/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System.Threading;
using System.Text;
using System.Xml;
using OpenSim.Framework;
using OpenSim.Framework.Console;
using OpenSim.Framework.Monitoring;
using OpenSim.Framework.Servers;
using log4net;
using log4net.Config;
using log4net.Appender;
using log4net.Core;
using log4net.Repository;
using Nini.Config;

namespace OpenSim.Server.Base
{
    public class ServicesServerBase : ServerBase
    {
        // Logger
        //
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        // Command line args
        //
        protected string[] m_Arguments;

        protected string m_configDirectory = ".";

        // Run flag
        //
        private bool m_Running = true;

        private static Mono.Unix.UnixSignal[] signals;


        // Handle all the automagical stuff
        //
        public ServicesServerBase(string prompt, string[] args) : base()
        {
            // Save raw arguments
            m_Arguments = args;

            // Read command line
            ArgvConfigSource argvConfig = new ArgvConfigSource(args);

            argvConfig.AddSwitch("Startup", "console", "c");
            argvConfig.AddSwitch("Startup", "logfile", "l");
            argvConfig.AddSwitch("Startup", "inifile", "i");
            argvConfig.AddSwitch("Startup", "prompt",  "p");
            argvConfig.AddSwitch("Startup", "logconfig", "g");

            // Automagically create the ini file name
            string fileName = "";
            if (Assembly.GetEntryAssembly() != null)
                fileName = Path.GetFileNameWithoutExtension(Assembly.GetEntryAssembly().Location);
            string iniFile = fileName + ".ini";
            string logConfig = null;

            IConfig startupConfig = argvConfig.Configs["Startup"];
            if (startupConfig != null)
            {
                // Check if a file name was given on the command line
                iniFile = startupConfig.GetString("inifile", iniFile);

                // Check if a prompt was given on the command line
                prompt = startupConfig.GetString("prompt", prompt);

                // Check for a Log4Net config file on the command line
                logConfig =startupConfig.GetString("logconfig", logConfig);
            }

            Config = ReadConfigSource(iniFile);

            List<string> sources = new List<string>();
            sources.Add(iniFile);

            int sourceIndex = 1;

            while (AddIncludes(Config, sources))
            {
                for ( ; sourceIndex < sources.Count ; ++sourceIndex)
                {
                    IConfigSource s = ReadConfigSource(sources[sourceIndex]);
                    Config.Merge(s);
                }
            }

            // Merge OpSys env vars
            Console.WriteLine("[CONFIG]: Loading environment variables for Config");
            Util.MergeEnvironmentToConfig(Config);

            // Merge the configuration from the command line into the loaded file
            Config.Merge(argvConfig);

            Config.ReplaceKeyValues();

            // Refresh the startupConfig post merge
            if (Config.Configs["Startup"] != null)
            {
                startupConfig = Config.Configs["Startup"];
            }

            if (startupConfig != null)
            {
                m_configDirectory = startupConfig.GetString("ConfigDirectory", m_configDirectory);

                prompt = startupConfig.GetString("Prompt", prompt);
            }
            // Allow derived classes to load config before the console is opened.
            ReadConfig();

            // Create main console
            string consoleType = "local";
            if (startupConfig != null)
                consoleType = startupConfig.GetString("console", consoleType);

            if (consoleType == "basic")
            {
                MainConsole.Instance = new CommandConsole(prompt);
            }
            else if (consoleType == "rest")
            {
                MainConsole.Instance = new RemoteConsole(prompt);
                ((RemoteConsole)MainConsole.Instance).ReadConfig(Config);
            }
            else if (consoleType == "mock")
            {
                MainConsole.Instance = new MockConsole();
            }
            else if (consoleType == "local")
            {
                MainConsole.Instance = new LocalConsole(prompt, startupConfig);
            }

            m_console = MainConsole.Instance;

            if (logConfig != null)
            {
                FileInfo cfg = new FileInfo(logConfig);
                XmlConfigurator.Configure(cfg);
            }
            else
            {
                XmlConfigurator.Configure();
            }

            LogEnvironmentInformation();
            RegisterCommonAppenders(startupConfig);

            if (startupConfig.GetString("PIDFile", String.Empty) != String.Empty)
            {
                CreatePIDFile(startupConfig.GetString("PIDFile"));
            }

            RegisterCommonCommands();
            RegisterCommonComponents(Config);

            Thread signal_thread = new Thread (delegate ()
            {
                while (true)
                {
                    // Wait for a signal to be delivered
                    int index = Mono.Unix.UnixSignal.WaitAny (signals, -1);

                    //Mono.Unix.Native.Signum signal = signals [index].Signum;
                    ShutdownSpecific();
                    m_Running = false;
                    Environment.Exit(0);
                }
            });

            if(!Util.IsWindows())
            {
                try
                {
                    // linux mac os specifics
                    signals = new Mono.Unix.UnixSignal[]
                    {
                        new Mono.Unix.UnixSignal(Mono.Unix.Native.Signum.SIGTERM)
                    };
                    signal_thread.Start();
                }
                catch (Exception e)
                {
                    m_log.Info("Could not set up UNIX signal handlers. SIGTERM will not");
                    m_log.InfoFormat("shut down gracefully: {0}", e.Message);
                    m_log.Debug("Exception was: ", e);
                }
            }

            // Allow derived classes to perform initialization that
            // needs to be done after the console has opened
            Initialise();
        }

        public bool Running
        {
            get { return m_Running; }
        }

        public virtual int Run()
        {
            Watchdog.Enabled = true;
            MemoryWatchdog.Enabled = true;

            while (m_Running)
            {
                try
                {
                    MainConsole.Instance.Prompt();
                }
                catch (Exception e)
                {
                    m_log.ErrorFormat("Command error: {0}", e);
                }
            }

            RemovePIDFile();

            return 0;
        }

        protected override void ShutdownSpecific()
        {
            m_Running = false;
            m_log.Info("[CONSOLE] Quitting");

            base.ShutdownSpecific();
        }

        protected virtual void ReadConfig()
        {
        }

        protected virtual void Initialise()
        {
        }

        /// <summary>
        /// Adds the included files as ini configuration files
        /// </summary>
        /// <param name="sources">List of URL strings or filename strings</param>
        private bool AddIncludes(IConfigSource configSource, List<string> sources)
        {
            bool sourcesAdded = false;

            //loop over config sources
            foreach (IConfig config in configSource.Configs)
            {
                // Look for Include-* in the key name
                string[] keys = config.GetKeys();
                foreach (string k in keys)
                {
                    if (k.StartsWith("Include-"))
                    {
                        // read the config file to be included.
                        string file = config.GetString(k);
                        if (IsUri(file))
                        {
                            if (!sources.Contains(file))
                            {
                                sourcesAdded = true;
                                sources.Add(file);
                            }
                        }
                        else
                        {
                            string basepath = Path.GetFullPath(m_configDirectory);
                            // Resolve relative paths with wildcards
                            string chunkWithoutWildcards = file;
                            string chunkWithWildcards = string.Empty;
                            int wildcardIndex = file.IndexOfAny(new char[] { '*', '?' });
                            if (wildcardIndex != -1)
                            {
                                chunkWithoutWildcards = file.Substring(0, wildcardIndex);
                                chunkWithWildcards = file.Substring(wildcardIndex);
                            }
                            string path = Path.Combine(basepath, chunkWithoutWildcards);
                            path = Path.GetFullPath(path) + chunkWithWildcards;
                            string[] paths = Util.Glob(path);

                            // If the include path contains no wildcards, then warn the user that it wasn't found.
                            if (wildcardIndex == -1 && paths.Length == 0)
                            {
                                Console.WriteLine("[CONFIG]: Could not find include file {0}", path);
                            }
                            else
                            {
                                foreach (string p in paths)
                                {
                                    if (!sources.Contains(p))
                                    {
                                        sourcesAdded = true;
                                        sources.Add(p);
                                    }
                                }
                            }
                        }
                    }
                }
            }

            return sourcesAdded;
        }

        /// <summary>
        /// Check if we can convert the string to a URI
        /// </summary>
        /// <param name="file">String uri to the remote resource</param>
        /// <returns>true if we can convert the string to a Uri object</returns>
        bool IsUri(string file)
        {
            Uri configUri;

            return Uri.TryCreate(file, UriKind.Absolute,
                    out configUri) && configUri.Scheme == Uri.UriSchemeHttp;
        }

        IConfigSource ReadConfigSource(string iniFile)
        {
            // Find out of the file name is a URI and remote load it if possible.
            // Load it as a local file otherwise.
            Uri configUri;
            IConfigSource s = null;

            try
            {
                if (Uri.TryCreate(iniFile, UriKind.Absolute, out configUri) &&
                    configUri.Scheme == Uri.UriSchemeHttp)
                {
                    XmlReader r = XmlReader.Create(iniFile);
                    s = new XmlConfigSource(r);
                }
                else
                {
                    s = new IniConfigSource(iniFile);
                }
            }
            catch (Exception e)
            {
                System.Console.WriteLine("Error reading from config source.  {0}", e.Message);
                Environment.Exit(1);
            }

            return s;
        }
    }
}