function Distance takes real x,real y,unit u returns real
    local real px = GetUnitX(u)
    local real py = GetUnitY(u)
    set px = px - x
    set py = py - y
    return SquareRoot(px * px + py * py)
endfunction

globals
    unit array Thunder_U
    integer Thunder_I = 0
endglobals
function Thunder_Conditions takes nothing returns boolean
    return GetSpellAbilityId() == 'AHtc'
endfunction

function FilterThunder takes nothing returns boolean
   return IsUnitAlly(GetFilterUnit(),GetOwningPlayer(GetSpellAbilityUnit())) == false and GetUnitState(GetFilterUnit(), UNIT_STATE_LIFE) >= 0
endfunction

function ThunderPick takes nothing returns nothing
   set Thunder_I = Thunder_I + 1
   set Thunder_U[Thunder_I] = GetEnumUnit()
endfunction

function Thunder_Actions takes nothing returns nothing
   local real x = GetUnitX(GetTriggerUnit())
   local real y = GetUnitY(GetTriggerUnit())
   local integer i = 0
   local unit min = null
   local rect r = bj_mapInitialPlayableArea
   local boolexpr b = Condition(function FilterThunder)
   local group g = CreateGroup()
   set Thunder_I = 0
   call GroupEnumUnitsInRect(g,r,b)
   call ForGroup(g,function ThunderPick)
   call BJDebugMsg(I2S(Thunder_I))
   set min = Thunder_U[1]
   loop
      set i = i + 1
      if Distance(x,y,min)>Distance(x,y,Thunder_U[i]) then
      set min = Thunder_U[i]
      endif
   exitwhen i == Thunder_I
   endloop
   call RemoveUnit(min)
   call BJDebugMsg(R2S(Distance(x,y,min)))
   set i = 1
   loop
   set Thunder_U[i] = null
   exitwhen i == Thunder_I
   endloop
   call DestroyBoolExpr(b)
   call DestroyGroup(g)
   call RemoveRect(r)
   set min = null
   set b = null
   set g = null
   set r = null
endfunction

//===========================================================================
function InitTrig_Thunder takes nothing returns nothing
    set gg_trg_Thunder = CreateTrigger(  )
    call TriggerRegisterAnyUnitEventBJ( gg_trg_Thunder, EVENT_PLAYER_UNIT_SPELL_EFFECT )
    call TriggerAddCondition( gg_trg_Thunder, Condition( function Thunder_Conditions ) )
    call TriggerAddAction( gg_trg_Thunder, function Thunder_Actions )
endfunction