/*
 * Copyright 2004-2008 H2 Group. Licensed under the H2 License, Version 1.0
 * (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */
package org.h2.server.ftp;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.sql.SQLException;

import org.h2.engine.Constants;
import org.h2.store.fs.FileSystem;
import org.h2.util.StringUtils;

/**
 * The implementation of the control channel of the FTP server.
 */
public class FtpControl extends Thread {

    private static final String SERVER_NAME = "Small FTP Server";

    private FtpServer server;
    private FileSystem fs;
    private Socket control;
    private FtpData data;
    private PrintWriter output;
    private String userName;
    private boolean connected, readonly;
    private String currentDir = "/";
    private String serverIpAddress;
    private boolean stop;
    private String renameFrom;
    private boolean replied;
    private long restart;

    public FtpControl(Socket control, FtpServer server, boolean stop) {
        this.server = server;
        this.fs = server.getFileSystem();
        this.control = control;
        this.stop = stop;
    }

    public void run() {
        try {
            output = new PrintWriter(new OutputStreamWriter(control.getOutputStream(), Constants.UTF8));
            if (stop) {
                reply(421, "Too many users");
            } else {
                reply(220, SERVER_NAME);
                // TODO need option to configure the serverIpAddress
                serverIpAddress = control.getLocalAddress().getHostAddress().replace('.', ',');
                BufferedReader input = new BufferedReader(new InputStreamReader(control.getInputStream()));
                while (!stop) {
                    String command = null;
                    try {
                        command = input.readLine();
                    } catch (IOException e) {
                        // ignore
                    }
                    if (command == null) {
                        break;
                    }
                    process(command);
                }
                if (data != null) {
                    data.close();
                }
            }
        } catch (Throwable t) {
            server.logError(t);
        }
        server.closeConnection();
    }

    private void process(String command) throws SQLException, IOException {
        int idx = command.indexOf(' ');
        String param = "";
        if (idx >= 0) {
            param = command.substring(idx).trim();
            command = command.substring(0, idx);
        }
        command = StringUtils.toUpperEnglish(command);
        if (command.length() == 0) {
            reply(506, "No command");
            return;
        }
        server.log(">" + command);
        FtpEventListener listener = server.getEventListener();
        FtpEvent event = null;
        if (listener != null) {
            event = new FtpEvent(this, command, param);
            listener.beforeCommand(event);
        }
        replied = false;
        if (connected) {
            processConnected(command, param);
        }
        if (!replied) {
            if ("USER".equals(command)) {
                userName = param;
                reply(331, "Need password");
            } else if ("QUIT".equals(command)) {
                reply(221, "Bye");
                stop = true;
            } else if ("PASS".equals(command)) {
                if (userName == null) {
                    reply(332, "Need username");
                } else if (server.checkUserPassword(userName, param)) {
                    reply(230, "Ok");
                    readonly = false;
                    connected = true;
                } else if (server.checkUserPasswordReadOnly(userName, param)) {
                    reply(230, "Ok, readonly");
                    readonly = true;
                    connected = true;
                } else {
                    reply(431, "Wrong user/password");
                }
            } else if ("REIN".equals(command)) {
                userName = null;
                connected = false;
                currentDir = "/";
                reply(200, "Ok");
            } else if ("HELP".equals(command)) {
                reply(214, SERVER_NAME);
            }
        }
        if (!replied) {
            listener.onUnsupportedCommand(event);
            reply(506, "Invalid command");
        }
        if (listener != null) {
            listener.afterCommand(event);
        }
    }

    private void processConnected(String command, String param) throws SQLException, IOException {
        switch (command.charAt(0)) {
        case 'C':
            if ("CWD".equals(command)) {
                String path = getPath(param);
                String fileName = getFileName(path);
                if (fs.exists(fileName) && fs.isDirectory(fileName)) {
                    if (!path.endsWith("/")) {
                        path += "/";
                    }
                    currentDir = path;
                    reply(250, "Ok");
                } else {
                    reply(550, "Failed");
                }
            } else if ("CDUP".equals(command)) {
                if (currentDir.length() > 1) {
                    int idx = currentDir.lastIndexOf("/", currentDir.length() - 2);
                    currentDir = currentDir.substring(0, idx + 1);
                    reply(250, "Ok");
                } else {
                    reply(550, "Failed");
                }
            }
            break;
        case 'D':
            if ("DELE".equals(command)) {
                String fileName = getFileName(param);
                if (!readonly && fs.exists(fileName) && !fs.isDirectory(fileName) && fs.tryDelete(fileName)) {
                    if (server.getAllowTask() && fileName.endsWith(FtpServer.TASK_SUFFIX)) {
                        server.stopTask(fileName);
                    }
                    reply(250, "Ok");
                } else {
                    reply(500, "Delete failed");
                }
            }
            break;
        case 'L':
            if ("LIST".equals(command)) {
                processList(param, true);
            }
            break;
        case 'M':
            if ("MKD".equals(command)) {
                processMakeDir(param);
            } else if ("MODE".equals(command)) {
                if ("S".equals(StringUtils.toUpperEnglish(param))) {
                    reply(200, "Ok");
                } else {
                    reply(504, "Invalid");
                }
            } else if ("MDTM".equals(command)) {
                String fileName = getFileName(param);
                if (fs.exists(fileName) && !fs.isDirectory(fileName)) {
                    reply(213, server.formatLastModified(fileName));
                } else {
                    reply(550, "Failed");
                }
            }
            break;
        case 'N':
            if ("NLST".equals(command)) {
                processList(param, false);