/****************************************************************************

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbPlugins module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

****************************************************************************/

#include <QTimer>

#include <hbinputmethod.h>

#include <hbinputkeymapfactory.h>

#include <hbinputpredictionengine.h>

#include <hbinputbutton.h>

#include <QTextCharFormat>

#include <HbColorScheme>

#include "hbinputpredictionqwertyhandler.h"

#include "hbinputpredictionhandler_p.h"

#include "hbinputabstractbase.h"

class HbInputPredictionQwertyHandlerPrivate: public HbInputPredictionHandlerPrivate

{

    Q_DECLARE_PUBLIC(HbInputPredictionQwertyHandler)

public:

    HbInputPredictionQwertyHandlerPrivate();

    ~HbInputPredictionQwertyHandlerPrivate();

    void deleteOneCharacter();

public:

    bool buttonPressed(const QKeyEvent *event);

    bool buttonReleased(const QKeyEvent *event);

    void init();

    void updateEditor();

    void commitSecondaryWord();

    QString getCommitString();

    void showExactWordPopupIfNeeded();

public:

    int mButton;    

    HbFnState mFnState;

    bool mExactPopupLaunched;    

    bool mShowExactWordInTooltip;

    int mPrimaryCandidateIndex;

    int mSecondaryCandidateIndex;

    int mTypingCorrectionLevel;

    HbTypingCorrectionLevel mCorrectionLevel;

};

HbInputPredictionQwertyHandlerPrivate::HbInputPredictionQwertyHandlerPrivate()

:mButton(0),    

    mFnState(HbFnOff),

    mExactPopupLaunched(false)

{

}

HbInputPredictionQwertyHandlerPrivate::~HbInputPredictionQwertyHandlerPrivate()

{

}

void HbInputPredictionQwertyHandlerPrivate::init()

{

}

bool HbInputPredictionQwertyHandlerPrivate::buttonReleased(const QKeyEvent *event)

{

    Q_Q(HbInputPredictionQwertyHandler);

    HbInputFocusObject *focusObject = 0;

    focusObject = mInputMethod->focusObject();

    if (!focusObject) {

        qDebug("HbVirtualQwerty::virtualButtonClicked : no focused editor widget!");

        return false;

    }

    int key = event->key();

    bool ret = true;

    switch(key) {    

    case Qt::Key_Alt:  //Fn

        if (mFnState == HbFnOff) {

                mFnState = HbFnNext;

            } else if (mFnState == HbFnNext) {

                mFnState = HbFnOn;

            } else {

                mFnState = HbFnOff;

            }

        break;

    case HbInputButton::ButtonKeyCodeShift: {

            HbTextCase currentTextCase = (HbTextCase)focusObject->editorInterface().textCase();

            HbInputLanguage language = mInputMethod->inputState().language();

            // Update the Case Information in HbInputState, it internally updates in HbEditorInterface as well

            switch(currentTextCase) {

            case HbTextCaseLower:

                // For Case-insensitive languages, Shift Key is used to switch between character sets (i.e lower case characters and shifted characters)

                if(!language.isCaseSensitiveLanguage()){

                    currentTextCase = HbTextCaseUpper; 

                }

                else {

                    currentTextCase = HbTextCaseAutomatic;

                }

                break;				

            case HbTextCaseUpper:	

                currentTextCase = HbTextCaseLower;				

                break;

            case HbTextCaseAutomatic:

                currentTextCase = HbTextCaseUpper;				                

                break;

            default:

                break;

            }

            HbInputState state = mInputMethod->inputState();

            state.setTextCase(currentTextCase);			

            mInputMethod->activateState(state);

        }

        break;

    case HbInputButton::ButtonKeyCodeSymbol: { // Ctrl/Chr

    case HbInputButton::ButtonKeyCodeAlphabet:

        mInputMethod->switchSpecialCharacterTable();

        }		

        break;

    case HbInputButton::ButtonKeyCodeSettings:

        mInputMethod->closeExactWordPopup();

		break;

    default: {

            HbTextCase currentTextCase = focusObject->editorInterface().textCase();

            Qt::KeyboardModifiers modifiers = Qt::NoModifier;

            if (mFnState == HbFnNext) {

                modifiers |= Qt::AltModifier;

                mFnState = HbFnOff;

            } else if (mFnState == HbFnOn) {

                modifiers |= Qt::AltModifier;

            }

            // If shift is pressed, the shifted characters have to be input.

            if ( HbTextCaseUpper == currentTextCase || HbTextCaseAutomatic == currentTextCase ) {

                modifiers |= Qt::ShiftModifier;

            }

            // let's pass it to the base class.

            ret = q->HbInputPredictionHandler::filterEvent(event);

            mInputMethod->updateState();

        }

        break;

    };

    return ret;

}

bool HbInputPredictionQwertyHandlerPrivate::buttonPressed(const QKeyEvent *event)

{

    if (event->isAutoRepeat() && mButton == event->key()) {

        if (mButton == HbInputButton::ButtonKeyCodeSymbol) {

            mInputMethod->selectSpecialCharacterTableMode();

            mButton = 0;        

            return true;

        }

    }

    mButton = event->key();

    return false;

}

HbInputPredictionQwertyHandler::HbInputPredictionQwertyHandler(HbInputAbstractMethod *inputMethod)

    :HbInputPredictionHandler(* new HbInputPredictionQwertyHandlerPrivate, inputMethod)

{

    Q_D(HbInputPredictionQwertyHandler);

    d->q_ptr = this;

    d->init();

}

HbInputPredictionQwertyHandler::~HbInputPredictionQwertyHandler()

{

}

/*!

Action Handler.

*/

bool HbInputPredictionQwertyHandler::actionHandler(HbInputModeAction action)

{

    Q_D(HbInputPredictionQwertyHandler);

    bool ret = true;

    switch (action) {

        case HbInputModeActionCancelButtonPress:

            break;

        case HbInputModeActionFocusRecieved:

            HbInputPredictionHandler::actionHandler(HbInputModeActionSetCandidateList);

            HbInputPredictionHandler::actionHandler(HbInputModeActionSetKeypad);

            break;

        case HbInputModeActionFocusLost:

            HbInputPredictionHandler::actionHandler(HbInputModeActionFocusLost);

            //TODO

            /*

            if (d->mExactPopupLaunched) {

                sendCommitString(d->mCandidates->at(1));

            } else {

                sendCommitString(d->mCandidates->at(0));

            }

            */

            // close exactword popup.

            d->mInputMethod->closeExactWordPopup();

            break;

        default: 

            ret = HbInputPredictionHandler::actionHandler(action);

    }

    return ret;

}

/*!

filterEvent for key event.

*/

bool HbInputPredictionQwertyHandler::filterEvent(const QKeyEvent * event)

{

    Q_D(HbInputPredictionQwertyHandler);

    if (event->type() == QEvent::KeyRelease) {

        return d->buttonReleased(event);

    } else {

        return d->buttonPressed(event);

    }

}

/*!

Commits the word and closes the exact popup if it is visible.

*/

void HbInputPredictionQwertyHandler::commitAndUpdate(const QString& string, int replaceFrom, int replaceLength)

{

    Q_D(HbInputPredictionQwertyHandler);

    HbInputModeHandler::commitAndUpdate(string, replaceFrom, replaceLength);

    d->mInputMethod->closeExactWordPopup();

    d->mExactPopupLaunched = false;  

}

/*!

    this function deletes one character and updates the engine and editor.

*/

void HbInputPredictionQwertyHandler::deleteOneCharacter()

{

    Q_D(HbInputPredictionHandler);

    d->deleteOneCharacter();

}

/*!

 this function is called by HbPredictionHandler when HbPredictionHandler encounters a exact word.

*/

void HbInputPredictionQwertyHandler::processExactWord(QString exactWord)

{

    Q_D(HbInputPredictionQwertyHandler);

    if (exactWord.size()) {

        d->mInputMethod->launchExactWordPopup(exactWord);

        d->mExactPopupLaunched = true;

    } else {

        d->mInputMethod->closeExactWordPopup();

        d->mExactPopupLaunched = false;

    }

}

/*!

 this slot should be called when exact word popup is closed.

*/

void HbInputPredictionQwertyHandler::exactWordPopupClosed()

{

    commitExactWord();

}

void HbInputPredictionQwertyHandler::exactWordSelected()

{

    Q_D(HbInputPredictionQwertyHandler);    

    d->commitSecondaryWord();

}

void HbInputPredictionQwertyHandler::sctCharacterSelected(QString character)

{	

    HbInputPredictionHandler::sctCharacterSelected(character);

}

void HbInputPredictionQwertyHandler::smileySelected(QString smiley)

{

    HbInputPredictionHandler::smileySelected(smiley);

}

/*!

Returns true if preidciton engine is available and initialized.

*/

bool HbInputPredictionQwertyHandler::isActive() const

{ 

    Q_D(const HbInputPredictionQwertyHandler);

    return d->mEngine != 0;

}

void HbInputPredictionQwertyHandlerPrivate::deleteOneCharacter()

{

    if (!mEngine && !mInputMethod->focusObject()) {

        return;

    }

    mShowTail = true;

    mShowTooltip = true;

    // A backspace in predictive means updating the engine for the delete key press

    // and get the new candidate list from the engine.

    if ( mEngine->inputLength() >= 1 ) {

        //Only autocomplition part should be deleted when autocompliton part is enable and user pressed a delete key

        //To prevent showing autocompletion part while deleting the characters using backspace key

        mShowTail = false;

        mShowTooltip = false;

        //The assumption here is that with deletion of a character we always

        //can go on with prediction. This is because when we delete a key press

        //we actually reduce ambiguity in the engine and hence we should have

        //some word getting predicted as a result to that.

        mCanContinuePrediction = true;

        int tailLength =  mInputMethod->focusObject()->preEditString().length() - mEngine->inputLength();

            mEngine->deleteKeyPress();

            mEngine->updateCandidates(mBestGuessLocation);

        }

        mBestGuessLocation = 0;

        if(mCandidates->count() && (mCandidates->count()>mBestGuessLocation) && tailLength <= 0 && false == mExactPopupLaunched) {

            QString currentWord = mCandidates->at(mBestGuessLocation);

            if(currentWord.length()) {

                currentWord.chop(1);

                mEngine->deleteKeyPress();

                //We are not supposed to re-construct the candidate list as deletion

                //does not cause reprediction. Also, candidate list construction is the

                //heaviest operation out of all engine operations.

                (*mCandidates)[mBestGuessLocation] = currentWord;

            } else {

                commit(QString(""),false);

            }

        } else if(!mCandidates->count() && mEngine->inputLength() >= 1) {

            //If Input length greater or equal to one then Append the current word to candidate 

            mCandidates->append(mEngine->currentWord());

        }

        // update the editor with the new preedit text.

        updateEditor();

        return;

    } else {

        // we come here if their is no data in engine.

        // once the word is committed, we can not bring it back to inline edit.

        // so if the engine does not have any data, we just send backspace event to the editor.

        Q_Q(HbInputPredictionQwertyHandler);

        QKeyEvent event = QKeyEvent(QEvent::KeyPress, Qt::Key_Backspace, Qt::NoModifier);		

        q->sendAndUpdate(event);

        event = QKeyEvent(QEvent::KeyRelease, Qt::Key_Backspace, Qt::NoModifier);

        q->sendAndUpdate(event);

        return;

    }

}

void HbInputPredictionQwertyHandler::setPrimaryCandidateMode(HbPrimaryCandidateMode mode)

{

    Q_D(HbInputPredictionQwertyHandler);

    if(mode == HbPrimaryCandidateModeExactTyping) {

        d->mShowExactWordInTooltip = false;

    } else {

        d->mShowExactWordInTooltip = true;

    }

    // we need to close the exact word popup when this happens.

    d->mInputMethod->closeExactWordPopup();

    d->mExactPopupLaunched = false;

}

void HbInputPredictionQwertyHandlerPrivate::updateEditor()

{

    Q_Q(HbInputPredictionQwertyHandler);

    if (!mEngine) {

        return;

    }

    HbInputFocusObject *focusedObject = 0;

    QList<QInputMethodEvent::Attribute> list;

    focusedObject = mInputMethod->focusObject();

    QTextCharFormat underlined;    

    underlined.setFontUnderline(true);

    Q_ASSERT(focusedObject);

    if (mEngine->inputLength() == 0) {

        QInputMethodEvent event(QString(), list);

        q->sendAndUpdate(event);

    } else {

        if (mCandidates->count() > 0) {

            // index of the candidate that is shown on the typing line

            mPrimaryCandidateIndex = mBestGuessLocation;

            // index of the candidate that is shown in the tooltip (if any)

            mSecondaryCandidateIndex = 0;    

            QString bestGuessWord = mCandidates->at(mBestGuessLocation);

            QString exactTypedWord = mCandidates->at(0);

            bool hasAutocompletionPart = (bestGuessWord.length() > exactTypedWord.length()) && (bestGuessWord.left(exactTypedWord.length()) == exactTypedWord);            

            // when we are showing the autocompletion part we generally do not show the tooltip,

            // both primary and secondary candidates are the same.

            if(hasAutocompletionPart && mAutocompletionEnabled && mShowTail) {

                mPrimaryCandidateIndex = mSecondaryCandidateIndex = mBestGuessLocation;                

            }

            // in case of exact tying, exact typed word in the primary candidate

            // and the best predicted word is the secondary candidate

            if(!mShowExactWordInTooltip && !(hasAutocompletionPart && mAutocompletionEnabled)) {

                mPrimaryCandidateIndex = 0;

                mSecondaryCandidateIndex = mBestGuessLocation;

            }

            if (hasAutocompletionPart && mShowTail && mAutocompletionEnabled) {

                // showing the word with auto completion

                int taillength = bestGuessWord.length() - exactTypedWord.length();

                // TODO: Color from skin should be used

                QColor col = HbColorScheme::color("qtc_input_hint_normal");

                QBrush brush(col);

                // underline formatting is applied to only the input length part of the word

                QInputMethodEvent::Attribute textstyle(QInputMethodEvent::TextFormat, 0, mEngine->inputLength(), underlined);

                list.append(textstyle);

                QTextCharFormat gray;

                gray.setForeground(brush);

                if((focusedObject->object())->inherits("QGraphicsWebView") || (focusedObject->object())->inherits("QWebView")) {

                    //QGraphicsWebView does not handle partial input length formatting well. Causes crash, a temporary fix provided,

                    //This makes the whole text field grey insted of just the auto-completion part. Anyways, it does not cause crash.

                    //This should be treated as a work around till QGraphicsWebView is fixed.

                    list.append(QInputMethodEvent::Attribute(QInputMethodEvent::TextFormat, 0, QInputMethodEvent::TextFormat, gray));

                } else {

                    list.append(QInputMethodEvent::Attribute(QInputMethodEvent::TextFormat, mEngine->inputLength(), taillength, gray));

                }				

                list.append(QInputMethodEvent::Attribute(QInputMethodEvent::Cursor, mEngine->inputLength(), 0, 0));

                // the best guess word is sent to the editor

                QInputMethodEvent event(bestGuessWord, list);

                focusedObject->sendEvent(event);

            } else {

                QInputMethodEvent::Attribute textstyle(QInputMethodEvent::TextFormat, 0, mCandidates->at(mPrimaryCandidateIndex).length(), underlined);

                list.append(textstyle);

                list.append(QInputMethodEvent::Attribute(QInputMethodEvent::Cursor, mCandidates->at(mPrimaryCandidateIndex).length(), 0, 0));

                QInputMethodEvent event(mCandidates->at(mPrimaryCandidateIndex), list);

                focusedObject->sendEvent(event);

            }

            if (mShowTooltip && mPrimaryCandidateIndex != mSecondaryCandidateIndex) {                

                q->processExactWord(mCandidates->at(mSecondaryCandidateIndex));

            } else {

                QString empty;

                q->processExactWord(empty);

            }

        } else {

            QInputMethodEvent event(QString(""), list);

            focusedObject->sendEvent(event);

        }

    }

}

void HbInputPredictionQwertyHandlerPrivate::commitSecondaryWord()

{

    if(mCandidates->count()>mSecondaryCandidateIndex) {

        QString commitString = mCandidates->at(mSecondaryCandidateIndex);

        commit(commitString, true, false);

    }

}

void HbInputPredictionQwertyHandlerPrivate::showExactWordPopupIfNeeded()

{

    Q_Q(HbInputPredictionHandler);

        q->processExactWord(mCandidates->at(mSecondaryCandidateIndex));

    } else {

        QString empty;

        q->processExactWord(empty);

    }

}

QString HbInputPredictionQwertyHandlerPrivate::getCommitString()

{

    QString commitString;

    if(mCandidates->count() <= mPrimaryCandidateIndex) {

        commitString = mCandidates->at(0);

    } else {

        commitString = mCandidates->at(mPrimaryCandidateIndex);

    }

    return commitString;

}

void HbInputPredictionQwertyHandler::setTypingCorrectionLevel(HbTypingCorrectionLevel correctionLevel)

{

    Q_D(HbInputPredictionQwertyHandler);

    HbPredictionEngine::HbErrorCorrectionLevel errorCorrectionLevel = HbPredictionEngine::HbErrorCorrectionLevelMedium;

    if(d->mCorrectionLevel == correctionLevel) {

        return;

    }

    d->mCorrectionLevel = correctionLevel;

    switch(correctionLevel) {

        case HbTypingCorrectionLevelLow:

            errorCorrectionLevel = HbPredictionEngine::HbErrorCorrectionLevelLow;

            break;

        case HbTypingCorrectionLevelMedium:

            errorCorrectionLevel = HbPredictionEngine::HbErrorCorrectionLevelMedium;

            break;

        case HbTypingCorrectionLevelHigh: