/*
   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"

#ifdef HAVE_FORMAT_MPEG
#ifdef HAVE_INPUT_FILE

#include "mpeg.h"
#include "TcpLog.h"

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

#ifndef _WIN32
#   define O_BINARY 0
#endif

extern TcpLog etiLog;

#define MPEG_FREQUENCY      -2
#define MPEG_PADDING        -3
#define MPEG_COPYRIGHT      -4
#define MPEG_ORIGINAL       -5
#define MPEG_EMPHASIS       -6

int checkDabMpegFrame(void* data)
{
    mpegHeader* header = (mpegHeader*)data;
    unsigned long* headerData = (unsigned long*)data;
    if ((*headerData & 0x0f0ffcff) == 0x0004fcff) return 0;
    if ((*headerData & 0x0f0ffcff) == 0x0004f4ff) return 0;
    if (getMpegFrequency(header) != 48000) {
        if (getMpegFrequency(header) != 24000) {
            return MPEG_FREQUENCY;
        }
    }
    if (header->padding != 0) {
        return MPEG_PADDING;
    }
    if (header->copyright != 0) {
        return MPEG_COPYRIGHT;
    }
    if (header->original != 0) {
        return MPEG_ORIGINAL;
    }
    if (header->emphasis != 0) {
        return MPEG_EMPHASIS;
    }
    return -1;
}

int InputMpegFile::ReadFrame(void* buffer, int size)
{
    int result;
    bool rewind = false;
READ_SUBCHANNEL:
    if (this->parity) {
        result = readData(this->file, buffer, size, 2);
        this->parity = false;
        return 0;
    }
    else {
        result = readMpegHeader(this->file, buffer, size);
        if (result > 0) {
            result = readMpegFrame(this->file, buffer, size);
            if (result < 0 && getMpegFrequency(buffer) == 24000) {
                this->parity = true;
                result = size;
            }
        }
    }

    switch (result) {
        case MPEG_BUFFER_UNDERFLOW:
            etiLog.print(TcpLog::WARNING, "data underflow -> frame muted\n");
            goto MUTE_SUBCHANNEL;
        case MPEG_BUFFER_OVERFLOW:
            etiLog.print(TcpLog::WARNING, "bitrate too high -> frame muted\n");
            goto MUTE_SUBCHANNEL;
        case MPEG_FILE_EMPTY:
            if (rewind) {
                etiLog.print(TcpLog::ERR, "file rewinded and still empty "
                        "-> frame muted\n");
                goto MUTE_SUBCHANNEL;
            } else {
                rewind = true;
                etiLog.print(TcpLog::NOTICE, "reach end of file -> rewinding\n");
                lseek(this->file, 0, SEEK_SET);
                goto READ_SUBCHANNEL;
            }
        case MPEG_FILE_ERROR:
            etiLog.print(TcpLog::CRIT, "can't read file (%i) -> frame muted\n", errno);
            perror("");
            goto MUTE_SUBCHANNEL;
        case MPEG_SYNC_NOT_FOUND:
            etiLog.print(TcpLog::CRIT, "mpeg sync not found, maybe is not a valid file "
                    "-> frame muted\n");
            goto MUTE_SUBCHANNEL;
        case MPEG_INVALID_FRAME:
            etiLog.print(TcpLog::CRIT, "file is not a valid mpeg file "
                    "-> frame muted\n");
            goto MUTE_SUBCHANNEL;
        default:
            if (result < 0) {
                etiLog.print(TcpLog::CRIT,
                        "unknown error (code = %i) -> frame muted\n",
                        result);
MUTE_SUBCHANNEL:
                memset(buffer, 0, size);
            }
            else {
                if (result < size) {
                    etiLog.print(TcpLog::WARNING, "bitrate too low from file "
                            "-> frame padded\n");
                    memset((char*)buffer + result, 0, size - result);
                }
                result = checkDabMpegFrame(buffer);
                switch (result) {
                    case MPEG_FREQUENCY:
                        etiLog.print(TcpLog::ERR, "file has a frame with an invalid "
                                "frequency: %i, should be 48000 or 24000\n",
                                getMpegFrequency(buffer));
                        break;
                    case MPEG_PADDING:
                        etiLog.print(TcpLog::WARNING,
                                "file has a frame with padding bit set\n");
                        break;
                    case MPEG_COPYRIGHT:
                        etiLog.print(TcpLog::WARNING,
                                "file has a frame with copyright bit set\n");
                        break;
                    case MPEG_ORIGINAL:
                        etiLog.print(TcpLog::WARNING,
                                "file has a frame with original bit set\n");
                        break;
                    case MPEG_EMPHASIS:
                        etiLog.print(TcpLog::WARNING,
                                "file has a frame with emphasis bits set\n");
                        break;
                    default:
                        if (result < 0) {
                            etiLog.print(TcpLog::CRIT, "mpeg file has an invalid DAB "
                                    "mpeg frame (unknown reason: %i)\n", result);
                        }
                        break;
                }
            }
    }
    return result;
}

#endif
#endif