
                Button("Подписка") {
                    Task { await model.importSubscription() }
                }
                .buttonStyle(.borderedProminent)
                .disabled(model.busy || model.subURL.trimmingCharacters(in: .whitespaces).isEmpty)

                Button("Ссылки") {
                    model.importPastedLinks()
                }
                .buttonStyle(.bordered)
                .disabled(model.busy || model.importText.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)

                Button("Пинг") {
                    Task { await model.pingAll() }
                }
                .buttonStyle(.bordered)
                .disabled(model.busy || model.profiles.isEmpty)
            }

            HStack {
                Toggle("Автолучший", isOn: Binding(
                    get: { model.autoBest },
                    set: { model.setAutoBest($0) }
                ))
                .disabled(model.busy)
                Spacer()
                vpnButtons
            }
        }
        .padding(.horizontal)
        .padding(.bottom, 8)
    }

    @ViewBuilder
    private var vpnButtons: some View {
        if model.vpn.canDisconnect || model.busy {
            Button("Отключить") {
                Task { await model.disconnect() }
            }
            .buttonStyle(.borderedProminent)
            .tint(.red)
        } else {
            Button("Подключить") {
                Task { await model.connectSelected() }
            }
            .buttonStyle(.borderedProminent)
            .disabled(model.activeID == nil)
        }
    }

    private var profileList: some View {
        List(model.profiles) { p in
            Button {
                model.select(p.id)
            } label: {
                HStack {
                    VStack(alignment: .leading, spacing: 2) {
                        Text(p.name)
                            .foregroundStyle(p.protocolKind.supportedOnIOS ? .primary : .secondary)
                            .lineLimit(1)
                        Text(subtitle(for: p))
                            .font(.caption)
                            .foregroundStyle(.secondary)
                            .lineLimit(1)
                    }
                    Spacer()
                    if let ping = model.pings[p.id] {
                        Text(ping.ok ? "\(ping.ms) ms" : "—")
                            .font(.caption.monospaced())
                            .foregroundStyle(ping.ok ? .green : .secondary)
                    }
                    if model.activeID == p.id {
                        Image(systemName: "checkmark.circle.fill")
                            .foregroundStyle(.blue)
                    }
                }
            }
        }
        .listStyle(.plain)
    }

    private func subtitle(for p: Profile) -> String {
        let base = "\(p.protocolKind.label) · \(p.host)"
        if p.protocolKind.supportedOnIOS { return base }
        return base + " · недоступен на iOS"
    }

    private var footer: some View {
        VStack(alignment: .leading, spacing: 4) {
            Text(statusLine)
                .font(.caption)
                .foregroundStyle(.secondary)
            Text(model.meta)
                .font(.footnote)
                .foregroundStyle(model.metaErr ? .red : .primary)
                .frame(maxWidth: .infinity, alignment: .leading)
        }
        .padding()
        .background(Color(uiColor: .secondarySystemBackground))
    }

    private var statusLine: String {
        switch model.vpn.status {
        case .invalid:
            return "VPN: ожидает разрешение — нажмите Подключить (нужен VLESS/Trojan)"
        case .disconnected:
            return "VPN: отключён"
        case .connecting:
            return "VPN: подключение…"
        case .connected:
            return "VPN: подключён"
        case .reasserting:
            return "VPN: переподключение…"
        case .disconnecting:
            return "VPN: отключение…"
        @unknown default:
            return "VPN: ?"
        }
    }
}