/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.wicket.examples.ajax.builtin;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.collections4.iterators.EmptyIterator;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.wicket.Component;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.markup.html.form.AjaxButton;
import org.apache.wicket.extensions.ajax.AjaxFileDropBehavior;
import org.apache.wicket.extensions.ajax.markup.html.form.upload.UploadProgressBar;
import org.apache.wicket.extensions.ajax.markup.html.repeater.data.table.AjaxFallbackDefaultDataTable;
import org.apache.wicket.extensions.markup.html.repeater.data.table.IColumn;
import org.apache.wicket.extensions.markup.html.repeater.data.table.PropertyColumn;
import org.apache.wicket.extensions.markup.html.repeater.util.SortableDataProvider;
import org.apache.wicket.markup.html.WebMarkupContainer;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.form.Button;
import org.apache.wicket.markup.html.form.Form;
import org.apache.wicket.markup.html.form.TextField;
import org.apache.wicket.markup.html.form.upload.FileDescription;
import org.apache.wicket.markup.html.form.upload.FileUpload;
import org.apache.wicket.markup.html.form.upload.FileUploadField;
import org.apache.wicket.markup.html.form.upload.FilesSelectedBehavior;
import org.apache.wicket.markup.html.panel.FeedbackPanel;
import org.apache.wicket.markup.html.panel.Panel;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.Model;
import org.apache.wicket.util.lang.Bytes;
import org.apache.wicket.validation.validator.StringValidator;

/**
 * Demos ajax handling of a multipart form
 * 
 * @author igor.vaynberg
 */
public class FileUploadPage extends BasePage
{
    private static final long serialVersionUID = 1L;

    private static class SingleFileUploadSamplePanel extends Panel {

        private final FileUploadField file;
        private final TextField<String> text;
        private final Label selectedFileInfo;
        private final AjaxButton ajaxSubmit;
        private final Button submit;
        private String fileInfo;

        public SingleFileUploadSamplePanel(String id) {
            super(id);

            // create a feedback panel
            final Component feedback = new FeedbackPanel("feedback").setOutputMarkupId(true);
            add(feedback);

            // create the form
            final Form<?> form = new Form<Void>("form")
            {
                private static final long serialVersionUID = 1L;

                @Override
                protected void onSubmit()
                {
                    // display uploaded info
                    info("Text: " + text.getModelObject());
                    FileUpload upload = file.getFileUpload();
                    if (upload == null)
                    {
                        info("No file uploaded");
                    }
                    else
                    {
                        info("File-Name: " + upload.getClientFileName() + " File-Size: " +
                                Bytes.bytes(upload.getSize()).toString());
                    }
                }
            };
            form.setMaxSize(Bytes.megabytes(1));
            add(form);

            // create a textfield to demo non-file content
            form.add(text = new TextField<>("text", Model.of()));
            text.add(StringValidator.minimumLength(2));

            // create the file upload field
            form.add(file = new FileUploadField("file"));

            add(selectedFileInfo = new Label("selectedFileInfo", (IModel<String>) () -> fileInfo) {
                @Override
                protected void onAfterRender() {
                    super.onAfterRender();
                    fileInfo = null;
                }
            });
            selectedFileInfo.setOutputMarkupId(true);
            form.add(selectedFileInfo);

            form.add(new Label("max", form::getMaxSize));

            form.add(new UploadProgressBar("progress", form, file));

            // create a submit button
            form.add(submit = new Button("submit"));
            submit.setOutputMarkupId(true);

            // create the ajax button used to submit the form
            form.add(ajaxSubmit = new AjaxButton("ajaxSubmit")
            {
                private static final long serialVersionUID = 1L;

                /**
                 * Need to trigger submit to initiate progressbar.
                 */
                @Override
                protected boolean shouldTriggerJavaScriptSubmitEvent()
                {
                    return true;
                }

                @Override
                protected void onSubmit(AjaxRequestTarget target)
                {
                    info("This request was processed using AJAX");

                    // ajax-update the feedback panel
                    target.add(feedback);
                }

                @Override
                protected void onError(AjaxRequestTarget target)
                {
                    // update feedback to display errors
                    target.add(feedback);
                }

            });
            ajaxSubmit.setOutputMarkupId(true);

            file.add(FilesSelectedBehavior.onSelected(
                    (AjaxRequestTarget target, List<FileDescription> fileDescriptions)->
                    {
                        FileDescription fileDescription = fileDescriptions.get(0);
                        Bytes bytes = Bytes.bytes(fileDescription.getFileSize());
                        fileInfo = "File " + fileDescription.getFileName() +
                                " (with size " + bytes + ") was selected at client side. "
                                + "File was last modified at: " + fileDescription.getLastModified()
                                + " and is of type " + fileDescription.getMimeType() +
                                ". It has not been uploaded yet. ";
                        if (bytes.greaterThan(form.getMaxSize()))
                        {
                            fileInfo += " File exceeds max allowed size.";
                            // disable buttons as file is not valid
                            submit.setEnabled(false);
                            ajaxSubmit.setEnabled(false);
                        }
                        else
                        {
                            fileInfo += " You can click on buttons bellow in order to upload it.";
                            // enable buttons as file is valid
                            submit.setEnabled(true);
                            ajaxSubmit.setEnabled(true);
                        }
                        target.add(selectedFileInfo, submit, ajaxSubmit);
                    }));
            WebMarkupContainer drop = new WebMarkupContainer("drop");
            drop.add(new AjaxFileDropBehavior() {
                protected void onFileUpload(AjaxRequestTarget target, List<FileUpload> files) {

                    // display uploaded info
                    if (files == null || files.isEmpty())
                    {
                        info("No file uploaded");
                    }
                    else
                    {
                        for (FileUpload file : files) {
                            info("File-Name: " + file.getClientFileName() + " File-Size: " +
                                    Bytes.bytes(file.getSize()).toString());
                        }
                    }

                    target.add(feedback);
                }

                @Override
                protected void onError(AjaxRequestTarget target, FileUploadException fux)
                {
                    info(fux.getMessage());

                    target.add(feedback);
                }
            });
            add(drop);
        }
    }

    private static class MultipleFileUploadsSamplePanel extends Panel {

        private static class DataProvider extends SortableDataProvider<FileDescription, String> {

            private List<FileDescription> fileDescriptions;

            public void setFileDescriptions(List<FileDescription> fileDescriptions) {
                this.fileDescriptions = new ArrayList<>(fileDescriptions);
            }

            @Override
            public Iterator<? extends FileDescription> iterator(long first, long count) {
                if (this.fileDescriptions == null) {
                    return EmptyIterator.emptyIterator();
                }
                return fileDescriptions.listIterator();
            }

            @Override
            public long size() {
                if (this.fileDescriptions == null) {
                    return 0L;
                }
                return this.fileDescriptions.size();
            }

            @Override
            public IModel<FileDescription> model(FileDescription object) {
                return Model.of(object);
            }

            @Override
            public void detach() {
                super.detach();
                this.fileDescriptions = null;
            }
        }

        private final FileUploadField file;
        private final TextField<String> text;
        private DataProvider dataProvider;
        private AjaxFallbackDefaultDataTable<FileDescription, String> selectedFileInfo;
        private final AjaxButton ajaxSubmit;
        private final Button submit;

        public MultipleFileUploadsSamplePanel(String id) {
            super(id);

            // create a feedback panel
            final Component feedback = new FeedbackPanel("feedback").setOutputMarkupId(true);
            add(feedback);

            // create the form
            final Form<?> form = new Form<Void>("form")
            {
                private static final long serialVersionUID = 1L;

                @Override
                protected void onSubmit()
                {
                    // display uploaded info
                    info("Text: " + text.getModelObject());
                    FileUpload upload = file.getFileUpload();
                    if (upload == null)
                    {
                        info("No file uploaded");
                    }
                    else
                    {
                        info("File-Name: " + upload.getClientFileName() + " File-Size: " +
                                Bytes.bytes(upload.getSize()).toString());
                    }
                }
            };
            form.setMaxSize(Bytes.megabytes(1));
            add(form);

            List<IColumn<FileDescription, String>> columns = new ArrayList<>();
            columns.add(new PropertyColumn<>(Model.of("File Name"), "fileName"));
            columns.add(new PropertyColumn<>(Model.of("Size"), "fileSize"));
            columns.add(new PropertyColumn<>(Model.of("Last Modified"), "lastModified"));
            columns.add(new PropertyColumn<>(Model.of("MIME Type"), "mimeType"));
            selectedFileInfo = new AjaxFallbackDefaultDataTable<>("selectedFileInfo", columns, dataProvider = new DataProvider(), 100) {
                @Override
                protected void onConfigure() {
                    super.onConfigure();
                    setVisible(dataProvider.size() > 0);
                }
            };
            form.add(selectedFileInfo);
            selectedFileInfo.setOutputMarkupPlaceholderTag(true);

            // create a textfield to demo non-file content
            form.add(text = new TextField<>("text", Model.of()));
            text.add(StringValidator.minimumLength(2));

            // create the file upload field
            form.add(file = new FileUploadField("file"));

            form.add(new Label("max", form::getMaxSize));

            form.add(new UploadProgressBar("progress", form, file));

            // create a submit button
            form.add(submit = new Button("submit"));
            submit.setOutputMarkupId(true);

            // create the ajax button used to submit the form
            form.add(ajaxSubmit = new AjaxButton("ajaxSubmit")
            {
                private static final long serialVersionUID = 1L;

                /**
                 * Need to trigger submit to initiate progressbar.
                 */
                @Override
                protected boolean shouldTriggerJavaScriptSubmitEvent()
                {
                    return true;
                }

                @Override
                protected void onSubmit(AjaxRequestTarget target)
                {
                    info("This request was processed using AJAX");

                    // ajax-update the feedback panel
                    target.add(feedback);
                }

                @Override
                protected void onError(AjaxRequestTarget target)
                {
                    // update feedback to display errors
                    target.add(feedback);
                }

            });
            ajaxSubmit.setOutputMarkupId(true);
            file.add(FilesSelectedBehavior.onSelected(
                    (AjaxRequestTarget target, List<FileDescription> fileDescriptions) ->
            {
                dataProvider.setFileDescriptions(fileDescriptions);
                Bytes bytes = Bytes.bytes(fileDescriptions.stream().mapToLong(FileDescription::getFileSize).sum());
                if (bytes.greaterThan(form.getMaxSize()))
                {
                    form.error("Total file size exceeds max allowed size.");
                    // disable buttons as file is not valid
                    submit.setEnabled(false);
                    ajaxSubmit.setEnabled(false);
                }
                else
                {
                    form.info("You can click on buttons bellow in order to upload selected files.");
                    // enable buttons as file is valid
                    submit.setEnabled(true);
                    ajaxSubmit.setEnabled(true);
                }
                target.add(selectedFileInfo, submit, ajaxSubmit, feedback);
            }));
        }
    }
    /**
     * Constructor
     */
    public FileUploadPage()
    {
        // sample of a single uploaded file.
        add(new SingleFileUploadSamplePanel("singleFileUpload"));
        add(new MultipleFileUploadsSamplePanel("multipleFileUpload"));


    }
}