package com.ts3client.ui;

import com.ts3client.net.ChannelNode;
import com.ts3client.net.TeamspeakConnection;
import com.ts3client.net.filetransfer.FileTransfer;
import com.ts3client.net.filetransfer.RemoteFile;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.ListSelectionModel;
import javax.swing.SwingUtilities;
import javax.swing.table.AbstractTableModel;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.File;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.List;

/**
 * Browses a channel's file repository and drives uploads and downloads. The table
 * lists the current directory; the toolbar navigates and acts on the selection; the
 * strip at the bottom shows live progress for each active transfer.
 *
 * <p>All server calls run on background threads so the dialog never blocks the EDT;
 * results are marshalled back with {@link SwingUtilities#invokeLater}.
 */
public final class FileBrowserDialog extends JDialog {

    private final TeamspeakConnection conn;
    private final int channelId;
    private final String channelPassword;

    private final FileTableModel tableModel = new FileTableModel();
    private final JTable table = new JTable(tableModel);
    private final JLabel pathLabel = new JLabel("/");
    private final JButton upButton = new JButton("Up", Icons.of("FILE_UP"));
    private final JButton downloadButton = new JButton("Download", Icons.of("DOWNLOAD"));
    private final JButton deleteButton = new JButton("Delete", Icons.of("DELETE"));
    private final JPanel transfersPanel = new JPanel();

    private volatile String currentPath = "/";

    public FileBrowserDialog(Frame owner, TeamspeakConnection conn, ChannelNode channel) {
        super(owner, "Files — " + channel.name, false);
        this.conn = conn;
        this.channelId = channel.id;
        this.channelPassword = "";

        JPanel content = new JPanel(new BorderLayout(0, 8));
        content.setBackground(Theme.WINDOW_BG);
        content.setBorder(BorderFactory.createEmptyBorder(10, 12, 10, 12));
        content.add(buildToolbar(), BorderLayout.NORTH);
        content.add(buildTable(), BorderLayout.CENTER);
        content.add(buildTransfers(), BorderLayout.SOUTH);
        setContentPane(content);

        setPreferredSize(new Dimension(640, 480));
        pack();
        setLocationRelativeTo(owner);

        refresh();
    }

    // ---- construction ----

    private JPanel buildToolbar() {
        JPanel bar = new JPanel();
        bar.setLayout(new BoxLayout(bar, BoxLayout.X_AXIS));
        bar.setBackground(Theme.WINDOW_BG);

        upButton.addActionListener(e -> navigateUp());
        JButton refresh = new JButton("Refresh", Icons.of("FILE_REFRESH"));
        refresh.addActionListener(e -> refresh());
        JButton mkdir = new JButton("New folder", Icons.of("ADD_FOLDER"));
        mkdir.addActionListener(e -> createDirectory());
        JButton upload = new JButton("Upload…", Icons.of("UPLOAD"));
        upload.addActionListener(e -> chooseUpload());
        downloadButton.addActionListener(e -> downloadSelected());
        deleteButton.addActionListener(e -> deleteSelected());

        bar.add(upButton);
        bar.add(Box.createHorizontalStrut(6));
        bar.add(refresh);
        bar.add(Box.createHorizontalStrut(16));
        bar.add(pathLabel);
        bar.add(Box.createHorizontalGlue());
        bar.add(mkdir);
        bar.add(Box.createHorizontalStrut(6));
        bar.add(upload);
        bar.add(Box.createHorizontalStrut(6));
        bar.add(downloadButton);
        bar.add(Box.createHorizontalStrut(6));
        bar.add(deleteButton);

        pathLabel.setFont(Theme.UI_FONT);
        pathLabel.setForeground(Theme.TREE_TEXT);
        return bar;
    }

    private JScrollPane buildTable() {
        table.setFont(Theme.UI_FONT);
        table.setRowHeight(20);
        table.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
        table.setFillsViewportHeight(true);
        table.getColumnModel().getColumn(0).setPreferredWidth(300);
        table.getColumnModel().getColumn(0).setCellRenderer(new NameRenderer());
        table.getColumnModel().getColumn(1).setPreferredWidth(90);
        table.getColumnModel().getColumn(2).setPreferredWidth(70);
        table.getColumnModel().getColumn(3).setPreferredWidth(150);
        table.getSelectionModel().addListSelectionListener(e -> updateButtons());
        table.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                if (SwingUtilities.isLeftMouseButton(e) && e.getClickCount() == 2) {
                    int row = table.rowAtPoint(e.getPoint());
                    if (row >= 0) openEntry(tableModel.get(row));
                }
            }
        });
        JScrollPane scroll = new JScrollPane(table);
        scroll.getViewport().setBackground(Theme.TREE_BG);
        return scroll;
    }

    private JScrollPane buildTransfers() {
        transfersPanel.setLayout(new BoxLayout(transfersPanel, BoxLayout.Y_AXIS));
        transfersPanel.setBackground(Theme.WINDOW_BG);
        JScrollPane scroll = new JScrollPane(transfersPanel);
        scroll.setBorder(BorderFactory.createTitledBorder("Transfers"));
        scroll.setPreferredSize(new Dimension(10, 120));
        scroll.getViewport().setBackground(Theme.WINDOW_BG);
        return scroll;
    }

    // ---- navigation ----

    private void navigateUp() {
        String path = currentPath;
        if (path.equals("/")) return;
        String trimmed = path.substring(0, path.length() - 1); // drop trailing slash
        int slash = trimmed.lastIndexOf('/');
        currentPath = slash <= 0 ? "/" : trimmed.substring(0, slash + 1);
        refresh();
    }

    private void openEntry(RemoteFile file) {
        if (file == null) return;
        if (file.isDirectory()) {
            currentPath = currentPath + file.getName() + "/";
            refresh();
        } else {
            download(file);
        }
    }

    /** Reloads the current directory listing from the server. */
    private void refresh() {
        pathLabel.setText(currentPath);
        upButton.setEnabled(!currentPath.equals("/"));
        final String path = currentPath;
        new Thread(() -> {
            try {
                List<RemoteFile> files = conn.listFiles(channelId, channelPassword, path);
                Collections.sort(files, DIRECTORIES_FIRST);
                SwingUtilities.invokeLater(() -> {
                    if (path.equals(currentPath)) tableModel.setFiles(files);
                    updateButtons();
                });
            } catch (Exception ex) {
                SwingUtilities.invokeLater(() -> {
                    if (path.equals(currentPath)) tableModel.setFiles(new ArrayList<>());
                    error("Could not list files", ex);
                });
            }
        }, "ts3j-ft-list").start();
    }

    private void updateButtons() {
        boolean hasSelection = table.getSelectedRowCount() > 0;
        deleteButton.setEnabled(hasSelection);
        boolean fileSelected = false;
        for (int row : table.getSelectedRows()) {
            if (!tableModel.get(row).isDirectory()) {
                fileSelected = true;
                break;
            }
        }
        downloadButton.setEnabled(fileSelected);
    }

    // ---- actions ----

    private void downloadSelected() {
        List<RemoteFile> files = new ArrayList<>();
        for (int row : table.getSelectedRows()) {
            RemoteFile f = tableModel.get(row);
            if (!f.isDirectory()) files.add(f);
        }
        if (files.isEmpty()) return;
        if (files.size() == 1) {
            download(files.get(0));
            return;
        }
        // Multiple files: pick a target directory once.
        JFileChooser chooser = new JFileChooser();
        chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        chooser.setDialogTitle("Download " + files.size() + " files to…");
        if (chooser.showSaveDialog(this) != JFileChooser.APPROVE_OPTION) return;
        File dir = chooser.getSelectedFile();
        for (RemoteFile f : files) {
            startDownload(f, new File(dir, f.getName()));
        }
    }

    private void download(RemoteFile file) {
        JFileChooser chooser = new JFileChooser();
        chooser.setSelectedFile(new File(file.getName()));
        chooser.setDialogTitle("Download " + file.getName());
        if (chooser.showSaveDialog(this) != JFileChooser.APPROVE_OPTION) return;
        startDownload(file, chooser.getSelectedFile());
    }

    private void startDownload(RemoteFile file, File target) {
        TransferRow row = new TransferRow();
        FileTransfer transfer = conn.downloadFile(channelId, channelPassword, file.getFullPath(), target,
                t -> SwingUtilities.invokeLater(() -> row.update(t)));
        row.attach(transfer);
        addTransferRow(row);
    }

    private void chooseUpload() {
        JFileChooser chooser = new JFileChooser();
        chooser.setMultiSelectionEnabled(true);
        chooser.setDialogTitle("Upload to " + currentPath);
        if (chooser.showOpenDialog(this) != JFileChooser.APPROVE_OPTION) return;
        for (File source : chooser.getSelectedFiles()) {
            if (!source.isFile()) continue;
            String remotePath = currentPath + source.getName();
            TransferRow row = new TransferRow();
            FileTransfer transfer = conn.uploadFile(channelId, channelPassword, remotePath, source, true,
                    t -> SwingUtilities.invokeLater(() -> {
                        row.update(t);
                        if (t.getState() == FileTransfer.State.COMPLETED) refresh();
                    }));
            row.attach(transfer);
            addTransferRow(row);
        }
    }

    private void createDirectory() {
        String name = JOptionPane.showInputDialog(this, "New folder name:", "New folder",
                JOptionPane.PLAIN_MESSAGE);
        if (name == null || name.trim().isEmpty()) return;
        final String dirPath = currentPath + name.trim();
        new Thread(() -> {
            try {
                conn.createDirectory(channelId, channelPassword, dirPath);
                SwingUtilities.invokeLater(this::refresh);
            } catch (Exception ex) {
                SwingUtilities.invokeLater(() -> error("Could not create folder", ex));
            }
        }, "ts3j-ft-mkdir").start();
    }

    private void deleteSelected() {
        List<RemoteFile> files = new ArrayList<>();
        for (int row : table.getSelectedRows()) files.add(tableModel.get(row));
        if (files.isEmpty()) return;
        int choice = JOptionPane.showConfirmDialog(this,
                "Delete " + (files.size() == 1 ? "\"" + files.get(0).getName() + "\"" : files.size() + " items")
                        + "?", "Delete", JOptionPane.OK_CANCEL_OPTION, JOptionPane.WARNING_MESSAGE);
        if (choice != JOptionPane.OK_OPTION) return;
        new Thread(() -> {
            Exception failure = null;
            for (RemoteFile f : files) {
                try {
                    conn.deleteFile(channelId, channelPassword, f.getFullPath());
                } catch (Exception ex) {
                    failure = ex;
                }
            }
            final Exception shown = failure;
            SwingUtilities.invokeLater(() -> {
                refresh();
                if (shown != null) error("Could not delete some items", shown);
            });
        }, "ts3j-ft-delete").start();
    }

    private void addTransferRow(TransferRow row) {
        transfersPanel.add(row);
        transfersPanel.revalidate();
        transfersPanel.repaint();
    }

    private void error(String title, Exception ex) {
        JOptionPane.showMessageDialog(this, rootMessage(ex), title, JOptionPane.ERROR_MESSAGE);
    }

    // ---- one transfer's row ----

    private final class TransferRow extends JPanel {
        private final JLabel label = new JLabel();
        private final JProgressBar bar = new JProgressBar(0, 1000);
        private final JButton action = new JButton("Cancel");
        private FileTransfer transfer;

        TransferRow() {
            setLayout(new BorderLayout(8, 0));
            setBackground(Theme.WINDOW_BG);
            setBorder(BorderFactory.createEmptyBorder(3, 2, 3, 2));
            setMaximumSize(new Dimension(Integer.MAX_VALUE, 44));
            label.setFont(Theme.UI_FONT);
            bar.setStringPainted(true);
            add(label, BorderLayout.NORTH);
            add(bar, BorderLayout.CENTER);
            add(action, BorderLayout.EAST);
        }

        void attach(FileTransfer t) {
            this.transfer = t;
            action.addActionListener(e -> {
                if (transfer.isDone()) {
                    transfersPanel.remove(this);
                    transfersPanel.revalidate();
                    transfersPanel.repaint();
                } else {
                    transfer.cancel();
                }
            });
            update(t);
        }

        void update(FileTransfer t) {
            String arrow = t.getDirection() == FileTransfer.Direction.UPLOAD ? "↑" : "↓";
            String head = arrow + " " + t.getRemoteName();
            switch (t.getState()) {
                case PENDING:
                    label.setText(head + " — starting…");
                    break;
                case ACTIVE:
                    label.setText(head + " — " + formatBytes(t.getTransferredBytes()) + " / "
                            + formatBytes(t.getTotalBytes()) + "  (" + formatRate(t.getAverageSpeed()) + ")");
                    break;
                case COMPLETED:
                    label.setText(head + " — done (" + formatBytes(t.getTotalBytes()) + ")");
                    break;
                case CANCELLED:
                    label.setText(head + " — cancelled");
                    break;
                case FAILED:
                    label.setText(head + " — failed: " + orEmpty(t.getErrorMessage()));
                    break;
                default:
                    break;
            }
            int permille = (int) Math.round(t.getProgress() * 1000);
            bar.setValue(permille);
            bar.setString(t.getTotalBytes() > 0 ? (permille / 10) + "%" : "");
            if (t.isDone()) {
                bar.setValue(t.getState() == FileTransfer.State.COMPLETED ? 1000 : bar.getValue());
                action.setText("Clear");
            }
        }
    }

    // ---- table model ----

    private static final Comparator<RemoteFile> DIRECTORIES_FIRST = (a, b) -> {
        if (a.isDirectory() != b.isDirectory()) return a.isDirectory() ? -1 : 1;
        return a.getName().compareToIgnoreCase(b.getName());
    };

    private static final class FileTableModel extends AbstractTableModel {
        private static final String[] COLUMNS = {"Name", "Size", "Type", "Modified"};
        private final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
        private List<RemoteFile> files = new ArrayList<>();

        void setFiles(List<RemoteFile> files) {
            this.files = files;
            fireTableDataChanged();
        }

        RemoteFile get(int row) {
            return files.get(row);
        }

        @Override
        public int getRowCount() {
            return files.size();
        }

        @Override
        public int getColumnCount() {
            return COLUMNS.length;
        }

        @Override
        public String getColumnName(int column) {
            return COLUMNS[column];
        }

        @Override
        public Object getValueAt(int rowIndex, int columnIndex) {
            RemoteFile f = files.get(rowIndex);
            switch (columnIndex) {
                case 0:
                    return f.getName();
                case 1:
                    return f.isDirectory() ? "" : formatBytes(f.getSize());
                case 2:
                    return f.isDirectory() ? "Folder" : "File";
                case 3:
                    long sec = f.getLastModifiedEpochSec();
                    return sec > 0 ? dateFormat.format(new Date(sec * 1000)) : "";
                default:
                    return "";
            }
        }
    }

    /** Marks folders and files with the icon pack's own glyphs. */
    private final class NameRenderer extends javax.swing.table.DefaultTableCellRenderer {
        @Override
        public java.awt.Component getTableCellRendererComponent(JTable t, Object value, boolean selected,
                                                                boolean focus, int row, int column) {
            super.getTableCellRendererComponent(t, value, selected, focus, row, column);
            boolean directory = row >= 0 && row < tableModel.getRowCount() && tableModel.get(row).isDirectory();
            setIcon(Icons.of(directory ? "FOLDER" : "DEFAULT"));
            return this;
        }
    }

    // ---- formatting ----

    private static String formatBytes(long bytes) {
        if (bytes < 0) return "—";
        if (bytes < 1024) return bytes + " B";
        double kib = bytes / 1024.0;
        if (kib < 1024) return new DecimalFormat("0.0").format(kib) + " KiB";
        double mib = kib / 1024.0;
        if (mib < 1024) return new DecimalFormat("0.00").format(mib) + " MiB";
        return new DecimalFormat("0.00").format(mib / 1024.0) + " GiB";
    }

    private static String formatRate(double bytesPerSecond) {
        if (bytesPerSecond <= 0) return "—";
        return formatBytes(Math.round(bytesPerSecond)) + "/s";
    }

    private static String orEmpty(String s) {
        return s == null ? "" : s;
    }

    private static String rootMessage(Throwable t) {
        Throwable r = t;
        while (r.getCause() != null && r.getCause() != r) r = r.getCause();
        String m = r.getMessage();
        return m != null ? m : r.getClass().getSimpleName();
    }
}