#include "selectfilesdialog.h"
#include "ui_selectfilesdialog.h"
#include "filelist.h"

#include <QTreeView>
#include <QVBoxLayout>
#include <QFileSystemModel>
#include <QStringList>
#include <QPushButton>

class SelectFilesModel : public QFileSystemModel {
private:
    QStringList selected;
    QStringList unselected;

    /**
     * Get index in stringlist where start of string matches. If
     * many strings in the stringlist match then return the index
     * for the longest string.
     * \param s stringlist with filepaths
     * \param filepath the filepath that is matched against the stringlist
     */
    int getindex(const QStringList &s, const QString &filepath) const {
        int matchlen = 0;
        int matchindex = -1;
        for (int i = 0; i < s.size(); ++i) {
            if (filepath.startsWith(s[i])) {
                // not a real match of paths..
                if (s[i].size() < filepath.size() && filepath[s[i].size()] != '/')
                    continue;

                // paths match. the return value is the index for the
                // longest match
                if (s[i].size() > matchlen)
                    matchindex = i;
            }
        }
        return matchindex;
    }

public:
    SelectFilesModel() : QFileSystemModel() {
        class FileLister : private FileList {
        public:
            static QStringList filters() {
                return GetDefaultFilters();
            }
        };
        setNameFilters(FileLister::filters());
        setNameFilterDisables(false);
        setRootPath("/");
    }

    Qt::ItemFlags flags(const QModelIndex& index) const {
        if (index.column() == 0)
            return QFileSystemModel::flags(index) | Qt::ItemIsUserCheckable;
        return QFileSystemModel::flags(index);
    }

    QVariant data(const QModelIndex& index, int role=Qt::DisplayRole) const {
        if (role == Qt::CheckStateRole) {
            const QString filepath = filePath(index);
            int selindex = getindex(selected, filepath);
            int unselindex = getindex(unselected, filepath);
            if (selindex >= 0 && unselindex == -1)
                return Qt::Checked;
            if (selindex >= 0 && unselindex >= 0 &&
                selected[selindex].size() > unselected[unselindex].size())
                return Qt::Checked;

            return Qt::Unchecked;
        }
        return QFileSystemModel::data(index, role);
    }

    bool setData(const QModelIndex& index, const QVariant& value, int role) {
        if (role == Qt::CheckStateRole) {
            const QString filepath = filePath(index);
            if (unselected.indexOf(filepath) != -1) {
                // remove unchecked path
                unselected.removeAll(filepath);
            } else if (selected.indexOf(filepath) != -1) {
                // remove child selected paths
                for (int i = selected.size() - 1; i >= 0; --i) {
                    if (selected[i].startsWith(filepath))
                        selected.removeAt(i);
                }

                // remove child unselected paths
                for (int i = unselected.size() - 1; i >= 0; --i) {
                    if (unselected[i].startsWith(filepath))
                        unselected.removeAt(i);
                }
            } else {
                int selindex = getindex(selected, filepath);
                int unselindex = getindex(unselected, filepath);
                if (selindex == -1)
                    selected.append(filepath);
                else if (unselindex >= 0 && selected[selindex].size() < unselected[unselindex].size())
                    selected.append(filepath);
                else
                    unselected.append(filepath);
            }

            if (rowCount(index) > 0)
                emit(dataChanged(index, index.child(rowCount(index)-1,0)));

            return true;
        }
        return QFileSystemModel::setData(index, value, role);
    }

    QStringList getFiles() const {
        QStringList ret;

        // List all files in "selected" folders..
        FileList fileLister;
        fileLister.AddPathList(selected);
        ret = fileLister.GetFileList();

        // Remove all items from ret that are unselected but not selected..
        for (int i = ret.size() - 1; i >= 0; i--) {
            int unselindex = getindex(unselected, ret[i]);
            if (unselindex == -1)
                continue;

            // both selected and unselected, check which to rely on
            int selindex = getindex(selected, ret[i]);
            if (selected[selindex].size() < unselected[unselindex].size())
                ret.removeAt(i);
        }

        return ret;
    }
};



SelectFilesDialog::SelectFilesDialog(QWidget *w) :
    QDialog(w),
    ui(new Ui::SelectFilesDialog)
{
    ui->setupUi(this);

    selectfilesmodel = new SelectFilesModel;

    ui->treeView->setModel(selectfilesmodel);
    for (int i = 1; i < 4; ++i)
        ui->treeView->setColumnHidden(i, true);

    // Change text of "OK" button to "Check"
    QPushButton *okbutton = ui->buttonBox->button(QDialogButtonBox::Ok);
    if (okbutton)
        okbutton->setText(tr("Check"));
}

SelectFilesDialog::~SelectFilesDialog()
{
    delete ui;
}

QStringList SelectFilesDialog::getFiles() const
{
    return selectfilesmodel->getFiles();
}