#include "GameData.h"

#include <string>
#include <sstream>
#include <algorithm>

#include <map>
#include <utility>
#include <zlib/zlib.h>

#include "bparse.h"
#include "DatCat.h"
#include "File.h"

namespace {
// Relation between category number and category name
// These names are taken straight from the exe, it helps resolve dispatching when getting files by path

std::unordered_map< std::string, uint32_t > categoryNameToIdMap =
  { { "common",      0x00 },
    { "bgcommon",    0x01 },
    { "bg",          0x02 },
    { "cut",         0x03 },
    { "chara",       0x04 },
    { "shader",      0x05 },
    { "ui",          0x06 },
    { "sound",       0x07 },
    { "vfx",         0x08 },
    { "ui_script",   0x09 },
    { "exd",         0x0A },
    { "game_script", 0x0B },
    { "music",       0x0C }
  };

std::unordered_map< uint32_t, std::string > categoryIdToNameMap =
  { { 0x00, "common" },
    { 0x01, "bgcommon" },
    { 0x02, "bg" },
    { 0x03, "cut" },
    { 0x04, "chara" },
    { 0x05, "shader" },
    { 0x06, "ui" },
    { 0x07, "sound" },
    { 0x08, "vfx" },
    { 0x09, "ui_script" },
    { 0x0A, "exd" },
    { 0x0B, "game_script" },
    { 0x0C, "music" } };
}

namespace xiv::dat
{
  GameData::GameData( std::filesystem::path path ) try :
    m_path( std::move( path ) )
  {
    int maxExLevel = 0;

    // msvc has retarded stdlib implementation
  #ifdef _WIN32
    static constexpr auto sep = "\\";
  #else
    static constexpr auto sep = std::filesystem::path::preferred_separator;
  #endif

    // Determine which expansions are available
    while( std::filesystem::exists( std::filesystem::path(
      m_path.string() + sep + "ex" + std::to_string( maxExLevel + 1 ) + sep + "ex" + std::to_string( maxExLevel + 1 ) +
      ".ver" ) ) )
    {
      maxExLevel++;
    }


    // Iterate over the files in path
    for( auto it = std::filesystem::directory_iterator( m_path.string() + "//ffxiv" );
         it != std::filesystem::directory_iterator(); ++it )
    {
      // Get the filename of the current element
      auto filename = it->path().filename().string();

      // If it contains ".win32.index" this is most likely a hit for a category
      if( filename.find( ".win32.index" ) != std::string::npos && filename.find( ".win32.index2" ) == std::string::npos )
      {
        // Format of indexes is XX0000.win32.index, so fetch the hex number for category number
        std::istringstream iss( filename.substr( 0, 2 ) );
        uint32_t cat_nb;
        iss >> std::hex >> cat_nb;


        // Add to the list of category number
        // creates the empty category in the cats map
        // instantiate the creation mutex for this category
        m_catNums.push_back( cat_nb );
        m_cats[ cat_nb ] = std::unique_ptr< Cat >();
        m_catCreationMutexes[ cat_nb ] = std::make_unique< std::mutex >();

        // Check for expansion
        for( int exNum = 1; exNum <= maxExLevel; exNum++ )
        {
          const std::string path =
            m_path.string() + sep + buildDatStr( "ex" + std::to_string( exNum ), cat_nb, exNum, 0, "win32", "index" );

          if( std::filesystem::exists( std::filesystem::path( path ) ) )
          {

            int chunkCount = 0;

            for( int chunkTest = 0; chunkTest < 256; chunkTest++ )
            {
              if( std::filesystem::exists( m_path.string() + sep +
                                           buildDatStr( "ex" + std::to_string( exNum ), cat_nb, exNum, chunkTest, "win32",
                                                        "index" ) ) )
              {
                m_exCats[ cat_nb ].exNumToChunkMap[ exNum ].chunkToCatMap[ chunkTest ] = std::unique_ptr< Cat >();
                chunkCount++;
              }
            }

          }
        }
      }
    }

  }
  catch( std::exception& e )
  {
    // In case of failure here, client is supposed to catch the exception because it is not recoverable on our side
    throw std::runtime_error( "GameData initialization failed: " + std::string( e.what() ) );
  }

  GameData::~GameData()
  {

  }

  const std::string GameData::buildDatStr( const std::string folder, const int cat, const int exNum, const int chunk,
                                           const std::string platform, const std::string type )
  {
    char dat[1024];
    sprintf( dat, "%s/%02x%02x%02x.%s.%s", folder.c_str(), cat, exNum, chunk, platform.c_str(), type.c_str() );
    return std::string( dat );
  }

  const std::vector< uint32_t >& GameData::getCatNumbers() const
  {
    return m_catNums;
  }

  std::unique_ptr< File > GameData::getFile( const std::string& path )
  {
    // Get the hashes, the category from the path then call the getFile of the category
    uint32_t dirHash;
    uint32_t filenameHash;
    getHashes( path, dirHash, filenameHash );

    return getCategoryFromPath( path ).getFile( dirHash, filenameHash );
  }

  bool GameData::doesFileExist( const std::string& path )
  {
    uint32_t dirHash;
    uint32_t filenameHash;
    getHashes( path, dirHash, filenameHash );

    return getCategoryFromPath( path ).doesFileExist( dirHash, filenameHash );
  }

  bool GameData::doesDirExist( const std::string& i_path )
  {
    uint32_t dirHash;
    uint32_t filenameHash;
    getHashes( i_path, dirHash, filenameHash );

    return getCategoryFromPath( i_path ).doesDirExist( dirHash );
  }

  const Cat& GameData::getCategory( uint32_t catNum )
  {
    // Check that the category number exists
    auto catIt = m_cats.find( catNum );
    if( catIt == m_cats.end() )
    {
      throw std::runtime_error( "Category not found: " + std::to_string( catNum ) );
    }

    // If it exists and already instantiated return it
    if( catIt->second )
    {
      return *( catIt->second );
    }
    else
    {
      // Else create it and return it
      createCategory( catNum );
      return *( m_cats[ catNum ] );
    }
  }

  const Cat& GameData::getCategory( const std::string& catName )
  {
    // Find the category number from the name
    auto categoryNameToIdMapIt = ::categoryNameToIdMap.find( catName );
    if( categoryNameToIdMapIt == ::categoryNameToIdMap.end() )
    {
      throw std::runtime_error( "Category not found: " + catName );
    }

    // From the category number return the category
    return getCategory( categoryNameToIdMapIt->second );
  }

  const Cat& GameData::getExCategory( const std::string& catName, uint32_t exNum, const std::string& path )
  {
    // Find the category number from the name
    auto categoryMapIt = ::categoryNameToIdMap.find( catName );
    if( categoryMapIt == ::categoryNameToIdMap.end() )
    {
      throw std::runtime_error( "Category not found: " + catName );
    }

    uint32_t dirHash;
    uint32_t filenameHash;
    getHashes( path, dirHash, filenameHash );

    for( auto const& chunk : m_exCats[ categoryMapIt->second ].exNumToChunkMap[ exNum ].chunkToCatMap )
    {
      if( !chunk.second )
        createExCategory( categoryMapIt->second );

      if( chunk.second->doesFileExist( dirHash, filenameHash ) )
      {
        return *( chunk.second );
      }
    }

    throw std::runtime_error( "Chunk not found for path: " + path );
  }

  const Cat& GameData::getCategoryFromPath( const std::string& path )
  {
    // Find the first / in the string, paths are in the format CAT_NAME/..../.../../....
    auto firstSlashPos = path.find( '/' );
    if( firstSlashPos == std::string::npos )
    {
      throw std::runtime_error( "Path does not have a / char: " + path );
    }

    if( path.substr( firstSlashPos + 1, 2 ) == "ex" )
    {
      return getExCategory( path.substr( 0, firstSlashPos ), std::stoi( path.substr( firstSlashPos + 3, 1 ) ), path );
    }
    else
    {
      // From the sub string found beforethe first / get the category
      return getCategory( path.substr( 0, firstSlashPos ) );
    }
  }

  void GameData::getHashes( const std::string& path, uint32_t& dirHash, uint32_t& filenameHash ) const
  {
    // Convert the path to lowercase before getting the hashes
    std::string pathLower;
    pathLower.resize( path.size() );
    std::transform( path.begin(), path.end(), pathLower.begin(), ::tolower );

    // Find last / to separate dir from filename
    auto lastSlashPos = pathLower.rfind( '/' );
    if( lastSlashPos == std::string::npos )
    {
      throw std::runtime_error( "Path does not have a / char: " + path );
    }

    std::string dirPart = pathLower.substr( 0, lastSlashPos );
    std::string filenamePart = pathLower.substr( lastSlashPos + 1 );

    // Get the crc32 values from zlib, to compensate the final XOR 0xFFFFFFFF that isnot done in the exe we just reXOR
    dirHash = crc32( 0, reinterpret_cast< const uint8_t* >( dirPart.data() ), static_cast< uInt >( dirPart.size() ) ) ^ 0xFFFFFFFF;
    filenameHash = crc32( 0, reinterpret_cast< const uint8_t* >( filenamePart.data() ), static_cast< uInt >( filenamePart.size() ) ) ^ 0xFFFFFFFF;
  }

  void GameData::createCategory( uint32_t catNum )
  {
    // Lock mutex in this scope
    std::lock_guard< std::mutex > lock( *( m_catCreationMutexes[ catNum ] ) );
    // Maybe after unlocking it has already been created, so check (most likely if it blocked)
    if( !m_cats[ catNum ] )
    {
      // Get the category name if we have it
      std::string catName;
      auto categoryMapIt = ::categoryIdToNameMap.find( catNum );
      if( categoryMapIt != ::categoryIdToNameMap.end() )
      {
        catName = categoryMapIt->second;
      }

      // Actually creates the category
      m_cats[ catNum ] = std::make_unique< Cat >( m_path, catNum, catName );
    }
  }

  void GameData::createExCategory( uint32_t catNum )
  {
    // Maybe after unlocking it has already been created, so check (most likely if it blocked)
    if( !m_exCats[ catNum ].exNumToChunkMap[ 1 ].chunkToCatMap[ 0 ] )
    {
      // Get the category name if we have it
      std::string catName;
      auto categoryMapIt = ::categoryIdToNameMap.find( catNum );
      if( categoryMapIt != ::categoryIdToNameMap.end() )
      {
        catName = categoryMapIt->second;
      }

      for( auto const& ex : m_exCats[ catNum ].exNumToChunkMap )
      {
        for( auto const& chunk : m_exCats[ catNum ].exNumToChunkMap[ ex.first ].chunkToCatMap )
        {
          // Actually creates the category
          m_exCats[ catNum ].exNumToChunkMap[ ex.first ].chunkToCatMap[ chunk.first ] = std::unique_ptr< Cat >(
            new Cat( m_path, catNum, catName, ex.first, chunk.first ) );
        }
      }
    }
  }

}