You could use the chain of responsability pattern (gof).
For each block in your if statement, you have a class that check if some conditions are validated, and if it's the case you can execute a statement.
Main -> Handler1 -> Handler2 -> Handler3 -> ... -> HandlerN
The advantages are
- different handlers could be triggered.
- Adding a new Handler is obvious.
- The condition are easier to read because no complex if statement.
- could be implemented in a way that if a statement is executed, the iteration on the chain is stopped
The disadvantage are
- be carefull of overlapping conditions (more than one statement is executed)
- testing could be difficult