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

#include <cstddef>
#include <memory>
#include <string>

#include "Common/Assert.h"
#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "Common/Logging/Log.h"
#include "Common/MathUtil.h"
#include "DiscIO/Blob.h"
#include "DiscIO/WiiWad.h"

namespace DiscIO
{
namespace
{
std::vector<u8> CreateWADEntry(IBlobReader& reader, u32 size, u64 offset)
{
  if (size == 0)
    return {};

  std::vector<u8> buffer(size);

  if (!reader.Read(offset, size, buffer.data()))
  {
    ERROR_LOG(DISCIO, "WiiWAD: Could not read from file");
    PanicAlertT("WiiWAD: Could not read from file");
  }

  return buffer;
}

bool IsWiiWAD(const CBlobBigEndianReader& reader)
{
  u32 header_size = 0;
  u32 header_type = 0;
  reader.ReadSwapped(0x0, &header_size);
  reader.ReadSwapped(0x4, &header_type);
  return header_size == 0x20 && (header_type == 0x49730000 || header_type == 0x69620000);
}
}  // Anonymous namespace

WiiWAD::WiiWAD(const std::string& name)
{
  std::unique_ptr<IBlobReader> reader(CreateBlobReader(name));
  if (reader == nullptr || File::IsDirectory(name))
  {
    m_valid = false;
    return;
  }

  m_valid = ParseWAD(*reader);
}

WiiWAD::~WiiWAD()
{
}

bool WiiWAD::ParseWAD(IBlobReader& reader)
{
  CBlobBigEndianReader big_endian_reader(reader);

  if (!IsWiiWAD(big_endian_reader))
    return false;

  u32 certificate_chain_size;
  u32 reserved;
  u32 ticket_size;
  u32 tmd_size;
  u32 data_app_size;
  u32 footer_size;

  if (!big_endian_reader.ReadSwapped(0x08, &certificate_chain_size) ||
      !big_endian_reader.ReadSwapped(0x0C, &reserved) ||
      !big_endian_reader.ReadSwapped(0x10, &ticket_size) ||
      !big_endian_reader.ReadSwapped(0x14, &tmd_size) ||
      !big_endian_reader.ReadSwapped(0x18, &data_app_size) ||
      !big_endian_reader.ReadSwapped(0x1C, &footer_size))
    return false;

  if (MAX_LOGLEVEL >= LogTypes::LOG_LEVELS::LDEBUG)
    _dbg_assert_msg_(BOOT, reserved == 0x00, "WiiWAD: Reserved must be 0x00");

  u32 offset = 0x40;
  m_certificate_chain = CreateWADEntry(reader, certificate_chain_size, offset);
  offset += ROUND_UP(certificate_chain_size, 0x40);
  m_ticket = CreateWADEntry(reader, ticket_size, offset);
  offset += ROUND_UP(ticket_size, 0x40);
  m_tmd = CreateWADEntry(reader, tmd_size, offset);
  offset += ROUND_UP(tmd_size, 0x40);
  m_data_app = CreateWADEntry(reader, data_app_size, offset);
  offset += ROUND_UP(data_app_size, 0x40);
  m_footer = CreateWADEntry(reader, footer_size, offset);
  offset += ROUND_UP(footer_size, 0x40);

  return true;
}

}  // namespace DiscIO