using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using QYZH.InteractiveMagazine.Models.Common;
using QYZH.InteractiveMagazine.Models.Dto;
using System.Text.Json;

namespace QYZH.InteractiveMagazine.Infrastructure.Middleware;

/// <summary>
/// 全局异常中间件
/// </summary>
public class GlobalExceptionMiddleware : IMiddleware
{
    private readonly ILogger<GlobalExceptionMiddleware> _logger;

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="logger">日志记录器</param>
    public GlobalExceptionMiddleware(ILogger<GlobalExceptionMiddleware> logger)
    {
        _logger = logger;
    }

    /// <summary>
    /// 执行中间件
    /// </summary>
    /// <param name="context">HTTP上下文</param>
    /// <param name="next">下一个中间件委托</param>
    public async Task InvokeAsync(HttpContext context, RequestDelegate next)
    {
        try
        {
            await next(context);
        }
        catch (BusinessException ex)
        {
            _logger.LogWarning(ex, "业务异常：{Message}", ex.Message);
            await HandleBusinessExceptionAsync(context, ex);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "系统异常：{Message}", ex.Message);
            await HandleSystemExceptionAsync(context, ex);
        }
    }

    /// <summary>
    /// 处理业务异常
    /// </summary>
    /// <param name="context">HTTP上下文</param>
    /// <param name="ex">业务异常</param>
    private static async Task HandleBusinessExceptionAsync(HttpContext context, BusinessException ex)
    {
        context.Response.ContentType = "application/json";
        context.Response.StatusCode = StatusCodes.Status400BadRequest;

        var response = BaseResponse<object>.Fail(ex.Message, ex.Code);
        var json = JsonSerializer.Serialize(response);

        await context.Response.WriteAsync(json);
    }

    /// <summary>
    /// 处理系统异常
    /// </summary>
    /// <param name="context">HTTP上下文</param>
    /// <param name="ex">系统异常</param>
    private static async Task HandleSystemExceptionAsync(HttpContext context, Exception ex)
    {
        context.Response.ContentType = "application/json";
        context.Response.StatusCode = StatusCodes.Status500InternalServerError;

        var response = BaseResponse<object>.Fail("系统内部错误，请稍后重试");
        var json = JsonSerializer.Serialize(response);

        await context.Response.WriteAsync(json);
    }
}