using System.Reflection;

namespace BotPages.Core.Messaging;

/// <summary>
/// Описание для кнопки.
/// </summary>
[AttributeUsage(AttributeTargets.Field)]
public class ButtonAttribute : Attribute
{
    ///<inheritdoc/>
    public ButtonAttribute(string label)
    {
        Label = label;
    }

    /// <summary>
    /// Описание кнопки.
    /// </summary>
    public string Label { get; }

    /// <summary>
    /// Значение кнопки. Используется в InlineButton.
    /// </summary>
    public string? Value { get; }
}

/// <summary>
/// Расширение для работы с кнопками.
/// </summary>
public static class ButtonExtensions
{
    private static readonly Dictionary<Type, Dictionary<string, object>> _cacheName = new();

    /// <summary>
    /// Получить подпись кнопки.
    /// </summary>
    /// <typeparam name="T">Enum тип.</typeparam>
    /// <param name="value">Значение enum.</param>
    /// <returns></returns>
    public static string GetButtonLabel<T>(this T value)
        where T : Enum
    {
        var fieldName = value.ToString();
        var type = value.GetType();
        var field = type.GetField(fieldName, BindingFlags.Public | BindingFlags.Static);
        return field?.GetCustomAttribute<ButtonAttribute>()?.Label ?? fieldName;
    }

    /// <summary>
    /// Получить значение кнопки.
    /// </summary>
    /// <typeparam name="T">Enum тип.</typeparam>
    /// <param name="value">Значение enum.</param>
    /// <returns></returns>
    public static string GetButtonValue<T>(this T value)
        where T : Enum
    {
        var fieldName = value.ToString();
        var type = value.GetType();
        var field = type.GetField(fieldName, BindingFlags.Public | BindingFlags.Static);
        return field?.GetCustomAttribute<ButtonAttribute>()?.Value ?? fieldName;
    }

    /// <summary>
    /// Получить значение enum из подписи кнопки.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="value"></param>
    /// <returns></returns>
    public static T? FromButtonLabel<T>(string? value) where T : struct, Enum
    {
        if (value == null) return null;

        var type = typeof(T);
        if (!_cacheName.TryGetValue(type, out var map))
        {
            map = new Dictionary<string, object>();

            var fields = type.GetFields(BindingFlags.Public | BindingFlags.Static);

            foreach (var field in fields)
            {
                var fieldValue = field.GetValue(null)!;
                var fieldName = field.Name;

                var attr = field.GetCustomAttribute<ButtonAttribute>();

                if (attr != null)
                {
                    fieldName = attr.Label;
                }

                map[fieldName] = fieldValue;
            }

        }

        return map.TryGetValue(value, out var result) ? (T)result : null;
    }
}