#include <cstdint>
#include <iostream>
#include <memory>
#include <vector>

#include <logvisor/logvisor.hpp>
#include "tinyxml2/tinyxml2.h"

#ifndef _WIN32
#include <cstdlib>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/statvfs.h>
#include <cerrno>
#else
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN 1
#endif
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <Windows.h>
#include <cwchar>
#define strncasecmp _strnicmp
#define strcasecmp _stricmp
#if UNICODE
#define IS_UCS2 1
#endif
#endif

namespace {
logvisor::Module Log("AssetNameParser");

// TODO: Clean this up
#undef bswap16
#undef bswap32
#undef bswap64

/* Type-sensitive byte swappers */
template <typename T>
constexpr T bswap16(T val) {
#if __GNUC__
  return __builtin_bswap16(val);
#elif _WIN32
  return _byteswap_ushort(val);
#else
  return (val = (val << 8) | ((val >> 8) & 0xFF));
#endif
}

template <typename T>
constexpr T bswap32(T val) {
#if __GNUC__
  return __builtin_bswap32(val);
#elif _WIN32
  return _byteswap_ulong(val);
#else
  val = (val & 0x0000FFFF) << 16 | (val & 0xFFFF0000) >> 16;
  val = (val & 0x00FF00FF) << 8 | (val & 0xFF00FF00) >> 8;
  return val;
#endif
}

template <typename T>
constexpr T bswap64(T val) {
#if __GNUC__
  return __builtin_bswap64(val);
#elif _WIN32
  return _byteswap_uint64(val);
#else
  return ((val & 0xFF00000000000000ULL) >> 56) | ((val & 0x00FF000000000000ULL) >> 40) |
         ((val & 0x0000FF0000000000ULL) >> 24) | ((val & 0x000000FF00000000ULL) >> 8) |
         ((val & 0x00000000FF000000ULL) << 8) | ((val & 0x0000000000FF0000ULL) << 24) |
         ((val & 0x000000000000FF00ULL) << 40) | ((val & 0x00000000000000FFULL) << 56);
#endif
}

#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
constexpr uint32_t SBig(uint32_t val) { return bswap32(val); }
constexpr uint64_t SBig(uint64_t val) { return bswap64(val); }
#ifndef SBIG
#define SBIG(q) (((q)&0x000000FF) << 24 | ((q)&0x0000FF00) << 8 | ((q)&0x00FF0000) >> 8 | ((q)&0xFF000000) >> 24)
#endif

#ifndef SLITTLE
#define SLITTLE(q) (q)
#endif
#else
#ifndef SLITTLE
#define SLITTLE(q) (((q)&0x000000FF) << 24 | ((q)&0x0000FF00) << 8 | ((q)&0x00FF0000) >> 8 | ((q)&0xFF000000) >> 24)
#endif

constexpr uint32_t SBig(uint32_t val) { return val; }
constexpr uint64_t SBig(uint64_t val) { return val; }
#ifndef SBIG
#define SBIG(q) (q)
#endif
#endif

class FourCC {
protected:
  union {
    char fcc[4];
    uint32_t num;
  };

public:
  FourCC() /* Sentinel FourCC */
  : num(0) {}
  FourCC(const FourCC& other) { num = other.num; }
  FourCC(const char* name) : num(*(uint32_t*)name) {}
  FourCC(uint32_t n) : num(n) {}
  bool operator==(const FourCC& other) const { return num == other.num; }
  bool operator!=(const FourCC& other) const { return num != other.num; }
  bool operator==(const char* other) const { return num == *(uint32_t*)other; }
  bool operator!=(const char* other) const { return num != *(uint32_t*)other; }
  bool operator==(int32_t other) const { return num == other; }
  bool operator!=(int32_t other) const { return num != other; }
  bool operator==(uint32_t other) const { return num == other; }
  bool operator!=(uint32_t other) const { return num != other; }
  std::string toString() const { return std::string(fcc, 4); }
  uint32_t toUint32() const { return num; }
  operator uint32_t() const { return num; }
};

struct SAsset {
  FourCC type;
  uint64_t id;
  std::string name;
  std::string dir;
};

enum class FileLockType { None = 0, Read, Write };

#if IS_UCS2
using SystemChar = wchar_t;
using SystemString = std::wstring;
#ifndef _SYS_STR
#define _SYS_STR(val) L##val
#endif
using Sstat = struct _stat;
#else
using SystemChar = char;
using SystemString = std::string;
#ifndef _SYS_STR
#define _SYS_STR(val) val
#endif
using Sstat = struct stat;
#endif

struct FILEDeleter {
  void operator()(FILE* file) const { std::fclose(file); }
};
using FILEPtr = std::unique_ptr<FILE, FILEDeleter>;

FILEPtr Fopen(const SystemChar* path, const SystemChar* mode, FileLockType lock = FileLockType::None) {
#if IS_UCS2
  FILEPtr fp{_wfopen(path, mode)};
  if (!fp) {
    return nullptr;
  }
#else
  FILEPtr fp{std::fopen(path, mode)};
  if (!fp) {
    return nullptr;
  }
#endif

  if (lock != FileLockType::None) {
#if _WIN32
    OVERLAPPED ov = {};
    LockFileEx((HANDLE)(uintptr_t)_fileno(fp.get()), (lock == FileLockType::Write) ? LOCKFILE_EXCLUSIVE_LOCK : 0, 0, 0,
               1, &ov);
#else
    if (flock(fileno(fp.get()), ((lock == FileLockType::Write) ? LOCK_EX : LOCK_SH) | LOCK_NB)) {
      std::fprintf(stderr, "flock %s: %s", path, strerror(errno));
    }
#endif
  }

  return fp;
}
} // Anonymous namespace

#if _WIN32
int wmain(int argc, const wchar_t* argv[])
#else
int main(int argc, const char* argv[])
#endif
{
  logvisor::RegisterStandardExceptions();
  logvisor::RegisterConsoleLogger();
  if (argc < 3) {
    Log.report(logvisor::Error, FMT_STRING(_SYS_STR("Usage: {} <input> <output>")), argv[0]);
    return 1;
  }

  SystemString inPath = argv[1];
  SystemString outPath = argv[2];

  tinyxml2::XMLDocument doc;
  std::vector<SAsset> assets;
  FILEPtr docF = Fopen(inPath.c_str(), _SYS_STR("rb"));
  if (doc.LoadFile(docF.get()) == tinyxml2::XML_SUCCESS) {
    const tinyxml2::XMLElement* elm = doc.RootElement();
    if (strcmp(elm->Name(), "AssetNameMap") != 0) {
      Log.report(logvisor::Fatal, FMT_STRING(_SYS_STR("Invalid database supplied")));
      return 1;
    }

    elm = elm->FirstChildElement("AssetNameMap");
    if (elm == nullptr) {
      Log.report(logvisor::Fatal, FMT_STRING(_SYS_STR("Malformed AssetName database")));
      return 1;
    }

    elm = elm->FirstChildElement("Asset");

    while (elm != nullptr ) {
      const tinyxml2::XMLElement* keyElm = elm->FirstChildElement("Key");
      const tinyxml2::XMLElement* valueElm = elm->FirstChildElement("Value");

      if (keyElm == nullptr || valueElm == nullptr) {
        Log.report(logvisor::Fatal, FMT_STRING(_SYS_STR("Malformed Asset entry, [Key,Value] required")));
        return 0;
      }

      const tinyxml2::XMLElement* nameElm = valueElm->FirstChildElement("Name");
      const tinyxml2::XMLElement* dirElm = valueElm->FirstChildElement("Directory");
      const tinyxml2::XMLElement* typeElm = valueElm->FirstChildElement("Type");
      const tinyxml2::XMLElement* autoGenNameElm = valueElm->FirstChildElement("AutoGenName");
      const tinyxml2::XMLElement* autoGenDirElm = valueElm->FirstChildElement("AutoGenDir");

      if (nameElm == nullptr || dirElm == nullptr || typeElm == nullptr) {
        Log.report(logvisor::Fatal, FMT_STRING(_SYS_STR("Malformed Value entry, [Name,Directory,Type] required")));
        return 0;
      }
      assets.emplace_back();
      bool autoGen = strncasecmp(autoGenNameElm->GetText(), "true", 4) == 0 && strncasecmp(autoGenDirElm->GetText(), "true", 4) == 0;
      if (!autoGen) {
        SAsset& asset = assets.back();
        asset.type = typeElm->GetText();
        asset.id = strtoull(keyElm->GetText(), nullptr, 16);
        asset.name = nameElm->GetText();
        asset.dir = dirElm->GetText();
      }
      elm = elm->NextSiblingElement("Asset");
    }

    FILEPtr f = Fopen(outPath.c_str(), _SYS_STR("wb"));
    if (f == nullptr) {
      Log.report(logvisor::Fatal, FMT_STRING(_SYS_STR("Unable to open destination")));
      return 0;
    }

    uint32_t assetCount = SBig(uint32_t(assets.size()));
    FourCC sentinel(SBIG('AIDM'));
    fwrite(&sentinel, sizeof(sentinel), 1, f.get());
    fwrite(&assetCount, sizeof(assetCount), 1, f.get());
    for (const SAsset& asset : assets) {
      fwrite(&asset.type, sizeof(asset.type), 1, f.get());
      uint64_t id = SBig(asset.id);
      fwrite(&id, sizeof(id), 1, f.get());
      uint32_t tmp = SBig(uint32_t(asset.name.length()));
      fwrite(&tmp, sizeof(tmp), 1, f.get());
      fwrite(asset.name.c_str(), 1, SBig(tmp), f.get());
      tmp = SBig(uint32_t(asset.dir.length()));
      fwrite(&tmp, sizeof(tmp), 1, f.get());
      fwrite(asset.dir.c_str(), SBig(tmp), 1, f.get());
    }
    fflush(f.get());
    return 0;
  }

  Log.report(logvisor::Fatal, FMT_STRING(_SYS_STR("failed to load")));
  return 1;
}