/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 * 
 *  http://aws.amazon.com/apache2.0
 * 
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

using Amazon.Runtime.Internal.Transform;
using Amazon.Runtime.Internal.Util;
using System;
using System.Collections.Generic;
using System.IO;

namespace Amazon.Runtime
{
    /// <summary>
    /// The interface for a HTTP request factory.
    /// </summary>
    /// <typeparam name="TRequestContent">The type used by the underlying HTTP API to represent the request body.</typeparam>
    public interface IHttpRequestFactory<TRequestContent> : IDisposable
    {
        /// <summary>
        /// Creates an HTTP request for the given URI.
        /// </summary>
        /// <param name="requestUri">The request URI.</param>
        /// <returns>An HTTP request.</returns>
        IHttpRequest<TRequestContent> CreateHttpRequest(Uri requestUri);
    }

    /// <summary>
    /// The interface for an HTTP request that is agnostic of the underlying HTTP API.
    /// </summary>
    /// <typeparam name="TRequestContent">The type used by the underlying HTTP API to represent the HTTP request content.</typeparam>
    public interface IHttpRequest<TRequestContent> : IDisposable
    {
        /// <summary>
        /// The HTTP method or verb.
        /// </summary>
        string Method { get; set; }

        /// <summary>
        /// The request URI.
        /// </summary>
        Uri RequestUri { get; }

        /// <summary>
        /// Configures a request as per the request context.
        /// </summary>
        /// <param name="requestContext">The request context.</param>
        void ConfigureRequest(IRequestContext requestContext);

        /// <summary>
        /// Sets the headers on the request.
        /// </summary>
        /// <param name="headers">A dictionary of header names and values.</param>
        void SetRequestHeaders(IDictionary<string, string> headers);

        /// <summary>
        /// Gets a handle to the request content.
        /// </summary>
        /// <returns>The request content.</returns>
        TRequestContent GetRequestContent();

        /// <summary>
        /// Returns the HTTP response.
        /// </summary>
        /// <returns>The HTTP response.</returns>
        IWebResponseData GetResponse();

        /// <summary>
        /// Writes a stream to the request body.
        /// </summary>
        /// <param name="requestContent">The destination where the content stream is written.</param>
        /// <param name="contentStream">The content stream to be written.</param>
        /// <param name="contentHeaders">HTTP content headers.</param>
        /// <param name="requestContext">The request context.</param>
        void WriteToRequestBody(TRequestContent requestContent, Stream contentStream, IDictionary<string,string> contentHeaders, IRequestContext requestContext);

        /// <summary>
        /// Writes a byte array to the request body.
        /// </summary>
        /// <param name="requestContent">The destination where the content stream is written.</param>
        /// <param name="content">The content stream to be written.</param>
        /// <param name="contentHeaders">HTTP content headers.</param>
        void WriteToRequestBody(TRequestContent requestContent, byte[] content, IDictionary<string,string> contentHeaders);

        /// <summary>
        /// Sets up the progress listeners
        /// </summary>
        /// <param name="originalStream">The content stream</param>
        /// <param name="progressUpdateInterval">The interval at which progress needs to be published</param>
        /// <param name="sender">The objects which is trigerring the progress changes</param>
        /// <param name="callback">The callback which will be invoked when the progress changed event is trigerred</param>
        /// <returns>an <see cref="EventStream"/> object, incase the progress is setup, else returns the original stream</returns>
        Stream SetupProgressListeners(Stream originalStream, long progressUpdateInterval, object sender, EventHandler<StreamTransferProgressArgs> callback);

        /// <summary>
        /// Aborts the HTTP request.
        /// </summary>
        void Abort();

#if AWS_ASYNC_API

        /// <summary>
        /// Gets a handle to the request content.
        /// </summary>
        /// <returns></returns>

        System.Threading.Tasks.Task<TRequestContent> GetRequestContentAsync();
#if BCL45
        System.Threading.Tasks.Task<TRequestContent> GetRequestContentAsync(System.Threading.CancellationToken cancellationToken);
#endif
        /// <summary>
        /// Returns the HTTP response.
        /// </summary>
        /// <param name="cancellationToken">A cancellation token that can be used to cancel the asynchronous operation.</param>
        /// <returns></returns>
        System.Threading.Tasks.Task<IWebResponseData> GetResponseAsync(System.Threading.CancellationToken cancellationToken);
#if BCL45
        System.Threading.Tasks.Task WriteToRequestBodyAsync(TRequestContent requestContent, Stream contentStream, IDictionary<string, string> contentHeaders, IRequestContext requestContext);

        System.Threading.Tasks.Task WriteToRequestBodyAsync(TRequestContent requestContent, byte[] requestData, IDictionary<string, string> headers, System.Threading.CancellationToken cancellationToken);
#endif
#elif AWS_APM_API

        /// <summary>
        /// Initiates the operation to gets a handle to the request content.
        /// </summary>
        /// <param name="callback">The async callback invoked when the operation completes.</param>
        /// <param name="state">The state object to be passed to the async callback.</param>
        /// <returns>IAsyncResult that represents an async operation.</returns>
        IAsyncResult BeginGetRequestContent(AsyncCallback callback, object state);

        /// <summary>
        /// Ends the operation to gets a handle to the request content.
        /// </summary>
        /// <param name="asyncResult">IAsyncResult that represents an async operation.</param>
        /// <returns>The request content.</returns>
        TRequestContent EndGetRequestContent(IAsyncResult asyncResult);

        /// <summary>
        /// Initiates the operation to Returns the HTTP response.
        /// </summary>
        /// <param name="callback">The async callback invoked when the operation completes.</param>
        /// <param name="state">The state object to be passed to the async callback.</param>
        /// <returns>IAsyncResult that represents an async operation.</returns>
        IAsyncResult BeginGetResponse(AsyncCallback callback, object state);

        /// <summary>
        /// Ends the operation to Returns the HTTP response.
        /// </summary>
        /// <param name="asyncResult">IAsyncResult that represents an async operation.</param>
        /// <returns>The HTTP response.</returns>
        IWebResponseData EndGetResponse(IAsyncResult asyncResult);

#endif

    }
}