sql multiple 'case when'

SELECT CASE WHEN ( Table.COLUMN1) IS NOT NULL THEN 1 ELSE 0 END,

  CASE WHEN ( CASE WHEN ( Table.COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN 1 ELSE 0 END,

  CASE WHEN ( CASE WHEN ( CASE WHEN ( Table.COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( Table 1.FULL) END ) IS NOT NULL THEN 1 ELSE 0 END,

  CASE WHEN ( CASE WHEN ( CASE WHEN ( Table.COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( CASE WHEN Table 3.DO = 'Z' THEN 'Y' END ) END ) IS NOT NULL THEN 1 ELSE 0 END,


  CASE WHEN ( CASE WHEN ( CASE WHEN ( Table.COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( NVL(( Table2.COLUMN3), ( Table2.COLUMN3 )) ) END ) IS NOT NULL THEN 1 ELSE 0 END,


  CASE WHEN ( CASE WHEN ( CASE WHEN ( Table 4. COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( NVL(( Table2.COLUMN3), ( Table2.COLUMN3)) ) END ) IS NOT NULL THEN 1 ELSE 0 END,


  CASE WHEN ( CASE WHEN ( CASE WHEN ( Table.COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( Table 3.FULL) END ) IS NOT NULL THEN 1 ELSE 0 END,


  CASE WHEN ( CASE WHEN ( CASE WHEN ( Table.COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( ( Table2.COLUMN3) ) END ) IS NOT NULL THEN 1 ELSE 0 END,


  CASE WHEN ( CASE WHEN ( CASE WHEN ( Table.COLUMN1) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  then CASE WHEN ( CASE WHEN ( CASE WHEN ( Table.COLUMN1 ) IS NOT NULL AND ( Table.COLUMN2) 
  IS NOT NULL THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( ( Table2.COLUMN3) ) END ) IS NOT NULL AND ( Table.COLUMN1) - ( CASE WHEN ( CASE WHEN ( Table.COLUMN1) 
  IS NOT NULL AND ( Table.COLUMN2) IS NOT NULL 
  THEN CASE WHEN ( Table.COLUMN1) - ( Table.COLUMN2) >= 180 THEN 'Y' ELSE 'N' END ELSE 'N' END ) = 'Y' 
  THEN ( ( Table2.COLUMN3) ) END ) < 90 THEN 'Y' ELSE 'N' END END ) = 'Y' THEN 1 ELSE 0 END,