namespace Spectre.Console.Cli;

internal sealed class CommandInfo : ICommandContainer
{
    public string Name { get; }
    public HashSet<string> Aliases { get; }
    public string? Description { get; }
    public object? Data { get; }
    public Type? CommandType { get; }
    public Type SettingsType { get; }
    public Func<CommandContext, CommandSettings, int>? Delegate { get; }
    public bool IsDefaultCommand { get; }
    public CommandInfo? Parent { get; }
    public IList<CommandInfo> Children { get; }
    public IList<CommandParameter> Parameters { get; }
    public IList<string[]> Examples { get; }

    public bool IsBranch => CommandType == null && Delegate == null;
    IList<CommandInfo> ICommandContainer.Commands => Children;

    // only branches can have a default command
    public CommandInfo? DefaultCommand => IsBranch ? Children.FirstOrDefault(c => c.IsDefaultCommand) : null;
    public bool IsHidden { get; }

    public CommandInfo(CommandInfo? parent, ConfiguredCommand prototype)
    {
        Parent = parent;

        Name = prototype.Name;
        Aliases = new HashSet<string>(prototype.Aliases);
        Description = prototype.Description;
        Data = prototype.Data;
        CommandType = prototype.CommandType;
        SettingsType = prototype.SettingsType;
        Delegate = prototype.Delegate;
        IsDefaultCommand = prototype.IsDefaultCommand;
        IsHidden = prototype.IsHidden;

        Children = new List<CommandInfo>();
        Parameters = new List<CommandParameter>();
        Examples = prototype.Examples ?? new List<string[]>();

        if (CommandType != null && string.IsNullOrWhiteSpace(Description))
        {
            var description = CommandType.GetCustomAttribute<DescriptionAttribute>();
            if (description != null)
            {
                Description = description.Description;
            }
        }
    }

    public List<CommandInfo> Flatten()
    {
        var result = new Stack<CommandInfo>();

        var current = this;
        while (current != null)
        {
            result.Push(current);
            current = current.Parent;
        }

        return result.ToList();
    }
}