namespace ScriptCs.Contracts

{

using System;

public interface ILog

{

/// <summary>

/// Logs a message for a specified log level, if the <see cref="ILog"/> is enabled for that log level.

/// </summary>

/// <param name="logLevel">The log level.</param>

/// <param name="createMessage">

/// Optional function which creates the message.

/// Specify <c>null</c> to simply check if the logger is enabled for the <paramref name="logLevel"/>.

/// </param>

/// <param name="exception">An optional exception to include with the message.</param>

/// <param name="formatArgs">

/// Optional arguments for formatting the message created by <paramref name="createMessage"/>.

/// </param>

/// <returns>

/// <c>true</c> if the <see cref="ILog"/> is enabled for the <paramref name="logLevel"/>.

/// Otherwise <c>false</c>.

/// </returns>

/// <remarks>

/// Note to implementers for optimal performance:

/// When the <paramref name="createMessage"/> is <c>null</c>, simply return a <see cref="bool"/>

/// indicating whether the <see cref="ILog"/> is enabled for the specified <paramref name="logLevel"/>.

/// When the <paramref name="createMessage"/> is not <c>null</c>, it should only be invoked

/// if the <see cref="ILog"/> is enabled for the specified <paramref name="logLevel"/>.

/// </remarks>

bool Log(

LogLevel logLevel,

Func<string> createMessage = null,

Exception exception = null,

params object[] formatArgs);

}

}