package com.vaadin.tests.dnd;

import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import com.vaadin.server.StreamVariable;
import com.vaadin.server.VaadinRequest;
import com.vaadin.shared.ui.dnd.FileParameters;
import com.vaadin.shared.ui.grid.DropMode;
import com.vaadin.tests.components.AbstractTestUIWithLog;
import com.vaadin.ui.Grid;
import com.vaadin.ui.Layout;
import com.vaadin.ui.Notification;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.ui.components.grid.GridDropTarget;
import com.vaadin.ui.dnd.FileDropTarget;

public class Html5FileDragAndDropUpload extends AbstractTestUIWithLog {

    private static final int FILE_SIZE_LIMIT = 1024 * 1024 * 5; // 5 MB

    @Override
    protected void setup(VaadinRequest request) {

        Grid<FileParameters> grid = new Grid<>(
                "Drop files or text on the Grid");
        grid.addColumn(FileParameters::getName).setCaption("File name");
        grid.addColumn(FileParameters::getSize).setCaption("File size");
        grid.addColumn(FileParameters::getMime).setCaption("Mime type");

        List<FileParameters> gridItems = new ArrayList<>();

        new FileDropTarget<Grid<FileParameters>>(grid,
                event -> event.getFiles().forEach(html5File -> {
                    if (html5File.getFileSize() > FILE_SIZE_LIMIT) {
                        Notification.show(html5File.getFileName()
                                + " is too large (max 5 MB)");
                        return;
                    }

                    html5File.setStreamVariable(new StreamVariable() {
                        @Override
                        public OutputStream getOutputStream() {
                            return new OutputStream() {
                                @Override
                                public void write(int b) throws IOException {
                                    // NOP
                                }
                            };
                        }

                        @Override
                        public boolean listenProgress() {
                            return true;
                        }

                        @Override
                        public void onProgress(StreamingProgressEvent event) {
                            log("Progress, bytesReceived="
                                    + event.getBytesReceived());
                        }

                        @Override
                        public void streamingStarted(
                                StreamingStartEvent event) {
                            log("Stream started, fileName="
                                    + event.getFileName());
                        }

                        @Override
                        public void streamingFinished(StreamingEndEvent event) {
                            gridItems
                                    .add(new FileParameters(event.getFileName(),
                                            event.getContentLength(),
                                            event.getMimeType()));
                            grid.setItems(gridItems);

                            log("Stream finished, fileName="
                                    + event.getFileName());
                        }

                        @Override
                        public void streamingFailed(StreamingErrorEvent event) {
                            log("Stream failed, fileName="
                                    + event.getFileName());
                        }

                        @Override
                        public boolean isInterrupted() {
                            return false;
                        }
                    });
                }));

        GridDropTarget<FileParameters> dropTarget = new GridDropTarget<>(grid,
                DropMode.ON_TOP);
        dropTarget.addGridDropListener(event -> {
            log("dataTransferText=" + event.getDataTransferText());
            Notification.show(event.getDataTransferText());
        });

        Layout layout = new VerticalLayout(grid);

        addComponent(layout);
    }

    @Override
    protected String getTestDescription() {
        return "Drop files onto the Grid to upload them or text";
    }
}