package com.ts3client.ui;

import com.ts3client.net.ChannelNode;
import com.ts3client.net.ChannelSettings;
import com.ts3client.net.ClientEntry;
import com.ts3client.net.Group;
import com.ts3client.net.ServerModel;

import javax.swing.DropMode;
import javax.swing.JScrollPane;
import javax.swing.JViewport;
import javax.swing.SwingUtilities;
import javax.swing.plaf.basic.BasicTreeUI;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.List;

/**
 * The server view: a tree of channels each containing its clients, styled to
 * resemble the TeamSpeak 3 client. Talk state colours clients green live.
 */
public final class ServerTreePanel extends JScrollPane {

    /** Actions the tree can request of the controller. */
    public interface Actions {
        void joinChannel(int channelId);

        void openPrivateChat(ClientEntry client);

        void pokeClient(ClientEntry client);

        void kickClientFromChannel(ClientEntry client);

        void kickClientFromServer(ClientEntry client);

        void banClient(ClientEntry client);

        void toggleClientMute(ClientEntry client);

        void showConnectionInfo(ClientEntry client);

        /** Moves a client into the channel we are currently in. */
        void moveClientToOwnChannel(ClientEntry client);

        /** Opens the channel editor for a channel. */
        void editChannel(ChannelNode channel);

        /**
         * Opens the channel creator.
         *
         * @param parent the channel the new one goes below, or {@code null} for a top-level one
         * @param type   the channel type to start with
         */
        void createChannel(ChannelNode parent, ChannelSettings.Type type);

        /** Opens the channel creator pre-filled as a spacer, which is always top-level. */
        void createSpacer();

        /** Whether the server is there to act on at all. */
        boolean isConnected();

        /** Open the file repository browser for a channel. */
        void browseFiles(ChannelNode channel);

        /**
         * Changes a channel's subscription.
         *
         * @param family whether the channels below it are included
         */
        void setChannelSubscribed(ChannelNode channel, boolean family, boolean subscribed);

        boolean isClientLocallyMuted(int clientId);

        /** Selects and scrolls to a client in the tree, e.g. from a chat/log link. */
        void findClientInTree(ClientEntry client);

        /** A channel or client node was selected (or {@code null} when cleared). */
        void onSelectionChanged(Object userObject);

        /** Drag-and-drop of a client onto a channel. */
        void moveClientToChannel(ClientEntry client, ChannelNode target);

        /**
         * Drag-and-drop of a channel to a new place in the tree.
         *
         * @param orderPredecessorId the channel it should sit below among its new
         *                           siblings, or 0 to place it first
         */
        void moveChannel(ChannelNode channel, int newParentId, int orderPredecessorId);

        /** Assigns or removes a server group for a client. */
        void setClientServerGroup(ClientEntry client, Group group, boolean assign);

        /** Assigns a channel group for a client in its current channel. */
        void setClientChannelGroup(ClientEntry client, Group group);

        /** Opens the full server-groups list dialog for a client. */
        void showServerGroupsDialog(ClientEntry client);

        /** Edits a client's description — our own included. */
        void changeClientDescription(ClientEntry client);

        /** A new nickname for ourselves, typed into the tree row. */
        void renameSelf(String nickname);
    }

    private final DropIndicatorTree tree;
    private final DefaultMutableTreeNode root = new DefaultMutableTreeNode();
    /**
     * The nodes only mirror the connection's model, so an edited row is not written
     * back into the tree: the new nickname goes to the server, and the row follows
     * once it reports the rename.
     */
    private final DefaultTreeModel treeModel = new DefaultTreeModel(root) {
        @Override
        public void valueForPathChanged(TreePath path, Object newValue) {
            String nickname = String.valueOf(newValue).trim();
            Object edited = ((DefaultMutableTreeNode) path.getLastPathComponent()).getUserObject();
            // The server answers a rename to the name already held with "nickname is
            // already in use", so a field closed unchanged is simply left alone.
            if (edited instanceof ClientEntry && nickname.equals(((ClientEntry) edited).nickname)) return;
            if (!nickname.isEmpty()) actions.renameSelf(nickname);
        }
    };
    /** True while {@link #rebuild()} clears and restores the selection, to swallow the transient null in between. */
    private boolean rebuilding;
    private final ServerModel model;
    private final GroupIcons groupIcons;
    private final Actions actions;
    private final NicknameCellEditor nicknameEditor;
    private int selfClientId = -1;

    public ServerTreePanel(ServerModel model, GroupIcons groupIcons, Actions actions) {
        this.model = model;
        this.groupIcons = groupIcons;
        this.actions = actions;
        root.setUserObject("Not connected");
        this.tree = new DropIndicatorTree(treeModel, model, groupIcons);
        tree.setRootVisible(true);
        // The server node is the only top-level row and always stays open, so it gets
        // no expand control. Nesting is tightened too: horizontal space in this view
        // is scarce and channel names are long.
        tree.setShowsRootHandles(false);
        if (tree.getUI() instanceof BasicTreeUI) {
            BasicTreeUI ui = (BasicTreeUI) tree.getUI();
            ui.setLeftChildIndent(4);
            ui.setRightChildIndent(10);
        }
        tree.setRowHeight(20);
        tree.setBackground(Theme.TREE_BG);
        tree.setFont(Theme.UI_FONT);
        ServerTreeCellRenderer renderer = new ServerTreeCellRenderer();
        tree.setCellRenderer(renderer);
        nicknameEditor = NicknameCellEditor.create(tree, renderer, id -> id == selfClientId);
        tree.setCellEditor(nicknameEditor);
        tree.setEditable(true);
        tree.setPathEditable(nicknameEditor::editsPath);
        tree.setInvokesStopCellEditing(true);
        setViewportView(tree);
        getViewport().setBackground(Theme.TREE_BG);
        // The icon strip is drawn against the viewport's right edge, so the blitted
        // pixels a scroll would reuse are stale; repaint the whole viewport instead.
        getViewport().setScrollMode(JViewport.SIMPLE_SCROLL_MODE);

        // Within the tree a drag moves the client or channel; dropped elsewhere it
        // yields the TS3 link BBCode, which the chat input accepts as plain text.
        tree.setDragEnabled(true);
        tree.setDropMode(DropMode.ON_OR_INSERT);
        tree.setTransferHandler(new ServerTreeDragAndDrop(model, actions, tree, this::pathOf).transferHandler());

        tree.addTreeSelectionListener(e -> {
            if (rebuilding) return;
            TreePath path = tree.getSelectionPath();
            Object obj = null;
            if (path != null) {
                obj = ((DefaultMutableTreeNode) path.getLastPathComponent()).getUserObject();
            }
            actions.onSelectionChanged(obj);
        });

        tree.addMouseListener(new MouseAdapter() {
            @Override
            public void mousePressed(MouseEvent e) {
                selectRowUnder(e);
                maybePopup(e);
            }

            @Override
            public void mouseReleased(MouseEvent e) {
                maybePopup(e);
            }

            @Override
            public void mouseClicked(MouseEvent e) {
                Object obj = nodeAt(e);
                if (SwingUtilities.isLeftMouseButton(e) && e.getClickCount() == 2) {
                    if (obj instanceof ChannelNode && !Spacers.isSpacer(((ChannelNode) obj).name)) {
                        actions.joinChannel(((ChannelNode) obj).id);
                    } else if (obj instanceof ClientEntry && ((ClientEntry) obj).id != selfClientId) {
                        actions.openPrivateChat((ClientEntry) obj);
                    }
                } else if (SwingUtilities.isMiddleMouseButton(e) && obj instanceof ClientEntry) {
                    actions.showConnectionInfo((ClientEntry) obj);
                }
            }
        });
    }

    /**
     * Selects the row a press landed on. A row acts on its whole line, but Swing's own
     * hit testing stops at the end of the label, so a press further right would leave
     * the selection where it was.
     */
    private void selectRowUnder(MouseEvent e) {
        if (!SwingUtilities.isLeftMouseButton(e) && !e.isPopupTrigger()) return;
        TreePath path = tree.pathAt(e.getY());
        if (path == null || path.equals(tree.getSelectionPath())) return;
        Rectangle bounds = tree.getPathBounds(path);
        // Left of the label is the expand handle, which Swing works the row without selecting it.
        if (bounds != null && e.getX() < bounds.x) return;
        tree.setSelectionPath(path);
    }

    public void setSelfClientId(int id) {
        this.selfClientId = id;
    }

    /** Selects and scrolls to the row showing {@code client}, if it is currently visible. */
    public void selectClient(int clientId) {
        ClientEntry client = model.getClient(clientId);
        if (client == null) return;
        TreePath path = pathOf(client);
        if (path == null) return;
        tree.setSelectionPath(path);
        tree.scrollPathToVisible(path);
    }

    private Object nodeAt(MouseEvent e) {
        TreePath path = tree.pathAt(e.getY());
        if (path == null) return null;
        DefaultMutableTreeNode n = (DefaultMutableTreeNode) path.getLastPathComponent();
        return n.getUserObject();
    }

    private void maybePopup(MouseEvent e) {
        if (!e.isPopupTrigger()) return;
        TreePath path = tree.pathAt(e.getY());
        if (path == null) return;
        tree.setSelectionPath(path);
        Object obj = ((DefaultMutableTreeNode) path.getLastPathComponent()).getUserObject();
        if (obj instanceof ClientEntry) {
            showClientMenu((ClientEntry) obj, e);
        } else if (obj instanceof ChannelNode) {
            showChannelMenu((ChannelNode) obj, e);
        } else if (path.getPathCount() == 1 && actions.isConnected()) {
            // The root row is the server itself, whose user object is just its name.
            ServerMenu.build(actions).show(tree, e.getX(), e.getY());
        }
    }

    private void showClientMenu(ClientEntry client, MouseEvent e) {
        ClientMenu.build(client, client.id == selfClientId, true, model, groupIcons, actions)
                .show(tree, e.getX(), e.getY());
    }

    private void showChannelMenu(ChannelNode channel, MouseEvent e) {
        if (Spacers.isSpacer(channel.name)) return; // spacers aren't interactive
        ChannelMenu.build(channel, actions).show(tree, e.getX(), e.getY());
    }

    /** The path of the tree node showing {@code target}, or {@code null}. */
    private TreePath pathOf(Object target) {
        java.util.Enumeration<?> nodes = root.breadthFirstEnumeration();
        while (nodes.hasMoreElements()) {
            DefaultMutableTreeNode n = (DefaultMutableTreeNode) nodes.nextElement();
            if (n.getUserObject() == target) return new TreePath(n.getPath());
        }
        return null;
    }

    /**
     * Rebuilds the tree from the model, preserving full expansion. Rebuilding
     * replaces every tree node, which would otherwise drop the current
     * selection on every update (a client talking, a group change, …); the
     * previously selected channel/client is restored by identity once the new
     * nodes are in place, so a selection sticks until the user changes it.
     */
    public void rebuild() {
        Object selected = selectedUserObject();
        rebuilding = true;
        try {
            root.setUserObject(model.getServerName());
            root.removeAllChildren();
            List<ChannelNode> roots = model.buildTree();
            for (ChannelNode c : roots) {
                root.add(buildChannel(c));
            }
            treeModel.reload();
            for (int i = 0; i < tree.getRowCount(); i++) {
                tree.expandRow(i);
            }
            if (selected != null) {
                TreePath path = pathOf(selected);
                if (path != null) tree.setSelectionPath(path);
            }
        } finally {
            rebuilding = false;
        }
        // The selection listener was swallowed above; tell the caller only if it actually changed
        // (e.g. the previously selected channel/client is gone), since it already knows the rest.
        Object nowSelected = selectedUserObject();
        if (nowSelected != selected) actions.onSelectionChanged(nowSelected);
    }

    private Object selectedUserObject() {
        TreePath path = tree.getSelectionPath();
        return path == null ? null : ((DefaultMutableTreeNode) path.getLastPathComponent()).getUserObject();
    }

    private DefaultMutableTreeNode buildChannel(ChannelNode c) {
        DefaultMutableTreeNode node = new DefaultMutableTreeNode(c);
        for (ClientEntry client : c.clients) {
            node.add(new DefaultMutableTreeNode(client));
        }
        for (ChannelNode child : c.children) {
            node.add(buildChannel(child));
        }
        return node;
    }

    /** Clears the tree back to the disconnected placeholder state. */
    public void showDisconnected() {
        root.setUserObject("Not connected");
        root.removeAllChildren();
        treeModel.reload();
    }

    /** Repaint only (e.g. talk-state changes) without rebuilding structure. */
    public void refreshVisual() {
        tree.repaint();
    }

    /**
     * Re-measures every visible row, for changes that alter a row's width (a group
     * icon that finished downloading). A plain repaint would keep the cached widths
     * and clip the new icons.
     */
    public void refreshRowSizes() {
        for (int i = tree.getRowCount() - 1; i >= 0; i--) {
            TreePath path = tree.getPathForRow(i);
            if (path != null) {
                treeModel.nodeChanged((DefaultMutableTreeNode) path.getLastPathComponent());
            }
        }
    }

}