/**************************************************************
 * 
 * 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
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License 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.
 * 
 *************************************************************/



// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_shell.hxx"

#ifndef INCLUDED_RECENTLY_USED_FILE
#include "recently_used_file.hxx"
#endif
#include <rtl/ustring.hxx>
#include <osl/process.h>
#include <osl/security.hxx>
#include <osl/thread.h>
#include <osl/file.hxx>

#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <unistd.h>

const rtl::OUString RECENTLY_USED_FILE_NAME = rtl::OUString::createFromAscii(".recently-used");
const rtl::OUString SLASH = rtl::OUString::createFromAscii("/");

namespace /* private */ {
    
inline void ensure_final_slash(/*inout*/ rtl::OUString& path)
{    
    if ((path.getLength() > 0) && 
		(SLASH.pData->buffer[0] != path.pData->buffer[path.getLength() - 1]))
        path += SLASH;    
}

} // namespace private

//------------------------------------------------
recently_used_file::recently_used_file() :
    file_(NULL)
{
    osl::Security sec;
    rtl::OUString homedir_url;
    
    if (sec.getHomeDir(homedir_url))
    {
		rtl::OUString homedir;
		osl::FileBase::getSystemPathFromFileURL(homedir_url, homedir);
		
        rtl::OUString rufn = homedir;        
        ensure_final_slash(rufn);            
        rufn += RECENTLY_USED_FILE_NAME;    
        
        rtl::OString tmp =
            rtl::OUStringToOString(rufn, osl_getThreadTextEncoding());
        
        file_ = fopen(tmp.getStr(), "r+");
        
        /* create if not exist */
        if (NULL == file_) {
            mode_t umask_ = umask(S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
            file_ = fopen(tmp.getStr(), "w+");
            umask(umask_);
        }
        
        if (NULL == file_)
            throw "I/O error opening ~/.recently-used";

        if (lockf(fileno(file_), F_LOCK, 0) != 0)
        {
            fclose(file_);
            throw "Cannot lock ~/.recently-used";
        }    
    }
    else
        throw "Cannot determine user home directory";
}

//------------------------------------------------
recently_used_file::~recently_used_file()
{
	lockf(fileno(file_), F_ULOCK, 0);    	
    fclose(file_);		
}

//------------------------------------------------
void recently_used_file::reset() const
{
    rewind(file_);
}

//------------------------------------------------
void recently_used_file::truncate(off_t length)
{
    if (ftruncate(fileno(file_), length) == -1)
        throw "I/O error: ftruncate failed";
}

//------------------------------------------------
size_t recently_used_file::read(char* buffer, size_t size) const
{
	size_t	r = fread(reinterpret_cast<void*>(buffer), sizeof(char), size, file_);
	
	if ((r < size) && ferror(file_))
		throw "I/O error: read failed";
	
    return r;
}

//----------------------------
void recently_used_file::write(const char* buffer, size_t size) const
{	
	if (size != fwrite(reinterpret_cast<const void*>(buffer), sizeof(char), size, file_))
		throw "I/O error: write failed";		
}

//----------------------------
bool recently_used_file::eof() const
{
	return feof(file_);
}