// Copyright(c) 2017-2019 Alejandro Sirgo Rica & Contributors
//
// This file is part of Flameshot.
//
//     Flameshot 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.
//
//     Flameshot 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 Flameshot.  If not, see <http://www.gnu.org/licenses/>.

#include "abstracttwopointtool.h"
#include <cmath>

namespace {

const double ADJ_UNIT = std::atan(1.0);
const int DIRS_NUMBER = 4;

enum UNIT {
    HORIZ_DIR = 0,
    DIAG1_DIR = 1,
    VERT_DIR = 2,
    DIAG2_DIR = 3
};

const double ADJ_DIAG_UNIT = 2 * ADJ_UNIT;
const int DIAG_DIRS_NUMBER = 2;

enum DIAG_UNIT {
    DIR1 = 0,
    DIR2 = 1
};

}

AbstractTwoPointTool::AbstractTwoPointTool(QObject *parent) :
    CaptureTool(parent), m_thickness(0), m_padding(0)
{

}

bool AbstractTwoPointTool::isValid() const {
    return (m_points.first != m_points.second);
}

bool AbstractTwoPointTool::closeOnButtonPressed() const {
    return false;
}

bool AbstractTwoPointTool::isSelectable() const {
    return true;
}

bool AbstractTwoPointTool::showMousePreview() const {
    return true;
}

void AbstractTwoPointTool::undo(QPixmap &pixmap) {
    QPainter p(&pixmap);
    p.drawPixmap(backupRect(pixmap.rect()).topLeft(), m_pixmapBackup);
}

void AbstractTwoPointTool::drawEnd(const QPoint &p) {
    Q_UNUSED(p);
}

void AbstractTwoPointTool::drawMove(const QPoint &p) {
    m_points.second = p;
}

void AbstractTwoPointTool::drawMoveWithAdjustment(const QPoint &p) {
    m_points.second = m_points.first + adjustedVector(p - m_points.first);
}

void AbstractTwoPointTool::colorChanged(const QColor &c) {
    m_color = c;
}

void AbstractTwoPointTool::thicknessChanged(const int th) {
    m_thickness = th;
}

void AbstractTwoPointTool::updateBackup(const QPixmap &pixmap) {
    m_pixmapBackup = pixmap.copy(backupRect(pixmap.rect()));
}

QRect AbstractTwoPointTool::backupRect(const QRect &limits) const {
    QRect r = QRect(m_points.first, m_points.second).normalized();
    const int val = m_thickness + m_padding;
    r += QMargins(val, val, val, val);
    return r.intersected(limits);
}

QPoint AbstractTwoPointTool::adjustedVector(QPoint v) const {
    if (m_supportsOrthogonalAdj && m_supportsDiagonalAdj) {
        int dir = ( static_cast<int>(round(atan2(-v.y(), v.x()) / ADJ_UNIT)) + DIRS_NUMBER ) % DIRS_NUMBER;
        if (dir == UNIT::HORIZ_DIR) {
            v.setY(0);
        } else if (dir == UNIT::VERT_DIR) {
            v.setX(0);
        } else if (dir == UNIT::DIAG1_DIR) {
            int newX = (v.x() - v.y()) / 2;
            int newY = -newX;
            v.setX(newX);
            v.setY(newY);
        } else {
            int newX = (v.x() + v.y()) / 2;
            int newY = newX;
            v.setX(newX);
            v.setY(newY);
        }
    } else if (m_supportsDiagonalAdj) {
        int dir = ( static_cast<int>(round((atan2(-v.y(), v.x()) - ADJ_DIAG_UNIT / 2) / ADJ_DIAG_UNIT))
                    + DIAG_DIRS_NUMBER ) % DIAG_DIRS_NUMBER;
        if (dir == DIAG_UNIT::DIR1) {
            int newX = (v.x() - v.y()) / 2;
            int newY = -newX;
            v.setX(newX);
            v.setY(newY);
        } else {
            int newX = (v.x() + v.y()) / 2;
            int newY = newX;
            v.setX(newX);
            v.setY(newY);
        }
    }
    return v;
}