package de.intevation.flys.client.client.ui;

import de.intevation.flys.client.client.event.DatacageHandler;
import de.intevation.flys.client.client.event.DatacageDoubleClickHandler;

import com.google.gwt.core.client.GWT;

import com.google.gwt.user.client.rpc.AsyncCallback;

import com.smartgwt.client.util.SC;

import com.smartgwt.client.widgets.Button;

import com.smartgwt.client.widgets.tree.Tree;
import com.smartgwt.client.widgets.tree.TreeGrid;
import com.smartgwt.client.widgets.tree.TreeNode;

import com.smartgwt.client.types.SelectionStyle;
import com.smartgwt.client.types.TreeModelType;

import com.smartgwt.client.widgets.layout.VLayout;

import com.smartgwt.client.widgets.events.ClickHandler;
import com.smartgwt.client.widgets.events.ClickEvent;

import com.smartgwt.client.widgets.grid.ListGridRecord;

import com.smartgwt.client.widgets.grid.events.RecordDoubleClickEvent;
import com.smartgwt.client.widgets.grid.events.RecordDoubleClickHandler;

import de.intevation.flys.client.shared.model.Artifact;
import de.intevation.flys.client.shared.model.User;
import de.intevation.flys.client.shared.model.ToLoad;

import de.intevation.flys.client.client.FLYSConstants;
import de.intevation.flys.client.client.Config;

import de.intevation.flys.client.client.services.MetaDataService;
import de.intevation.flys.client.client.services.MetaDataServiceAsync;

import de.intevation.flys.client.shared.model.DataCageTree;
import de.intevation.flys.client.shared.model.DataCageNode;
import de.intevation.flys.client.shared.model.AttrList;

import java.util.ArrayList;
import java.util.List;
import java.util.Stack;

// TODO: refactor, extract ~DataCageGrid
public class DatacageWidget
extends      VLayout
{
    protected MetaDataServiceAsync metaDataService =
        GWT.create(MetaDataService.class);

    protected FLYSConstants messages =
        GWT.create(FLYSConstants.class);

    protected Artifact artifact;
    protected User     user;
    protected String   outs;
    protected String   parameters;

    protected TreeGrid treeGrid;
    protected Tree     tree;

    protected ToLoad   toLoad;

    protected List<DatacageHandler>            handlers;
    protected List<DatacageDoubleClickHandler> doubleHandlers;


    public DatacageWidget() {
        handlers       = new ArrayList<DatacageHandler>();
        doubleHandlers = new ArrayList<DatacageDoubleClickHandler>();
    }


    public DatacageWidget(Artifact artifact, User user) {
        this(artifact, user, null);
    }

    public DatacageWidget(Artifact artifact, User user, String outs) {
        this(artifact, user, outs, true);
    }

    public DatacageWidget(
        Artifact   artifact,
        User       user,
        String     outs,
        boolean    showButton
    ) {
        this(artifact, user, outs, null, showButton);
    }


    public DatacageWidget(
        Artifact   artifact,
        User       user,
        String     outs,
        String     parameters,
        boolean    showButton
    ) {
        this();

        this.artifact   = artifact;
        this.user       = user;
        this.outs       = outs;
        this.parameters = parameters;

        toLoad = new ToLoad();

        setWidth100();

        tree = new Tree();
        tree.setModelType(TreeModelType.PARENT);
        tree.setNameProperty("name");
        tree.setIdField("id");
        tree.setParentIdField("parent-id");

        treeGrid = new TreeGrid();
        treeGrid.setLoadDataOnDemand(false);
        treeGrid.setWidth100();
        treeGrid.setHeight100();
        treeGrid.setShowRoot(false);

        treeGrid.addRecordDoubleClickHandler(new RecordDoubleClickHandler() {
            @Override
            public void onRecordDoubleClick(RecordDoubleClickEvent event) {
                doubleClickedOnTree(event);
            }
        });

        addMember(treeGrid);

        if (showButton) {
            addMember(createPlusButton());
        }

        triggerTreeBuilding();
    }


    /**
     * @param handler Handler to be added (notified on add-action).
     */
    public DatacageWidget(Artifact artifact, User user, String outs,
        DatacageHandler handler) {
        this(artifact, user, outs);
        this.addDatacageHandler(handler);
    }


    public DatacageWidget(
        Artifact        artifact,
        User            user,
        String          outs,
        DatacageHandler handler,
        String          parameters
    ) {
        this(artifact, user, outs, handler);
        this.parameters = parameters;
    }


    public void setIsMutliSelectable(boolean multi) {
        if (multi) {
            treeGrid.setSelectionType(SelectionStyle.MULTIPLE);
        }
        else {
            treeGrid.setSelectionType(SelectionStyle.SINGLE);
        }
    }


    /**
     * @param handler Handler to be added (notified on add-action).
     */
    public void addDatacageHandler(DatacageHandler handler) {
        if (!handlers.contains(handler)) {
            handlers.add(handler);
        }
    }


    /**
     * @param h Handler to be added (notified on Double click on node).
     */
    public void addDatacageDoubleClickHandler(DatacageDoubleClickHandler h) {
        if (!doubleHandlers.contains(h)) {
            doubleHandlers.add(h);
        }
    }


    /**
     * @param handler Handler to remove from list.
     */
    public void removeDatacageHandler(DatacageHandler handler) {
        handlers.remove(handler);
    }


    public ToLoad getToLoad() {
        return toLoad;
    }


    public ToLoad getSelection() {
        // Reset content of toLoads.
        toLoad = new ToLoad();

        if (treeGrid == null) {
            return toLoad;
        }

        ListGridRecord [] selection = treeGrid.getSelection();

        if (selection != null) {
            for (ListGridRecord record: selection) {
                if (record instanceof TreeNode) {
                    collectToLoads((TreeNode)record);
                }
            }
        }

        return toLoad;
    }


    /**
     * Callback for add-button.
     * Fires to load for every selected element and handler.
     */
    public void plusClicked() {
        if (!getSelection().isEmpty()) {
            fireToLoad();
        }
    }


    protected Button createPlusButton() {
        // TODO: i18n + icon
        Button plusBtn = new Button("+");
        plusBtn.addClickHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                plusClicked();
            }
        });
        return plusBtn;
    }


    protected void fireToLoad() {
        for (DatacageHandler handler: handlers) {
            handler.toLoad(toLoad);
        }
    }


    protected void fireOnDoubleClick() {
        for (DatacageDoubleClickHandler handler: doubleHandlers) {
            handler.onDoubleClick(toLoad);
        }
    }


    protected void doubleClickedOnTree(RecordDoubleClickEvent event) {
        TreeNode node = (TreeNode)event.getRecord();
        collectToLoads(node);
        fireOnDoubleClick();
    }


    protected void collectToLoads(TreeNode node) {
        Stack<TreeNode> stack = new Stack<TreeNode>();

        stack.push(node);

        while (!stack.isEmpty()) {
            node = stack.pop();
            String factory = node.getAttribute("factory");
            if (factory != null) { // we need at least a factory
                String artifact = node.getAttribute("artifact-id");
                String out      = node.getAttribute("out");
                String name     = node.getAttribute("facet");
                String ids      = node.getAttribute("ids");

                toLoad.add(artifact, factory, out, name, ids);
            }
            TreeNode [] children = tree.getChildren(node);
            if (children != null) {
                for (TreeNode child: children) {
                    stack.push(child);
                }
            }
        }
    }


    protected void triggerTreeBuilding() {
        Config config = Config.getInstance();
        String url    = config.getServerUrl();
        String locale = config.getLocale();

        String artifactId = artifact.getUuid();
        String userId     = (user != null) ? user.identifier() : null;

        metaDataService.getMetaData(
            url, locale,
            artifactId,
            userId,
            outs,
            parameters,
            new AsyncCallback<DataCageTree>() {
                public void onFailure(Throwable caught) {
                    GWT.log("Could not load meta data.");
                    SC.warn(caught.getMessage());
                }

                public void onSuccess(DataCageTree dcTree) {
                    GWT.log("Successfully loaded meta data.");
                    tree.setData(treeToData(dcTree));
                    treeGrid.setData(tree);
                }
            });
    }

    private static class IdGenerator {
        protected int current;

        public IdGenerator() {
        }

        public IdGenerator(int start) {
            current = start;
        }

        public int next() {
            return current++;
        }
    } // class IdGenerator

    protected static void buildRecursive(
        DataCageNode   node, 
        int            parentId,
        IdGenerator    idGenerator,
        List<TreeNode> nodes
    ) {
        TreeNode tn = new TreeNode();
        int id = idGenerator.next();
        tn.setAttribute("parent-id", parentId);
        tn.setAttribute("id", id);
        // TODO: i18n
        tn.setAttribute("name", node.getDescription());
        tn.setAttribute("facet", node.getName());
        nodes.add(tn);
        AttrList attrs = node.getAttributes();
        if (attrs != null) {
            for (int i = 0, N = attrs.size(); i < N; ++i) {
                String key   = attrs.getKey(i);
                String value = attrs.getValue(i);
                tn.setAttribute(key, value);
            }
        }
        List<DataCageNode> children = node.getChildren();
        if (children != null) {
            for (DataCageNode child: children) {
                buildRecursive(child, id, idGenerator, nodes);
            }
        }
    }


    protected static TreeNode [] treeToData(DataCageTree tree) {
        List<TreeNode> nodes = new ArrayList<TreeNode>();

        DataCageNode root = tree.getRoot();

        IdGenerator idGenerator = new IdGenerator();

        buildRecursive(root, idGenerator.next(), idGenerator, nodes);

        return nodes.toArray(new TreeNode[nodes.size()]);
    }
}
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