/* -*- 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 .
 */

#include "recently_used_file.hxx"
#include <rtl/ustring.hxx>
#include <sal/log.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 <fcntl.h>
#include <unistd.h>

const char SLASH[] = "/";

namespace {

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

} // namespace private


recently_used_file::recently_used_file() :
    file_(nullptr)
{
    osl::Security sec;
    OUString homedir_url;

    if (!sec.getHomeDir(homedir_url))
        throw "Cannot determine user home directory";

    OUString homedir;
    osl::FileBase::getSystemPathFromFileURL(homedir_url, homedir);

    OUString rufn = homedir;
    ensure_final_slash(rufn);
    rufn += ".recently-used";

    OString tmp =
        OUStringToOString(rufn, osl_getThreadTextEncoding());

    int fd = open(tmp.getStr(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
    if (fd != -1) {
        file_ = fdopen(fd, "w+");
        if (file_ == nullptr) {
            close(fd);
        }
    }

    if (nullptr == file_)
        throw "I/O error opening ~/.recently-used";

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


recently_used_file::~recently_used_file()
{
    int ret = lockf(fileno(file_), F_ULOCK, 0);
    SAL_WARN_IF(ret != 0, "shell", "cannot unlock recently unused file");
    fclose(file_);
}


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


void recently_used_file::truncate()
{
    if (ftruncate(fileno(file_), 0) == -1)
        throw "I/O error: ftruncate failed";
}


size_t recently_used_file::read(char* buffer, size_t size) const
{
    size_t  r = fread(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(buffer, sizeof(char), size, file_))
        throw "I/O error: write failed";
}


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


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