/*
   Copyright (C) 2009 Her Majesty the Queen in Right of Canada (Communications
   Research Center Canada)

   Copyright (C) 2013 Matthias P. Braendli
   http://mpb.li

   Base class for all file and fifo-based inputs.

   */
/*
   This file is part of CRC-DabMux.

   CRC-DabMux is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as
   published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   CRC-DabMux is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with CRC-DabMux.  If not, see <http://www.gnu.org/licenses/>.
   */

#include "inputs/Input.h"

#include <string>
#include <cstdlib>
#include <cstdio>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>

#ifndef _WIN32
#   define O_BINARY 0
#endif

#ifdef HAVE_INPUT_FILE

int InputFile::Open()
{
    fprintf(stderr, "Opening %s\n", m_filename.c_str());
    this->file = open(this->m_filename.c_str(), O_RDONLY | O_BINARY);
    if (this->file == -1) {
        perror(m_filename.c_str());
        return -1;
    }
    return 0;
}

/**
 *  This function replace the read function by trying many times a reading.
 *  It tries to read until all bytes are read. Very useful when reading from a
 *  pipe because sometimes 2 pass is necessary to read all bytes.
 *  @param file     File descriptor.
 *  @param data     Address of the buffer to write data into.
 *  @param size     Number of bytes to read.
 *  @param tries    Max number of tries to read.
 *  @return         Same as read function:
 *                  Nb of bytes read.
 *                  -1 if error.
 */
long InputFile::ReadData(void* data, size_t size, unsigned int tries)
{
    size_t result;
    size_t offset = 0;
    if (size == 0) return 0;
    if (tries == 0) return 0;
    result = read(file, data, size);
    if (result == -1) {
        if (errno == EAGAIN) {
            return ReadData(data, size, tries - 1);
        }
        return -1;
    }
    offset = result;
    size -= offset;
    data = (char*)data + offset;
    result = ReadData(data, size, tries - 1);
    if (result == -1) {
        return -1;
    }
    offset += result;
    return offset;
}


int InputFile::Rewind()
{
    return lseek(this->file, 0, SEEK_SET);
}

int InputFile::Close()
{
    if (this->file != -1) {
        close(this->file);
    }
    return 0;
}

#endif