Asynchronous replication in postgresql

Hi,

I am new to postgresql and evaluating the streaming replication for my use case. My use case is:

1. Need to replicate data from primary database (master) to secondary database (slave) asynchronously.

2. If master goes down, the slave should automatically be promoted to master.

3. Later, when the original primary server (original master) is brought up again, it should obtain back its master role and the new master should assume the slave again as it was with original setup.

For #1, the streaming replication of postgresql is good enough.
For #2, we need to create the trigger file. How can we do this automatically?
For #3, this seems to be quite complicated. Is this even possible using streaming replication? If yes, how can this be achieved?

Your help is greatly appreciated in this regard.
Thank you very much..