#include <NtxCmdList.h>

namespace ntx
{

  NtxCmdList::NtxCmdList()
    : m_executedCount(0)
  {
    setDescription("Multi Command");
  }

  NtxCmdList::NtxCmdList(const NtxString& description)
    : m_executedCount(0)
  {
    setDescription(description);
  }

  bool NtxCmdList::execute()
  {
    m_executedCount = 0;

    for (size_t i = 0; i < m_commands.size(); ++i)
    {
      if (!m_commands[i]->canExecute())
      {
        rollback(i);
        return false;
      }

      if (!m_commands[i]->execute())
      {
        rollback(i);
        return false;
      }

      m_executedCount++;
    }

    return true;
  }

  bool NtxCmdList::undo()
  {
    if (m_executedCount == 0)
      return false;

    for (size_t i = m_executedCount; i > 0; --i)
    {
      size_t index = i - 1;

      if (!m_commands[index]->canUndo())
        continue;

      m_commands[index]->undo();
    }

    m_executedCount = 0;
    return true;
  }

  bool NtxCmdList::canExecute() const
  {
    if (m_commands.empty())
      return false;

    for (const auto& cmd : m_commands)
    {
      if (!cmd->canExecute())
        return false;
    }

    return true;
  }

  bool NtxCmdList::canUndo() const
  {
    if (m_executedCount == 0)
      return false;

    for (size_t i = 0; i < m_executedCount; ++i)
    {
      if (m_commands[i]->canUndo())
        return true;
    }

    return false;
  }

  NtxString NtxCmdList::getDescription() const
  {
    NtxString desc = NtxICommand::getDescription();
    
    if (!desc.empty())
      return desc;

    if (m_commands.empty())
      return "Empty Multi Command";

    return "Multi Command (" + std::to_string(m_commands.size()) + " commands)";
  }

  void NtxCmdList::addCommand(NtxCommandUPtr command)
  {
    if (command)
    {
      m_commands.push_back(std::move(command));
    }
  }

  void NtxCmdList::clear()
  {
    m_commands.clear();
    m_executedCount = 0;
  }

  size_t NtxCmdList::count() const
  {
    return m_commands.size();
  }

  bool NtxCmdList::isEmpty() const
  {
    return m_commands.empty();
  }

  void NtxCmdList::rollback(size_t upToIndex)
  {
    for (size_t i = upToIndex; i > 0; --i)
    {
      size_t index = i - 1;

      if (m_commands[index]->canUndo())
      {
        m_commands[index]->undo();
      }
    }

    m_executedCount = 0;
  }

} // namespace ntx