/****************************************************************************
*                                                                           *
* Project64 - A Nintendo 64 emulator.                                      *
* http://www.pj64-emu.com/                                                  *
* Copyright (C) 2012 Project64. All rights reserved.                        *
*                                                                           *
* License:                                                                  *
* GNU/GPLv2 http://www.gnu.org/licenses/gpl-2.0.html                        *
*                                                                           *
****************************************************************************/
#include "stdafx.h"
#include "N64RomClass.h"
#include "SystemGlobals.h"
#include <Project64-core/3rdParty/zip.h>
#include <Project64-core/3rdParty/7zip.h>
#include <Common/md5.h>
#include <Common/Platform.h>
#include <Common/MemoryManagement.h>
#include <memory>

CN64Rom::CN64Rom() :
m_ROMImage(NULL),
m_ROMImageBase(NULL),
m_ErrorMsg(EMPTY_STRING),
m_Country(UnknownCountry),
m_CicChip(CIC_UNKNOWN)
{
}

CN64Rom::~CN64Rom()
{
    UnallocateRomImage();
}

bool CN64Rom::AllocateRomImage(uint32_t RomFileSize)
{
    WriteTrace(TraceN64System, TraceDebug, "Allocating memory for rom");
    std::auto_ptr<uint8_t> ImageBase(new uint8_t[RomFileSize + 0x1000]);
    if (ImageBase.get() == NULL)
    {
        SetError(MSG_MEM_ALLOC_ERROR);
        WriteTrace(TraceN64System, TraceError, "Failed to allocate memory for rom (size: 0x%X)", RomFileSize);
        return false;
    }
    uint8_t * Image = (uint8_t *)(((uint64_t)ImageBase.get() + 0xFFF) & ~0xFFF); // start at begining of memory page
    WriteTrace(TraceN64System, TraceDebug, "Allocated rom memory (%p)", Image);

    //save information about the rom loaded
    m_ROMImageBase = ImageBase.release();
    m_ROMImage = Image;
    m_RomFileSize = RomFileSize;
    return true;
}

bool CN64Rom::AllocateAndLoadN64Image(const char * FileLoc, bool LoadBootCodeOnly)
{
    WriteTrace(TraceN64System, TraceDebug, "Trying to open %s", FileLoc);
    if (!m_RomFile.Open(FileLoc, CFileBase::modeRead))
    {
        WriteTrace(TraceN64System, TraceError, "Failed to open %s", FileLoc);
        return false;
    }

    //Read the first 4 bytes and make sure it is a valid n64 image
    uint8_t Test[4];
    m_RomFile.SeekToBegin();
    if (m_RomFile.Read(Test, sizeof(Test)) != sizeof(Test))
    {
        m_RomFile.Close();
        WriteTrace(TraceN64System, TraceError, "Failed to read ident bytes");
        return false;
    }
    if (!IsValidRomImage(Test))
    {
        m_RomFile.Close();
        WriteTrace(TraceN64System, TraceError, "invalid image file %X %X %X %X", Test[0], Test[1], Test[2], Test[3]);
        return false;
    }
    uint32_t RomFileSize = m_RomFile.GetLength();
    WriteTrace(TraceN64System, TraceDebug, "Successfully Opened, size: 0x%X", RomFileSize);

    //if loading boot code then just load the first 0x1000 bytes
    if (LoadBootCodeOnly)
    {
        WriteTrace(TraceN64System, TraceDebug, "loading boot code, so loading the first 0x1000 bytes", RomFileSize);
        RomFileSize = 0x1000;
    }

    if (!AllocateRomImage(RomFileSize))
    {
        m_RomFile.Close();
        return false;
    }

    //Load the n64 rom to the allocated memory
    g_Notify->DisplayMessage(5, MSG_LOADING);
    m_RomFile.SeekToBegin();

    uint32_t count, TotalRead = 0;
    for (count = 0; count < (int)RomFileSize; count += ReadFromRomSection)
    {
        uint32_t dwToRead = RomFileSize - count;
        if (dwToRead > ReadFromRomSection) { dwToRead = ReadFromRomSection; }

        if (m_RomFile.Read(&m_ROMImage[count], dwToRead) != dwToRead)
        {
            m_RomFile.Close();
            SetError(MSG_FAIL_IMAGE);
            WriteTrace(TraceN64System, TraceError, "Failed to read file (TotalRead: 0x%X)", TotalRead);
            return false;
        }
        TotalRead += dwToRead;

        //Show Message of how much % wise of the rom has been loaded
        g_Notify->DisplayMessage(0, stdstr_f("%s: %.2f%c", GS(MSG_LOADED), ((float)TotalRead / (float)RomFileSize) * 100.0f, '%').c_str());
    }

    if (RomFileSize != TotalRead)
    {
        m_RomFile.Close();
        SetError(MSG_FAIL_IMAGE);
        WriteTrace(TraceN64System, TraceError, "Expected to read: 0x%X, read: 0x%X", TotalRead, RomFileSize);
        return false;
    }

    g_Notify->DisplayMessage(5, MSG_BYTESWAP);
    ByteSwapRom();

    //Protect the memory so that it can not be written to.
    ProtectMemory(m_ROMImage, m_RomFileSize, MEM_READONLY);
    return true;
}

bool CN64Rom::AllocateAndLoadZipImage(const char * FileLoc, bool LoadBootCodeOnly)
{
    unzFile file = unzOpen(FileLoc);
    if (file == NULL)
    {
        return false;
    }

    int port = unzGoToFirstFile(file);
    bool FoundRom = false;

    //scan through all files in zip to a suitable file is found
    while (port == UNZ_OK && !FoundRom)
    {
        unz_file_info info;
        char zname[_MAX_PATH];

        unzGetCurrentFileInfo(file, &info, zname, sizeof(zname), NULL, 0, NULL, 0);
        if (unzLocateFile(file, zname, 1) != UNZ_OK)
        {
            SetError(MSG_FAIL_ZIP);
            break;
        }
        if (unzOpenCurrentFile(file) != UNZ_OK)
        {
            SetError(MSG_FAIL_ZIP);
            break;
        }

        //Read the first 4 bytes to check magic number
        uint8_t Test[4];
        unzReadCurrentFile(file, Test, sizeof(Test));
        if (IsValidRomImage(Test))
        {
            //Get the size of the rom and try to allocate the memory needed.
            uint32_t RomFileSize = info.uncompressed_size;
            if (LoadBootCodeOnly)
            {
                RomFileSize = 0x1000;
            }

            if (!AllocateRomImage(RomFileSize))
            {
                m_RomFile.Close();
                return false;
            }

            //Load the n64 rom to the allocated memory
            g_Notify->DisplayMessage(5, MSG_LOADING);
            memcpy(m_ROMImage, Test, 4);

            uint32_t dwRead, count, TotalRead = 0;
            for (count = 4; count < (int)RomFileSize; count += ReadFromRomSection)
            {
                uint32_t dwToRead = RomFileSize - count;
                if (dwToRead > ReadFromRomSection) { dwToRead = ReadFromRomSection; }

                dwRead = unzReadCurrentFile(file, &m_ROMImage[count], dwToRead);
                if (dwRead == 0)
                {
                    SetError(MSG_FAIL_ZIP);
                    unzCloseCurrentFile(file);
                    break;
                }
                TotalRead += dwRead;

                //Show Message of how much % wise of the rom has been loaded
                g_Notify->DisplayMessage(5, stdstr_f("%s: %.2f%c", GS(MSG_LOADED), ((float)TotalRead / (float)RomFileSize) * 100.0f, '%').c_str());
            }
            dwRead = TotalRead + 4;

            if (RomFileSize != dwRead)
            {
                unzCloseCurrentFile(file);
                SetError(MSG_FAIL_ZIP);
                g_Notify->DisplayMessage(1, "");
                break;
            }
            FoundRom = true;

            g_Notify->DisplayMessage(5, MSG_BYTESWAP);
            ByteSwapRom();

            //Protect the memory so that it can not be written to.
            ProtectMemory(m_ROMImage, m_RomFileSize, MEM_READONLY);
        }
        unzCloseCurrentFile(file);

        if (!FoundRom)
        {
            port = unzGoToNextFile(file);
        }
    }
    unzClose(file);

    return FoundRom;
}

void CN64Rom::ByteSwapRom()
{
    uint32_t count;

    switch (*((uint32_t *)&m_ROMImage[0]))
    {
    case 0x12408037:
        for (count = 0; count < m_RomFileSize; count += 4)
        {
            m_ROMImage[count] ^= m_ROMImage[count + 2];
            m_ROMImage[count + 2] ^= m_ROMImage[count];
            m_ROMImage[count] ^= m_ROMImage[count + 2];
            m_ROMImage[count + 1] ^= m_ROMImage[count + 3];
            m_ROMImage[count + 3] ^= m_ROMImage[count + 1];
            m_ROMImage[count + 1] ^= m_ROMImage[count + 3];
        }
        break;
    case 0x40072780: //64DD IPL
    case 0x40123780:
        for (count = 0; count < m_RomFileSize; count += 4)
        {
            m_ROMImage[count] ^= m_ROMImage[count + 3];
            m_ROMImage[count + 3] ^= m_ROMImage[count];
            m_ROMImage[count] ^= m_ROMImage[count + 3];
            m_ROMImage[count + 1] ^= m_ROMImage[count + 2];
            m_ROMImage[count + 2] ^= m_ROMImage[count + 1];
            m_ROMImage[count + 1] ^= m_ROMImage[count + 2];
        }
        break;
    case 0x80371240: break;
    default:
        g_Notify->DisplayError(stdstr_f("ByteSwapRom: %X", m_ROMImage[0]).c_str());
    }
}

void CN64Rom::CalculateCicChip()
{
    int64_t CRC = 0;

    if (m_ROMImage == NULL)
    {
        m_CicChip = CIC_UNKNOWN;
        return;
    }

    for (int count = 0x40; count < 0x1000; count += 4)
    {
        CRC += *(uint32_t *)(m_ROMImage + count);
    }
    switch (CRC) {
    case 0x000000D0027FDF31: m_CicChip = CIC_NUS_6101; break;
    case 0x000000CFFB631223: m_CicChip = CIC_NUS_6101; break;
    case 0x000000D057C85244: m_CicChip = CIC_NUS_6102; break;
    case 0x000000D6497E414B: m_CicChip = CIC_NUS_6103; break;
    case 0x0000011A49F60E96: m_CicChip = CIC_NUS_6105; break;
    case 0x000000D6D5BE5580: m_CicChip = CIC_NUS_6106; break;
    case 0x000001053BC19870: m_CicChip = CIC_NUS_5167; break;	//64DD CONVERSION CIC
    case 0x000000D2E53EF008: m_CicChip = CIC_NUS_8303; break;	//64DD IPL
    default:
        if (bHaveDebugger())
        {
            g_Notify->DisplayError(stdstr_f("Unknown CIC checksum:\n%I64X.", CRC).c_str());
        }
        m_CicChip = CIC_UNKNOWN; break;
    }
}

void CN64Rom::CalculateRomCrc()
{
    uint32_t t0, t2, t3, t4, t5;
    uint32_t a0, a1, a2, a3;
    uint32_t s0;
    uint32_t v0, v1;

    // CIC_NUS_6101	at=0x5D588B65 , s6=0x3F
    // CIC_NUS_6102	at=0x5D588B65 , s6=0x3F
    // CIC_NUS_6103	at=0x6C078965 , s6=0x78
    // CIC_NUS_6105	at=0x5d588b65 , s6=0x91
    // CIC_NUS_6106	at=0x6C078965 , s6=0x85

    // 64DD IPL		at=0x02E90EDD , s6=0xdd

    //v0 = 0xFFFFFFFF & (0x3F * at) + 1;
    switch (m_CicChip)
    {
    case CIC_NUS_6101:
    case CIC_NUS_6102: v0 = 0xF8CA4DDC; break;
    case CIC_NUS_6103: v0 = 0xA3886759; break;
    case CIC_NUS_6105: v0 = 0xDF26F436; break;
    case CIC_NUS_6106: v0 = 0x1FEA617A; break;
    default:
        return;
    }

    ProtectMemory(m_ROMImage, m_RomFileSize, MEM_READWRITE);

    v1 = 0;
    t0 = 0;
    t5 = 0x20;

    a3 = v0;
    t2 = v0;
    t3 = v0;
    s0 = v0;
    a2 = v0;
    t4 = v0;

    for (t0 = 0; t0 < 0x00100000; t0 += 4)
    {
        v0 = *(uint32_t *)(m_ROMImage + t0 + 0x1000);

        v1 = a3 + v0;
        a1 = v1;

        if (v1 < a3) t2 += 0x1;
        v1 = v0 & 0x001F;

        a0 = (v0 << v1) | (v0 >> (t5 - v1));

        a3 = a1;
        t3 = t3 ^ v0;

        s0 = s0 + a0;
        if (a2 < v0) a2 = a3 ^ v0 ^ a2;
        else a2 = a2 ^ a0;

        if (m_CicChip == CIC_NUS_6105)
        {
            t4 = (v0 ^ (*(uint32_t *)(m_ROMImage + (0xFF & t0) + 0x750))) + t4;
        }
        else t4 = (v0 ^ s0) + t4;
    }
    if (m_CicChip == CIC_NUS_6103)
    {
        a3 = (a3 ^ t2) + t3;
        s0 = (s0 ^ a2) + t4;
    }
    else if (m_CicChip == CIC_NUS_6106)
    {
        a3 = 0xFFFFFFFF & (a3 * t2) + t3;
        s0 = 0xFFFFFFFF & (s0 * a2) + t4;
    }
    else
    {
        a3 = a3 ^ t2 ^ t3;
        s0 = s0 ^ a2 ^ t4;
    }

    *(uint32_t *)(m_ROMImage + 0x10) = a3;
    *(uint32_t *)(m_ROMImage + 0x14) = s0;

    ProtectMemory(m_ROMImage, m_RomFileSize, MEM_READONLY);
}

CICChip CN64Rom::CicChipID()
{
    return m_CicChip;
}

bool CN64Rom::IsValidRomImage(uint8_t Test[4])
{
    if (*((uint32_t *)&Test[0]) == 0x40123780) { return true; }
    if (*((uint32_t *)&Test[0]) == 0x12408037) { return true; }
    if (*((uint32_t *)&Test[0]) == 0x80371240) { return true; }
    if (*((uint32_t *)&Test[0]) == 0x40072780) { return true; } //64DD IPL
    return false;
}

void CN64Rom::NotificationCB(const char * Status, CN64Rom * /*_this*/)
{
    g_Notify->DisplayMessage(5, stdstr_f("%s", Status).c_str());
}

bool CN64Rom::LoadN64Image(const char * FileLoc, bool LoadBootCodeOnly)
{
    UnallocateRomImage();
    m_ErrorMsg = EMPTY_STRING;

    stdstr ext = CPath(FileLoc).GetExtension();
    bool Loaded7zFile = false;

    if (strstr(FileLoc, "?") != NULL || _stricmp(ext.c_str(), "7z") == 0)
    {
        stdstr FullPath = FileLoc;

        //this should be a 7zip file
        char * SubFile = strstr(const_cast<char*>(FullPath.c_str()), "?");
        if (SubFile == NULL)
        {
            //Pop up a dialog and select file
            //allocate memory for sub name and copy selected file name to var
            return false; //remove once dialog is done
        }
        else
        {
            *SubFile = '\0';
            SubFile += 1;
        }

        C7zip ZipFile(FullPath.c_str());
        ZipFile.SetNotificationCallback((C7zip::LP7ZNOTIFICATION)NotificationCB, this);
        for (int i = 0; i < ZipFile.NumFiles(); i++)
        {
            CSzFileItem * f = ZipFile.FileItem(i);
            if (f->IsDir)
            {
                continue;
            }

            stdstr ZipFileName;
            ZipFileName.FromUTF16(ZipFile.FileNameIndex(i).c_str());
            if (SubFile != NULL)
            {
                if (_stricmp(ZipFileName.c_str(), SubFile) != 0)
                {
                    continue;
                }
            }

            //Get the size of the rom and try to allocate the memory needed.
            uint32_t RomFileSize = (uint32_t)f->Size;
            //if loading boot code then just load the first 0x1000 bytes
            if (LoadBootCodeOnly) { RomFileSize = 0x1000; }

            if (!AllocateRomImage(RomFileSize))
            {
                return false;
            }

            //Load the n64 rom to the allocated memory
            g_Notify->DisplayMessage(5, MSG_LOADING);
            if (!ZipFile.GetFile(i, m_ROMImage, RomFileSize))
            {
                SetError(MSG_FAIL_IMAGE);
                return false;
            }

            if (!IsValidRomImage(m_ROMImage))
            {
                SetError(MSG_FAIL_IMAGE);
                return false;
            }
            g_Notify->DisplayMessage(5, MSG_BYTESWAP);
            ByteSwapRom();

            //Protect the memory so that it can not be written to.
            ProtectMemory(m_ROMImage, m_RomFileSize, MEM_READONLY);
            Loaded7zFile = true;
            break;
        }
        if (!Loaded7zFile)
        {
            SetError(MSG_7Z_FILE_NOT_FOUND);
            return false;
        }
    }

    //Try to open the file as a zip file
    if (!Loaded7zFile)
    {
        if (!AllocateAndLoadZipImage(FileLoc, LoadBootCodeOnly))
        {
            if (m_ErrorMsg != EMPTY_STRING)
            {
                return false;
            }
            if (!AllocateAndLoadN64Image(FileLoc, LoadBootCodeOnly))
            {
                return false;
            }
        }
    }

    char RomName[260];
    int  count;
    //Get the header from the rom image
    memcpy(&RomName[0], (void *)(m_ROMImage + 0x20), 20);
    for (count = 0; count < 20; count += 4)
    {
        RomName[count] ^= RomName[count + 3];
        RomName[count + 3] ^= RomName[count];
        RomName[count] ^= RomName[count + 3];
        RomName[count + 1] ^= RomName[count + 2];
        RomName[count + 2] ^= RomName[count + 1];
        RomName[count + 1] ^= RomName[count + 2];
    }

    //truncate all the spaces at the end of the string
    for (count = 19; count >= 0; count--)
    {
        if (RomName[count] == ' ')
        {
            RomName[count] = '\0';
        }
        else if (RomName[count] == '\0')
        {
        }
        else
        {
            count = -1;
        }
    }
    RomName[20] = '\0';
    if (strlen(RomName) == 0)
    {
        strcpy(RomName, CPath(FileLoc).GetName().c_str());
    }

    //remove all /,\,: from the string
    for (count = 0; count < (int)strlen(RomName); count++)
    {
        switch (RomName[count])
        {
        case '/': case '\\': RomName[count] = '-'; break;
        case ':': RomName[count] = ';'; break;
        }
    }
    WriteTrace(TraceN64System, TraceDebug, "RomName %s", RomName);

    m_RomName = RomName;
    m_FileName = FileLoc;
    m_MD5 = "";

    if (!LoadBootCodeOnly)
    {
        //Calculate files MD5
        m_MD5 = MD5((const unsigned char *)m_ROMImage, m_RomFileSize).hex_digest();
        WriteTrace(TraceN64System, TraceDebug, "MD5: %s", m_MD5.c_str());
    }

    m_Country = (Country)m_ROMImage[0x3D];
    m_RomIdent.Format("%08X-%08X-C:%X", *(uint32_t *)(&m_ROMImage[0x10]), *(uint32_t *)(&m_ROMImage[0x14]), m_ROMImage[0x3D]);
    WriteTrace(TraceN64System, TraceDebug, "Ident: %s", m_RomIdent.c_str());
    CalculateCicChip();

    if (!LoadBootCodeOnly && g_Rom == this)
    {
        g_Settings->SaveBool(GameRunning_LoadingInProgress, false);
        SaveRomSettingID(false);
    }

    if (g_Settings->LoadBool(Game_CRC_Recalc))
    {
        //Calculate ROM Header CRC
        CalculateRomCrc();
    }

    return true;
}

//Save the settings of the loaded rom, so all loaded settings about rom will be identified with
//this rom
void CN64Rom::SaveRomSettingID(bool temp)
{
    g_Settings->SaveBool(Game_TempLoaded, temp);
    g_Settings->SaveString(Game_GameName, m_RomName.c_str());
    g_Settings->SaveString(Game_IniKey, m_RomIdent.c_str());

    switch (GetCountry())
    {
    case Germany: case french:  case Italian:
    case Europe:  case Spanish: case Australia:
    case X_PAL:   case Y_PAL:
        g_Settings->SaveDword(Game_SystemType, SYSTEM_PAL);
        break;
    default:
        g_Settings->SaveDword(Game_SystemType, SYSTEM_NTSC);
        break;
    }
}

void CN64Rom::ClearRomSettingID()
{
    g_Settings->SaveString(Game_GameName, "");
    g_Settings->SaveString(Game_IniKey, "");
}

void CN64Rom::SetError(LanguageStringID ErrorMsg)
{
    m_ErrorMsg = ErrorMsg;
}

void CN64Rom::UnallocateRomImage()
{
    m_RomFile.Close();

    if (m_ROMImageBase)
    {
        ProtectMemory(m_ROMImage, m_RomFileSize, MEM_READWRITE);
        delete[] m_ROMImageBase;
        m_ROMImageBase = NULL;
    }
    m_ROMImage = NULL;
}