using FASS.Scheduler.Models;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using System.Text;

namespace FASS.Scheduler.Extensions.Configure
{
    public static class AuthExtension
    {
        public static IServiceCollection AddAuth(this IServiceCollection services, AppSettings appSettings)
        {
            services
                .AddAuthentication(options =>
                {
                    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
                    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
                })
                .AddJwtBearer(options =>
                {
                    options.TokenValidationParameters = new TokenValidationParameters()
                    {
                        ValidateIssuer = true,
                        ValidIssuer = appSettings.Auth.Issuer,

                        ValidateAudience = true,
                        ValidAudience = appSettings.Auth.Audience,

                        ValidateIssuerSigningKey = true,
                        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(appSettings.Auth.SigningKey)),

                        ValidateLifetime = true,
                        RequireExpirationTime = true,
                        ClockSkew = TimeSpan.Zero
                    };
                    options.Events = new JwtBearerEvents()
                    {
                        OnMessageReceived = context =>
                        {
                            if (context.Request.Headers.ContainsKey("Authorization"))
                            {
                                context.Token = context.Request.Headers["Authorization"].FirstOrDefault()?.Substring("Bearer ".Length);
                            }
                            return Task.CompletedTask;
                        },
                        OnAuthenticationFailed = context =>
                        {
                            if (context.Exception is SecurityTokenExpiredException)
                            {
                                context.Response.Headers.Append("Token-Expired", "true");
                            }
                            return Task.CompletedTask;
                        }
                    };
                });
            return services;
        }

        public static IApplicationBuilder UseAuth(this IApplicationBuilder app)
        {
            app.UseAuthentication();
            app.UseAuthorization();
            return app;
        }
    }
}