import SwiftUI

struct SettingsView: View {
    @ObservedObject var monitor: ServerMonitor
    @State private var draft = ServerProfile()
    @State private var editingID: UUID?
    @State private var validation = ""
    @State private var interval = 5
    @State private var notifications = true

    var body: some View {
        HStack(spacing: 0) {
            VStack(spacing: 8) {
                Text("Servers").font(.headline).frame(maxWidth: .infinity, alignment: .leading)
                List(selection: $editingID) {
                    ForEach(monitor.servers) { server in
                        HStack {
                            Image(systemName: "server.rack")
                            Text(server.name)
                            if !server.enabled { Image(systemName: "pause.circle") }
                        }.tag(server.id)
                    }
                    .onMove { monitor.move(from: $0, to: $1) }
                }
                HStack {
                    Button { newProfile() } label: { Image(systemName: "plus") }
                    Button { if let id = editingID { monitor.remove(id); editingID = monitor.servers.first?.id } } label: { Image(systemName: "minus") }
                        .disabled(editingID == nil)
                    Spacer()
                }
                .buttonStyle(.borderless)
            }
            .frame(width: 205)
            .padding()
            Divider()
            VStack(alignment: .leading, spacing: 14) {
                Text(editingID == nil ? "Add a server" : "Connection details")
                    .font(.title3.bold())
                Form {
                    TextField("Display name", text: $draft.name)
                    TextField("Host / SSH alias", text: $draft.host)
                    TextField("SSH username", text: $draft.user)
                    TextField("SSH port", text: $draft.port)
                    TextField("SSH key path (optional)", text: $draft.keyFile)
                    TextField("Remote health command", text: $draft.remoteCommand)
                    Toggle("Monitoring enabled", isOn: $draft.enabled)
                }
                Text("Use the Pegasus adapter for Pegasus, or install server/remote-health-json on other Linux servers. SSH must work without interactive prompts. SSH known_hosts is enforced.")
                    .font(.caption).foregroundStyle(.secondary)
                if !validation.isEmpty { Text(validation).foregroundStyle(.red).font(.caption) }
                HStack {
                    Button("New Server") { newProfile() }
                    Spacer()
                    Button("Save and Refresh") { save() }
                        .buttonStyle(.borderedProminent)
                }
                Divider()
                HStack {
                    Picker("Refresh every", selection: $interval) {
                        ForEach([1, 5, 10, 15, 30], id: \.self) { value in
                            Text("\(value) min").tag(value)
                        }
                    }
                    Toggle("Notifications", isOn: $notifications)
                }
            }
            .padding(20)
        }
        .onAppear {
            interval = monitor.intervalMinutes
            notifications = monitor.notifications
            editingID = monitor.selectedID
            if let selected = monitor.selected { draft = selected }
        }
        .onChange(of: editingID) { _, newValue in
            if let id = newValue, let server = monitor.servers.first(where: { $0.id == id }) { draft = server }
            validation = ""
        }
        .onChange(of: interval) { _, value in monitor.intervalMinutes = value }
        .onChange(of: notifications) { _, value in monitor.notifications = value }
    }

    private func newProfile() {
        editingID = nil
        draft = ServerProfile()
        validation = ""
    }
    private func save() {
        guard !draft.name.trimmingCharacters(in: .whitespaces).isEmpty,
              !draft.host.trimmingCharacters(in: .whitespaces).isEmpty,
              !draft.user.trimmingCharacters(in: .whitespaces).isEmpty,
              let port = Int(draft.port), (1...65535).contains(port),
              !draft.remoteCommand.trimmingCharacters(in: .whitespaces).isEmpty else {
            validation = "Enter a name, host, SSH username, valid port and remote command."
            return
        }
        monitor.save(draft)
        editingID = draft.id
        validation = ""
    }
}