// Copyright 2009 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <algorithm>
#include <array>
#include <cstddef>
#include <cstdio>
#include <cstring>
#include <functional>
#include <map>
#include <mbedtls/aes.h>
#include <string>
#include <utility>
#include <vector>

#include "Common/CommonFuncs.h"
#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "Common/Logging/Log.h"
#include "Common/MathUtil.h"
#include "Common/MsgHandler.h"
#include "Common/NandPaths.h"
#include "Common/StringUtil.h"

#include "DiscIO/Enums.h"
#include "DiscIO/NANDContentLoader.h"
#include "DiscIO/WiiWad.h"

namespace DiscIO
{
CNANDContentData::~CNANDContentData() = default;

CSharedContent::CSharedContent()
{
  UpdateLocation();
}

void CSharedContent::UpdateLocation()
{
  m_Elements.clear();
  m_LastID = 0;
  m_ContentMap =
      StringFromFormat("%s/shared1/content.map", File::GetUserPath(D_WIIROOT_IDX).c_str());

  File::IOFile pFile(m_ContentMap, "rb");
  SElement Element;
  while (pFile.ReadArray(&Element, 1))
  {
    m_Elements.push_back(Element);
    m_LastID++;
  }
}

CSharedContent::~CSharedContent()
{
}

std::string CSharedContent::GetFilenameFromSHA1(const u8* hash)
{
  for (auto& Element : m_Elements)
  {
    if (memcmp(hash, Element.SHA1Hash, 20) == 0)
    {
      return StringFromFormat(
          "%s/shared1/%c%c%c%c%c%c%c%c.app", File::GetUserPath(D_WIIROOT_IDX).c_str(),
          Element.FileName[0], Element.FileName[1], Element.FileName[2], Element.FileName[3],
          Element.FileName[4], Element.FileName[5], Element.FileName[6], Element.FileName[7]);
    }
  }
  return "unk";
}

std::string CSharedContent::AddSharedContent(const u8* hash)
{
  std::string filename = GetFilenameFromSHA1(hash);

  if (strcasecmp(filename.c_str(), "unk") == 0)
  {
    std::string id = StringFromFormat("%08x", m_LastID);
    SElement Element;
    memcpy(Element.FileName, id.c_str(), 8);
    memcpy(Element.SHA1Hash, hash, 20);
    m_Elements.push_back(Element);

    File::CreateFullPath(m_ContentMap);

    File::IOFile pFile(m_ContentMap, "ab");
    pFile.WriteArray(&Element, 1);

    filename =
        StringFromFormat("%s/shared1/%s.app", File::GetUserPath(D_WIIROOT_IDX).c_str(), id.c_str());
    m_LastID++;
  }

  return filename;
}

void CNANDContentDataFile::EnsureOpen()
{
  if (!m_file)
    m_file = std::make_unique<File::IOFile>(m_filename, "rb");
  else if (!m_file->IsOpen())
    m_file->Open(m_filename, "rb");
}
void CNANDContentDataFile::Open()
{
  EnsureOpen();
}
std::vector<u8> CNANDContentDataFile::Get()
{
  std::vector<u8> result;
  EnsureOpen();
  if (!m_file->IsGood())
    return result;

  u64 size = m_file->GetSize();
  if (size == 0)
    return result;

  result.resize(size);
  m_file->ReadBytes(result.data(), result.size());

  return result;
}

bool CNANDContentDataFile::GetRange(u32 start, u32 size, u8* buffer)
{
  EnsureOpen();
  if (!m_file->IsGood())
    return false;

  if (!m_file->Seek(start, SEEK_SET))
    return false;

  return m_file->ReadBytes(buffer, static_cast<size_t>(size));
}
void CNANDContentDataFile::Close()
{
  if (m_file && m_file->IsOpen())
    m_file->Close();
}

bool CNANDContentDataBuffer::GetRange(u32 start, u32 size, u8* buffer)
{
  if (start + size > m_buffer.size())
    return false;

  std::copy(&m_buffer[start], &m_buffer[start + size], buffer);
  return true;
}

CNANDContentLoader::CNANDContentLoader(const std::string& content_name)
    : m_Valid(false), m_IsWAD(false), m_TitleID(-1), m_IosVersion(0x09), m_BootIndex(-1)
{
  m_Valid = Initialize(content_name);
}

CNANDContentLoader::~CNANDContentLoader()
{
}

const SNANDContent* CNANDContentLoader::GetContentByIndex(int index) const
{
  for (auto& Content : m_Content)
  {
    if (Content.m_Index == index)
    {
      return &Content;
    }
  }
  return nullptr;
}

bool CNANDContentLoader::Initialize(const std::string& name)
{
  if (name.empty())
    return false;

  m_Path = name;

  WiiWAD wad(name);
  std::vector<u8> data_app;
  std::vector<u8> tmd;
  std::vector<u8> decrypted_title_key;

  if (wad.IsValid())
  {
    m_IsWAD = true;
    m_Ticket = wad.GetTicket();
    decrypted_title_key = GetKeyFromTicket(m_Ticket);
    tmd = wad.GetTMD();
    data_app = wad.GetDataApp();
  }
  else
  {
    std::string tmd_filename(m_Path);

    if (tmd_filename.back() == '/')
      tmd_filename += "title.tmd";
    else
      m_Path = tmd_filename.substr(0, tmd_filename.find("title.tmd"));

    File::IOFile tmd_file(tmd_filename, "rb");
    if (!tmd_file)
    {
      WARN_LOG(DISCIO, "CreateFromDirectory: error opening %s", tmd_filename.c_str());
      return false;
    }

    tmd.resize(static_cast<size_t>(File::GetSize(tmd_filename)));
    tmd_file.ReadBytes(tmd.data(), tmd.size());
  }

  std::copy(&tmd[0], &tmd[TMD_HEADER_SIZE], m_TMDHeader);
  std::copy(&tmd[0x180], &tmd[0x180 + TMD_VIEW_SIZE], m_TMDView);

  m_TitleVersion = Common::swap16(&tmd[0x01DC]);
  m_NumEntries = Common::swap16(&tmd[0x01DE]);
  m_BootIndex = Common::swap16(&tmd[0x01E0]);
  m_TitleID = Common::swap64(&tmd[0x018C]);
  m_IosVersion = Common::swap16(&tmd[0x018A]);
  m_Country = static_cast<u8>(m_TitleID & 0xFF);

  if (m_Country == 2)  // SYSMENU
    m_Country = GetSysMenuRegion(m_TitleVersion);

  InitializeContentEntries(tmd, decrypted_title_key, data_app);
  return true;
}

void CNANDContentLoader::InitializeContentEntries(const std::vector<u8>& tmd,
                                                  const std::vector<u8>& decrypted_title_key,
                                                  const std::vector<u8>& data_app)
{
  m_Content.resize(m_NumEntries);

  std::array<u8, 16> iv;
  u32 data_app_offset = 0;

  for (u32 i = 0; i < m_NumEntries; i++)
  {
    const u32 entry_offset = 0x24 * i;

    SNANDContent& content = m_Content[i];
    content.m_ContentID = Common::swap32(&tmd[entry_offset + 0x01E4]);
    content.m_Index = Common::swap16(&tmd[entry_offset + 0x01E8]);
    content.m_Type = Common::swap16(&tmd[entry_offset + 0x01EA]);
    content.m_Size = static_cast<u32>(Common::swap64(&tmd[entry_offset + 0x01EC]));

    const auto header_begin = std::next(tmd.begin(), entry_offset + 0x01E4);
    const auto header_end = std::next(header_begin, ArraySize(content.m_Header));
    std::copy(header_begin, header_end, content.m_Header);

    const auto hash_begin = std::next(tmd.begin(), entry_offset + 0x01F4);
    const auto hash_end = std::next(hash_begin, ArraySize(content.m_SHA1Hash));
    std::copy(hash_begin, hash_end, content.m_SHA1Hash);

    if (m_IsWAD)
    {
      u32 rounded_size = ROUND_UP(content.m_Size, 0x40);

      iv.fill(0);
      std::copy(&tmd[entry_offset + 0x01E8], &tmd[entry_offset + 0x01E8 + 2], iv.begin());

      content.m_Data = std::make_unique<CNANDContentDataBuffer>(AESDecode(
          decrypted_title_key.data(), iv.data(), &data_app[data_app_offset], rounded_size));

      data_app_offset += rounded_size;
      continue;
    }

    std::string filename;
    if (content.m_Type & 0x8000)  // shared app
      filename = CSharedContent::AccessInstance().GetFilenameFromSHA1(content.m_SHA1Hash);
    else
      filename = StringFromFormat("%s/%08x.app", m_Path.c_str(), content.m_ContentID);

    content.m_Data = std::make_unique<CNANDContentDataFile>(filename);

    // Be graceful about incorrect TMDs.
    if (File::Exists(filename))
      content.m_Size = static_cast<u32>(File::GetSize(filename));
  }
}

std::vector<u8> CNANDContentLoader::AESDecode(const u8* key, u8* iv, const u8* src, u32 size)
{
  mbedtls_aes_context aes_ctx;
  std::vector<u8> buffer(size);

  mbedtls_aes_setkey_dec(&aes_ctx, key, 128);
  mbedtls_aes_crypt_cbc(&aes_ctx, MBEDTLS_AES_DECRYPT, size, iv, src, buffer.data());

  return buffer;
}

std::vector<u8> CNANDContentLoader::GetKeyFromTicket(const std::vector<u8>& ticket)
{
  const u8 common_key[16] = {0xeb, 0xe4, 0x2a, 0x22, 0x5e, 0x85, 0x93, 0xe4,
                             0x48, 0xd9, 0xc5, 0x45, 0x73, 0x81, 0xaa, 0xf7};
  u8 iv[16] = {};

  std::copy(&ticket[0x01DC], &ticket[0x01DC + 8], iv);
  return AESDecode(common_key, iv, &ticket[0x01BF], 16);
}

DiscIO::Country CNANDContentLoader::GetCountry() const
{
  if (!IsValid())
    return DiscIO::Country::COUNTRY_UNKNOWN;

  return CountrySwitch(m_Country);
}

CNANDContentManager::~CNANDContentManager()
{
}

const CNANDContentLoader& CNANDContentManager::GetNANDLoader(const std::string& content_path)
{
  auto it = m_map.find(content_path);
  if (it != m_map.end())
    return *it->second;
  return *m_map
              .emplace_hint(it, std::make_pair(content_path,
                                               std::make_unique<CNANDContentLoader>(content_path)))
              ->second;
}

const CNANDContentLoader& CNANDContentManager::GetNANDLoader(u64 title_id,
                                                             Common::FromWhichRoot from)
{
  std::string path = Common::GetTitleContentPath(title_id, from);
  return GetNANDLoader(path);
}

bool CNANDContentManager::RemoveTitle(u64 title_id, Common::FromWhichRoot from)
{
  auto& loader = GetNANDLoader(title_id, from);
  if (!loader.IsValid())
    return false;
  loader.RemoveTitle();
  return GetNANDLoader(title_id, from).IsValid();
}

void CNANDContentManager::ClearCache()
{
  m_map.clear();
}

void CNANDContentLoader::RemoveTitle() const
{
  INFO_LOG(DISCIO, "RemoveTitle %08x/%08x", (u32)(m_TitleID >> 32), (u32)m_TitleID);
  if (IsValid())
  {
    // remove TMD?
    for (u32 i = 0; i < m_NumEntries; i++)
    {
      if (!(m_Content[i].m_Type & 0x8000))  // skip shared apps
      {
        std::string filename =
            StringFromFormat("%s/%08x.app", m_Path.c_str(), m_Content[i].m_ContentID);
        INFO_LOG(DISCIO, "Delete %s", filename.c_str());
        File::Delete(filename);
      }
    }
    CNANDContentManager::Access().ClearCache();  // deletes 'this'
  }
}

cUIDsys::cUIDsys()
{
  UpdateLocation();
}

void cUIDsys::UpdateLocation()
{
  m_Elements.clear();
  m_LastUID = 0x00001000;
  m_UidSys = File::GetUserPath(D_SESSION_WIIROOT_IDX) + "/sys/uid.sys";

  File::IOFile pFile(m_UidSys, "rb");
  SElement Element;
  while (pFile.ReadArray(&Element, 1))
  {
    *(u32*)&(Element.UID) = Common::swap32(m_LastUID++);
    m_Elements.push_back(Element);
  }
  pFile.Close();

  if (m_Elements.empty())
  {
    *(u64*)&(Element.titleID) = Common::swap64(TITLEID_SYSMENU);
    *(u32*)&(Element.UID) = Common::swap32(m_LastUID++);

    File::CreateFullPath(m_UidSys);
    pFile.Open(m_UidSys, "wb");
    if (!pFile.WriteArray(&Element, 1))
      ERROR_LOG(DISCIO, "Failed to write to %s", m_UidSys.c_str());
  }
}

cUIDsys::~cUIDsys()
{
}

u32 cUIDsys::GetUIDFromTitle(u64 title_id)
{
  for (auto& Element : m_Elements)
  {
    if (Common::swap64(title_id) == *(u64*)&(Element.titleID))
    {
      return Common::swap32(Element.UID);
    }
  }
  return 0;
}

void cUIDsys::AddTitle(u64 title_id)
{
  if (GetUIDFromTitle(title_id))
  {
    INFO_LOG(DISCIO, "Title %08x%08x, already exists in uid.sys", (u32)(title_id >> 32),
             (u32)title_id);
    return;
  }

  SElement Element;
  *(u64*)&(Element.titleID) = Common::swap64(title_id);
  *(u32*)&(Element.UID) = Common::swap32(m_LastUID++);
  m_Elements.push_back(Element);

  File::CreateFullPath(m_UidSys);
  File::IOFile pFile(m_UidSys, "ab");

  if (!pFile.WriteArray(&Element, 1))
    ERROR_LOG(DISCIO, "fwrite failed");
}

void cUIDsys::GetTitleIDs(std::vector<u64>& title_ids, bool owned)
{
  for (auto& Element : m_Elements)
  {
    if ((owned &&
         Common::CheckTitleTIK(Common::swap64(Element.titleID), Common::FROM_SESSION_ROOT)) ||
        (!owned &&
         Common::CheckTitleTMD(Common::swap64(Element.titleID), Common::FROM_SESSION_ROOT)))
      title_ids.push_back(Common::swap64(Element.titleID));
  }
}

u64 CNANDContentManager::Install_WiiWAD(const std::string& filename)
{
  if (filename.find(".wad") == std::string::npos)
    return 0;
  const CNANDContentLoader& content_loader = GetNANDLoader(filename);
  if (content_loader.IsValid() == false)
    return 0;

  u64 title_id = content_loader.GetTitleID();

  // copy WAD's TMD header and contents to content directory

  std::string content_path(Common::GetTitleContentPath(title_id, Common::FROM_CONFIGURED_ROOT));
  std::string tmd_filename(Common::GetTMDFileName(title_id, Common::FROM_CONFIGURED_ROOT));
  File::CreateFullPath(tmd_filename);

  File::IOFile tmd_file(tmd_filename, "wb");
  if (!tmd_file)
  {
    PanicAlertT("WAD installation failed: error creating %s", tmd_filename.c_str());
    return 0;
  }

  tmd_file.WriteBytes(content_loader.GetTMDHeader(), CNANDContentLoader::TMD_HEADER_SIZE);

  for (u32 i = 0; i < content_loader.GetContentSize(); i++)
  {
    const SNANDContent& content = content_loader.GetContent()[i];

    tmd_file.WriteBytes(content.m_Header, CNANDContentLoader::CONTENT_HEADER_SIZE);

    std::string app_filename;
    if (content.m_Type & 0x8000)  // shared
      app_filename = CSharedContent::AccessInstance().AddSharedContent(content.m_SHA1Hash);
    else
      app_filename = StringFromFormat("%s%08x.app", content_path.c_str(), content.m_ContentID);

    if (!File::Exists(app_filename))
    {
      File::CreateFullPath(app_filename);
      File::IOFile app_file(app_filename, "wb");
      if (!app_file)
      {
        PanicAlertT("WAD installation failed: error creating %s", app_filename.c_str());
        return 0;
      }

      app_file.WriteBytes(content.m_Data->Get().data(), content.m_Size);
    }
    else
    {
      INFO_LOG(DISCIO, "Content %s already exists.", app_filename.c_str());
    }
  }

  // Extract and copy WAD's ticket to ticket directory
  if (!AddTicket(title_id, content_loader.GetTicket()))
  {
    PanicAlertT("WAD installation failed: error creating ticket");
    return 0;
  }

  cUIDsys::AccessInstance().AddTitle(title_id);

  ClearCache();

  return title_id;
}

bool AddTicket(u64 title_id, const std::vector<u8>& ticket)
{
  std::string ticket_filename = Common::GetTicketFileName(title_id, Common::FROM_CONFIGURED_ROOT);
  File::CreateFullPath(ticket_filename);

  File::IOFile ticket_file(ticket_filename, "wb");
  if (!ticket_file)
    return false;

  return ticket_file.WriteBytes(ticket.data(), ticket.size());
}

}  // namespace end