import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTree;
import javax.swing.JOptionPane;
import javax.swing.BorderFactory;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeNode;
import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeSelectionModel;
import javax.swing.event.TreeSelectionListener;
import javax.swing.event.TreeSelectionEvent;
import java.awt.Dimension;
import java.awt.Cursor;
import java.awt.BorderLayout;
import java.util.Enumeration;
import cafe.biskuteri.hinoki.Tree;
import java.io.IOException;

class
RepliesWindow extends JFrame {

    private JKomasto
    primaire;

    private MastodonApi
    api;

    private PostWindow
    postWindow;

//   -  -%-  -

    private RepliesComponent
    display;

//  ---%-@-%---

    public void
    showFor(String postId)
    {
        display.setCursor(new Cursor(Cursor.WAIT_CURSOR));
        Tree<String> thread = getThread(postId);
        if (thread != null) display.showThread(thread);
        display.setCursor(null);
        if (thread == null) dispose();
    }

//   -  -%-  -

    public void
    postSelected(Tree<String> post)
    {
        postWindow.readEntity(post);
    }

    private Tree<String>
    getThread(String postId)
    {
        abstract class Handler implements RequestListener {

            boolean
            failed = false;

//          -=%=-

            public void
            connectionFailed(IOException eIo)
            {
                JOptionPane.showMessageDialog(
                    RepliesWindow.this,
                    "Failed to fetch post context...."
                    + "\n" + eIo.getMessage()
                );
                failed = true;
            }

            public void
            requestFailed(int httpCode, Tree<String> json)
            {
                JOptionPane.showMessageDialog(
                    RepliesWindow.this,
                    "Failed to fetch post context...."
                    + "\n" + json.get("error").value
                    + "\n(HTTP code: " + httpCode + ")"
                );
                failed = true;
            }

        }

        class TopPostIdGetter extends Handler {

            String
            topPostId;

//          -=%=-

            public void
            requestSucceeded(Tree<String> json)
            {
                Tree<String> ancestors = json.get("ancestors");
                if (ancestors.size() == 0) topPostId = postId;
                else topPostId = ancestors.get(0).get("id").value;
            }

        };

        class DescendantsGetter extends Handler {

            Tree<String>
            descendants;

//          -=%=-

            public void
            requestSucceeded(Tree<String> json)
            {
                descendants = json.get("descendants");
            }

        };

        class PostGetter extends Handler {

            Tree<String>
            post;

//          -=%=-

            public void
            requestSucceeded(Tree<String> json)
            {
                post = json;
            }

        }

        TopPostIdGetter phase1 = new TopPostIdGetter();
        api.getPostContext(postId, phase1);
        if (phase1.failed) return null;
        DescendantsGetter phase2 = new DescendantsGetter();
        api.getPostContext(phase1.topPostId, phase2);
        if (phase2.failed) return null;
        PostGetter phase3 = new PostGetter();
        api.getSpecificPost(phase1.topPostId, phase3);
        if (phase3.failed) return null;

        Tree<String> thread = new Tree<String>();
        phase3.post.key = "top";
        thread.add(phase3.post);
        thread.add(phase2.descendants);
        return thread;
    }

//  ---%-@-%---

    RepliesWindow(JKomasto primaire, PostWindow postWindow)
    {
        super("Thread");

        this.primaire = primaire;
        this.api = primaire.getMastodonApi();
        this.postWindow = postWindow;

        display = new RepliesComponent(this);
        setContentPane(display);
        setSize(384, 224);
    }

}

class
RepliesComponent extends JPanel
implements TreeSelectionListener {

    private RepliesWindow
    primaire;

    private Tree<String>
    thread;

//   -  -%-  -

    private JTree
    tree;

//  ---%-@-%---

    public void
    showThread(Tree<String> thread)
    {
        Enumeration<TreeNode> e;
        DefaultMutableTreeNode root;
        TreeItem item;
        item = new TreeItem(thread.get("top"));
        root = new DefaultMutableTreeNode(item);
        for (Tree<String> desc: thread.get("descendants"))
        {
            String target = desc.get("in_reply_to_id").value;
            assert target != null;

            DefaultMutableTreeNode p = null;
            e = root.breadthFirstEnumeration();
            while (e.hasMoreElements())
            {
                DefaultMutableTreeNode node;
                node = (DefaultMutableTreeNode)e.nextElement();
                item = (TreeItem)node.getUserObject();

                String postId = item.post.get("id").value;
                if (postId.equals(target))
                {
                    p = node;
                    break;
                }
            }
            if (p == null)
            {
                assert false;
                continue;
            }

            item = new TreeItem(desc);
            p.add(new DefaultMutableTreeNode(item));
        }

        tree.setModel(new DefaultTreeModel(root));
    }

//   -  -%-  -

    public void
    valueChanged(TreeSelectionEvent eT)
    {
        Object selected = eT.getPath().getLastPathComponent();
        assert selected instanceof DefaultMutableTreeNode;

        TreeItem item = (TreeItem)
            ((DefaultMutableTreeNode)selected)
                .getUserObject();

        primaire.postSelected(item.post);
    }

//  ---%-@-%---

    private static class
    TreeItem {

        public Tree<String>
        post;

//      -=%=-

        public String
        toString()
        {
            String html = post.get("content").value;
            return TimelineWindow.textApproximation(html);
        }

//      -=%=-

        TreeItem(Tree<String> post)
        {
            this.post = post;
        }

    }

//  ---%-@-%---

    RepliesComponent(RepliesWindow primaire)
    {
        this.primaire = primaire;

        tree = new JTree();
        tree.setBackground(null);
        DefaultTreeCellRenderer renderer;
        renderer = new DefaultTreeCellRenderer();
        renderer.setBackgroundNonSelectionColor(null);
        renderer.setOpenIcon(null);
        renderer.setClosedIcon(null);
        renderer.setLeafIcon(null);
        tree.setCellRenderer(renderer);
        int mode = TreeSelectionModel.SINGLE_TREE_SELECTION;
        tree.getSelectionModel().setSelectionMode(mode);
        tree.addTreeSelectionListener(this);
        tree.setFont(tree.getFont().deriveFont(16f));

        setBorder(BorderFactory.createEmptyBorder(8, 8, 8, 8));

        setLayout(new BorderLayout());
        add(tree);
    }

}