API:UnitCastingTime

__NOTOC__
UnitCastingTime
local name, maxValue, currValue = UnitCastingTime("unit")
== Parameter ==
:;unit
::String - the UnitID (e.g. "target", "party1", "raid1", etc..) 
== Returns ==
:;name 
::String - the localized name of the buff currently casted
:;maxValue
::float - the total duration for casting the spell. 
:;currValue 
::float - the current time already spent for casting.
== Examples ==
=== Check if Target is casting ===
If for some reason you want to check, if the target is casting, you can try to compare the name of the spell to nil:
name = UnitCastingTime("target")
if name == nil then
 [...]
end
UnitCastingTime