-----------------------------------------------------------------
-- Name: check_event_log.lua
-- Author: Robert Aronsson, Intellipool AB
-- Required INM version: 3.4
-- Version: 1.0
-- Date: 2009-03-11
-- Description: This is an example of how to query the Windows event log
-- using WMI and Lua. It is not to be seen as a complete script, but a starting
-- point for a specialized event log monitor
--
-----------------------------------------------------------------

function OnEnumerate(sFieldToEnum)

    -- The variable returned must be called "Enum" so INM can find it.
    Enum = LuaScriptEnumResult()

    -- Second argument
    if sFieldToEnum == "Event Type" then
        Enum:Add("Error","1")
        Enum:Add("Warning","2")
        Enum:Add("Informational","3")
        Enum:Add("Audit success","4")
        Enum:Add("Audit failure","5")
    end

    -- Second argument
    if sFieldToEnum == "Event Log" then
        Enum:Add("System")
        Enum:Add("Application")
        Enum:Add("Security")
        Enum:Add("Directory Service")
        Enum:Add("DNS Server")
    end

    return Enum
end

-- This function is called by INM to retrieve a script configuration

function OnConfigure()

    -- The variable returned must be called "Config" so INM can find it.
    Config = LuaScriptConfigurator()

    -- Author.
    Config:SetAuthor("Robert Aronsson")

    -- Description.
    Config:SetDescription("Example Lua script to query a Windows event log using WMI");

    -- Minimum build version of INM, set to zero for if no specific build version is required.
    Config:SetMinBuildVersion(0)

    -- Script version (major/minor)
    Config:SetScriptVersion(1,0)

    -- Event ID
    Config:AddArgument("Event ID","Event ID to trigger on, separate multiple numbers with a comma. To include all event ids, leave the field blank.",LuaScriptConfigurator.CHECK_NOTHING)

    -- Event type
    Config:AddArgument("Event Type","Select the type of event to look for",LuaScriptConfigurator.ENUM_AVAIL + LuaScriptConfigurator.CHECK_NOT_EMPTY)

    -- Event type
    Config:AddArgument("Event Log","Select the log file to search",LuaScriptConfigurator.ENUM_AVAIL + LuaScriptConfigurator.CHECK_NOT_EMPTY)

    -- Set the entry point, this is the function called by INM
    Config:SetEntryPoint("main")

    -- Done with configuration, return the object
    return Config
end

-- Global table to hold the messages extracted
vMessagesTable = {}

-- The function that makes the query
function QueryEventLog(sEventLog,sEventID,_sEventType)

    Query = TLuaWMIQuery:new();
    QueryString = "SELECT * FROM Win32_NTLogEvent"

    -- Sorry about this.......
    sEventType = "1";
    if _sEventType == "Warning" then
        sEventType = "2"
    end
    if _sEventType == "Informational" then
        sEventType = "3"
    end
    if _sEventType == "Audit success" then
        sEventType = "4"
    end
    if _sEventType == "Audit failure" then
        sEventType = "5"
    end

    -- Format the query string
    QueryString = QueryString .. " WHERE LogFile=\'"..sEventLog.."\' AND EventIdentifier="..sEventID.." AND EventType="..sEventType

    print(QueryString)
    if Query:Execute(QueryString) == false then
        print(Query:GetErrorDescription());
        Query:delete()
        return
    end

    -- Now, for each entry returned, get the message property field from each    
    while (Query:NextInstance()) do
             sMessage = ""
           bOk,sMessage = Query:GetProperty("Message",sMessage)
        if bOk == true then
            print(sMessage)
            table.insert(vMessagesTable,sMessage)
            print(sStatus)
        end
    end    
    Query:delete()
end

function PrintResult(iResultNum)

    sTemp = "Message# "..iResultNum.." "..vMessagesTable[iResultNum]
    print(sTemp)
    print("")
end

function main()

    -- Extract the arguments
    sEventID = GetArgument(0)
    sEventType = GetArgument(1)
    sEventLog = GetArgument(2)

    -- Do the query
    QueryEventLog(sEventLog,sEventID,sEventType)    

    -- Print Messages
    table.foreach(vMessagesTable,PrintResult)

    -- Done
    SetExitStatus("OK",true)

end