using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Text.Encodings.Web;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace AuthSamples.VirtualScheme.PathSchemeSelection
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();

            services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
                .AddScheme<AuthenticationSchemeOptions, ApiAuthHandler>("Api", o => { })
                .AddCookie(options =>
                {
                    // Foward any requests that start with /api to that scheme
                    options.ForwardDefaultSelector = ctx =>
                    {
                        return ctx.Request.Path.StartsWithSegments("/api") ? "Api" : null;
                    };
                    options.AccessDeniedPath = "/account/denied";
                    options.LoginPath = "/account/login";
                });
        }

        public class ApiAuthHandler : AuthenticationHandler<AuthenticationSchemeOptions>
        {
            private readonly ClaimsPrincipal _id;

            public ApiAuthHandler(IOptionsMonitor<AuthenticationSchemeOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock) : base(options, logger, encoder, clock)
            {
                var id = new ClaimsIdentity("Api");
                id.AddClaim(new Claim(ClaimTypes.Name, "Hao", ClaimValueTypes.String, "Api"));
                _id = new ClaimsPrincipal(id);
            }

            protected override Task<AuthenticateResult> HandleAuthenticateAsync()
                => Task.FromResult(AuthenticateResult.Success(new AuthenticationTicket(_id, "Api")));
        }


        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
            }

            app.UseStaticFiles();

            // Must go before UseMvc
            app.UseAuthentication();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
                routes.MapRoute(
                    name: "api",
                    template: "api/{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}