If record exist update partlevel from 1 to 0?

Question

problem

if record exist on trade code table update partlevel from 1 to 0 ?

the code below insert new record on trade code for codetypeto and codevalueto if not exist on table tradecode

i need to modify code below if codevalueto and code typeto both exist on table tradecode

then update partlevel from 1 to 0 to codetypeto and codevalueto on tradecode table that already exist

else

insert record on tradecode table to codetypeto and codevalueto that not exist 

create table #MappingCodeValue
 (
 id int identity (1,1),
  CodeTypeFrom  nvarchar(50),
 CodeValueFrom  nvarchar(50),
 CodeTypeTo  nvarchar(50),
 CodeValueTo  nvarchar(50)
 )
 INSERT INTO #MappingCodeValue
 (CodeTypeFrom,CodeValueFrom,CodeTypeTo,CodeValueTo)
 VALUES
 ('ECCS-US','AB123-US','ECCS-URB','AB123-URB'),
 ('ECCS-US','AB555-US','ECCS-URB','AB555-URB'),
 ('ECCS-US','AB666-US','ECCS-URB','AB666-URB'),
 ('ECCS-US','AB756-US','ECCS-URB','AB778-URB')


 CREATE TABLE #TradeCode
 (
 TradeCodeId int identity(1,1),
 PartId  int,
 Partlevel int,
 CodeType  nvarchar(50),
 CodeValue nvarchar(50)
 )
 insert into #TradeCode(PartId,Partlevel,CodeType,CodeValue)VALUES
 (1222,1,'ECCS-US','AB123-US'),
 (1255,1,'ECCS-US','AB555-US'),
 (1444,1,'ECCS-US','AB666-US'),
 (1931,1,'ECCS-US','AB756-US')

insert into #TradeCode
select c.PartId, c.Partlevel, c.CodeType, m.CodeValueTo
from #MappingCodeValue as m
inner join #TradeCode as c on c.CodeType = m.CodeTypeFrom and c.CodeValue = m.CodeValueFrom
where not exists( select * from #TradeCode where CodeType = c.CodeType and CodeValue = m.CodeValueTo)
Select * from #TradeCode

 Expected Result

TradeCodeId PartId  Partlevel   CodeType    CodeValue
1            1222     1          ECCS-US    AB123-US
2            1255     1          ECCS-US    AB555-US
3            1444     1          ECCS-US    AB666-US
4            1931     1          ECCS-US    AB756-US
5            1222     0          ECCS-URB    AB123-URB
6            1255     0          ECCS-URB    AB555-URB
7            1444     0          ECCS-URB    AB666-URB
8            1931     0          ECCS-URB    AB778-URB