package org.simantics.district.imports.ui;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.layout.TableColumnLayout;
import org.eclipse.jface.layout.TreeColumnLayout;
import org.eclipse.jface.viewers.ColumnViewerToolTipSupport;
import org.eclipse.jface.viewers.ColumnWeightData;
import org.eclipse.jface.viewers.IContentProvider;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.wizard.WizardPage;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.TableItem;
import org.simantics.district.imports.DistrictImportUtils.CSVHeader;
import org.simantics.utils.ui.widgets.FileOrDirectorySelectionWidget;
import org.simantics.utils.ui.widgets.FileSelectionListener;
import org.simantics.utils.ui.widgets.FileSelectionWidget;

public class CSVImportWizardPage extends WizardPage implements FileSelectionListener {

    private CSVImportModel model;
    private FileSelectionWidget csvSelection;
    private Table headerTable;
    private Button firstAsHeader;
    private Combo delimiterCombo;
    private TableColumnLayout tableColumnLayout;
    private TableViewer tableViewer;
    private Composite tableComposite;

    protected CSVImportWizardPage(CSVImportModel model) {
        super("Import CSV Data");
        this.model = model;
        setMessage("Select CSV file to import");
    }

    @Override
    public void createControl(Composite parent) {
        Composite composite = new Composite(parent, SWT.NONE);
        composite.setLayout(new GridLayout(1,false));
        GridDataFactory.fillDefaults().grab(true, true).align(SWT.FILL, SWT.FILL).applyTo(composite);
        
        csvSelection = new FileSelectionWidget(composite, "CSV file", SWT.OPEN);
        csvSelection.addListener(this);
        
        delimiterCombo = new Combo(composite, SWT.DROP_DOWN | SWT.READ_ONLY);
        delimiterCombo.setItems(model.getDelimiterFormats());
        delimiterCombo.addSelectionListener(new SelectionListener() {
            
            @Override
            public void widgetSelected(SelectionEvent e) {
                model.setDelimiterByLabel(delimiterCombo.getItem(delimiterCombo.getSelectionIndex()));
                updateHeaders();
            }
            
            @Override
            public void widgetDefaultSelected(SelectionEvent e) {
                
            }
        });
        
        firstAsHeader = new Button(composite, SWT.CHECK);
        firstAsHeader.setText("Read first row as header");
        firstAsHeader.setSelection(model.getReadFirstAsHeader());
        firstAsHeader.addSelectionListener(new SelectionListener() {
            
            @Override
            public void widgetSelected(SelectionEvent e) {
                model.setReadFirstAsHeader(firstAsHeader.getSelection());
                updateHeaders();
            }
            
            @Override
            public void widgetDefaultSelected(SelectionEvent e) {
                
            }
        });
        
        
        tableComposite = new Composite(composite, SWT.BORDER);
        tableColumnLayout = new TableColumnLayout();
        tableComposite.setLayout(tableColumnLayout);

        updateHeaders();
        
        setControl(composite);
        
        
        
        setPageComplete(false);
    }

    @Override
    public void fileSelected(FileOrDirectorySelectionWidget source, String[] filename) {
        String[] selection = csvSelection.getFilename();
        if (selection != null && selection.length > 0) {
            Path csvFile = Paths.get(selection[0]);
            if (!Files.exists(csvFile)) {
                setErrorMessage("File " + csvFile.toAbsolutePath() + " does not exist");
            } else {
                model.setSource(csvFile);
                updateHeaders();
                setPageComplete(true);
            }
        } else {
            setPageComplete(false);
        }
    }

    private void updateHeaders() {
        if (headerTable != null)
            headerTable.dispose();
        headerTable = new Table(tableComposite, SWT.NONE);
        headerTable.setHeaderVisible(true);
        headerTable.setLinesVisible(true);
        GridDataFactory.fillDefaults().grab(true, true).align(SWT.FILL, SWT.FILL).applyTo(tableComposite);
        for (int i = 0; i < headerTable.getColumns().length; i++) {
            TableColumn column = headerTable.getColumns()[i];
            column.dispose();
        }
        for (int i = 0; i < headerTable.getItemCount(); i++) {
            TableItem item = headerTable.getItem(i);
            item.dispose();
        }
        try {
            Map<CSVHeader, List<String>> headerAndValues = model.getHeaderAndRows(5);
            
            int coo = headerTable.getColumns().length;
            int count = headerTable.getColumnCount();
            
            for (Map.Entry<CSVHeader, List<String>> entr : headerAndValues.entrySet()) {
                CSVHeader he = entr.getKey();
                int index = he.getIndex();
                TableColumn headerCol = new TableColumn(headerTable, SWT.NONE);
                headerCol.setText(he.getHeader());
                
                tableColumnLayout.setColumnData(headerCol, new ColumnWeightData(10));
                headerCol.pack();
                
                for (String val : entr.getValue()) {
                    TableItem item = new TableItem(headerTable, SWT.NONE);
                    item.setText(val);
                }
            }
        } catch (IOException e) {
            setErrorMessage(e.getMessage());
        }
    }

}