#include "databaseview.h"
#include <QVBoxLayout>
#include <QPushButton>
#include <QSettings>
#include <QDialogButtonBox>
#include <QHeaderView>
#include <QSqlError>
#include <QDebug>

const QStringList DEFAULT_COLUMNS = {"EXPTIME", "OBJECT", "RA", "DEC"};

SelectColumnsDialog::SelectColumnsDialog(QWidget *parent) : QDialog(parent)
{
    m_listWidget = new QListWidget(this);
    m_listWidget->setSelectionMode(QAbstractItemView::MultiSelection);
    QVBoxLayout *layout = new QVBoxLayout(this);
    setLayout(layout);
    layout->addWidget(m_listWidget);

    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
    connect(buttonBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
    connect(buttonBox, &QDialogButtonBox::rejected, this, &QDialog::reject);
    layout->addWidget(buttonBox);

    setWindowTitle(tr("Select columns"));
}

void SelectColumnsDialog::setColumns(QStringList columns)
{
    QSettings settings;
    m_listWidget->addItems(columns);
    QStringList selected = settings.value("databaseview/selectedColumns", DEFAULT_COLUMNS).toStringList();
    for(auto &sel : selected)
    {
        int i = columns.indexOf(sel);
        if(i>=0)
            m_listWidget->item(i)->setSelected(true);
    }
}

QStringList SelectColumnsDialog::selectedColumns()
{
    QStringList ret;
    for(auto &sel : m_listWidget->selectedItems())
        ret.append(sel->text());
    return ret;
}

FITSFileModel::FITSFileModel(QObject *parent) : QSqlQueryModel(parent)
{

}

void FITSFileModel::sort(int column, Qt::SortOrder order)
{
    if(column < 0)
        m_sort.clear();
    else if(column <= m_columns.size())
    {
        if(column == 0)m_sort = " ORDER BY file ";
        else m_sort = QString(" ORDER BY \"%1\" ").arg(m_columns.at(column-1));
        m_sort += order == Qt::AscendingOrder ? "ASC" : "DESC";
        prepareQuery();
    }
}

void FITSFileModel::setColumns(const QStringList &columns)
{
    m_columns = columns;
    prepareQuery();
}

void FITSFileModel::setFilter(const QString &key, const QString &value)
{
    if(value.isEmpty())
    {
        m_having.clear();
    }
    else
    {
        if(!m_columns.contains(key) && key != "file")m_columns.append(key);
        m_having = QString(" HAVING \"%1\" LIKE \"%2\"").arg(key).arg(value);
    }
    prepareQuery();
}

void FITSFileModel::prepareQuery()
{
    QString sql = "SELECT file,";
    for(auto &column : m_columns)
    {
        sql += QString("GROUP_CONCAT(CASE WHEN key=\"%1\" THEN value END) AS \"%1\",").arg(column);
    }
    sql.chop(1);
    sql += " FROM fits_files LEFT JOIN fits_headers ON fits_files.id=id_file GROUP BY fits_files.id" + m_having + m_sort;
    setQuery(sql);
    qDebug() << sql;
    if(lastError().type() != QSqlError::NoError)
        qDebug() << lastError();
}

DataBaseView::DataBaseView(Database *database, QWidget *parent) : QWidget(parent)
  ,m_database(database)
{
    QVBoxLayout *layout = new QVBoxLayout(this);
    setLayout(layout);

    m_tableView = new QTableView(this);
    m_tableView->verticalHeader()->setDefaultSectionSize(1);
    m_tableView->setSortingEnabled(true);
    m_tableView->horizontalHeader()->setSortIndicatorShown(true);
    layout->addWidget(m_tableView);
    connect(m_tableView, &QTableView::activated, this, &DataBaseView::itemActivated);

    m_model = new FITSFileModel(this);

    QSettings settings;
    m_tableView->setModel(m_model);
    m_model->setColumns(settings.value("databaseview/selectedColumns", DEFAULT_COLUMNS).toStringList());
    m_tableView->horizontalHeader()->restoreState(settings.value("databaseview/header").toByteArray());

    QHBoxLayout *hlayout = new QHBoxLayout();
    layout->addLayout(hlayout);

    QPushButton *selectColumnsButton = new QPushButton(tr("Select columns"), this);
    hlayout->addWidget(selectColumnsButton);
    connect(selectColumnsButton, &QPushButton::pressed, this, &DataBaseView::selectColumns);

    m_filterKeyword = new QComboBox(this);
    m_filterKeyword->addItem("file");
    m_filterKeyword->addItems(m_database->getFitsKeywords());

    m_search = new QLineEdit(this);
    m_search->setPlaceholderText(tr("Text to search, you can % as wildcard"));
    connect(m_search, &QLineEdit::returnPressed, this, &DataBaseView::applyFilter);

    QPushButton *filterButton = new QPushButton(tr("Filter"), this);
    connect(filterButton, SIGNAL(pressed()), this, SLOT(applyFilter()));

    hlayout->addWidget(m_filterKeyword);
    hlayout->addWidget(m_search);
    hlayout->addWidget(filterButton);
}

DataBaseView::~DataBaseView()
{
    QSettings settings;
    settings.setValue("databaseview/header", m_tableView->horizontalHeader()->saveState());
}

void DataBaseView::selectColumns()
{
    SelectColumnsDialog dialog;
    QStringList columns = m_database->getFitsKeywords();
    dialog.setColumns(columns);
    if(dialog.exec() == QDialog::Accepted)
    {
        QSettings settings;
        QStringList columns = dialog.selectedColumns();
        settings.setValue("databaseview/selectedColumns", columns);
        m_model->setColumns(columns);
    }
}

void DataBaseView::loadDatabase()
{
    QSettings settings;
    m_model->setColumns(settings.value("databaseview/selectedColumns", DEFAULT_COLUMNS).toStringList());
}

void DataBaseView::itemActivated(const QModelIndex &index)
{
    emit loadFile(m_model->data(index.siblingAtColumn(0)).toString());
}

void DataBaseView::applyFilter()
{
    m_model->setFilter(m_filterKeyword->currentText(), m_search->text());
}