/*
 * This file is part of libsidplayfp, a SID player engine.
 *
 * Copyright 2011-2013 Leandro Nini <drfiemost@users.sourceforge.net>
 * Copyright 2007-2010 Antti Lankila
 * Copyright 2000 Simon White
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include "SidTuneBase.h"

#include <cstring>
#include <climits>
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <iterator>
#include <fstream>

#include "SmartPtr.h"
#include "SidTuneTools.h"
#include "SidTuneInfoImpl.h"
#include "sidendian.h"
#include "sidmemory.h"
#include "stringutils.h"

#include "MUS.h"
#include "p00.h"
#include "prg.h"
#include "PSID.h"

// Error and status message strings.
const char ERR_EMPTY[]               = "SIDTUNE ERROR: No data to load";
const char ERR_UNRECOGNIZED_FORMAT[] = "SIDTUNE ERROR: Could not determine file format";
const char ERR_NOT_ENOUGH_MEMORY[]   = "SIDTUNE ERROR: Not enough free memory";
const char ERR_CANT_LOAD_FILE[]      = "SIDTUNE ERROR: Could not load input file";
const char ERR_CANT_OPEN_FILE[]      = "SIDTUNE ERROR: Could not open file for binary input";
const char ERR_FILE_TOO_LONG[]       = "SIDTUNE ERROR: Input data too long";
const char ERR_DATA_TOO_LONG[]       = "SIDTUNE ERROR: Size of music data exceeds C64 memory";
const char ERR_BAD_ADDR[]            = "SIDTUNE ERROR: Bad address data";
const char ERR_BAD_RELOC[]           = "SIDTUNE ERROR: Bad reloc data";
const char ERR_CORRUPT[]             = "SIDTUNE ERROR: File is incomplete or corrupt";

/**
* Petscii to Ascii conversion table.
*
* CHR$ conversion table (0x01 = no output)
*/
static const char CHR_tab[256] =
{
   0x0, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0xd, 0x1, 0x1,
   0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1,
  0x20,0x21, 0x1,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f,
  0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f,
  0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f,
  0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x5b,0x24,0x5d,0x20,0x20,
  // alternative: CHR$(92=0x5c) => ISO Latin-1(0xa3)
  0x2d,0x23,0x7c,0x2d,0x2d,0x2d,0x2d,0x7c,0x7c,0x5c,0x5c,0x2f,0x5c,0x5c,0x2f,0x2f,
  0x5c,0x23,0x5f,0x23,0x7c,0x2f,0x58,0x4f,0x23,0x7c,0x23,0x2b,0x7c,0x7c,0x26,0x5c,
  // 0x80-0xFF
   0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1,
   0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1, 0x1,
  0x20,0x7c,0x23,0x2d,0x2d,0x7c,0x23,0x7c,0x23,0x2f,0x7c,0x7c,0x2f,0x5c,0x5c,0x2d,
  0x2f,0x2d,0x2d,0x7c,0x7c,0x7c,0x7c,0x2d,0x2d,0x2d,0x2f,0x5c,0x5c,0x2f,0x2f,0x23,
  0x2d,0x23,0x7c,0x2d,0x2d,0x2d,0x2d,0x7c,0x7c,0x5c,0x5c,0x2f,0x5c,0x5c,0x2f,0x2f,
  0x5c,0x23,0x5f,0x23,0x7c,0x2f,0x58,0x4f,0x23,0x7c,0x23,0x2b,0x7c,0x7c,0x26,0x5c,
  0x20,0x7c,0x23,0x2d,0x2d,0x7c,0x23,0x7c,0x23,0x2f,0x7c,0x7c,0x2f,0x5c,0x5c,0x2d,
  0x2f,0x2d,0x2d,0x7c,0x7c,0x7c,0x7c,0x2d,0x2d,0x2d,0x2f,0x5c,0x5c,0x2f,0x2f,0x23
};

SidTuneBase* SidTuneBase::load(const char* fileName, const char **fileNameExt,
                 bool separatorIsSlash)
{
    if (!fileName)
        return 0;

#if !defined(SIDTUNE_NO_STDIN_LOADER)
    // Filename "-" is used as a synonym for standard input.
    if (strcmp(fileName, "-") == 0)
        return getFromStdIn();
#endif
    return getFromFiles(fileName, fileNameExt, separatorIsSlash);
}

SidTuneBase* SidTuneBase::read(const uint_least8_t* sourceBuffer, uint_least32_t bufferLen)
{
    return getFromBuffer(sourceBuffer, bufferLen);
}

const SidTuneInfo* SidTuneBase::getInfo() const
{
    return info.get();
}

const SidTuneInfo* SidTuneBase::getInfo(unsigned int songNum)
{
    selectSong(songNum);
    return info.get();
}

unsigned int SidTuneBase::selectSong(unsigned int selectedSong)
{
    // Check whether selected song is valid, use start song if not
    const unsigned int song = (selectedSong == 0 || selectedSong > info->m_songs) ? info->m_startSong : selectedSong;

    // Copy any song-specific variable information
    // such a speed/clock setting to the info structure.
    info->m_currentSong = song;

    // Retrieve song speed definition.
    switch (info->m_compatibility)
    {
    case SidTuneInfo::COMPATIBILITY_R64:
        info->m_songSpeed = SidTuneInfo::SPEED_CIA_1A;
        break;
    case SidTuneInfo::COMPATIBILITY_PSID:
        // This does not take into account the PlaySID bug upon evaluating the
        // SPEED field. It would most likely break compatibility to lots of
        // sidtunes, which have been converted from .SID format and vice versa.
        // The .SID format does the bit-wise/song-wise evaluation of the SPEED
        // value correctly, like it is described in the PlaySID documentation.
        info->m_songSpeed = songSpeed[(song-1)&31];
        break;
    default:
        info->m_songSpeed = songSpeed[song-1];
        break;
    }

    info->m_clockSpeed = clockSpeed[song-1];

    return info->m_currentSong;
}

// ------------------------------------------------- private member functions

bool SidTuneBase::placeSidTuneInC64mem(sidmemory* mem)
{
    if (mem != 0)
    {
        // The Basic ROM sets these values on loading a file.
        // Program end address
        const uint_least16_t start = info->m_loadAddr;
        const uint_least16_t end   = start + info->m_c64dataLen;
        mem->writeMemWord(0x2d, end); // Variables start
        mem->writeMemWord(0x2f, end); // Arrays start
        mem->writeMemWord(0x31, end); // Strings start
        mem->writeMemWord(0xac, start);
        mem->writeMemWord(0xae, end);

        // Copy data from cache to the correct destination.
        mem->fillRam(info->m_loadAddr, &cache[fileOffset], info->m_c64dataLen);

        return true;
    }
    return false;
}

void SidTuneBase::loadFile(const char* fileName, buffer_t& bufferRef)
{
    std::ifstream inFile(fileName, std::ifstream::binary);

    if (!inFile.is_open())
    {
        throw loadError(ERR_CANT_OPEN_FILE);
    }

    inFile.seekg(0, inFile.end);
    const int fileLen = inFile.tellg();

    if (fileLen <= 0)
    {
        throw loadError(ERR_EMPTY);
    }

    inFile.seekg(0, inFile.beg);

    buffer_t fileBuf;
    fileBuf.reserve(fileLen);

    try
    {
        fileBuf.assign(std::istreambuf_iterator<char>(inFile), std::istreambuf_iterator<char>());
    }
    catch (std::exception &ex)
    {
        throw loadError(ex.what());
    }

    if (inFile.bad())
    {
        throw loadError(ERR_CANT_LOAD_FILE);
    }

    inFile.close();

    bufferRef.swap(fileBuf);
}

SidTuneBase::SidTuneBase() :
    info(new SidTuneInfoImpl()),
    fileOffset(0)
{
    // Initialize the object with some safe defaults.
    for (unsigned int si = 0; si < MAX_SONGS; si++)
    {
        songSpeed[si] = info->m_songSpeed;
        clockSpeed[si] = info->m_clockSpeed;
    }
}

#if !defined(SIDTUNE_NO_STDIN_LOADER)

SidTuneBase* SidTuneBase::getFromStdIn()
{
    buffer_t fileBuf;

    // We only read as much as fits in the buffer.
    // This way we avoid choking on huge data.
    char datb;
    while (std::cin.get(datb) && fileBuf.size() < MAX_FILELEN)
    {
        fileBuf.push_back((uint_least8_t)datb);
    }

    return getFromBuffer(&fileBuf.front(), fileBuf.size());
}

#endif

SidTuneBase* SidTuneBase::getFromBuffer(const uint_least8_t* const buffer, uint_least32_t bufferLen)
{
    if (buffer == 0 || bufferLen == 0)
    {
        throw loadError(ERR_EMPTY);
    }

    if (bufferLen > MAX_FILELEN)
    {
        throw loadError(ERR_FILE_TOO_LONG);
    }

    buffer_t buf1(buffer, buffer+bufferLen);

    // Here test for the possible single file formats.
    std::auto_ptr<SidTuneBase> s(PSID::load(buf1));
    if (!s.get())
    {
        buffer_t buf2;  // empty
        s.reset(MUS::load(buf1, buf2, 0, true));
    }

    if (s.get())
    {
        s->acceptSidTune("-", "-", buf1, false);
        return s.release();

    }

    throw loadError(ERR_UNRECOGNIZED_FORMAT);
}

void SidTuneBase::acceptSidTune(const char* dataFileName, const char* infoFileName,
                            buffer_t& buf, bool isSlashedFileName)
{
    // Make a copy of the data file name and path, if available.
    if (dataFileName != 0)
    {
        const size_t fileNamePos = isSlashedFileName ?
            SidTuneTools::slashedFileNameWithoutPath(dataFileName) :
            SidTuneTools::fileNameWithoutPath(dataFileName);
        info->m_path = std::string(dataFileName, fileNamePos);
        info->m_dataFileName = std::string(dataFileName + fileNamePos);
    }

    // Make a copy of the info file name, if available.
    if (infoFileName != 0)
    {
        const size_t fileNamePos = isSlashedFileName ?
            SidTuneTools::slashedFileNameWithoutPath(infoFileName) :
            SidTuneTools::fileNameWithoutPath(infoFileName);
        info->m_infoFileName = std::string(infoFileName + fileNamePos);
    }

    // Fix bad sidtune set up.
    if (info->m_songs > MAX_SONGS)
    {
        info->m_songs = MAX_SONGS;
    }
    else if (info->m_songs == 0)
    {
        info->m_songs++;
    }

    if (info->m_startSong > info->m_songs)
    {
        info->m_startSong = 1;
    }
    else if (info->m_startSong == 0)
    {
        info->m_startSong++;
    }

    info->m_dataFileLen = buf.size();
    info->m_c64dataLen = buf.size() - fileOffset;

    // Calculate any remaining addresses and then
    // confirm all the file details are correct
    resolveAddrs(&buf[fileOffset]);

    if (checkRelocInfo() == false)
    {
        throw loadError(ERR_BAD_RELOC);
    }
    if (checkCompatibility() == false)
    {
         throw loadError(ERR_BAD_ADDR);
    }

    if (info->m_dataFileLen >= 2)
    {
        // We only detect an offset of two. Some position independent
        // sidtunes contain a load address of 0xE000, but are loaded
        // to 0x0FFE and call player at 0x1000.
        info->m_fixLoad = (endian_little16(&buf[fileOffset])==(info->m_loadAddr+2));
    }

    // Check the size of the data.
    if (info->m_c64dataLen > MAX_MEMORY)
    {
        throw loadError(ERR_DATA_TOO_LONG);
    }
    else if (info->m_c64dataLen == 0)
    {
        throw loadError(ERR_EMPTY);
    }

    cache.swap(buf);
}

void SidTuneBase::createNewFileName(std::string& destString,
                                const char* sourceName,
                                const char* sourceExt)
{
    destString.assign(sourceName);
    destString.erase(destString.find_last_of('.'));
    destString.append(sourceExt);
}

// Initializing the object based upon what we find in the specified file.

SidTuneBase* SidTuneBase::getFromFiles(const char* fileName, const char **fileNameExtensions, bool separatorIsSlash)
{
    buffer_t fileBuf1;

    loadFile(fileName, fileBuf1);

    // File loaded. Now check if it is in a valid single-file-format.
    std::auto_ptr<SidTuneBase> s(PSID::load(fileBuf1));
    if (!s.get())
    {
        buffer_t fileBuf2;

        // Try some native C64 file formats
        s.reset(MUS::load(fileBuf1, fileBuf2, 0, true));
        if (s.get())
        {
            // Try to find second file.
            std::string fileName2;
            int n = 0;
            while (fileNameExtensions[n] != 0)
            {
                createNewFileName(fileName2, fileName, fileNameExtensions[n]);
                // 1st data file was loaded into "fileBuf1",
                // so we load the 2nd one into "fileBuf2".
                // Do not load the first file again if names are equal.
                if (!stringutils::equal(fileName, fileName2.data(), fileName2.size()))
                {
                    try
                    {
                        loadFile(fileName2.c_str(), fileBuf2);
                        // Check if tunes in wrong order and therefore swap them here
                        if (stringutils::equal(fileNameExtensions[n], ".mus"))
                        {
                            std::auto_ptr<SidTuneBase> s2(MUS::load(fileBuf2, fileBuf1, 0, true));
                            if (s2.get())
                            {
                                s2->acceptSidTune(fileName2.c_str(), fileName, fileBuf2, separatorIsSlash);
                                return s2.release();
                            }
                        }
                        else
                        {
                            std::auto_ptr<SidTuneBase> s2(MUS::load(fileBuf1, fileBuf2, 0, true));
                            if (s2.get())
                            {
                                s2->acceptSidTune(fileName, fileName2.c_str(), fileBuf1, separatorIsSlash);
                                return s2.release();
                            }
                        }
                    // The first tune loaded ok, so ignore errors on the
                    // second tune, may find an ok one later
                    }
                    catch (loadError const &e) {}
                }
                n++;
            }

            s->acceptSidTune(fileName, 0, fileBuf1, separatorIsSlash);
            return s.release();
        }
    }
    if (!s.get()) s.reset(p00::load(fileName, fileBuf1));
    if (!s.get()) s.reset(prg::load(fileName, fileBuf1));

    if (s.get())
    {
        s->acceptSidTune(fileName, 0, fileBuf1, separatorIsSlash);
        return s.release();
    }

    throw loadError(ERR_UNRECOGNIZED_FORMAT);
}

void SidTuneBase::convertOldStyleSpeedToTables(uint_least32_t speed, SidTuneInfo::clock_t clock)
{
    // Create the speed/clock setting tables.
    //
    // This routine implements the PSIDv2NG compliant speed conversion. All tunes
    // above 32 use the same song speed as tune 32
    // NOTE: The cast here is used to avoid undefined references
    // as the std::min function takes its parameters by reference
    const unsigned int toDo = std::min(info->m_songs, static_cast<unsigned int>(MAX_SONGS));
    for (unsigned int s = 0; s < toDo; s++)
    {
        clockSpeed[s] = clock;
        songSpeed[s] = (speed & 1) ? SidTuneInfo::SPEED_CIA_1A : SidTuneInfo::SPEED_VBI;

        if (s < 31)
        {
            speed >>= 1;
        }
    }
}

bool SidTuneBase::checkRelocInfo()
{
    // Fix relocation information
    if (info->m_relocStartPage == 0xFF)
    {
        info->m_relocPages = 0;
        return true;
    }
    else if (info->m_relocPages == 0)
    {
        info->m_relocStartPage = 0;
        return true;
    }

    // Calculate start/end page
    const uint_least8_t startp = info->m_relocStartPage;
    const uint_least8_t endp   = (startp + info->m_relocPages - 1) & 0xff;
    if (endp < startp)
    {
        return false;
    }

    {    // Check against load range
        const uint_least8_t startlp = (uint_least8_t) (info->m_loadAddr >> 8);
        const uint_least8_t endlp   = startlp + (uint_least8_t) ((info->m_c64dataLen - 1) >> 8);

        if (((startp <= startlp) && (endp >= startlp))
            || ((startp <= endlp)   && (endp >= endlp)))
        {
            return false;
        }
    }

    // Check that the relocation information does not use the following
    // memory areas: 0x0000-0x03FF, 0xA000-0xBFFF and 0xD000-0xFFFF
    if ((startp < 0x04)
        || ((0xa0 <= startp) && (startp <= 0xbf))
        || (startp >= 0xd0)
        || ((0xa0 <= endp) && (endp <= 0xbf))
        || (endp >= 0xd0))
    {
        return false;
    }

    return true;
}

void SidTuneBase::resolveAddrs(const uint_least8_t *c64data)
{
    // Originally used as a first attempt at an RSID
    // style format. Now reserved for future use
    if (info->m_playAddr == 0xffff)
    {
        info->m_playAddr = 0;
    }

    // loadAddr = 0 means, the address is stored in front of the C64 data.
    if (info->m_loadAddr == 0)
    {
        if (info->m_c64dataLen < 2)
        {
            throw loadError(ERR_CORRUPT);
        }

        info->m_loadAddr = endian_16(*(c64data+1), *c64data);
        fileOffset += 2;
        info->m_c64dataLen -= 2;
    }

    if (info->m_compatibility == SidTuneInfo::COMPATIBILITY_BASIC)
    {
        if (info->m_initAddr != 0)
        {
            throw loadError(ERR_BAD_ADDR);
        }
    }
    else if (info->m_initAddr == 0)
    {
        info->m_initAddr = info->m_loadAddr;
    }
}

bool SidTuneBase::checkCompatibility()
{
    if  (info->m_compatibility == SidTuneInfo::COMPATIBILITY_R64)
    {
        // Check valid init address
        switch (info->m_initAddr >> 12)
        {
        case 0x0F:
        case 0x0E:
        case 0x0D:
        case 0x0B:
        case 0x0A:
            return false;
        default:
            if ((info->m_initAddr < info->m_loadAddr)
                || (info->m_initAddr > (info->m_loadAddr + info->m_c64dataLen - 1)))
            {
                return false;
            }
        }

        // Check tune is loadable on a real C64
        if (info->m_loadAddr < SIDTUNE_R64_MIN_LOAD_ADDR)
        {
            return false;
        }
    }

    return true;
}

const char* SidTuneBase::PetsciiToAscii::convert(SmartPtr_sidtt<const uint8_t>& spPet)
{
    char c;
    do
    {
        c = CHR_tab[*spPet];  // ASCII CHR$ conversion
        if ((c >= 0x20) && (buffer.length() <= 31))
            buffer.push_back(c);  // copy to info string

        // If character is 0x9d (left arrow key) then move back.
        if ((*spPet == 0x9d) && (!buffer.empty()))
        {
            buffer.resize(buffer.size() - 1);
        }

        spPet++;
    }
    while (!((c == 0x0D) || (c == 0x00) || spPet.fail()));

    return buffer.c_str();
}
