/*

 * Hedgewars, a free turn based strategy game

 * Copyright (c) 2006-2007 Igor Ulyanov <iulyanov@gmail.com>

 * Copyright (c) 2007-2011 Andrey Korotaev <unC0Rr@gmail.com>

 *

 * 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; version 2 of the License

 *

 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA

 */

#include <QStringList>

#include "SmartLineEdit.h"

: QLineEdit(parent)

{

    m_whitespace = QRegExp("\\s");

    m_cmds  = new QStringList();

    m_nicks = new QStringList();

    resetAutoCompletionStatus();

    // reset autocompletion status when cursor is moved or content is changed

    connect(this, SIGNAL(cursorPositionChanged(int, int)),

            this, SLOT(resetAutoCompletionStatus()));

    connect(this, SIGNAL(textChanged(const QString&)),

            this, SLOT(resetAutoCompletionStatus()));

}

void SmartLineEdit::addCommands(const QStringList & commands)

{

    m_cmds->append(commands);

}

void SmartLineEdit::removeCommands(const QStringList & commands)

{

    foreach (const QString & cmd, commands)

    {

        m_cmds->removeAll(cmd);

    }

}

void SmartLineEdit::addNickname(const QString & name)

{

    m_nicks->append(name);

}

void SmartLineEdit::removeNickname(const QString & name)

{

    m_nicks->removeAll(name);

}

void SmartLineEdit::forgetEverything()

{

    m_cmds->clear();

    m_nicks->clear();

    resetAutoCompletionStatus();

}

bool SmartLineEdit::event(QEvent * event)

{

    // we only want special treatment for key press events

    if (event->type() == QEvent::KeyPress)

    {

        QKeyEvent * keyEvent = static_cast<QKeyEvent*>(event);

        // TAB key pressed and any useful chars in the matchMe -> let's process those

        if ((keyEvent->key() == Qt::Key_Tab) && (!text().trimmed().isEmpty()))

        {

            keyPressEvent(keyEvent);

            if (event->isAccepted())

                return true;

        }

    }

    return QLineEdit::event(event);

}

void SmartLineEdit::keyPressEvent(QKeyEvent * event)

{

    int key = event->key(); // retrieve pressed key

    // auto-complete on pressed TAB (except for whitespace-only contents)

    if ((key == Qt::Key_Tab) && (!text().trimmed().isEmpty()))

    {

        autoComplete();

        event->accept();

    }

    // otherwise forward keys to parent

    else

        QLineEdit::keyPressEvent(event);

}

void SmartLineEdit::autoComplete()

{

    QString match = "";

    bool isNick = false;

    QString matchMe = text();

    QString prefix = "";

    QString postfix = "";

    bool isFirstWord;

    // we are trying to rematch, so use the data from earlier

    if (m_hasJustMatched)

    {

        // restore values from earlier auto-completion

        matchMe = m_beforeMatch;

        prefix = m_prefix;

        postfix = m_postfix;

        isFirstWord = prefix.isEmpty();

    }

    else

    {

        m_cmds->sort();

        m_nicks->sort();

        int cp = cursorPosition();

        // cursor is not in or at end/beginning of word

        if ((cp = matchMe.length()) || (QString(matchMe.at(cp)).contains(m_whitespace)))

            if ((cp < 1) || (QString(matchMe.at(cp-1)).contains(m_whitespace)))

                return;

        // crop matchMe at cursor position

        prefix  = matchMe.left (cp);

        postfix = matchMe.right(matchMe.length()-cp);

        matchMe = "";

        // use the whole word the curser is on for matching

        int prefixLen = prefix.lastIndexOf(m_whitespace) + 1;

        int preWordLen = prefix.length() - prefixLen;

        int postWordLen = postfix.indexOf(m_whitespace);

        int postfixLen = 0;

        if (postWordLen < 0)

            postWordLen = postfix.length();

        else

            postfixLen = postfix.length() - (postWordLen + 1);

        matchMe = prefix.right(preWordLen) + postfix.left(postWordLen);

        prefix  = prefix.left(prefixLen);

        postfix = postfix.right(postfixLen);

        isFirstWord = prefix.isEmpty(); // true if first word

    }

    if (isFirstWord)

    {

        // find matching commands

        foreach (const QString & cmd, *m_cmds)

        {

            if (cmd.startsWith(matchMe, Qt::CaseInsensitive))

            {

                match = cmd;

                // move match to end so next time new matches will be prefered

                if (m_cmds->removeAll(cmd) > 0);

                    m_cmds->append(cmd);

                break;

            }

        }

    }

    if (match.isEmpty())

    {

        // find matching nicks

        foreach (const QString & nick, *m_nicks)

        {

            if (nick.startsWith(matchMe, Qt::CaseInsensitive))

            {

                match = nick;

                isNick = true;

                // move match to end so next time new matches will be prefered

                if (m_nicks->removeAll(nick) > 0);

                    m_nicks->append(nick);

                break;

            }

        }

    }

    // we found a single match?

    if (!match.isEmpty())

    {

        // replace last word with match

        // and append ':' if a name at the beginning of the matchMe got completed

        // also add a space at the very end to ease further typing

        QString addAfter = ((isNick && isFirstWord)?": ":" ");

        match = prefix + match + addAfter;

        setText(match + postfix);

        setCursorPosition(match.length());

        // save values for for the case a rematch is requested

        m_beforeMatch = matchMe;

        m_hasJustMatched = true;

        m_prefix = prefix;

        m_postfix = postfix;

    }

}

void SmartLineEdit::resetAutoCompletionStatus()

{

    m_beforeMatch = "";

    m_hasJustMatched = false;

    m_prefix = "";

    m_postfix = "";

}