/WCFWebApi/src/Microsoft.ApplicationServer.Http/Microsoft/ApplicationServer/Http/HttpTypeHelper.cs

// <copyright>

//   Copyright (c) Microsoft Corporation.  All rights reserved.

// </copyright>



namespace Microsoft.ApplicationServer.Http

{

    using System;

    using System.Json;

    using System.Net;

    using System.Net.Http;

    using System.Net.Http.Headers;

    using Microsoft.Server.Common;



    /// <summary>

    /// A static class that provides HTTP related types and functionality

    /// around checking types against the set of HTTP related types.

    /// </summary>

    internal static class HttpTypeHelper 

    {

        internal static readonly Type JsonValueType = typeof(JsonValue);

        internal static readonly Type HttpRequestMessageType = typeof(HttpRequestMessage);

        internal static readonly Type HttpRequestHeadersType = typeof(HttpRequestHeaders);

        internal static readonly Type UriType = typeof(Uri);

        internal static readonly Type HttpMethodType = typeof(HttpMethod);

        internal static readonly Type HttpContentType = typeof(HttpContent);

        internal static readonly Type HttpResponseMessageType = typeof(HttpResponseMessage);

        internal static readonly Type HttpResponseHeadersType = typeof(HttpResponseHeaders);

        internal static readonly Type HttpStatusCodeType = typeof(HttpStatusCode);

        internal static readonly Type HttpRequestMessageGenericType = typeof(HttpRequestMessage<>);

        internal static readonly Type HttpResponseMessageGenericType = typeof(HttpResponseMessage<>);

        internal static readonly Type ObjectContentGenericType = typeof(ObjectContent<>);



        internal static bool IsHttpContent(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            return HttpContentType.IsAssignableFrom(type);

        }



        internal static bool IsHttpResponse(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            return HttpResponseMessageType.IsAssignableFrom(type);

        }



        internal static bool IsHttpRequest(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            return HttpRequestMessageType.IsAssignableFrom(type);

        }



        internal static bool IsHttpResponseOrContent(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            return HttpContentType.IsAssignableFrom(type) || 

                   HttpResponseMessageType.IsAssignableFrom(type);

        }



        internal static bool IsHttpRequestOrContent(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            return HttpContentType.IsAssignableFrom(type) || 

                   HttpRequestMessageType.IsAssignableFrom(type);

        }



        internal static bool IsHttp(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            return HttpContentType.IsAssignableFrom(type) || 

                   HttpRequestMessageType.IsAssignableFrom(type) || 

                   HttpResponseMessageType.IsAssignableFrom(type);

        }



        internal static bool IsHttpContentGenericTypeDefinition(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericTypeDefinition &&

                ObjectContentGenericType.IsAssignableFrom(type))

            {

                return true;

            }



            return false;

        }



        internal static bool IsHttpRequestGenericTypeDefinition(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericTypeDefinition &&

                HttpRequestMessageGenericType.IsAssignableFrom(type))

            {

                return true;

            }



            return false;

        }



        internal static bool IsHttpResponseGenericTypeDefinition(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericTypeDefinition &&

                HttpResponseMessageGenericType.IsAssignableFrom(type))

            {

                return true;

            }



            return false;

        }



        internal static bool IsHttpRequestOrContentGenericTypeDefinition(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericTypeDefinition)

            {

                if (HttpRequestMessageGenericType.IsAssignableFrom(type) ||

                    ObjectContentGenericType.IsAssignableFrom(type))

                {

                    return true;

                }

            }



            return false;

        }



        internal static bool IsHttpResponseOrContentGenericTypeDefinition(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericTypeDefinition)

            {

                if (HttpResponseMessageGenericType.IsAssignableFrom(type) ||

                    ObjectContentGenericType.IsAssignableFrom(type))

                {

                    return true;

                }

            }



            return false;

        }



        internal static bool IsHttpGenericTypeDefinition(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericTypeDefinition)

            {

                if (HttpRequestMessageGenericType.IsAssignableFrom(type) ||

                    HttpResponseMessageGenericType.IsAssignableFrom(type) ||

                    ObjectContentGenericType.IsAssignableFrom(type))

                {

                    return true;

                }

            }



            return false;

        }



        internal static bool IsJsonValue(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            return JsonValueType.IsAssignableFrom(type);

        }



        internal static Type GetHttpContentInnerTypeOrNull(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericType && !type.IsGenericTypeDefinition)

            {

                Type genericTypeDefinition = type.GetGenericTypeDefinition();

                if (IsHttpContentGenericTypeDefinition(genericTypeDefinition))

                {

                    Type[] typeArgs = type.GetGenericArguments();

                    if (typeArgs.Length > 1)

                    {

                        throw Fx.Exception.AsError(

                            new InvalidOperationException(

                                SR.MultipleTypeParametersForHttpContentType(type.Name)));

                    }



                    return typeArgs[0];

                }

            }



            return null;

        }



        internal static Type GetHttpRequestInnerTypeOrNull(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericType && !type.IsGenericTypeDefinition)

            {

                Type genericTypeDefinition = type.GetGenericTypeDefinition();

                if (IsHttpRequestGenericTypeDefinition(genericTypeDefinition))

                {

                    Type[] typeArgs = type.GetGenericArguments();

                    if (typeArgs.Length > 1)

                    {

                        throw Fx.Exception.AsError(

                            new InvalidOperationException(

                                SR.MultipleTypeParametersForHttpContentType(type.Name)));

                    }



                    return typeArgs[0];

                }

            }



            return null;

        }



        internal static Type GetHttpResponseInnerTypeOrNull(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericType && !type.IsGenericTypeDefinition)

            {

                Type genericTypeDefinition = type.GetGenericTypeDefinition();

                if (IsHttpResponseGenericTypeDefinition(genericTypeDefinition))

                {

                    Type[] typeArgs = type.GetGenericArguments();

                    if (typeArgs.Length > 1)

                    {

                        throw Fx.Exception.AsError(

                            new InvalidOperationException(

                                SR.MultipleTypeParametersForHttpContentType(type.Name)));

                    }



                    return typeArgs[0];

                }

            }



            return null;

        }



        internal static Type GetHttpRequestOrContentInnerTypeOrNull(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericType && !type.IsGenericTypeDefinition)

            {

                Type genericTypeDefinition = type.GetGenericTypeDefinition();

                if (IsHttpRequestOrContentGenericTypeDefinition(genericTypeDefinition))

                {

                    Type[] typeArgs = type.GetGenericArguments();

                    if (typeArgs.Length > 1)

                    {

                        throw Fx.Exception.AsError(

                            new InvalidOperationException(

                                SR.MultipleTypeParametersForHttpContentType(type.Name)));

                    }



                    return typeArgs[0];

                }

            }



            return null;

        }



        internal static Type GetHttpResponseOrContentInnerTypeOrNull(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericType && !type.IsGenericTypeDefinition)

            {

                Type genericTypeDefinition = type.GetGenericTypeDefinition();

                if (IsHttpResponseOrContentGenericTypeDefinition(genericTypeDefinition))

                {

                    Type[] typeArgs = type.GetGenericArguments();

                    if (typeArgs.Length > 1)

                    {

                        throw Fx.Exception.AsError(

                            new InvalidOperationException(

                                SR.MultipleTypeParametersForHttpContentType(type.Name)));

                    }



                    return typeArgs[0];

                }

            }



            return null;

        }



        internal static Type GetHttpInnerTypeOrNull(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            if (type.IsGenericType && !type.IsGenericTypeDefinition)

            {

                Type genericTypeDefinition = type.GetGenericTypeDefinition();

                if (IsHttpGenericTypeDefinition(genericTypeDefinition))

                {

                    Type[] typeArgs = type.GetGenericArguments();

                    if (typeArgs.Length > 1)

                    {

                        // TODO: Throw exception because there is more than one type argument so we

                        //  don't know which argument is the body content.

                        throw new InvalidOperationException("Exception Message");

                    }



                    return typeArgs[0];

                }

            }



            return null;

        }



        internal static Type MakeHttpRequestMessageOf(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            Type[] typeParams = new Type[] { type };

            return HttpTypeHelper.HttpRequestMessageGenericType.MakeGenericType(typeParams);

        }



        internal static Type MakeHttpResponseMessageOf(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            Type[] typeParams = new Type[] { type };

            return HttpTypeHelper.HttpResponseMessageGenericType.MakeGenericType(typeParams);

        }



        internal static Type MakeObjectContentOf(Type type)

        {

            Fx.Assert(type != null, "The 'type' parameter should not be null.");



            Type[] typeParams = new Type[] { type };

            return HttpTypeHelper.ObjectContentGenericType.MakeGenericType(typeParams);

        }

    }

}