using FluentValidation;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Mirea.Api.DataAccess.Application.Common.Exceptions;
using Mirea.Api.Endpoint.Common.Exceptions;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Security;
using System.Text.Json;
using System.Threading.Tasks;

namespace Mirea.Api.Endpoint.Configuration.Core.Middleware;

public class CustomExceptionHandlerMiddleware(RequestDelegate next, ILogger<CustomExceptionHandlerMiddleware> logger)
{
    public async Task InvokeAsync(HttpContext context)
    {
        try
        {
            await next(context);
        }
        catch (Exception exception)
        {
            await HandleExceptionAsync(context, exception);
        }
    }

    private Task HandleExceptionAsync(HttpContext context, Exception exception)
    {
        var traceId = Activity.Current?.Id ?? context.TraceIdentifier;

        var problemDetails = new ProblemDetails
        {
            Type = "https://tools.ietf.org/html/rfc9110#section-15.6",
            Title = "An unexpected error occurred.",
            Status = StatusCodes.Status500InternalServerError,
            Detail = exception.Message,
            Extensions = new Dictionary<string, object?>()
            {
                { "traceId", traceId }
            }
        };

        switch (exception)
        {
            case ValidationException validationException:
                problemDetails.Status = StatusCodes.Status400BadRequest;
                problemDetails.Type = "https://tools.ietf.org/html/rfc9110#section-15.5.1";
                problemDetails.Title = "Validation errors occurred.";
                problemDetails.Extensions = new Dictionary<string, object?>
                {
                    { "errors", validationException.Errors.Select(e => e.ErrorMessage).ToArray() },
                    { "traceId", traceId }
                };
                break;
            case NotFoundException:
                problemDetails.Status = StatusCodes.Status404NotFound;
                problemDetails.Type = "https://tools.ietf.org/html/rfc9110#section-15.5.4";
                problemDetails.Title = "Resource not found.";
                break;
            case ControllerArgumentException:
                problemDetails.Status = StatusCodes.Status400BadRequest;
                problemDetails.Type = "https://tools.ietf.org/html/rfc9110#section-15.5.1";
                problemDetails.Title = "Invalid arguments provided.";
                break;
            case SecurityException:
                problemDetails.Status = StatusCodes.Status401Unauthorized;
                problemDetails.Type = "https://tools.ietf.org/html/rfc9110#section-15.5.2";
                problemDetails.Title = "Unauthorized access.";
                break;
            case ServerUnavailableException unavailableException:
                problemDetails.Status = StatusCodes.Status503ServiceUnavailable;
                problemDetails.Type = "https://datatracker.ietf.org/doc/html/rfc9110#section-15.6.4";
                problemDetails.Title = "Server unavailable.";
                problemDetails.Detail = unavailableException.Message;
                if (unavailableException.AddRetryAfter)
                    context.Response.Headers.RetryAfter = "600";
                break;
        }

        if (problemDetails.Status == StatusCodes.Status500InternalServerError)
            logger.LogError(exception, "Internal server error when processing the request");

        context.Response.ContentType = "application/json";
        context.Response.StatusCode = problemDetails.Status.Value;

        return context.Response.WriteAsync(JsonSerializer.Serialize(problemDetails));
    }
}