// Logger.cs
// 
// Copyright (C) 2002-2004 Ryan Seghers
//
// This software is provided AS IS. No warranty is granted, 
// neither expressed nor implied. USE THIS SOFTWARE AT YOUR OWN RISK.
// NO REPRESENTATION OF MERCHANTABILITY or FITNESS FOR ANY 
// PURPOSE is given.
//
// License to use this software is limited by the following terms:
// 1) This code may be used in any program, including programs developed
//    for commercial purposes, provided that this notice is included verbatim.
//    
// Also, in return for using this code, please attempt to make your fixes and
// updates available in some way, such as by sending your updates to the
// author.

using System;

namespace RTools_NTS.Util
{
    /// <summary>
    /// This is a simple implementation of a Logger class.
    /// The purpose is to threshold output based on a verbosity setting,
    /// format messages similarly, and collect all message writes such that
    /// they can be redirected easily.  You (and I) should probably use
    /// the some other library for this, but I haven't found one that suits
    /// my needs.
    /// </summary>
    /// <remarks>
    /// This doesn't implement much of the functionality possible
    /// with this interface.  This could redirect messages to other
    /// text writers, forward messages to subscribers, etc.
    /// </remarks>
    public class Logger
    {
        // NOTE: modified for "safe" assembly in Sql 2005
        // Readonly added!

        ///<summary>Backer for Log.</summary>
        protected static readonly Logger log = new Logger(String.Empty);

        ///<summary>The name is prepended to all messages. </summary>
        protected string name;

        /// <summary>
        /// The verbosity of this logger.  Messages are filtered
        /// based on this setting.
        /// </summary>
        protected VerbosityLevel verbosity;

        /// <summary>
        /// Default constructor.
        /// </summary>
        public Logger()
        {
            name = String.Empty;
        }

        /// <summary>
        /// Construct and set name.
        /// </summary>
        /// <param name="name">The name for this logger.  This name
        /// is prepended to output messages (except Out messages).</param>
        public Logger(string name)
        {
            this.name = name;
            verbosity = VerbosityLevel.Debug;
        }

        ///<summary>
        ///A static instance you can use without creating your own.
        ///</summary>
        public static Logger Log
        {
            get
            {
                return (log);
            }
        }

        /// <summary>
        /// The verbosity of this logger.  Messages are filtered
        /// based on this setting.
        /// </summary>
        public VerbosityLevel Verbosity
        {
            get
            {
                return (verbosity);
            }
            set
            {
                verbosity = value;
            }
        }

        /// <summary>
        /// Write a string with no verbosity checking and no formatting.
        /// </summary>
        /// <param name="msg">The format string.</param>
        /// <param name="args">The arguments.</param>
        public void Write(string msg, params object[] args) {}

        /// <summary>
        /// Write a line with no verbosity checking and no formatting.
        /// </summary>
        /// <param name="msg">The format string.</param>
        /// <param name="args">The arguments.</param>
        public void WriteLine(string msg, params object[] args) {}

        /// <summary>
        /// Write a string of this particular verbosity.
        /// This will not output the string unless the verbosity is
        /// greater than or equal to this object's threshold.
        /// This prepends the level of the message and
        /// the name of this Logger.
        /// </summary>
        /// <param name="msg">The format string.</param>
        /// <param name="args">The arguments.</param>
        public void Debug(string msg, params object[] args)
        {
            if (verbosity >= VerbosityLevel.Debug) {}
        }

        /// <summary>
        /// Write a string of this particular verbosity.
        /// This will not output the string unless the verbosity is
        /// greater than or equal to this object's threshold.
        /// This prepends the level of the message and
        /// the name of this Logger.
        /// </summary>
        /// <param name="msg">The format string.</param>
        /// <param name="args">The arguments.</param>
        public void Info(string msg, params object[] args)
        {
            if (verbosity >= VerbosityLevel.Info) {}
        }

        /// <summary>
        /// Write a string of this particular verbosity.
        /// This will not output the string unless the verbosity is
        /// greater than or equal to this object's threshold.
        /// This prepends the level of the message and
        /// the name of this Logger.
        /// </summary>
        /// <param name="msg">The format string.</param>
        /// <param name="args">The arguments.</param>
        public void Warn(string msg, params object[] args)
        {
            if (verbosity >= VerbosityLevel.Warn) {}
        }

        /// <summary>
        /// Write a string of this particular verbosity.
        /// This will not output the string unless the verbosity is
        /// greater than or equal to this object's threshold.
        /// This prepends the level of the message and
        /// the name of this Logger.
        /// </summary>
        /// <param name="msg">The format string.</param>
        /// <param name="args">The arguments.</param>
        public void Error(string msg, params object[] args)
        {
            if (verbosity >= VerbosityLevel.Error) {}
        }

        /// <summary>
        /// A simple static self test method.
        /// </summary>
        /// <returns>bool - currently always true</returns>
        public static bool TestSelf()
        {
            Logger log = new Logger("Logger: TestSelf");
            log.Debug("A debug message.");
            log.Info("An info message.");
            log.Warn("A warn message.");
            log.Error("An error message.");

            log.Write("Some writes: ");
            for (int i = 0; i < 5; i++)
            {
                log.Write("{0},", i);
            }
            log.WriteLine(String.Empty);

            log.WriteLine("This WriteLine message will always be displayed.");
            return (true);
        }
    }
}