using System;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.FileProviders;
using System.IO;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;
using System.Text;
using Microsoft.Extensions.Logging;
using System.Collections.Generic;
using Microsoft.AspNetCore.Cors.Infrastructure;
using Microsoft.AspNetCore.StaticFiles;

namespace jsonjumble
{
	public class Startup
	{

		public IConfiguration Configuration { get; }

		public Startup(IConfiguration configuration)
		{
			Configuration = configuration;
		}

		public void ConfigureServices(IServiceCollection services)
		{
			services.AddControllers();

			services.AddAuthentication(options =>
			{
				options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
				options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
				options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
			}).AddJwtBearer(options =>
			{
				options.RequireHttpsMetadata = false;
				options.SaveToken = true;
				options.TokenValidationParameters = new TokenValidationParameters()
				{
					ValidateIssuerSigningKey = true,
					IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["JwtSettings:SecretKey"])),
					ValidateIssuer = true,
					ValidIssuer = Configuration["JwtSettings:Issuer"],
					ValidateAudience = true,
					ValidAudience = Configuration["JwtSettings:Audience"],
					ValidateLifetime = true,
					ClockSkew = TimeSpan.FromMinutes(Configuration.GetValue<int>("JwtSettings:ExpirationInHours"))
				};
			});
			services.AddMvc().AddNewtonsoftJson();


			var validOrigins = Configuration.GetSection("RegisteredDomains").Get<List<string>>().ToArray();
			var originString = new StringBuilder();
			originString.AppendJoin(", ", validOrigins);

			Console.WriteLine($"Allowing Origins: {originString}");

			services.AddCors(options =>
			{
				// options.AddDefaultPolicy(policy =>
				// {
				// 	policy.WithOrigins(validOrigins);
				// 	policy.WithMethods(new string[] { "GET" });
				// 	policy.WithHeaders(new string[] { "Access-Control-Allow-Origin", "Content-Type" });
				// });
				options.AddPolicy(name: "jsonjumble_corspolicy",
				policy =>
				{
					// policy.AllowAnyOrigin();
					// policy.AllowAnyMethod();
					// policy.AllowAnyHeader();

					policy.WithOrigins(validOrigins);
					policy.WithMethods(new string[] {"GET"});
					policy.WithHeaders(new string[] {"Access-Control-Allow-Origin", "Content-Type"});

				});
			});
		}

		public void Configure(
			ILogger<Startup> logger,
			IApplicationBuilder app,
			IWebHostEnvironment env,
			ICorsService corsService,
			ICorsPolicyProvider corsPolicyProvider
		)
		{
			if (env.IsDevelopment())
			{
				app.UseDeveloperExceptionPage();
			}

			if (Configuration.GetValue<Boolean>("UseHttps"))
			{
				app.UseHttpsRedirection();
			}

			string errorPath = Path.Combine(Directory.GetCurrentDirectory(), Configuration.GetValue<string>("RelativeErrorFilePath"));
			logger.LogInformation($"Loading static error pages from {errorPath}");

			app.UseStatusCodePages(new StatusCodePagesOptions()
			{
				HandleAsync = async (context) =>
				{
					var filePath = Path.Combine(errorPath, context.HttpContext.Response.StatusCode + ".html");
					var responseMessage = $"Error {context.HttpContext.Response.StatusCode}";
					if (System.IO.File.Exists(filePath))
					{
						responseMessage = System.IO.File.ReadAllText(filePath);
					}
					await context.HttpContext.Response.WriteAsync(responseMessage);
				}
			});

			string staticPath = Path.Combine(Directory.GetCurrentDirectory(), Configuration.GetValue<string>("RelativeStaticFilePath"));
			logger.LogInformation($"Loading static files from {staticPath}");
			PhysicalFileProvider staticFileProvider = new PhysicalFileProvider(staticPath);

			app.UseDefaultFiles(new DefaultFilesOptions()
			{
				FileProvider = staticFileProvider,
				DefaultFileNames = new string[] { "index.html", "index.json" }
			});

			app.UseStaticFiles(new StaticFileOptions()
			{
				FileProvider = staticFileProvider,
				ServeUnknownFileTypes = true,
				OnPrepareResponse = (ctx) =>
				{
					AddCorsHeadersToStaticFiles(ctx, corsService, corsPolicyProvider);
				}
			});



			app.UseRouting();

			// app.UseCors("jsonjumble_corspolicy");
			app.UseCors("jsonjumble_corspolicy");

			app.UseAuthentication();
			app.UseAuthorization();

			app.UseEndpoints(endpoints =>
			{
				endpoints.MapControllers();
			});
		}

		public void AddCorsHeadersToStaticFiles(StaticFileResponseContext ctx,ICorsService corsService,ICorsPolicyProvider corsPolicyProvider) {
			var policy = corsPolicyProvider.GetPolicyAsync(ctx.Context, "jsonjumble_corspolicy")
						.ConfigureAwait(false)
						.GetAwaiter().GetResult();

					var corsResult = corsService.EvaluatePolicy(ctx.Context, policy);

					corsService.ApplyResult(corsResult, ctx.Context.Response);

					// ctx.Context.Response.Headers.Add("X-Content-Type-Options", "nosniff");
		}
	}
}