/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

/**************************************************************************
                                TODO
 **************************************************************************

 *************************************************************************/

#include <sal/config.h>
#include <sal/log.hxx>

#include <rtl/ustrbuf.hxx>
#include <com/sun/star/ucb/OpenMode.hpp>
#include <string.h>
#include <rtl/uri.hxx>
#include <o3tl/safeint.hxx>

#include "ftpurl.hxx"
#include "ftpcontentprovider.hxx"
#include "ftpcfunc.hxx"
#include "ftpcontainer.hxx"
#include <memory>

using namespace ftp;
using namespace com::sun::star::ucb;
using namespace com::sun::star::uno;

namespace {

OUString encodePathSegment(OUString const & decoded) {
    return rtl::Uri::encode(
        decoded, rtl_UriCharClassPchar, rtl_UriEncodeIgnoreEscapes,
        RTL_TEXTENCODING_UTF8);
}

OUString decodePathSegment(OUString const & encoded) {
    return rtl::Uri::decode(
        encoded, rtl_UriDecodeWithCharset, RTL_TEXTENCODING_UTF8);
}

}

MemoryContainer::MemoryContainer()
    : m_nLen(0),
      m_nWritePos(0),
      m_pBuffer(nullptr)
{
}

MemoryContainer::~MemoryContainer()
{
    std::free(m_pBuffer);
}


int MemoryContainer::append(
    const void* pBuffer,
    size_t size,
    size_t nmemb
) noexcept
{
    sal_uInt32 nLen = size*nmemb;
    sal_uInt32 tmp(nLen + m_nWritePos);

    if(m_nLen < tmp) { // enlarge in steps of multiples of 1K
        do {
            m_nLen+=1024;
        } while(m_nLen < tmp);

        if (auto p = std::realloc(m_pBuffer, m_nLen))
            m_pBuffer = p;
        else
            return 0;
    }

    memcpy(static_cast<sal_Int8*>(m_pBuffer)+m_nWritePos,
                   pBuffer,nLen);
    m_nWritePos = tmp;
    return nLen;
}


extern "C" {

    int memory_write(void *buffer,size_t size,size_t nmemb,void *stream)
    {
        MemoryContainer *_stream =
            static_cast<MemoryContainer*>(stream);

        if(!_stream)
            return 0;

        return _stream->append(buffer,size,nmemb);
    }

}


FTPURL::FTPURL(const FTPURL& r)
    : m_pFCP(r.m_pFCP),
      m_aUsername(r.m_aUsername),
      m_bShowPassword(r.m_bShowPassword),
      m_aHost(r.m_aHost),
      m_aPort(r.m_aPort),
      m_aPathSegmentVec(r.m_aPathSegmentVec)

{
}


FTPURL::FTPURL(const OUString& url,
               FTPContentProvider* pFCP)
    : m_pFCP(pFCP),
      m_aUsername("anonymous"),
      m_bShowPassword(false),
      m_aPort("21")
{
    parse(url);  // can reset m_bShowPassword
}


FTPURL::~FTPURL()
{
}


void FTPURL::parse(const OUString& url)
{
    OUString aPassword, urlRest;

    if(url.getLength() < 6 || !url.startsWithIgnoreAsciiCase("ftp://", &urlRest))
        throw malformed_exception();

    // determine "username:password@host:port"
    OUString aExpr;
    sal_Int32 nIdx = urlRest.indexOf('/');
    if (nIdx == -1)
    {
        aExpr = urlRest;
        urlRest = "";
    }
    else
    {
        aExpr = urlRest.copy(0, nIdx);
        urlRest = urlRest.copy(nIdx + 1);
    }

    sal_Int32 l = aExpr.indexOf('@');
    m_aHost = aExpr.copy(1+l);

    if(l != -1) {
        // Now username and password.
        aExpr = aExpr.copy(0,l);
        l = aExpr.indexOf(':');
        if(l != -1) {
            aPassword = aExpr.copy(1+l);
            if(!aPassword.isEmpty())
                m_bShowPassword = true;
        }
        if(l > 0)
            // Overwritten only if the username is not empty.
            m_aUsername = aExpr.copy(0,l);
        else if(!aExpr.isEmpty())
            m_aUsername = aExpr;
    }

    l = m_aHost.lastIndexOf(':');
    sal_Int32 ipv6Back = m_aHost.lastIndexOf(']');
    if((ipv6Back == -1 && l != -1) // not ipv6, but a port
       ||
       (ipv6Back != -1 && 1+ipv6Back == l) // ipv6, and a port
    )
    {
        if(1+l<m_aHost.getLength())
            m_aPort = m_aHost.copy(1+l);
        m_aHost = m_aHost.copy(0,l);
    }

    // now determine the pathsegments ...
    while(!urlRest.isEmpty())
    {
        nIdx = urlRest.indexOf('/');
        OUString segment;
        if(nIdx == -1)
        {
            segment = urlRest;
            urlRest = "";
        }
        else
        {
            segment = urlRest.copy(0, nIdx);
            urlRest = urlRest.copy(nIdx + 1);
        }
        if( segment == ".." && !m_aPathSegmentVec.empty() && m_aPathSegmentVec.back() != ".." )
            m_aPathSegmentVec.pop_back();
        else if( segment == "." )
            ; // Ignore
        else
            // This is a legal name.
            m_aPathSegmentVec.push_back( segment );
    }

    if(m_bShowPassword)
        m_pFCP->setHost(m_aHost,
                        m_aPort,
                        m_aUsername,
                        aPassword,
                        ""/*aAccount*/);

    // now check for something like ";type=i" at end of url
    if(!m_aPathSegmentVec.empty())
    {
        l = m_aPathSegmentVec.back().indexOf(';');
        if (l != -1)
        {
            m_aType = m_aPathSegmentVec.back().copy(l);
            m_aPathSegmentVec.back() = m_aPathSegmentVec.back().copy(0,l);
        }
    }
}


OUString FTPURL::ident(bool withslash,bool internal) const
{
    // rebuild the url as one without ellipses,
    // and more important, as one without username and
    // password. ( These are set together with the command. )

    OUStringBuffer bff;
    bff.append("ftp://");

    if( m_aUsername != "anonymous" ) {
        bff.append(m_aUsername);

        OUString aPassword,aAccount;
        m_pFCP->forHost(m_aHost,
                        m_aPort,
                        m_aUsername,
                        aPassword,
                        aAccount);

        if((m_bShowPassword || internal) &&
           !aPassword.isEmpty() )
            bff.append(':')
                .append(aPassword);

        bff.append('@');
    }
    bff.append(m_aHost);

    if( m_aPort != "21" )
        bff.append(':')
            .append(m_aPort)
            .append('/');
    else
        bff.append('/');

    for(size_t i = 0; i < m_aPathSegmentVec.size(); ++i)
        if(i == 0)
            bff.append(m_aPathSegmentVec[i]);
        else
            bff.append('/').append(m_aPathSegmentVec[i]);
    if(withslash)
        if(!bff.isEmpty() && bff[bff.getLength()-1] != '/')
            bff.append('/');

    bff.append(m_aType);
    return bff.makeStringAndClear();
}


OUString FTPURL::parent(bool internal) const
{
    OUStringBuffer bff;

    bff.append("ftp://");

    if( m_aUsername != "anonymous" ) {
        bff.append(m_aUsername);

        OUString aPassword,aAccount;
        m_pFCP->forHost(m_aHost,
                        m_aPort,
                        m_aUsername,
                        aPassword,
                        aAccount);

        if((internal || m_bShowPassword) && !aPassword.isEmpty())
            bff.append(':')
                .append(aPassword);

        bff.append('@');
    }

    bff.append(m_aHost);

    if( m_aPort != "21" )
        bff.append(':')
            .append(m_aPort)
            .append('/');
    else
        bff.append('/');

    OUString last;

    for(size_t i = 0; i < m_aPathSegmentVec.size(); ++i)
        if(1+i == m_aPathSegmentVec.size())
            last = m_aPathSegmentVec[i];
        else if(i == 0)
            bff.append(m_aPathSegmentVec[i]);
        else
            bff.append('/').append(m_aPathSegmentVec[i]);

    if(last.isEmpty())
        bff.append("..");
    else if ( last == ".." )
        bff.append(last + "/..");

    bff.append(m_aType);
    return bff.makeStringAndClear();
}


void FTPURL::child(const OUString& title)
{
    m_aPathSegmentVec.push_back(encodePathSegment(title));
}


OUString FTPURL::child() const
{
    return
        !m_aPathSegmentVec.empty() ?
        decodePathSegment(m_aPathSegmentVec.back()) : OUString();
}


/** Listing of a directory.
 */

namespace ftp {

    namespace {

    enum OS {
        FTP_DOS,FTP_UNIX,FTP_VMS,FTP_UNKNOWN
    };

    }

}


#define SET_CONTROL_CONTAINER \
    MemoryContainer control;                                      \
    (void)curl_easy_setopt(curl,                                  \
                     CURLOPT_HEADERFUNCTION,                      \
                     memory_write);                               \
    (void)curl_easy_setopt(curl,                                  \
                     CURLOPT_WRITEHEADER,                         \
                     &control)


static void setCurlUrl(CURL* curl, OUString const & url)
{
    OString urlParAscii(url.getStr(),
                             url.getLength(),
                             RTL_TEXTENCODING_UTF8);
    (void)curl_easy_setopt(curl,
                     CURLOPT_URL,
                     urlParAscii.getStr());
};

oslFileHandle FTPURL::open()
{
    if(m_aPathSegmentVec.empty())
        throw curl_exception(CURLE_FTP_COULDNT_RETR_FILE);

    CURL *curl = m_pFCP->handle();

    SET_CONTROL_CONTAINER;
    OUString url(ident(false,true));
    setCurlUrl(curl, url);

    oslFileHandle res( nullptr );
    if ( osl_createTempFile( nullptr, &res, nullptr ) == osl_File_E_None )
    {
        (void)curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,file_write);
        (void)curl_easy_setopt(curl,CURLOPT_WRITEDATA,res);

        (void)curl_easy_setopt(curl,CURLOPT_POSTQUOTE,0);
        CURLcode err = curl_easy_perform(curl);

        if(err == CURLE_OK)
        {
            oslFileError rc = osl_setFilePos( res, osl_Pos_Absolut, 0 );
            SAL_WARN_IF(rc != osl_File_E_None, "ucb.ucp.ftp",
                    "osl_setFilePos failed");
        }
        else {
            osl_closeFile(res);
            res = nullptr;
            throw curl_exception(err);
        }
    }

    return res;
}


std::vector<FTPDirentry> FTPURL::list(
    sal_Int16 nMode
) const
{
    CURL *curl = m_pFCP->handle();

    SET_CONTROL_CONTAINER;
    (void)curl_easy_setopt(curl,CURLOPT_NOBODY,false);
    MemoryContainer data;
    (void)curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,memory_write);
    (void)curl_easy_setopt(curl,CURLOPT_WRITEDATA,&data);

    OUString url(ident(true,true));
    setCurlUrl(curl, url);
    (void)curl_easy_setopt(curl,CURLOPT_POSTQUOTE,0);

    CURLcode err = curl_easy_perform(curl);
    if(err != CURLE_OK)
        throw curl_exception(err);

    // now evaluate the error messages

    sal_uInt32 len = data.m_nWritePos;
    char* fwd = static_cast<char*>(data.m_pBuffer);
    char *p1, *p2;
    p1 = p2 = fwd;

    OS osKind(FTP_UNKNOWN);
    std::vector<FTPDirentry> resvec;
    FTPDirentry aDirEntry;
    // ensure slash at the end
    OUString viewurl(ident(true,false));

    while(true) {
        while(o3tl::make_unsigned(p2-fwd) < len && *p2 != '\n') ++p2;
        if(o3tl::make_unsigned(p2-fwd) == len) break;

        *p2 = 0;
        switch(osKind) {
            // While FTP knows the 'system'-command,
            // which returns the operating system type,
            // this is not usable here: There are Windows-server
            // formatting the output like UNIX-ls command.
        case FTP_DOS:
            FTPDirectoryParser::parseDOS(aDirEntry,p1);
            break;
        case FTP_UNIX:
            FTPDirectoryParser::parseUNIX(aDirEntry,p1);
            break;
        case FTP_VMS:
            FTPDirectoryParser::parseVMS(aDirEntry,p1);
            break;
        default:
            if(FTPDirectoryParser::parseUNIX(aDirEntry,p1))
                osKind = FTP_UNIX;
            else if(FTPDirectoryParser::parseDOS(aDirEntry,p1))
                osKind = FTP_DOS;
            else if(FTPDirectoryParser::parseVMS(aDirEntry,p1))
                osKind = FTP_VMS;
        }
        aDirEntry.m_aName = aDirEntry.m_aName.trim();
        if( osKind != int(FTP_UNKNOWN) && aDirEntry.m_aName != ".." && aDirEntry.m_aName != "." ) {
            aDirEntry.m_aURL = viewurl + encodePathSegment(aDirEntry.m_aName);

            bool isDir = (aDirEntry.m_nMode & INETCOREFTP_FILEMODE_ISDIR) == INETCOREFTP_FILEMODE_ISDIR;
            switch(nMode) {
                case OpenMode::DOCUMENTS:
                    if(!isDir)
                        resvec.push_back(aDirEntry);
                    break;
                case OpenMode::FOLDERS:
                    if(isDir)
                        resvec.push_back(aDirEntry);
                    break;
                default:
                    resvec.push_back(aDirEntry);
            };
        }
        aDirEntry.clear();
        p1 = p2 + 1;
    }

    return resvec;
}


OUString FTPURL::net_title() const
{
    CURL *curl = m_pFCP->handle();

    SET_CONTROL_CONTAINER;
    (void)curl_easy_setopt(curl,CURLOPT_NOBODY,true);       // no data => no transfer
    struct curl_slist *slist = nullptr;
    // post request
    slist = curl_slist_append(slist,"PWD");
    (void)curl_easy_setopt(curl,CURLOPT_POSTQUOTE,slist);

    bool try_more(true);
    CURLcode err;
    OUString aNetTitle;

    while(true) {
        OUString url(ident(false,true));

        if(try_more && !url.endsWith("/"))
            url += "/";  // add end-slash
        else if(!try_more && url.endsWith("/"))
            url = url.copy(0,url.getLength()-1);         // remove end-slash

        setCurlUrl(curl, url);
        err = curl_easy_perform(curl);

        if(err == CURLE_OK) {       // get the title from the server
            char* fwd = static_cast<char*>(control.m_pBuffer);
            sal_uInt32 len = control.m_nWritePos;

            aNetTitle = OUString(fwd,len,RTL_TEXTENCODING_UTF8);
            // the buffer now contains the name of the file;
            // analyze the output:
            // Format of current working directory:
            // 257 "/bla/bla" is current directory
            sal_Int32 index1 = aNetTitle.lastIndexOf("257");
            index1 = aNetTitle.indexOf('"', index1 + std::strlen("257")) + 1;
            sal_Int32 index2 = aNetTitle.indexOf('"', index1);
            aNetTitle = index2 > index1
                ? aNetTitle.copy(index1, index2 - index1) : OUString();
            if( aNetTitle != "/" ) {
                index1 = aNetTitle.lastIndexOf('/');
                aNetTitle = aNetTitle.copy(1+index1);
            }
            try_more = false;
        } else if(err == CURLE_BAD_PASSWORD_ENTERED)
            // the client should retry after getting the correct
            // username + password
            throw curl_exception(err);
#if LIBCURL_VERSION_NUM>=0x070d01 /* 7.13.1 */
        else if(err == CURLE_LOGIN_DENIED)
            // the client should retry after getting the correct
            // username + password
            throw curl_exception(err);
#endif
        else if(try_more && err == CURLE_FTP_ACCESS_DENIED) {
            // We were either denied access when trying to login to
            //  an FTP server or when trying to change working directory
            //  to the one given in the URL.
            if(!m_aPathSegmentVec.empty())
                // determine title from URL
                aNetTitle = decodePathSegment(m_aPathSegmentVec.back());
            else
                // must be root
                aNetTitle = "/";
            try_more = false;
        }

        if(try_more)
            try_more = false;
        else
            break;
    }

    curl_slist_free_all(slist);
    return aNetTitle;
}


FTPDirentry FTPURL::direntry() const
{
    OUString nettitle = net_title();
    FTPDirentry aDirentry;

    aDirentry.m_aName = nettitle;                 // init aDirentry
    if( nettitle == "/" || nettitle == ".." )
        aDirentry.m_nMode = INETCOREFTP_FILEMODE_ISDIR;
    else
        aDirentry.m_nMode = INETCOREFTP_FILEMODE_UNKNOWN;

    aDirentry.m_nSize = 0;

    if( nettitle != "/" ) {
        // try to open the parent directory
        FTPURL aURL(parent(),m_pFCP);

        std::vector<FTPDirentry> aList = aURL.list(OpenMode::ALL);

        for(const FTPDirentry & d : aList) {
            if(d.m_aName == nettitle) { // the relevant file is found
                aDirentry = d;
                break;
            }
        }
    }
    return aDirentry;
}


extern "C" {

    static size_t memory_read(void *ptr,size_t size,size_t nmemb,void *stream)
    {
        sal_Int32 nRequested = sal_Int32(size*nmemb);
        CurlInput *curlInput = static_cast<CurlInput*>(stream);
        if(curlInput)
            return size_t(curlInput->read(static_cast<sal_Int8*>(ptr),nRequested));
        else
            return 0;
    }

}


void FTPURL::insert(bool replaceExisting,void* stream) const
{
    if(!replaceExisting) {
//          FTPDirentry aDirentry(direntry());
//          if(aDirentry.m_nMode == INETCOREFTP_FILEMODE_UNKNOWN)
        // throw curl_exception(FILE_EXIST_DURING_INSERT);
        throw curl_exception(FILE_MIGHT_EXIST_DURING_INSERT);
    } // else
    // overwrite is default in libcurl

    CURL *curl = m_pFCP->handle();

    SET_CONTROL_CONTAINER;
    (void)curl_easy_setopt(curl,CURLOPT_NOBODY,false);    // no data => no transfer
    (void)curl_easy_setopt(curl,CURLOPT_POSTQUOTE,0);
    (void)curl_easy_setopt(curl,CURLOPT_QUOTE,0);
    (void)curl_easy_setopt(curl,CURLOPT_READFUNCTION,memory_read);
    (void)curl_easy_setopt(curl,CURLOPT_READDATA,stream);
    (void)curl_easy_setopt(curl, CURLOPT_UPLOAD,1);

    OUString url(ident(false,true));
    setCurlUrl(curl, url);

    CURLcode err = curl_easy_perform(curl);
    (void)curl_easy_setopt(curl, CURLOPT_UPLOAD,false);

    if(err != CURLE_OK)
        throw curl_exception(err);
}


void FTPURL::mkdir(bool ReplaceExisting) const
{
    OString title;
    if(!m_aPathSegmentVec.empty()) {
        OUString titleOU = m_aPathSegmentVec.back();
        titleOU = decodePathSegment(titleOU);
        title = OString(titleOU.getStr(),
                            titleOU.getLength(),
                            RTL_TEXTENCODING_UTF8);
    }
    else
        // will give an error
        title = OString("/");

    OString aDel = "del " + title;
    OString mkd = "mkd " + title;

    struct curl_slist *slist = nullptr;

    FTPDirentry aDirentry(direntry());
    if(!ReplaceExisting) {
//          if(aDirentry.m_nMode != INETCOREFTP_FILEMODE_UNKNOWN)
//              throw curl_exception(FOLDER_EXIST_DURING_INSERT);
        throw curl_exception(FOLDER_MIGHT_EXIST_DURING_INSERT);
    } else if(aDirentry.m_nMode != INETCOREFTP_FILEMODE_UNKNOWN)
        slist = curl_slist_append(slist,aDel.getStr());

    slist = curl_slist_append(slist,mkd.getStr());

    CURL *curl = m_pFCP->handle();
    SET_CONTROL_CONTAINER;
    (void)curl_easy_setopt(curl,CURLOPT_NOBODY,true);       // no data => no transfer
    (void)curl_easy_setopt(curl,CURLOPT_QUOTE,0);

    // post request
    (void)curl_easy_setopt(curl,CURLOPT_POSTQUOTE,slist);

    OUString url(parent(true));
    if(!url.endsWith("/"))
        url += "/";
    setCurlUrl(curl, url);

    CURLcode err = curl_easy_perform(curl);
    curl_slist_free_all(slist);
    if(err != CURLE_OK)
        throw curl_exception(err);
}


OUString FTPURL::ren(const OUString& NewTitle)
{
    CURL *curl = m_pFCP->handle();

    // post request
    OUString OldTitle = net_title();
    OString renamefrom = "RNFR " +
        OString(OldTitle.getStr(),
                     OldTitle.getLength(),
                     RTL_TEXTENCODING_UTF8);

    OString renameto = "RNTO " +
        OString(NewTitle.getStr(),
                     NewTitle.getLength(),
                     RTL_TEXTENCODING_UTF8);

    struct curl_slist *slist = nullptr;
    slist = curl_slist_append(slist,renamefrom.getStr());
    slist = curl_slist_append(slist,renameto.getStr());
    (void)curl_easy_setopt(curl,CURLOPT_POSTQUOTE,slist);

    SET_CONTROL_CONTAINER;
    (void)curl_easy_setopt(curl,CURLOPT_NOBODY,true);       // no data => no transfer
    (void)curl_easy_setopt(curl,CURLOPT_QUOTE,0);

    OUString url(parent(true));
    if(!url.endsWith("/"))
        url += "/";
    setCurlUrl(curl, url);

    CURLcode err = curl_easy_perform(curl);
    curl_slist_free_all(slist);
    if(err != CURLE_OK)
        throw curl_exception(err);
    else if( !m_aPathSegmentVec.empty() && m_aPathSegmentVec.back() != ".." )
        m_aPathSegmentVec.back() = encodePathSegment(NewTitle);
    return OldTitle;
}


void FTPURL::del() const
{
    FTPDirentry aDirentry(direntry());

    OString dele(aDirentry.m_aName.getStr(),
                      aDirentry.m_aName.getLength(),
                      RTL_TEXTENCODING_UTF8);

    if(aDirentry.m_nMode & INETCOREFTP_FILEMODE_ISDIR) {
        std::vector<FTPDirentry> vec = list(sal_Int16(OpenMode::ALL));
        for(const FTPDirentry & i : vec)
        {
            try {
                FTPURL url(i.m_aURL,m_pFCP);
                url.del();
            } catch(const curl_exception&) {
            }
        }
        dele = "RMD " + dele;
    }
    else if(aDirentry.m_nMode != INETCOREFTP_FILEMODE_UNKNOWN)
        dele = "DELE " + dele;
    else
        return;

    // post request
    CURL *curl = m_pFCP->handle();
    struct curl_slist *slist = nullptr;
    slist = curl_slist_append(slist,dele.getStr());
    (void)curl_easy_setopt(curl,CURLOPT_POSTQUOTE,slist);

    SET_CONTROL_CONTAINER;
    (void)curl_easy_setopt(curl,CURLOPT_NOBODY,true);       // no data => no transfer
    (void)curl_easy_setopt(curl,CURLOPT_QUOTE,0);

    OUString url(parent(true));
    if(!url.endsWith("/"))
        url += "/";
    setCurlUrl(curl, url);

    CURLcode err = curl_easy_perform(curl);
    curl_slist_free_all(slist);
    if(err != CURLE_OK)
        throw curl_exception(err);
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
