/* $Id: RTCRestClientApiBase.cpp 74052 2018-09-03 20:09:45Z vboxsync $ */
/** @file
 * IPRT - C++ REST, RTCRestClientApiBase implementation.
 */

/*
 * Copyright (C) 2018 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
 * VirtualBox OSE distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 */


/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#define LOG_GROUP RTLOGGROUP_REST
#include <iprt/cpp/restclient.h>

#include <iprt/err.h>
#include <iprt/http.h>
#include <iprt/log.h>


/**
 * The destructor.
 */
RTCRestClientApiBase::~RTCRestClientApiBase()
{
    if (m_hHttp != NIL_RTHTTP)
    {
        int rc = RTHttpDestroy(m_hHttp);
        AssertRC(rc);
        m_hHttp = NIL_RTHTTP;
    }
}


int RTCRestClientApiBase::reinitHttpInstance()
{
    if (m_hHttp != NIL_RTHTTP)
        return RTHttpReset(m_hHttp);

    int rc = RTHttpCreate(&m_hHttp);
    if (RT_FAILURE(rc))
        m_hHttp = NIL_RTHTTP;
    return rc;
}


int RTCRestClientApiBase::xmitReady(RTHTTP a_hHttp, RTCString const &a_rStrFullUrl, RTHTTPMETHOD a_enmHttpMethod,
                                    RTCString const &a_rStrXmitBody, uint32_t a_fFlags)
{
    RT_NOREF(a_hHttp, a_rStrFullUrl, a_enmHttpMethod, a_rStrXmitBody, a_fFlags);
    return VINF_SUCCESS;
}


int RTCRestClientApiBase::doCall(RTCRestClientRequestBase const &a_rRequest, RTHTTPMETHOD a_enmHttpMethod,
                                 RTCRestClientResponseBase *a_pResponse, const char *a_pszMethod, uint32_t a_fFlags)
{
    LogFlow(("doCall: %s %s\n", a_pszMethod, RTHttpMethodName(a_enmHttpMethod)));


    /*
     * Reset the response object (allowing reuse of such) and check the request
     * object for assignment errors.
     */
    int    rc;
    RTHTTP hHttp = NIL_RTHTTP;

    a_pResponse->reset();
    if (!a_rRequest.hasAssignmentErrors())
    {
        /*
         * Initialize the HTTP instance.
         */
        rc = reinitHttpInstance();
        if (RT_SUCCESS(rc))
        {
            hHttp = m_hHttp;
            Assert(hHttp != NIL_RTHTTP);

            /*
             * Prepare the response side.  This may install output callbacks and
             * indicate this by clearing the ppvBody/ppvHdr variables.
             */
            size_t   cbHdrs  = 0;
            void    *pvHdrs  = NULL;
            void   **ppvHdrs = &pvHdrs;

            size_t   cbBody  = 0;
            void    *pvBody  = NULL;
            void   **ppvBody = &pvBody;

            rc = a_pResponse->receivePrepare(hHttp, &ppvBody, &ppvHdrs);
            if (RT_SUCCESS(rc))
            {
                /*
                 * Prepare the request for the transmission.
                 */
                RTCString strExtraPath;
                RTCString strQuery;
                RTCString strXmitBody;
                rc = a_rRequest.xmitPrepare(&strExtraPath, &strQuery, hHttp, &strXmitBody);
                if (RT_SUCCESS(rc))
                {
                    /*
                     * Construct the full URL.
                     */
                    RTCString strFullUrl;
                    rc = strFullUrl.assignNoThrow(m_strBasePath);
                    if (strExtraPath.isNotEmpty())
                    {
                        if (!strExtraPath.startsWith("/") && !strFullUrl.endsWith("/") && RT_SUCCESS(rc))
                            rc = strFullUrl.appendNoThrow('/');
                        if (RT_SUCCESS(rc))
                            rc = strFullUrl.appendNoThrow(strExtraPath);
                        strExtraPath.setNull();
                    }
                    if (strQuery.isNotEmpty())
                    {
                        Assert(strQuery.startsWith("?"));
                        rc = strFullUrl.appendNoThrow(strQuery);
                        strQuery.setNull();
                    }
                    if (RT_SUCCESS(rc))
                    {
                        rc = xmitReady(hHttp, strFullUrl, a_enmHttpMethod, strXmitBody, a_fFlags);
                        if (RT_SUCCESS(rc))
                        {
                            /*
                             * Perform HTTP request.
                             */
                            uint32_t uHttpStatus = 0;
                            rc = RTHttpPerform(hHttp, strFullUrl.c_str(), a_enmHttpMethod,
                                               strXmitBody.c_str(), strXmitBody.length(),
                                               &uHttpStatus, ppvHdrs, &cbHdrs, ppvBody, &cbBody);
                            if (RT_SUCCESS(rc))
                            {
                                a_rRequest.xmitComplete(uHttpStatus, hHttp);

                                /*
                                 * Do response processing.
                                 */
                                a_pResponse->receiveComplete(uHttpStatus, hHttp);
                                if (pvHdrs)
                                {
                                    a_pResponse->consumeHeaders((const char *)pvHdrs, cbHdrs);
                                    RTHttpFreeResponse(pvHdrs);
                                }
                                if (pvBody)
                                {
                                    a_pResponse->consumeBody((const char *)pvBody, cbBody);
                                    RTHttpFreeResponse(pvBody);
                                }
                                a_pResponse->receiveFinal();

                                return a_pResponse->getStatus();
                            }
                        }
                    }
                }
                a_rRequest.xmitComplete(rc, hHttp);
            }
        }
    }
    else
        rc = VERR_NO_MEMORY;

    a_pResponse->receiveComplete(rc, hHttp);
    RT_NOREF_PV(a_pszMethod);

    return a_pResponse->getStatus();
}