API GetDetailedItemLevelInfo

Returns detailed item level information about a given item. effectiveILvl, isPreview, baseILvl = GetDetailedItemLevelInfo(itemID or "itemString" or "itemName" or "itemLink")

Arguments
One of the following four ways to specify which item to query:
 * itemId : Number - Numeric ID of the item. e.g. 30234 for Nordrassil Wrath-Kilt
 * itemName : String - Name of an item owned by the player at some point during this play session, e.g. "Nordrassil Wrath-Kilt".
 * itemString : String - A fragment of the itemString for the item, e.g. "item:30234:0:0:0:0:0:0:0" or "item:30234".
 * itemLink : String - The full itemLink.

Returns

 * effectiveILvl : Number - same as in tooltip.
 * isPreview : Boolean - True means it would have a + in the tooltip, a minimal level for item used in loot preview in encounter journal
 * baseILvl : Number - base item level

Details
effectiveLevel:
 * matches all the upgrades (WF/TF) applied to item
 * does not show scaling down in timewalking instances - i.e. matches number in parenthesis in tooltip
 * does not show correct item level for artifact off-hand items - it always stays as 750 instead of matching main hand