/*
 *  This file is part of Konsole, a terminal emulator for KDE.
 *
 *  Copyright 2012  Frederik Gladhorn <gladhorn@kde.org>
 *
 *  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 2 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, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 *  02110-1301  USA.
 */

#include "TerminalDisplayAccessible.h"
#include "SessionController.h"
#include <klocalizedstring.h>

using namespace Konsole;

TerminalDisplayAccessible::TerminalDisplayAccessible(TerminalDisplay *display) :
    QAccessibleWidget(display, QAccessible::Terminal, display->sessionController()->userTitle())
{
}

QString TerminalDisplayAccessible::text(QAccessible::Text t) const
{
    if (t == QAccessible::Value) {
        return visibleText();
    }
    return QAccessibleWidget::text(t);
}

int TerminalDisplayAccessible::characterCount() const
{
    return display()->_usedLines * display()->_usedColumns;
}

int TerminalDisplayAccessible::cursorPosition() const
{
    if (display()->screenWindow() == nullptr) {
        return 0;
    }

    int offset = display()->_usedColumns * display()->screenWindow()->screen()->getCursorY();
    return offset + display()->screenWindow()->screen()->getCursorX();
}

void TerminalDisplayAccessible::selection(int selectionIndex, int *startOffset,
                                          int *endOffset) const
{
    *startOffset = 0;
    *endOffset = 0;
    if ((display()->screenWindow() == nullptr) || (selectionIndex != 0)) {
        return;
    }

    int startLine = 0;
    int startColumn = 0;
    int endLine = 0;
    int endColumn = 0;
    display()->screenWindow()->getSelectionStart(startColumn, startLine);
    display()->screenWindow()->getSelectionEnd(endColumn, endLine);
    if ((startLine == endLine) && (startColumn == endColumn)) {
        return;
    }
    *startOffset = positionToOffset(startColumn, startLine);
    *endOffset = positionToOffset(endColumn, endLine);
}

int TerminalDisplayAccessible::selectionCount() const
{
    if (display()->screenWindow() == nullptr) {
        return 0;
    }

    int startLine = 0;
    int startColumn = 0;
    int endLine = 0;
    int endColumn = 0;
    display()->screenWindow()->getSelectionStart(startColumn, startLine);
    display()->screenWindow()->getSelectionEnd(endColumn, endLine);
    return ((startLine == endLine) && (startColumn == endColumn)) ? 0 : 1;
}

QString TerminalDisplayAccessible::visibleText() const
{
    // This function should be const to allow calling it from const interface functions.
    TerminalDisplay *display = const_cast<TerminalDisplayAccessible *>(this)->display();
    if (display->screenWindow() == nullptr) {
        return QString();
    }

    return display->screenWindow()->screen()->text(0, display->_usedColumns * display->_usedLines, Screen::PreserveLineBreaks);
}

void TerminalDisplayAccessible::addSelection(int startOffset, int endOffset)
{
    if (display()->screenWindow() == nullptr) {
        return;
    }
    display()->screenWindow()->setSelectionStart(columnForOffset(startOffset),
                                                 lineForOffset(startOffset), false);
    display()->screenWindow()->setSelectionEnd(columnForOffset(endOffset),
                                               lineForOffset(endOffset));
}

QString TerminalDisplayAccessible::attributes(int offset, int *startOffset, int *endOffset) const
{
    // FIXME: this function should return css like attributes
    // as defined in the web ARIA standard
    Q_UNUSED(offset)
    *startOffset = 0;
    *endOffset = characterCount();
    return QString();
}

QRect TerminalDisplayAccessible::characterRect(int offset) const
{
    int row = offset / display()->_usedColumns;
    int col = offset - row * display()->_usedColumns;
    QPoint position = QPoint(col * display()->fontWidth(), row * display()->fontHeight());
    return QRect(position, QSize(display()->fontWidth(), display()->fontHeight()));
}

int TerminalDisplayAccessible::offsetAtPoint(const QPoint &point) const
{
    // FIXME return the offset into the text from the given point
    Q_UNUSED(point)
    return 0;
}

void TerminalDisplayAccessible::removeSelection(int selectionIndex)
{
    if ((display()->screenWindow() == nullptr) || (selectionIndex != 0)) {
        return;
    }
    display()->screenWindow()->clearSelection();
}

void TerminalDisplayAccessible::scrollToSubstring(int startIndex, int endIndex)
{
    // FIXME: make sure the string between startIndex and endIndex is visible
    Q_UNUSED(startIndex)
    Q_UNUSED(endIndex)
}

void TerminalDisplayAccessible::setCursorPosition(int position)
{
    if (display()->screenWindow() == nullptr) {
        return;
    }

    display()->screenWindow()->screen()->setCursorYX(lineForOffset(position),
                                                     columnForOffset(position));
}

void *TerminalDisplayAccessible::interface_cast(QAccessible::InterfaceType type)
{
    if (type == QAccessible::TextInterface) {
        return static_cast<QAccessibleTextInterface *>(this);
    }

    return QAccessibleWidget::interface_cast(type);
}

void TerminalDisplayAccessible::setSelection(int selectionIndex, int startOffset, int endOffset)
{
    if (selectionIndex != 0) {
        return;
    }
    addSelection(startOffset, endOffset);
}

QString TerminalDisplayAccessible::text(int startOffset, int endOffset) const
{
    if (display()->screenWindow() == nullptr) {
        return QString();
    }

    return display()->screenWindow()->screen()->text(startOffset, endOffset, Screen::PreserveLineBreaks);
}

TerminalDisplay *TerminalDisplayAccessible::display() const
{
    return qobject_cast<TerminalDisplay *>(widget());
}