/*  This file is part of the KDE libraries

    Copyright (c) 2004 Zack Rusin <zack@kde.org>
    Copyright (c) 2006 Jacob R Rideout <kde@jacobrideout.net>
    Copyright (c) 2009 Jakub Stachowski <qbast@go2.pl>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include <QtCore/QList>
#include <QtCore/QString>

#include "tokenizer_p.h"
#include "textbreaks_p.h"

namespace Sonnet {
class BreakTokenizerPrivate
{
public:
    enum Type {
        Words, Sentences
    };

    BreakTokenizerPrivate(Type s)
        : breakFinder(new TextBreaks)
        , itemPosition(-1)
        , cacheValid(false)
        , type(s)
        , inAddress(false)
        , ignoreUppercase(false)
    {
    }

    ~BreakTokenizerPrivate()
    {
        delete breakFinder;
    }

    TextBreaks::Positions breaks() const;
    void invalidate();
    void shiftBreaks(int from, int offset);
    void replace(int pos, int len, const QString &newWord);

    QStringRef currentItem() const;

    TextBreaks *breakFinder;
    QString buffer;

    int itemPosition;
    mutable bool cacheValid;
    QStringRef last;
    Type type;
    bool inAddress;
    bool ignoreUppercase;

    bool hasNext() const;
    QStringRef next();
    void setBuffer(const QString &b)
    {
        invalidate();
        buffer = b;
    }

private:
    void regenerateCache() const;
    mutable TextBreaks::Positions cachedBreaks;
};

void BreakTokenizerPrivate::invalidate()
{
    cacheValid = false;
    itemPosition = -1;
}

bool BreakTokenizerPrivate::hasNext() const
{
    if (itemPosition >= (breaks().size()-1)) {
        return false;
    }

    return true;
}

TextBreaks::Positions BreakTokenizerPrivate::breaks() const
{
    if (!cacheValid) {
        regenerateCache();
    }

    return cachedBreaks;
}

void BreakTokenizerPrivate::shiftBreaks(int from, int offset)
{
    for (int i = 0; i < cachedBreaks.size(); i++) {
        if (cachedBreaks[i].start > from) {
            cachedBreaks[i].start = cachedBreaks[i].start - offset;
        }
    }
}

void BreakTokenizerPrivate::regenerateCache() const
{
    if (!breakFinder || buffer.isEmpty()) {
        cachedBreaks = TextBreaks::Positions();
    }

    if (breakFinder) {
        breakFinder->setText(buffer);

        if (type == Sentences) {
            cachedBreaks = breakFinder->sentenceBreaks();
        } else if (type == Words) {
            cachedBreaks = breakFinder->wordBreaks();
        }
    }

    cacheValid = true;
}

QStringRef BreakTokenizerPrivate::next()
{
    QStringRef block;

    if (!hasNext()) {
        last = block;
        return block;
    }

    itemPosition++;
    last = QStringRef(&buffer, breaks().at(itemPosition).start, breaks().at(itemPosition).length);
    return last;
}

void BreakTokenizerPrivate::replace(int pos, int len, const QString &newWord)
{
    buffer.replace(pos, len, newWord);
    int offset = len-newWord.length();
    if (cacheValid) {
        shiftBreaks(pos, offset);
    }
}

/*-----------------------------------------------------------*/

WordTokenizer::WordTokenizer(const QString &buffer)
    : d(new BreakTokenizerPrivate(BreakTokenizerPrivate::Words))
{
    setBuffer(buffer);
}

WordTokenizer::~WordTokenizer()
{
    delete d;
}

bool WordTokenizer::hasNext() const
{
    return d->hasNext();
}

void WordTokenizer::setBuffer(const QString &buffer)
{
    d->setBuffer(buffer);
}

QStringRef WordTokenizer::next()
{
    QStringRef n = d->next();

    // end of address of url?
    if (d->inAddress && n.position() > 0 && d->buffer[n.position()-1].isSpace()) {
        d->inAddress = false;
    }

    // check if this word starts an email address of url
    if (!d->inAddress || hasNext()) {
        int pos = n.position()+n.length();
        if (d->buffer[pos] == QLatin1Char('@')) {
            d->inAddress = true;
        }
        if (d->buffer[pos] == QLatin1Char(':') && d->buffer[pos+1] == QLatin1Char('/')
            && d->buffer[pos+2] == QLatin1Char('/')) {
            d->inAddress = true;
        }
    }
    return n;
}

QString WordTokenizer::buffer() const
{
    return d->buffer;
}

bool WordTokenizer::isUppercase(const QStringRef &word) const
{
    for (int i = 0; i < word.length(); ++i) {
        if (word.at(i).isLetter() && !word.at(i).isUpper()) {
            return false;
        }
    }
    return true;
}

void WordTokenizer::setIgnoreUppercase(bool val)
{
    d->ignoreUppercase = val;
}

void WordTokenizer::replace(int pos, int len, const QString &newWord)
{
    d->replace(pos, len, newWord);
}

bool WordTokenizer::isSpellcheckable() const
{
    if (d->last.isNull() || d->last.isEmpty()) {
        return false;
    }
    if (!d->last.at(0).isLetter()) {
        return false;
    }
    if (d->inAddress) {
        return false;
    }
    if (d->ignoreUppercase && isUppercase(d->last)) {
        return false;
    }
    return true;
}

/* --------------------------------------------------------------------*/

SentenceTokenizer::SentenceTokenizer(const QString &buffer)
    : d(new BreakTokenizerPrivate(BreakTokenizerPrivate::Sentences))
{
    setBuffer(buffer);
}

SentenceTokenizer::~SentenceTokenizer()
{
    delete d;
}

bool SentenceTokenizer::hasNext() const
{
    return d->hasNext();
}

void SentenceTokenizer::setBuffer(const QString &buffer)
{
    d->setBuffer(buffer);
}

QStringRef SentenceTokenizer::next()
{
    return d->next();
}

QString SentenceTokenizer::buffer() const
{
    return d->buffer;
}

void SentenceTokenizer::replace(int pos, int len, const QString &newWord)
{
    d->replace(pos, len, newWord);
}
}
