/*
    Scan Tailor - Interactive post-processing tool for scanned pages.
    Copyright (C) 2007-2009  Joseph Artsimovich <joseph_a@mail.ru>

    This program 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.

    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "InteractionState.h"
#include <limits>

InteractionState::Captor&
InteractionState::Captor::operator=(Captor& other)
{
    swap_nodes(other);
    other.unlink();
    return *this;
}

InteractionState::Captor&
InteractionState::Captor::operator=(CopyHelper other)
{
    return (*this = *other.captor);
}

InteractionState::InteractionState()
    :   m_proximityThreshold(Proximity::fromDist(10.0)),
        m_bestProximityPriority(std::numeric_limits<int>::min()),
        m_redrawRequested(false)
{
}

void
InteractionState::capture(Captor& captor)
{
    captor.unlink();
    m_captorList.push_back(captor);
}

bool
InteractionState::capturedBy(Captor const& captor) const
{
    return !m_captorList.empty() && &m_captorList.back() == &captor;
}

void
InteractionState::resetProximity()
{
    m_proximityLeader.clear();
    m_bestProximity = Proximity();
    m_bestProximityPriority = std::numeric_limits<int>::min();
}

void
InteractionState::updateProximity(
    Captor& captor, Proximity const& proximity,
    int priority, Proximity proximity_threshold)
{
    if (captor.is_linked()) {
        return;
    }

    if (proximity_threshold == Proximity()) {
        proximity_threshold = m_proximityThreshold;
    }

    if (proximity <= proximity_threshold) {
        if (betterProximity(proximity, priority)) {
            m_proximityLeader.clear();
            m_proximityLeader.push_back(captor);
            m_bestProximity = proximity;
            m_bestProximityPriority = priority;
        }
    }
}

bool
InteractionState::proximityLeader(Captor const& captor) const
{
    return !m_proximityLeader.empty() && &m_proximityLeader.front() == &captor;
}

bool
InteractionState::betterProximity(Proximity const& proximity, int const priority) const
{
    if (priority != m_bestProximityPriority) {
        return priority > m_bestProximityPriority;
    }
    return proximity < m_bestProximity;
}

QCursor
InteractionState::cursor() const
{
    if (!m_captorList.empty()) {
        return m_captorList.back().interactionCursor();
    } else if (!m_proximityLeader.empty()) {
        return m_proximityLeader.front().proximityCursor();
    } else {
        return QCursor();
    }
}

QString
InteractionState::statusTip() const
{
    if (!m_captorList.empty()) {
        return m_captorList.back().interactionOrProximityStatusTip();
    } else if (!m_proximityLeader.empty()) {
        return m_proximityLeader.front().proximityStatusTip();
    } else {
        return m_defaultStatusTip;
    }
}
