jplogging.lua

--[[[
@module Logging
@description 
This module provides a Logger instance which can be initialized with a Log-Level 
([code]jps.LogLevel.DEBUG[/code],[code]jps.LogLevel.INFO[/code],[code]jps.LogLevel.WARN[/code],[code]jps.LogLevel.ERROR[/code] or [code]jps.LogLevel.NONE[/code]).
All calls to it's logging functions will then either be ignored or printed with Log Level and the calling file/line number. A limited number of varargs are supported, which
then are used to as input for the format string.[br]
[br]
Usage in your code:[br]
[code]
local LOG=jps.Logger(jps.LogLevel.DEBUG)[br]
LOG.debug("debug message")[br]
LOG.debug("this is a number: %s", 2)[br]
[/code]
]]--


jps.LogLevel={ DEBUG=1, INFO=2, WARN=3, ERROR=4, NONE=5 }
local function split(str, sep)
	local sep, fields = sep or ":", {}
	local pattern = string.format("([^%s]+)", sep)
	str:gsub(pattern, function(c) fields[#fields+1] = c end)
	return fields
end

local function logPrint(logLevel,msgLevel)
	return function (msg,a,b,c,d,e,f,g,h)
		if msgLevel >= logLevel or ( jps.Debug and tonumber(msgLevel) >= tonumber(jps.DebugLevel))  then
			local stackTrace = split(debugstack(2,1,0), ":")
			local file	= split(stackTrace[1], "\\")
			--local prefix = ""
			local prefix = string.format("%s:%s - ", file[#file], stackTrace[2])--string.format("%s:%s - ", debug.getinfo(1, "S").short_src, debug.getinfo(2, "l").currentline)
			--TODO: Check if DEFAULT_CHAT_FRAME:AddMessage() has any significant advantages
			print(prefix .. string.format(msg, tostring(a), tostring(b), tostring(c), tostring(d), tostring(e), tostring(f), tostring(g), tostring(h)) )
		end
	end
end

--[[[
@function jps.Logger
@param level Log-Level, one of [code]jps.LogLevel.DEBUG[/code],[code]jps.LogLevel.INFO[/code],[code]jps.LogLevel.WARN[/code],[code]jps.LogLevel.ERROR[/code] or [code]jps.LogLevel.NONE[/code]
@returns Logging instance with [code]debug[/code],[code]info[/code],[code]warn[/code] and [code]error[/code] methods
@description 
Creates a Logging instance set to the given Log-Level 
([code]jps.LogLevel.DEBUG[/code],[code]jps.LogLevel.INFO[/code],[code]jps.LogLevel.WARN[/code],[code]jps.LogLevel.ERROR[/code] or [code]jps.LogLevel.NONE[/code]).
All calls to it's logging functions will then either be ignored or printed with Log Level and the calling file/line number. A limited number of varargs are supported, which
then are used to as input for the format string.[br]
[br]
Usage in your code:[br]
[code]
local LOG=jps.Logger(jps.LogLevel.DEBUG)[br]
LOG.debug("debug message")[br]
LOG.debug("this is a number: %s", 2)[br]
[/code]
]]--
function jps.Logger(level)
	local newLogger = {}
	if not level or not tonumber(level) or (level < jps.LogLevel.DEBUG and level > jps.LogLevel.NONE) then
		newLogger["logLevel"] = jps.LogLevel.NONE
	else
		newLogger["logLevel"] = level
	end
	newLogger["debug"] = logPrint(newLogger.logLevel, jps.LogLevel.DEBUG)
	newLogger["info"] = logPrint(newLogger.logLevel, jps.LogLevel.INFO)
	newLogger["warn"] = logPrint(newLogger.logLevel, jps.LogLevel.WARN)
	newLogger["error"] = logPrint(newLogger.logLevel, jps.LogLevel.ERROR)
	newLogger["isDebugEnabled"] = newLogger.logLevel <= jps.LogLevel.DEBUG
	newLogger["isInfoEnabled"] = newLogger.logLevel <= jps.LogLevel.INFO
	newLogger["isWarnEnabled"] = newLogger.logLevel <= jps.LogLevel.WARN
	newLogger["isErrorEnabled"] = newLogger.logLevel <= jps.LogLevel.ERROR
	return newLogger
end