namespace Webzine.WebApplication.Filters;

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;

/// <summary>
/// Filtre d'exception global qui intercepte toute exception non geree et la journalise automatiquement.
/// </summary>
public class GlobalExceptionFilter : IExceptionFilter
{
    private readonly ILogger<GlobalExceptionFilter> logger;

    /// <summary>
    /// Initializes a new instance of the <see cref="GlobalExceptionFilter"/> class.
    /// </summary>
    /// <param name="logger">Service de journalisation injecte.</param>
    public GlobalExceptionFilter(ILogger<GlobalExceptionFilter> logger)
    {
        this.logger = logger;
    }

    /// <inheritdoc/>
    public void OnException(ExceptionContext context)
    {
        string detail = BuildExceptionDetail(context.Exception);

        this.logger.LogError(
            context.Exception,
            "Erreur non geree dans {Action} : {Message} | Details: {Details}",
            context.ActionDescriptor.DisplayName,
            context.Exception.Message,
            detail);

        context.Result = new ObjectResult(new
        {
            erreur = "Une erreur inattendue est survenue.",
            detail = context.Exception.Message,
        })
        {
            StatusCode = StatusCodes.Status500InternalServerError,
        };

        context.ExceptionHandled = true;
    }

    private static string BuildExceptionDetail(Exception exception)
    {
        var messages = new List<string>();
        Exception? current = exception;

        while (current != null)
        {
            messages.Add($"{current.GetType().Name}: {current.Message}");
            current = current.InnerException;
        }

        return string.Join(" --> ", messages);
    }
}