#include <iostream>
#include <fstream>
#include <unistd.h>
#include <pwd.h>
#include <vector>
#include <cstring>
#include <openssl/md5.h> /* md5sum */

#include "../include/etw-lmm_config.h"
#include "../include/rapidjson/document.h"


std::string to_hex(unsigned char*);
void md5sum(std::string, unsigned char [MD5_DIGEST_LENGTH]);
void print_md5_sum(unsigned char*);
int calibrate_preferences();
int calibrate_text_bug_fix();
int calibrate_backup(const std::string&);
int yn_query(const std::string&, bool);
int dir_not_exists(const std::string&);

/**
* Brings up the command list/help menu
*/
void help_menu()
{
  std::cout << "EMPIRE: TOTAL WAR -- LINUX MOD MANAGER "
            << std::to_string(etw_lmm_VERSION_MAJOR) << "." << std::to_string(etw_lmm_VERSION_MINOR) << "\n"
            << "Options:\n"
            << "\thelp\t\tShow this help message\n"
            << "\tinstall [MOD]\tInstall a mod\n"
            << "\tuninstall [MOD]\tUninstall a mod\n"
            << "\tcalibrate\tCalibrate original game files for modding\n"
            << "\tlist\t\tList installed mods\n"
            << "\tquery [MOD]\tQuery available mods"
            << std::endl;
}

/**
* Lists installed mods in mods filepath
*
* @param Path for file MODS
*/
int list(const std::string& hd)
{
  const std::string mods = hd + "/.config/etw-lmm/MODS";

  /* If file MODS doesn't exist */
  if (access(mods.c_str(), F_OK) == -1)
  {
    std::cout << "No mods installed!";
    return 0;
  }

  std::ifstream ioMODS(mods);
  std::string name;

  while (std::getline (ioMODS, name))
  {
    if (name == "\0")
    {
      std::cout << "No mods installed!";
    }
    std::cout << name << std::endl;
  }

  ioMODS.close();

  return 0;
}

int calibrate(const std::string& hd, const std::vector<std::string>& path, const char* path_md5[])
{
  const std::string mods = hd + "/.config/etw-lmm/MODS";

  /* If file MODS exists */
  if (access(mods.c_str(), F_OK) != -1)
  {
    std::ifstream ioMODS(mods);
    std::string name;

    std::getline (ioMODS, name);
    if (name != "\0")
    {
      std::cerr << "Either get a fresh install of Empire: Total War or uninstall the following mods: " << std::endl;
      list(mods);
      ioMODS.close();
      return 1;
    }

    ioMODS.close();
  }

  unsigned int x = 0;

  std::cout << "No mods installed! Calibrating files now..." << std::endl;
  for (unsigned int i = 0; i < path.size(); i++)
  {
    unsigned char md5_local[MD5_DIGEST_LENGTH];
    md5sum(path[i], md5_local);
    if ((strcmp(to_hex(md5_local).c_str(), path_md5[i]) != 0))
    {
      /* write_preferences_at_exit false in preferences.empire_script.txt */
      if (i == 0 && to_hex(md5_local) == "fbf65ef80563e0bd76836c150e49ecd0")
      {
        if (calibrate_preferences())
        {
          return 1;
        }

        continue;
      }

      /* preferences has VBOSurfaces set to 1, TEXT BUG FIX */
      if (i == 1 && to_hex(md5_local) == "1d7c5d84f79a3d361bfa7c608b71d8c8")
      {
        if (calibrate_text_bug_fix())
        {
          return 1;
        }

        continue;
      }
      print_md5_sum(md5_local);
      std::cerr << " != " << path_md5[i] << "\n" << path[i] << " is not calibrated!" << std::endl;
      x++;
    }
  }

  if (x > 0)
  {
    std::cerr << "Number of files uncalibrated: " << x << std::endl;
    return 1;
  }

  std::cout << "All files are calibrated!" << std::endl;

  /* GAME FILE BACKUPS */

  if (calibrate_backup(hd))
  {
    if (yn_query("Would you like to backup your game files? This is recommended.", true))
    {
      std::cout << "Backing up files now..." << std::endl;

      const std::string dir_main_backup = hd + "/.local/share/Steam/steamapps/common/Empire\ Total\ War/data/campaigns/main_backup";
      const std::string dir_global_map_backup = hd + "/.local/share/Steam/steamapps/common/Empire\ Total\ War/data/campaign_maps/global_map_backup";

      if (dir_not_exists(dir_main_backup))
      {
        const std::string dir_main = hd + "/.local/share/Steam/steamapps/common/Empire\ Total\ War/data/campaigns/main/";

        const std::string backup_main = "cp -R " + dir_main + ". " + dir_main_backup;

        if (system(backup_main.c_str()))
        {
          std::cerr << "Failed to backup data/campaigns/main/!" << std::endl;
          return 1;
        }
      }

      if (dir_not_exists(dir_global_map_backup))
      {
        const std::string dir_global_map = hd + "/.local/share/Steam/steamapps/common/Empire\ Total\ War/data/campaign_maps/global_map/";

        const std::string backup_global_map = "cp -R " + dir_global_map + ". " + dir_global_map_backup;

        if (system(backup_global_map.c_str()))
        {
          std::cerr << "Failed to backup data/campaign_map/global_map/!" << std::endl;
          return 1;
        }
      }

      std::cout << "Critical game data is now backed up!" << std::endl;
    }
  }

  std::cout << "The game is now ready to install mods." << std::endl;

  return 0;
}