// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include "Core/Boot/Boot.h"

#include <string>
#include <vector>

#include <zlib.h>

#include "Common/Align.h"
#include "Common/CommonPaths.h"
#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "Common/Logging/Log.h"
#include "Common/MsgHandler.h"
#include "Common/StringUtil.h"

#include "Core/Boot/Boot_DOL.h"
#include "Core/ConfigManager.h"
#include "Core/Core.h"
#include "Core/Debugger/Debugger_SymbolMap.h"
#include "Core/HLE/HLE.h"
#include "Core/HW/DVD/DVDInterface.h"
#include "Core/HW/EXI/EXI_DeviceIPL.h"
#include "Core/HW/Memmap.h"
#include "Core/HW/VideoInterface.h"
#include "Core/Host.h"
#include "Core/IOS/IOS.h"
#include "Core/PatchEngine.h"
#include "Core/PowerPC/PPCAnalyst.h"
#include "Core/PowerPC/PPCSymbolDB.h"
#include "Core/PowerPC/PowerPC.h"
#include "Core/PowerPC/SignatureDB/SignatureDB.h"

#include "DiscIO/Enums.h"
#include "DiscIO/NANDContentLoader.h"
#include "DiscIO/Volume.h"
#include "DiscIO/VolumeCreator.h"

// Inserts a disc into the emulated disc drive and returns a pointer to it.
// The returned pointer must only be used while we are still booting,
// because DVDThread can do whatever it wants to the disc after that.
static const DiscIO::IVolume* SetDisc(std::unique_ptr<DiscIO::IVolume> volume)
{
  const DiscIO::IVolume* pointer = volume.get();
  DVDInterface::SetDisc(std::move(volume));
  return pointer;
}

bool CBoot::DVDRead(const DiscIO::IVolume& volume, u64 dvd_offset, u32 output_address, u32 length,
                    const DiscIO::Partition& partition)
{
  std::vector<u8> buffer(length);
  if (!volume.Read(dvd_offset, length, buffer.data(), partition))
    return false;
  Memory::CopyToEmu(output_address, buffer.data(), length);
  return true;
}

void CBoot::Load_FST(bool is_wii, const DiscIO::IVolume* volume)
{
  if (!volume)
    return;

  const DiscIO::Partition partition = volume->GetGamePartition();

  // copy first 32 bytes of disc to start of Mem 1
  DVDRead(*volume, /*offset*/ 0, /*address*/ 0, /*length*/ 0x20, DiscIO::PARTITION_NONE);

  // copy of game id
  Memory::Write_U32(Memory::Read_U32(0x0000), 0x3180);

  u32 shift = 0;
  if (is_wii)
    shift = 2;

  u32 fst_offset = 0;
  u32 fst_size = 0;
  u32 max_fst_size = 0;

  volume->ReadSwapped(0x0424, &fst_offset, partition);
  volume->ReadSwapped(0x0428, &fst_size, partition);
  volume->ReadSwapped(0x042c, &max_fst_size, partition);

  u32 arena_high = Common::AlignDown(0x817FFFFF - (max_fst_size << shift), 0x20);
  Memory::Write_U32(arena_high, 0x00000034);

  // load FST
  DVDRead(*volume, fst_offset << shift, arena_high, fst_size << shift, partition);
  Memory::Write_U32(arena_high, 0x00000038);
  Memory::Write_U32(max_fst_size << shift, 0x0000003c);

  if (is_wii)
  {
    // the apploader changes IOS MEM1_ARENA_END too
    Memory::Write_U32(arena_high, 0x00003110);
  }
}

void CBoot::UpdateDebugger_MapLoaded()
{
  Host_NotifyMapLoaded();
}

bool CBoot::FindMapFile(std::string* existing_map_file, std::string* writable_map_file,
                        std::string* title_id)
{
  std::string title_id_str;
  size_t name_begin_index;

  SConfig& _StartupPara = SConfig::GetInstance();
  switch (_StartupPara.m_BootType)
  {
  case SConfig::BOOT_WII_NAND:
  {
    const DiscIO::CNANDContentLoader& Loader =
        DiscIO::CNANDContentManager::Access().GetNANDLoader(_StartupPara.m_strFilename);
    if (Loader.IsValid())
    {
      u64 TitleID = Loader.GetTMD().GetTitleId();
      title_id_str = StringFromFormat("%08X_%08X", (u32)(TitleID >> 32) & 0xFFFFFFFF,
                                      (u32)TitleID & 0xFFFFFFFF);
    }
    break;
  }

  case SConfig::BOOT_ELF:
  case SConfig::BOOT_DOL:
    // Strip the .elf/.dol file extension and directories before the name
    name_begin_index = _StartupPara.m_strFilename.find_last_of("/") + 1;
    if ((_StartupPara.m_strFilename.find_last_of("\\") + 1) > name_begin_index)
    {
      name_begin_index = _StartupPara.m_strFilename.find_last_of("\\") + 1;
    }
    title_id_str = _StartupPara.m_strFilename.substr(
        name_begin_index, _StartupPara.m_strFilename.size() - 4 - name_begin_index);
    break;

  default:
    title_id_str = _StartupPara.GetGameID();
    break;
  }

  if (writable_map_file)
    *writable_map_file = File::GetUserPath(D_MAPS_IDX) + title_id_str + ".map";

  if (title_id)
    *title_id = title_id_str;

  bool found = false;
  static const std::string maps_directories[] = {File::GetUserPath(D_MAPS_IDX),
                                                 File::GetSysDirectory() + MAPS_DIR DIR_SEP};
  for (size_t i = 0; !found && i < ArraySize(maps_directories); ++i)
  {
    std::string path = maps_directories[i] + title_id_str + ".map";
    if (File::Exists(path))
    {
      found = true;
      if (existing_map_file)
        *existing_map_file = path;
    }
  }

  return found;
}

bool CBoot::LoadMapFromFilename()
{
  std::string strMapFilename;
  bool found = FindMapFile(&strMapFilename, nullptr);
  if (found && g_symbolDB.LoadMap(strMapFilename))
  {
    UpdateDebugger_MapLoaded();
    return true;
  }

  return false;
}

// If ipl.bin is not found, this function does *some* of what BS1 does:
// loading IPL(BS2) and jumping to it.
// It does not initialize the hardware or anything else like BS1 does.
bool CBoot::Load_BS2(const std::string& boot_rom_filename)
{
  // CRC32 hashes of the IPL file; including source where known
  // https://forums.dolphin-emu.org/Thread-unknown-hash-on-ipl-bin?pid=385344#pid385344
  constexpr u32 USA_v1_0 = 0x6D740AE7;
  // https://forums.dolphin-emu.org/Thread-unknown-hash-on-ipl-bin?pid=385334#pid385334
  constexpr u32 USA_v1_1 = 0xD5E6FEEA;
  // https://forums.dolphin-emu.org/Thread-unknown-hash-on-ipl-bin?pid=385399#pid385399
  constexpr u32 USA_v1_2 = 0x86573808;
  // GameCubes sold in Brazil have this IPL. Same as USA v1.2 but localized
  constexpr u32 BRA_v1_0 = 0x667D0B64;
  // Redump
  constexpr u32 JAP_v1_0 = 0x6DAC1F2A;
  // https://bugs.dolphin-emu.org/issues/8936
  constexpr u32 JAP_v1_1 = 0xD235E3F9;
  // Redump
  constexpr u32 PAL_v1_0 = 0x4F319F43;
  // https://forums.dolphin-emu.org/Thread-ipl-with-unknown-hash-dd8cab7c-problem-caused-by-my-pal-gamecube-bios?pid=435463#pid435463
  constexpr u32 PAL_v1_1 = 0xDD8CAB7C;
  // Redump
  constexpr u32 PAL_v1_2 = 0xAD1B7F16;

  // Load the whole ROM dump
  std::string data;
  if (!File::ReadFileToString(boot_rom_filename, data))
    return false;

  // Use zlibs crc32 implementation to compute the hash
  u32 ipl_hash = crc32(0L, Z_NULL, 0);
  ipl_hash = crc32(ipl_hash, (const Bytef*)data.data(), (u32)data.size());
  DiscIO::Region ipl_region;
  switch (ipl_hash)
  {
  case USA_v1_0:
  case USA_v1_1:
  case USA_v1_2:
  case BRA_v1_0:
    ipl_region = DiscIO::Region::NTSC_U;
    break;
  case JAP_v1_0:
  case JAP_v1_1:
    ipl_region = DiscIO::Region::NTSC_J;
    break;
  case PAL_v1_0:
  case PAL_v1_1:
  case PAL_v1_2:
    ipl_region = DiscIO::Region::PAL;
    break;
  default:
    PanicAlertT("IPL with unknown hash %x", ipl_hash);
    ipl_region = DiscIO::Region::UNKNOWN_REGION;
    break;
  }

  const DiscIO::Region boot_region = SConfig::GetInstance().m_region;
  if (ipl_region != DiscIO::Region::UNKNOWN_REGION && boot_region != ipl_region)
    PanicAlertT("%s IPL found in %s directory. The disc might not be recognized",
                SConfig::GetDirectoryForRegion(ipl_region),
                SConfig::GetDirectoryForRegion(boot_region));

  // Run the descrambler over the encrypted section containing BS1/BS2
  ExpansionInterface::CEXIIPL::Descrambler((u8*)data.data() + 0x100, 0x1AFE00);

  // TODO: Execution is supposed to start at 0xFFF00000, not 0x81200000;
  // copying the initial boot code to 0x81200000 is a hack.
  // For now, HLE the first few instructions and start at 0x81200150
  // to work around this.
  Memory::CopyToEmu(0x01200000, data.data() + 0x100, 0x700);
  Memory::CopyToEmu(0x01300000, data.data() + 0x820, 0x1AFE00);
  PowerPC::ppcState.gpr[3] = 0xfff0001f;
  PowerPC::ppcState.gpr[4] = 0x00002030;
  PowerPC::ppcState.gpr[5] = 0x0000009c;
  PowerPC::ppcState.msr = 0x00002030;
  PowerPC::ppcState.spr[SPR_HID0] = 0x0011c464;
  PowerPC::ppcState.spr[SPR_IBAT0U] = 0x80001fff;
  PowerPC::ppcState.spr[SPR_IBAT0L] = 0x00000002;
  PowerPC::ppcState.spr[SPR_IBAT3U] = 0xfff0001f;
  PowerPC::ppcState.spr[SPR_IBAT3L] = 0xfff00001;
  PowerPC::ppcState.spr[SPR_DBAT0U] = 0x80001fff;
  PowerPC::ppcState.spr[SPR_DBAT0L] = 0x00000002;
  PowerPC::ppcState.spr[SPR_DBAT1U] = 0xc0001fff;
  PowerPC::ppcState.spr[SPR_DBAT1L] = 0x0000002a;
  PowerPC::ppcState.spr[SPR_DBAT3U] = 0xfff0001f;
  PowerPC::ppcState.spr[SPR_DBAT3L] = 0xfff00001;
  PowerPC::DBATUpdated();
  PowerPC::IBATUpdated();
  PC = 0x81200150;
  return true;
}

// Third boot step after BootManager and Core. See Call schedule in BootManager.cpp
bool CBoot::BootUp()
{
  SConfig& _StartupPara = SConfig::GetInstance();

  if (_StartupPara.m_BootType == SConfig::BOOT_BS2)
    NOTICE_LOG(BOOT, "Booting %s", _StartupPara.m_strBootROM.c_str());
  else
    NOTICE_LOG(BOOT, "Booting %s", _StartupPara.m_strFilename.c_str());

  g_symbolDB.Clear();

  // PAL Wii uses NTSC framerate and linecount in 60Hz modes
  VideoInterface::Preset(DiscIO::IsNTSC(_StartupPara.m_region) ||
                         (_StartupPara.bWii && _StartupPara.bPAL60));

  switch (_StartupPara.m_BootType)
  {
  case SConfig::BOOT_ISO:
  {
    const DiscIO::IVolume* volume =
        SetDisc(DiscIO::CreateVolumeFromFilename(_StartupPara.m_strFilename));

    if (!volume)
      return false;

    if ((volume->GetVolumeType() == DiscIO::Platform::WII_DISC) != _StartupPara.bWii)
    {
      PanicAlertT("Warning - starting ISO in wrong console mode!");
    }

    _StartupPara.bWii = volume->GetVolumeType() == DiscIO::Platform::WII_DISC;

    // We HLE the bootrom if requested or if LLEing it fails
    if (_StartupPara.bHLE_BS2 || !Load_BS2(_StartupPara.m_strBootROM))
      EmulatedBS2(_StartupPara.bWii, volume);

    PatchEngine::LoadPatches();

    // Scan for common HLE functions
    if (_StartupPara.bHLE_BS2 && !_StartupPara.bEnableDebugging)
    {
      PPCAnalyst::FindFunctions(0x80004000, 0x811fffff, &g_symbolDB);
      SignatureDB db(SignatureDB::HandlerType::DSY);
      if (db.Load(File::GetSysDirectory() + TOTALDB))
      {
        db.Apply(&g_symbolDB);
        HLE::PatchFunctions();
        db.Clear();
      }
    }

    // Try to load the symbol map if there is one, and then scan it for
    // and eventually replace code
    if (LoadMapFromFilename())
      HLE::PatchFunctions();

    break;
  }

  case SConfig::BOOT_DOL:
  {
    CDolLoader dolLoader(_StartupPara.m_strFilename);
    if (!dolLoader.IsValid())
      return false;

    // Check if we have gotten a Wii file or not
    bool dolWii = dolLoader.IsWii();
    if (dolWii != _StartupPara.bWii)
    {
      PanicAlertT("Warning - starting DOL in wrong console mode!");
    }

    const DiscIO::IVolume* volume = nullptr;
    if (!_StartupPara.m_strDVDRoot.empty())
    {
      NOTICE_LOG(BOOT, "Setting DVDRoot %s", _StartupPara.m_strDVDRoot.c_str());
      volume = SetDisc(DiscIO::CreateVolumeFromDirectory(_StartupPara.m_strDVDRoot, dolWii,
                                                         _StartupPara.m_strApploader,
                                                         _StartupPara.m_strFilename));
    }
    else if (!_StartupPara.m_strDefaultISO.empty())
    {
      NOTICE_LOG(BOOT, "Loading default ISO %s", _StartupPara.m_strDefaultISO.c_str());
      volume = SetDisc(DiscIO::CreateVolumeFromFilename(_StartupPara.m_strDefaultISO));
    }

    // Poor man's bootup
    if (dolWii)
    {
      HID4.SBE = 1;
      SetupBAT(dolWii);

      // Because there is no TMD to get the requested system (IOS) version from,
      // we default to IOS58, which is the version used by the Homebrew Channel.
      SetupWiiMemory(volume, 0x000000010000003a);
    }
    else
    {
      EmulatedBS2_GC(volume, true);
    }

    Load_FST(dolWii, volume);
    dolLoader.Load();
    PC = dolLoader.GetEntryPoint();

    if (LoadMapFromFilename())
      HLE::PatchFunctions();

    break;
  }

  case SConfig::BOOT_ELF:
  {
    const DiscIO::IVolume* volume = nullptr;

    // load image or create virtual drive from directory
    if (!_StartupPara.m_strDVDRoot.empty())
    {
      NOTICE_LOG(BOOT, "Setting DVDRoot %s", _StartupPara.m_strDVDRoot.c_str());
      volume =
          SetDisc(DiscIO::CreateVolumeFromDirectory(_StartupPara.m_strDVDRoot, _StartupPara.bWii));
    }
    else if (!_StartupPara.m_strDefaultISO.empty())
    {
      NOTICE_LOG(BOOT, "Loading default ISO %s", _StartupPara.m_strDefaultISO.c_str());
      volume = SetDisc(DiscIO::CreateVolumeFromFilename(_StartupPara.m_strDefaultISO));
    }

    // Poor man's bootup
    if (_StartupPara.bWii)
    {
      // Because there is no TMD to get the requested system (IOS) version from,
      // we default to IOS58, which is the version used by the Homebrew Channel.
      SetupWiiMemory(volume, 0x000000010000003a);
    }
    else
    {
      EmulatedBS2_GC(volume, true);
    }

    Load_FST(_StartupPara.bWii, volume);
    if (!Boot_ELF(_StartupPara.m_strFilename))
      return false;

    // Note: Boot_ELF calls HLE::PatchFunctions()

    UpdateDebugger_MapLoaded();
    Dolphin_Debugger::AddAutoBreakpoints();
    break;
  }

  case SConfig::BOOT_WII_NAND:
    Boot_WiiWAD(_StartupPara.m_strFilename);

    PatchEngine::LoadPatches();

    // Not bootstrapped yet, can't translate memory addresses. Thus, prevents Symbol Map usage.
    // if (LoadMapFromFilename())
    //   HLE::PatchFunctions();

    // load default image or create virtual drive from directory
    if (!_StartupPara.m_strDVDRoot.empty())
      SetDisc(DiscIO::CreateVolumeFromDirectory(_StartupPara.m_strDVDRoot, true));
    else if (!_StartupPara.m_strDefaultISO.empty())
      SetDisc(DiscIO::CreateVolumeFromFilename(_StartupPara.m_strDefaultISO));

    break;

  // Bootstrap 2 (AKA: Initial Program Loader, "BIOS")
  case SConfig::BOOT_BS2:
  {
    if (!Load_BS2(_StartupPara.m_strBootROM))
      return false;

    if (LoadMapFromFilename())
      HLE::PatchFunctions();

    break;
  }

  case SConfig::BOOT_DFF:
    // do nothing
    break;

  default:
  {
    PanicAlertT("Tried to load an unknown file type.");
    return false;
  }
  }

  HLE::PatchFixedFunctions();
  return true;
}