//
//  ServerListSettingsView.swift
//  QueueCube
//
//  Created by James Magahern on 6/10/25.
//

import SwiftUI

struct ServerListSettingsView: View
{
    @State var model = ViewModel()
    
    var body: some View {
        VStack {
            if model.configuredServers.isEmpty {
                contentPlaceholderView(title: .noServersConfigured, systemImage: "server.rack") {
                    Button {
                        model.isAddServerPresented = true
                    } label: {
                        Text(.addServer)
                    }
                }
            } else {
                Form {
                    List($model.configuredServers, editActions: [.delete]) { server in
                        serverListItem(server.wrappedValue)
                            .tag(server.id)
                    }
                }
            }
        }
        
        .navigationTitle(.servers)
        
        .toolbar {
            Button {
                model.isAddServerPresented = true
            } label: {
                Image(systemName: "plus")
            }
        }
        
        .sheet(isPresented: $model.isAddServerPresented) {
            NavigationView {
                AddServerView(onAddServer: { model.onAddServer(server: $0) })
                    .navigationTitle(.addServer)
                    .navigationBarTitleDisplayMode(.inline)
                    .toolbar {
                        ToolbarItemGroup(placement: .cancellationAction) {
                            Button(.cancel) { model.isAddServerPresented = false }
                        }
                    }
                    
            }
        }
    }
    
    @ViewBuilder
    func serverListItem(_ server: Server) -> some View {
        HStack {
            Image(systemName: "hifispeaker.fill")
            
            VStack(alignment: .leading) {
                Text(server.displayName)
                    .lineLimit(1)
                    .bold()
                
                Text(server.baseURL.absoluteString)
                    .foregroundStyle(.secondary)
                    .font(.caption)
            }
            
            Spacer()
        }
    }
    
    // MARK: - Types
    
    @Observable
    class ViewModel
    {
        var configuredServers: [Server]
        var isAddServerPresented = false
        var selectedItems: [Server.ID] = []
        
        init() {
            self.configuredServers = Settings
                .fromDefaults()
                .configuredServers
            
            observeForChanges()
        }
        
        func observeForChanges() {
            withObservationTracking {
                _ = configuredServers
            } onChange: {
                Task { @MainActor [weak self] in
                    guard let self else { return }
                    saveToSettings()
                    observeForChanges()
                }
            }
        }
        
        func onAddServer(server: Server) {
            isAddServerPresented = false
            configuredServers = configuredServers + [ server ]
            saveToSettings()
        }
        
        func saveToSettings() {
            Settings
                .fromDefaults()
                .configuredServers(configuredServers)
                .save()
        }
    }
}