/*
Copyright (C) 2012 Sebastian Herbord. All rights reserved.

This file is part of Mod Organizer.

Mod Organizer is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Mod Organizer is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Mod Organizer.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "categories.h"

#include <log.h>
#include <report.h>
#include <utility.h>

#include <QCoreApplication>
#include <QDir>
#include <QFile>
#include <QList>
#include <QObject>

using namespace MOBase;

CategoryFactory* CategoryFactory::s_Instance = nullptr;

QString CategoryFactory::categoriesFilePath()
{
  return qApp->property("dataPath").toString() + "/categories.dat";
}

CategoryFactory::CategoryFactory()
{
  atexit(&cleanup);
}

void CategoryFactory::loadCategories()
{
  reset();

  QFile categoryFile(categoriesFilePath());

  if (!categoryFile.open(QIODevice::ReadOnly)) {
    loadDefaultCategories();
  } else {
    int lineNum = 0;
    while (!categoryFile.atEnd()) {
      QByteArray line = categoryFile.readLine();
      ++lineNum;
      QList<QByteArray> cells = line.split('|');
      if (cells.count() != 4) {
        log::error("invalid category line {}: {} ({} cells)", lineNum, line.constData(),
                   cells.count());
      } else {
        std::vector<int> nexusIDs;
        if (cells[2].length() > 0) {
          QList<QByteArray> nexusIDStrings = cells[2].split(',');
          for (QList<QByteArray>::iterator iter = nexusIDStrings.begin();
               iter != nexusIDStrings.end(); ++iter) {
            bool ok  = false;
            int temp = iter->toInt(&ok);
            if (!ok) {
              log::error("invalid category id {}", iter->constData());
            }
            nexusIDs.push_back(temp);
          }
        }
        bool cell0Ok = true;
        bool cell3Ok = true;
        int id       = cells[0].toInt(&cell0Ok);
        int parentID = cells[3].trimmed().toInt(&cell3Ok);
        if (!cell0Ok || !cell3Ok) {
          log::error("invalid category line {}: {}", lineNum, line.constData());
        }
        addCategory(id, QString::fromUtf8(cells[1].constData()), nexusIDs, parentID);
      }
    }
    categoryFile.close();
  }
  std::sort(m_Categories.begin(), m_Categories.end());
  setParents();
}

CategoryFactory& CategoryFactory::instance()
{
  if (s_Instance == nullptr) {
    s_Instance = new CategoryFactory;
  }
  return *s_Instance;
}

void CategoryFactory::reset()
{
  m_Categories.clear();
  m_IDMap.clear();
  // 28 =
  // 43 = Savegames (makes no sense to install them through MO)
  // 45 = Videos and trailers
  // 87 = Miscelanous
  addCategory(0, "None", {4, 28, 43, 45, 87}, 0);
}

void CategoryFactory::setParents()
{
  for (std::vector<Category>::iterator iter = m_Categories.begin();
       iter != m_Categories.end(); ++iter) {
    iter->m_HasChildren = false;
  }

  for (std::vector<Category>::const_iterator categoryIter = m_Categories.begin();
       categoryIter != m_Categories.end(); ++categoryIter) {
    if (categoryIter->m_ParentID != 0) {
      std::map<int, unsigned int>::const_iterator iter =
          m_IDMap.find(categoryIter->m_ParentID);
      if (iter != m_IDMap.end()) {
        m_Categories[iter->second].m_HasChildren = true;
      }
    }
  }
}

void CategoryFactory::cleanup()
{
  delete s_Instance;
  s_Instance = nullptr;
}

void CategoryFactory::saveCategories()
{
  QFile categoryFile(categoriesFilePath());

  if (!categoryFile.open(QIODevice::WriteOnly)) {
    reportError(QObject::tr("Failed to save custom categories"));
    return;
  }

  categoryFile.resize(0);
  for (std::vector<Category>::const_iterator iter = m_Categories.begin();
       iter != m_Categories.end(); ++iter) {
    if (iter->m_ID == 0) {
      continue;
    }
    QByteArray line;
    line.append(QByteArray::number(iter->m_ID))
        .append("|")
        .append(iter->m_Name.toUtf8())
        .append("|")
        .append(VectorJoin(iter->m_NexusIDs, ",").toUtf8())
        .append("|")
        .append(QByteArray::number(iter->m_ParentID))
        .append("\n");
    categoryFile.write(line);
  }
  categoryFile.close();
}

unsigned int
CategoryFactory::countCategories(std::function<bool(const Category& category)> filter)
{
  unsigned int result = 0;
  for (const Category& cat : m_Categories) {
    if (filter(cat)) {
      ++result;
    }
  }
  return result;
}

int CategoryFactory::addCategory(const QString& name, const std::vector<int>& nexusIDs,
                                 int parentID)
{
  int id = 1;
  while (m_IDMap.find(id) != m_IDMap.end()) {
    ++id;
  }
  addCategory(id, name, nexusIDs, parentID);

  saveCategories();
  return id;
}

void CategoryFactory::addCategory(int id, const QString& name,
                                  const std::vector<int>& nexusIDs, int parentID)
{
  int index = static_cast<int>(m_Categories.size());
  m_Categories.push_back(Category(index, id, name, nexusIDs, parentID));
  for (int nexusID : nexusIDs) {
    m_NexusMap[nexusID] = index;
  }
  m_IDMap[id] = index;
}

void CategoryFactory::loadDefaultCategories()
{
  // the order here is relevant as it defines the order in which the
  // mods appear in the combo box
  addCategory(1, "Animations", {2, 4, 51}, 0);
  addCategory(52, "Poses", {1, 29}, 1);
  addCategory(2, "Armour", {2, 5, 54}, 0);
  addCategory(53, "Power Armor", {1, 53}, 2);
  addCategory(3, "Audio", {3, 33, 35, 106}, 0);
  addCategory(38, "Music", {2, 34, 61}, 0);
  addCategory(39, "Voice", {2, 36, 107}, 0);
  addCategory(5, "Clothing", {2, 9, 60}, 0);
  addCategory(41, "Jewelry", {1, 102}, 5);
  addCategory(42, "Backpacks", {1, 49}, 5);
  addCategory(6, "Collectables", {2, 10, 92}, 0);
  addCategory(28, "Companions", {3, 11, 66, 96}, 0);
  addCategory(7, "Creatures, Mounts, & Vehicles", {4, 12, 65, 83, 101}, 0);
  addCategory(8, "Factions", {2, 16, 25}, 0);
  addCategory(9, "Gameplay", {2, 15, 24}, 0);
  addCategory(27, "Combat", {1, 77}, 9);
  addCategory(43, "Crafting", {2, 50, 100}, 9);
  addCategory(48, "Overhauls", {2, 24, 79}, 9);
  addCategory(49, "Perks", {1, 27}, 9);
  addCategory(54, "Radio", {1, 31}, 9);
  addCategory(55, "Shouts", {1, 104}, 9);
  addCategory(22, "Skills & Levelling", {2, 46, 73}, 9);
  addCategory(58, "Weather & Lighting", {1, 56}, 9);
  addCategory(44, "Equipment", {1, 44}, 43);
  addCategory(45, "Home/Settlement", {1, 45}, 43);
  addCategory(10, "Body, Face, & Hair", {2, 17, 26}, 0);
  addCategory(56, "Tattoos", {1, 57}, 10);
  addCategory(40, "Character Presets", {1, 58}, 0);
  addCategory(11, "Items", {2, 27, 85}, 0);
  addCategory(32, "Mercantile", {2, 23, 69}, 0);
  addCategory(37, "Ammo", {1, 3}, 11);
  addCategory(19, "Weapons", {2, 41, 55}, 11);
  addCategory(36, "Weapon & Armour Sets", {1, 42}, 11);
  addCategory(23, "Player Homes", {2, 28, 67}, 0);
  addCategory(25, "Castles & Mansions", {1, 68}, 23);
  addCategory(51, "Settlements", {1, 48}, 23);
  addCategory(12, "Locations", {10, 20, 21, 22, 30, 47, 70, 88, 89, 90, 91}, 0);
  addCategory(4, "Cities", {1, 53}, 12);
  addCategory(31, "Landscape Changes", {1, 58}, 0);
  addCategory(29, "Environment", {2, 14, 74}, 0);
  addCategory(30, "Immersion", {2, 51, 78}, 0);
  addCategory(20, "Magic", {3, 75, 93, 94}, 0);
  addCategory(21, "Models & Textures", {2, 19, 29}, 0);
  addCategory(33, "Modders resources", {2, 18, 82}, 0);
  addCategory(13, "NPCs", {3, 22, 33, 99}, 0);
  addCategory(24, "Bugfixes", {2, 6, 95}, 0);
  addCategory(14, "Patches", {2, 25, 84}, 24);
  addCategory(35, "Utilities", {2, 38, 39}, 0);
  addCategory(26, "Cheats", {1, 8}, 0);
  addCategory(15, "Quests", {2, 30, 35}, 0);
  addCategory(16, "Races & Classes", {1, 34}, 0);
  addCategory(34, "Stealth", {1, 76}, 0);
  addCategory(17, "UI", {2, 37, 42}, 0);
  addCategory(18, "Visuals", {2, 40, 62}, 0);
  addCategory(50, "Pip-Boy", {1, 52}, 18);
  addCategory(46, "Shader Presets", {3, 13, 97, 105}, 0);
  addCategory(47, "Miscellaneous", {2, 2, 28}, 0);
}

int CategoryFactory::getParentID(unsigned int index) const
{
  if (index >= m_Categories.size()) {
    throw MyException(QObject::tr("invalid category index: %1").arg(index));
  }

  return m_Categories[index].m_ParentID;
}

bool CategoryFactory::categoryExists(int id) const
{
  return m_IDMap.find(id) != m_IDMap.end();
}

bool CategoryFactory::isDescendantOf(int id, int parentID) const
{
  // handles cycles
  std::set<int> seen;
  return isDescendantOfImpl(id, parentID, seen);
}

bool CategoryFactory::isDescendantOfImpl(int id, int parentID,
                                         std::set<int>& seen) const
{
  if (!seen.insert(id).second) {
    log::error("cycle in category: {}", id);
    return false;
  }

  std::map<int, unsigned int>::const_iterator iter = m_IDMap.find(id);

  if (iter != m_IDMap.end()) {
    unsigned int index = iter->second;
    if (m_Categories[index].m_ParentID == 0) {
      return false;
    } else if (m_Categories[index].m_ParentID == parentID) {
      return true;
    } else {
      return isDescendantOfImpl(m_Categories[index].m_ParentID, parentID, seen);
    }
  } else {
    log::warn("{} is no valid category id", id);
    return false;
  }
}

bool CategoryFactory::hasChildren(unsigned int index) const
{
  if (index >= m_Categories.size()) {
    throw MyException(QObject::tr("invalid category index: %1").arg(index));
  }

  return m_Categories[index].m_HasChildren;
}

QString CategoryFactory::getCategoryName(unsigned int index) const
{
  if (index >= m_Categories.size()) {
    throw MyException(QObject::tr("invalid category index: %1").arg(index));
  }

  return m_Categories[index].m_Name;
}

QString CategoryFactory::getSpecialCategoryName(SpecialCategories type) const
{
  QString label;
  switch (type) {
  case Checked:
    label = QObject::tr("Active");
    break;
  case UpdateAvailable:
    label = QObject::tr("Update available");
    break;
  case HasCategory:
    label = QObject::tr("Has category");
    break;
  case Conflict:
    label = QObject::tr("Conflicted");
    break;
  case HasHiddenFiles:
    label = QObject::tr("Has hidden files");
    break;
  case Endorsed:
    label = QObject::tr("Endorsed");
    break;
  case Backup:
    label = QObject::tr("Has backup");
    break;
  case Managed:
    label = QObject::tr("Managed");
    break;
  case HasGameData:
    label = QObject::tr("Has valid game data");
    break;
  case HasNexusID:
    label = QObject::tr("Has Nexus ID");
    break;
  case Tracked:
    label = QObject::tr("Tracked on Nexus");
    break;
  default:
    return {};
  }
  return QString("<%1>").arg(label);
}

QString CategoryFactory::getCategoryNameByID(int id) const
{
  auto itor = m_IDMap.find(id);

  if (itor == m_IDMap.end()) {
    return getSpecialCategoryName(static_cast<SpecialCategories>(id));
  } else {
    const auto index = itor->second;
    if (index >= m_Categories.size()) {
      return {};
    }

    return m_Categories[index].m_Name;
  }
}

int CategoryFactory::getCategoryID(unsigned int index) const
{
  if (index >= m_Categories.size()) {
    throw MyException(QObject::tr("invalid category index: %1").arg(index));
  }

  return m_Categories[index].m_ID;
}

int CategoryFactory::getCategoryIndex(int ID) const
{
  std::map<int, unsigned int>::const_iterator iter = m_IDMap.find(ID);
  if (iter == m_IDMap.end()) {
    throw MyException(QObject::tr("invalid category id: %1").arg(ID));
  }
  return iter->second;
}

int CategoryFactory::getCategoryID(const QString& name) const
{
  auto iter = std::find_if(m_Categories.begin(), m_Categories.end(),
                           [name](const Category& cat) -> bool {
                             return cat.m_Name == name;
                           });

  if (iter != m_Categories.end()) {
    return iter->m_ID;
  } else {
    return -1;
  }
}

unsigned int CategoryFactory::resolveNexusID(int nexusID) const
{
  std::map<int, unsigned int>::const_iterator iter = m_NexusMap.find(nexusID);
  if (iter != m_NexusMap.end()) {
    log::debug("nexus category id {} maps to internal {}", nexusID, iter->second);
    return iter->second;
  } else {
    log::debug("nexus category id {} not mapped", nexusID);
    return 0U;
  }
}