using System.Collections.ObjectModel;
using System.IO;
using Avalonia.Threading;
using CommonwealthOnline.Host.Services;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;

namespace CommonwealthOnline.Host.ViewModels;

public partial class MainWindowViewModel : ObservableObject
{
    private const int MaxLogLines = 2000;

    private readonly ServerController _controller = new();
    private readonly string _serverDir = System.IO.Directory.GetCurrentDirectory();
    private readonly string _configPath =
        Path.Combine(System.IO.Directory.GetCurrentDirectory(), "commonwealth-server.json");

    [ObservableProperty] private string _serverName;
    [ObservableProperty] private string _host;
    [ObservableProperty] private int _port;
    [ObservableProperty] private int _maxPlayers;
    [ObservableProperty] private int _adminPort;
    [ObservableProperty] private string _logVerbosity;
    [ObservableProperty] private bool _enableGnsTransport;
    [ObservableProperty] private bool _isRunning;
    [ObservableProperty] private string _statusText = "Stopped";

    public ObservableCollection<string> Log { get; } = new();

    public string[] VerbosityOptions { get; } = { "error", "warning", "info", "debug" };

    public MainWindowViewModel()
    {
        var config = ServerConfig.Load(_configPath);
        _serverName = config.ServerName;
        _host = config.Host;
        _port = config.Port;
        _maxPlayers = config.MaxPlayers;
        _adminPort = config.AdminPort;
        _logVerbosity = config.LogVerbosity;
        _enableGnsTransport = config.EnableGnsTransport;

        _controller.LogReceived += line =>
            Dispatcher.UIThread.Post(() => Append(line));
        _controller.RunningChanged += running =>
            Dispatcher.UIThread.Post(() =>
            {
                IsRunning = running;
                StatusText = running ? "Running" : "Stopped";
                StartCommand.NotifyCanExecuteChanged();
                StopCommand.NotifyCanExecuteChanged();
            });
    }

    private void Append(string line)
    {
        Log.Add(line);
        while (Log.Count > MaxLogLines)
        {
            Log.RemoveAt(0);
        }
    }

    private ServerConfig CurrentConfig() => new()
    {
        ServerName = ServerName,
        Host = Host,
        Port = Port,
        MaxPlayers = MaxPlayers,
        AdminPort = AdminPort,
        LogVerbosity = LogVerbosity,
        EnableGnsTransport = EnableGnsTransport,
    };

    [RelayCommand]
    private void Save() => CurrentConfig().Save(_configPath);

    [RelayCommand(CanExecute = nameof(CanStart))]
    private void Start()
    {
        Save();
        Append($"[host] starting server on {Host}:{Port}...");
        _controller.Start(_serverDir, _configPath);
    }

    private bool CanStart() => !IsRunning;

    [RelayCommand(CanExecute = nameof(CanStop))]
    private void Stop()
    {
        Append("[host] stopping server...");
        _controller.Stop();
    }

    private bool CanStop() => IsRunning;
}