using System.Text;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using Microsoft.Net.Http.Headers;
using StopShopping.Services;

namespace StopShopping.Api.Extensions;

public static class JwtExtensions
{
    public static IServiceCollection AddAuthServices(this IServiceCollection services, IConfiguration jwtOptions)
    {
        services.Configure<JwtOptions>(jwtOptions);
        services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
            .AddJwtBearer(jwtBearerOptions =>
            {
                var jwtConfiguration = jwtOptions.Get<JwtOptions>()!;

                var signingKey = new SymmetricSecurityKey(
                    Encoding.UTF8.GetBytes(jwtConfiguration.SigningKey!)
                );

                jwtBearerOptions.MapInboundClaims = false;
                jwtBearerOptions.TokenValidationParameters = new TokenValidationParameters
                {
                    ValidAudience = jwtConfiguration.ValidAudience,
                    ValidIssuer = jwtConfiguration.ValidIssuer,
                    IssuerSigningKey = signingKey,
                    ClockSkew = TimeSpan.FromSeconds(30) //宽容时间，30秒后才失效
                };
                jwtBearerOptions.Events = new JwtBearerEvents
                {
                    OnMessageReceived = async (context) =>
                    {
                        var accessTokenService = context.HttpContext.RequestServices.GetRequiredService<IAccessTokenService>();
                        var authorizationHeader = context.Request.Headers[HeaderNames.Authorization];
                        if (authorizationHeader.Count == 0)
                        {
                            context.Fail($"未找到{HeaderNames.Authorization}请求头");
                        }
                        else
                        {
                            var token = authorizationHeader.First()!.Split(" ").Last();
                            if (string.IsNullOrWhiteSpace(token))
                                context.Fail("未找到token");
                            if (await accessTokenService.IsAccessTokenBlacklistAsync(token))
                                context.Fail("token已失效");
                        }
                    }
                };
            });
        services.AddAuthorization();

        return services;
    }
}