using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.OpenApi.Models;
using NDB.Extensions.Swagger.Constants;
using NDB.Extensions.Swagger.Filters;
using NDB.Extensions.Swagger.ReverseProxy;
using Swashbuckle.AspNetCore.SwaggerGen;
using System;
using System.Collections.Generic;

namespace NDB.Extensions.Swagger
{
    public static class SwaggerExtensions
    {
        public static IServiceCollection AddSwagger(this IServiceCollection services, string title, AuthorizationType authorizationType = AuthorizationType.Basic)
        {
            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new OpenApiInfo { Title = title, Version = "v1" });
                c.SetAuthorization(authorizationType);
            });

            return services;
        }

        public static IServiceCollection AddSwaggerWithFilters(this IServiceCollection services, string title, AuthorizationType authorizationType = AuthorizationType.Basic)
        {
            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1",
                    new OpenApiInfo
                    {
                        Title = title,
                        Version = "v1"
                    });

                c.SetAuthorization(authorizationType);
                c.OperationFilter<PathParamsOperationFilter>();
                c.SchemaFilter<DtoSchemaFilter>();
                c.CustomSchemaIds(type => type.ToString());
            });

            return services;
        }

        private static void SetAuthorization(this SwaggerGenOptions options, AuthorizationType authorizationType)
        {
            switch (authorizationType)
            {
                case AuthorizationType.None:
                    return;

                case AuthorizationType.Basic:
                    options.AddSecurityDefinition("Basic",
                        new OpenApiSecurityScheme
                        {
                            In = ParameterLocation.Header,
                            Description = @"JWT Authorization header using the Basic scheme. Enter 'Basic' [space] and then your token in the text input below. Example: 'Basic 12345abcdef'",
                            Name = "Authorization",
                            Scheme = "Basic",
                            Type = SecuritySchemeType.ApiKey
                        });

                    options.AddSecurityRequirement(new OpenApiSecurityRequirement()
                    {
                        {
                            new OpenApiSecurityScheme
                            {
                                Reference = new OpenApiReference
                                {
                                    Type = ReferenceType.SecurityScheme,
                                    Id = "Basic"
                                },
                                Scheme = "Basic",
                                Name = "Authorization",
                                In = ParameterLocation.Header
                            },
                            new List<string>()
                        }
                    });
                    break;

                default:
                    throw new NotImplementedException($"Swagger extensions: Authorization type '{authorizationType}' is not implemented.");
            }
        }

        public static IApplicationBuilder ConfigureSwagger(this IApplicationBuilder applicationBuilder, string endpointName)
        {
            applicationBuilder.UseSwagger(c =>
            {
                c.PreSerializeFilters.Add((swagger, httpRequest) =>
                {
                    var (host, basePath, scheme) = ReverseProxyHelper.GetUrlComponents(httpRequest);

                    swagger.Servers = new List<OpenApiServer>
                    {
                        new OpenApiServer {Url = $"{scheme}://{host}{basePath}"}
                    };
                });
                c.RouteTemplate = "swagger/{documentName}/swagger.json";
            });

            applicationBuilder.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("v1/swagger.json", endpointName);
                c.RoutePrefix = $"swagger";
            });

            return applicationBuilder;
        }
    }
}