/**
 ******************************************************************************
 *
 * @file       submiteditorwidget.cpp
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 *             Parts by Nokia Corporation (qt-info@nokia.com) Copyright (C) 2009.
 * @brief      
 * @see        The GNU Public License (GPL) Version 3
 * @defgroup   
 * @{
 * 
 *****************************************************************************/
/* 
 * 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 3 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., 
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "submiteditorwidget.h"
#include "submitfieldwidget.h"
#include "ui_submiteditorwidget.h"

#include <QtCore/QDebug>
#include <QtCore/QPointer>
#include <QtCore/QTimer>

#include <QtGui/QPushButton>
#include <QtGui/QMenu>
#include <QtGui/QHBoxLayout>
#include <QtGui/QToolButton>
#include <QtGui/QSpacerItem>

enum { debug = 0 };
enum { defaultLineWidth = 72 };

namespace Utils {

// QActionPushButton: A push button tied to an action
// (similar to a QToolButton)
class QActionPushButton : public QPushButton
{
    Q_OBJECT
public:
    explicit QActionPushButton(QAction *a);

private slots:
    void actionChanged();
};

QActionPushButton::QActionPushButton(QAction *a) :
     QPushButton(a->icon(), a->text())
{
    connect(a, SIGNAL(changed()), this, SLOT(actionChanged()));
    connect(this, SIGNAL(clicked()), a, SLOT(trigger()));
    setEnabled(a->isEnabled());
}

void QActionPushButton::actionChanged()
{
    if (const QAction *a = qobject_cast<QAction*>(sender()))
        setEnabled(a->isEnabled());
}

// Helpers to retrieve model data
static inline bool listModelChecked(const QAbstractItemModel *model, int row, int column = 0)
{
    const QModelIndex checkableIndex = model->index(row, column, QModelIndex());
    return model->data(checkableIndex, Qt::CheckStateRole).toInt() == Qt::Checked;
}

static inline QString listModelText(const QAbstractItemModel *model, int row, int column)
{
    const QModelIndex index = model->index(row, column, QModelIndex());
    return model->data(index, Qt::DisplayRole).toString();
}

// Find a check item in a model
static bool listModelContainsCheckedItem(const QAbstractItemModel *model)
{
    const int count = model->rowCount();
    for (int i = 0; i < count; i++)
        if (listModelChecked(model, i, 0))
            return true;
    return false;
}

// Convenience to extract a list of selected indexes
QList<int> selectedRows(const QAbstractItemView *view)
{
    const QModelIndexList indexList = view->selectionModel()->selectedRows(0);
    if (indexList.empty())
        return QList<int>();
    QList<int> rc;
    const QModelIndexList::const_iterator cend = indexList.constEnd();
    for (QModelIndexList::const_iterator it = indexList.constBegin(); it != cend; ++it)
        rc.push_back(it->row());
    return rc;
}

// -----------  SubmitEditorWidgetPrivate

struct SubmitEditorWidgetPrivate
{
    // A pair of position/action to extend context menus
    typedef QPair<int, QPointer<QAction> > AdditionalContextMenuAction;

    SubmitEditorWidgetPrivate();

    Ui::SubmitEditorWidget m_ui;
    bool m_filesSelected;
    bool m_filesChecked;
    int m_fileNameColumn;
    int m_activatedRow;

    QList<AdditionalContextMenuAction> descriptionEditContextMenuActions;
    QVBoxLayout *m_fieldLayout;
    QList<SubmitFieldWidget *> m_fieldWidgets;
    int m_lineWidth;
};

SubmitEditorWidgetPrivate::SubmitEditorWidgetPrivate() :
    m_filesSelected(false),
    m_filesChecked(false),
    m_fileNameColumn(1),
    m_activatedRow(-1),
    m_fieldLayout(0),
    m_lineWidth(defaultLineWidth)
{
}

SubmitEditorWidget::SubmitEditorWidget(QWidget *parent) :
    QWidget(parent),
    m_d(new SubmitEditorWidgetPrivate)
{
    m_d->m_ui.setupUi(this);
    m_d->m_ui.description->setContextMenuPolicy(Qt::CustomContextMenu);
    m_d->m_ui.description->setLineWrapMode(QTextEdit::NoWrap);
    m_d->m_ui.description->setWordWrapMode(QTextOption::WordWrap);
    connect(m_d->m_ui.description, SIGNAL(customContextMenuRequested(QPoint)),
            this, SLOT(editorCustomContextMenuRequested(QPoint)));

    // File List
    m_d->m_ui.fileView->setSelectionMode(QAbstractItemView::ExtendedSelection);
    m_d->m_ui.fileView->setRootIsDecorated(false);
    connect(m_d->m_ui.fileView, SIGNAL(doubleClicked(QModelIndex)),
            this, SLOT(diffActivated(QModelIndex)));

    setFocusPolicy(Qt::StrongFocus);
    setFocusProxy(m_d->m_ui.description);
}

SubmitEditorWidget::~SubmitEditorWidget()
{
    delete m_d;
}

void SubmitEditorWidget::registerActions(QAction *editorUndoAction, QAction *editorRedoAction,
                         QAction *submitAction, QAction *diffAction)
{
    if (editorUndoAction) {
        editorUndoAction->setEnabled(m_d->m_ui.description->document()->isUndoAvailable());
        connect(m_d->m_ui.description, SIGNAL(undoAvailable(bool)), editorUndoAction, SLOT(setEnabled(bool)));
        connect(editorUndoAction, SIGNAL(triggered()), m_d->m_ui.description, SLOT(undo()));
    }
    if (editorRedoAction) {
        editorRedoAction->setEnabled(m_d->m_ui.description->document()->isRedoAvailable());
        connect(m_d->m_ui.description, SIGNAL(redoAvailable(bool)), editorRedoAction, SLOT(setEnabled(bool)));
        connect(editorRedoAction, SIGNAL(triggered()), m_d->m_ui.description, SLOT(redo()));
    }

    if (submitAction) {
        if (debug) {
            int count = 0;
            if (const QAbstractItemModel *model = m_d->m_ui.fileView->model())
                count = model->rowCount();
            qDebug() << Q_FUNC_INFO << submitAction << count << "items" << m_d->m_filesChecked;
        }
        submitAction->setEnabled(m_d->m_filesChecked);
        connect(this, SIGNAL(fileCheckStateChanged(bool)), submitAction, SLOT(setEnabled(bool)));
        m_d->m_ui.buttonLayout->addWidget(new QActionPushButton(submitAction));
    }
    if (diffAction) {
        if (debug)
            qDebug() << diffAction << m_d->m_filesSelected;
        diffAction->setEnabled(m_d->m_filesSelected);
        connect(this, SIGNAL(fileSelectionChanged(bool)), diffAction, SLOT(setEnabled(bool)));
        connect(diffAction, SIGNAL(triggered()), this, SLOT(triggerDiffSelected()));
        m_d->m_ui.buttonLayout->addWidget(new QActionPushButton(diffAction));
    }
}

void SubmitEditorWidget::unregisterActions(QAction *editorUndoAction,  QAction *editorRedoAction,
                                           QAction *submitAction, QAction *diffAction)
{
    if (editorUndoAction) {
        disconnect(m_d->m_ui.description, SIGNAL(undoAvailableChanged(bool)), editorUndoAction, SLOT(setEnabled(bool)));
        disconnect(editorUndoAction, SIGNAL(triggered()), m_d->m_ui.description, SLOT(undo()));
    }
    if (editorRedoAction) {
        disconnect(m_d->m_ui.description, SIGNAL(redoAvailableChanged(bool)), editorRedoAction, SLOT(setEnabled(bool)));
        disconnect(editorRedoAction, SIGNAL(triggered()), m_d->m_ui.description, SLOT(redo()));
    }

    if (submitAction)
        disconnect(this, SIGNAL(fileCheckStateChanged(bool)), submitAction, SLOT(setEnabled(bool)));

    if (diffAction) {
         disconnect(this, SIGNAL(fileSelectionChanged(bool)), diffAction, SLOT(setEnabled(bool)));
         disconnect(diffAction, SIGNAL(triggered()), this, SLOT(triggerDiffSelected()));
    }
}

// Make sure we have one terminating NL
static inline QString trimMessageText(const QString &t)
{
    QString rc = t.trimmed();
    rc += QLatin1Char('\n');
    return rc;
}

// Extract the wrapped text from a text edit, which performs
// the wrapping only optically.
static QString wrappedText(const QTextEdit *e)
{
    const QChar newLine = QLatin1Char('\n');
    QString rc;
    QTextCursor cursor(e->document());
    cursor.movePosition(QTextCursor::Start);    
    while (!cursor.atEnd()) {
        cursor.select(QTextCursor::LineUnderCursor);
        rc += cursor.selectedText();
        rc += newLine;
        cursor.movePosition(QTextCursor::EndOfLine); // Mac needs it
        cursor.movePosition(QTextCursor::Right);
    }
    return rc;
}

QString SubmitEditorWidget::descriptionText() const
{
    QString rc = trimMessageText(lineWrap() ? wrappedText(m_d->m_ui.description) : m_d->m_ui.description->toPlainText());
    // append field entries
    foreach(const SubmitFieldWidget *fw, m_d->m_fieldWidgets)
        rc += fw->fieldValues();
    return rc;
}

void SubmitEditorWidget::setDescriptionText(const QString &text)
{
    m_d->m_ui.description->setPlainText(text);
}

bool SubmitEditorWidget::lineWrap() const
{
    return m_d->m_ui.description->lineWrapMode() != QTextEdit::NoWrap;
}

void SubmitEditorWidget::setLineWrap(bool v)
{
    if (debug)
        qDebug() << Q_FUNC_INFO << v;
    if (v) {
        m_d->m_ui.description->setLineWrapColumnOrWidth(m_d->m_lineWidth);
        m_d->m_ui.description->setLineWrapMode(QTextEdit::FixedColumnWidth);        
    } else {
        m_d->m_ui.description->setLineWrapMode(QTextEdit::NoWrap);
    }
}

int SubmitEditorWidget::lineWrapWidth() const
{
    return m_d->m_lineWidth;
}

void SubmitEditorWidget::setLineWrapWidth(int v)
{
    if (debug)
        qDebug() << Q_FUNC_INFO << v << lineWrap();
    if (m_d->m_lineWidth == v)
        return;
    m_d->m_lineWidth = v;
    if (lineWrap())
        m_d->m_ui.description->setLineWrapColumnOrWidth(v);
}

int SubmitEditorWidget::fileNameColumn() const
{
    return m_d->m_fileNameColumn;
}

void SubmitEditorWidget::setFileNameColumn(int c)
{
    m_d->m_fileNameColumn = c;
}

QAbstractItemView::SelectionMode SubmitEditorWidget::fileListSelectionMode() const
{
    return m_d->m_ui.fileView->selectionMode();
}

void SubmitEditorWidget::setFileListSelectionMode(QAbstractItemView::SelectionMode sm)
{
    m_d->m_ui.fileView->setSelectionMode(sm);
}

void SubmitEditorWidget::setFileModel(QAbstractItemModel *model)
{
    m_d->m_ui.fileView->clearSelection(); // trigger the change signals

    m_d->m_ui.fileView->setModel(model);

    if (model->rowCount()) {
        const int columnCount = model->columnCount();
        for (int c = 0;  c < columnCount; c++)
            m_d->m_ui.fileView->resizeColumnToContents(c);
    }

    connect(model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),
            this, SLOT(updateSubmitAction()));
    connect(model, SIGNAL(modelReset()),
            this, SLOT(updateSubmitAction()));
    connect(model, SIGNAL(rowsInserted(QModelIndex,int,int)),
            this, SLOT(updateSubmitAction()));
    connect(model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
            this, SLOT(updateSubmitAction()));
    connect(m_d->m_ui.fileView->selectionModel(), SIGNAL(selectionChanged(QItemSelection, QItemSelection)),
            this, SLOT(updateDiffAction()));
    updateActions();
}

QAbstractItemModel *SubmitEditorWidget::fileModel() const
{
    return m_d->m_ui.fileView->model();
}

QStringList SubmitEditorWidget::selectedFiles() const
{
    const QList<int> selection = selectedRows(m_d->m_ui.fileView);
    if (selection.empty())
        return QStringList();

    QStringList rc;
    const QAbstractItemModel *model = m_d->m_ui.fileView->model();
    const int count = selection.size();
    for (int i = 0; i < count; i++)
        rc.push_back(listModelText(model, selection.at(i), fileNameColumn()));
    return rc;
}

QStringList SubmitEditorWidget::checkedFiles() const
{
    QStringList rc;
    const QAbstractItemModel *model = m_d->m_ui.fileView->model();
    if (!model)
        return rc;
    const int count = model->rowCount();
    for (int i = 0; i < count; i++)
        if (listModelChecked(model, i, 0))
            rc.push_back(listModelText(model, i, fileNameColumn()));
    return rc;
}

QTextEdit *SubmitEditorWidget::descriptionEdit() const
{
    return m_d->m_ui.description;
}

void SubmitEditorWidget::triggerDiffSelected()
{
    const QStringList sel = selectedFiles();
    if (!sel.empty())
        emit diffSelected(sel);
}

void SubmitEditorWidget::diffActivatedDelayed()
{
    const QStringList files = QStringList(listModelText(m_d->m_ui.fileView->model(), m_d->m_activatedRow, fileNameColumn()));
    emit diffSelected(files);
}

void SubmitEditorWidget::diffActivated(const QModelIndex &index)
{
    // We need to delay the signal, otherwise, the diff editor will not
    // be in the foreground.
    m_d->m_activatedRow = index.row();
    QTimer::singleShot(0, this, SLOT(diffActivatedDelayed()));
}

void SubmitEditorWidget::updateActions()
{
    updateSubmitAction();
    updateDiffAction();
}

// Enable submit depending on having checked files
void SubmitEditorWidget::updateSubmitAction()
{
    const bool newFilesCheckedState = hasCheckedFiles();
    if (m_d->m_filesChecked != newFilesCheckedState) {
        m_d->m_filesChecked = newFilesCheckedState;
        emit fileCheckStateChanged(m_d->m_filesChecked);
    }
}

// Enable diff depending on selected files
void SubmitEditorWidget::updateDiffAction()
{
    const bool filesSelected = hasSelection();
    if (m_d->m_filesSelected != filesSelected) {
        m_d->m_filesSelected = filesSelected;
        emit fileSelectionChanged(m_d->m_filesSelected);
    }
}

bool SubmitEditorWidget::hasSelection() const
{
    // Not present until model is set
    if (const QItemSelectionModel *sm = m_d->m_ui.fileView->selectionModel())
        return sm->hasSelection();
    return false;
}

bool SubmitEditorWidget::hasCheckedFiles() const
{
    if (const QAbstractItemModel *model = m_d->m_ui.fileView->model())
        return listModelContainsCheckedItem(model);
    return false;
}

void SubmitEditorWidget::changeEvent(QEvent *e)
{
    QWidget::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        m_d->m_ui.retranslateUi(this);
        break;
    default:
        break;
    }
}

void SubmitEditorWidget::insertTopWidget(QWidget *w)
{
    m_d->m_ui.vboxLayout->insertWidget(0, w);
}

void SubmitEditorWidget::addSubmitFieldWidget(SubmitFieldWidget *f)
{
    if (!m_d->m_fieldLayout) {
        // VBox with horizontal, expanding spacer
        m_d->m_fieldLayout = new QVBoxLayout;
        QHBoxLayout *outerLayout = new QHBoxLayout;
        outerLayout->addLayout(m_d->m_fieldLayout);
        outerLayout->addItem(new QSpacerItem(0, 0, QSizePolicy::Expanding, QSizePolicy::Ignored));
        QBoxLayout *descrLayout = qobject_cast<QBoxLayout*>(m_d->m_ui.descriptionBox->layout());
        Q_ASSERT(descrLayout);
        descrLayout->addLayout(outerLayout);
    }
    m_d->m_fieldLayout->addWidget(f);
    m_d->m_fieldWidgets.push_back(f);
}

QList<SubmitFieldWidget *> SubmitEditorWidget::submitFieldWidgets() const
{
    return m_d->m_fieldWidgets;
}

void SubmitEditorWidget::addDescriptionEditContextMenuAction(QAction *a)
{
    m_d->descriptionEditContextMenuActions.push_back(SubmitEditorWidgetPrivate::AdditionalContextMenuAction(-1, a));
}

void SubmitEditorWidget::insertDescriptionEditContextMenuAction(int pos, QAction *a)
{
    m_d->descriptionEditContextMenuActions.push_back(SubmitEditorWidgetPrivate::AdditionalContextMenuAction(pos, a));
}

void SubmitEditorWidget::editorCustomContextMenuRequested(const QPoint &pos)
{
    QMenu *menu = m_d->m_ui.description->createStandardContextMenu();    
    // Extend
    foreach (const SubmitEditorWidgetPrivate::AdditionalContextMenuAction &a, m_d->descriptionEditContextMenuActions) {
        if (a.second) {
            if (a.first >= 0) {
                menu->insertAction(menu->actions().at(a.first), a.second);
            } else {
                menu->addAction(a.second);
            }
        }
    }
    menu->exec(m_d->m_ui.description->mapToGlobal(pos));
    delete menu;
}

} // namespace Utils

#include "submiteditorwidget.moc"