using JetBrains.Annotations;
using Microsoft.Extensions.Logging;
using Remora.Discord.Commands.Contexts;
using Remora.Discord.Commands.Extensions;
using Remora.Discord.Commands.Services;
using Remora.Results;

namespace Boyfriend.Commands.Events;

/// <summary>
///     Handles error logging for slash commands that couldn't be successfully prepared.
/// </summary>
[UsedImplicitly]
public class LoggingPreparationErrorEvent : IPreparationErrorEvent {
    private readonly ILogger<LoggingPreparationErrorEvent> _logger;

    public LoggingPreparationErrorEvent(ILogger<LoggingPreparationErrorEvent> logger) {
        _logger = logger;
    }

    /// <summary>
    ///     Logs a warning using the injected <see cref="ILogger" /> if the <paramref name="preparationResult" /> has not
    ///     succeeded.
    /// </summary>
    /// <param name="context">The context of the slash command. Unused.</param>
    /// <param name="preparationResult">The result whose success is checked.</param>
    /// <param name="ct">The cancellation token for this operation. Unused.</param>
    /// <returns>A result which has succeeded.</returns>
    public Task<Result> PreparationFailed(
        IOperationContext context, IResult preparationResult, CancellationToken ct = default) {
        if (!preparationResult.IsSuccess && !preparationResult.Error.IsUserOrEnvironmentError()) {
            _logger.LogWarning("Error in slash command preparation.\n{ErrorMessage}", preparationResult.Error.Message);
            if (preparationResult.Error is ExceptionError exerr)
                _logger.LogError(exerr.Exception, "An exception has been thrown");
        }

        return Task.FromResult(Result.FromSuccess());
    }
}