using IM.Commons;
using IM.DomainCommons;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;

namespace IM.ASPNETCore
{
    public class ExceptionMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger<ExceptionMiddleware> logger;

        public ExceptionMiddleware(RequestDelegate next, ILogger<ExceptionMiddleware> logger)
        {
            _next = next;
            this.logger = logger;
        }

        public async Task InvokeAsync(HttpContext context)
        {
            try
            {
                await _next(context);
            }
            catch (DomainException ex)
            {
                await DomainExceptionHandlerAsync(context, ex);
            }
            catch (Exception ex)
            {
                await UnhandledExceptionHandlerAsync(context, ex);
            }
        }

        public Task DomainExceptionHandlerAsync(HttpContext context, DomainException ex)
        {
            context.Response.ContentType = "application/json";
            context.Response.StatusCode = StatusCodes.Status400BadRequest;
            var result = Result<object>.Fail(ResultCode.PARAMETER_ERROR, ex.Message);
            return context.Response.WriteAsJsonAsync(result);
        }

        private Task UnhandledExceptionHandlerAsync(HttpContext context, Exception ex)
        {
            var correlationId = context.TraceIdentifier;
            logger.LogError(ex,
                "Unhandled exception. CorrelationId: {CorrelationId}, Path: {Path}",
                correlationId,
                context.Request.Path);

            context.Response.ContentType = "application/json";
            context.Response.StatusCode = StatusCodes.Status500InternalServerError;
            context.Response.Headers["X-Correlation-ID"] = correlationId;

            var result = Result<object>.Fail(
                ResultCode.SYSTEM_ERROR,
                $"系统错误，关联编号：{correlationId}");
            return context.Response.WriteAsJsonAsync(result);
        }
    }
}