Handled MetadataState event.

[mariacarmina]

Fixes #46 .

Changes proposed in this PR:

• process MetadataState event
• create functionality for updating the state of the ddo nft in Indexer/index.ts
• add integration test

[bogdanfazakas]

Also i think it's good that you added lots of logs but maybe we should remove the duplicated ones, so maybe worth taking a look and clear some of the logs, this optional tho

[mariacarmina]

Also i think it's good that you added lots of logs but maybe we should remove the duplicated ones, so maybe worth taking a look and clear some of the logs, this optional tho

There are no duplicates as far as I saw, but I filtered some of them. If you still want to delete some, please specify here which. Thanks!

[bogdanfazakas]

Still not sure if we need that new instance of database in the event processor, in the PR we are using that to get the get the DDO and the other instance from indexer main thread to save or update the DDO.
So i think we need to decide how we are going fwd with the database instance singleton or not and keep just one approach, in this case if singleton use the db only from indexer main thread otherwise do anything related to the db in the working threads.

[mariacarmina]

Still not sure if we need that new instance of database in the event processor, in the PR we are using that to get the get the DDO and the other instance from indexer main thread to save or update the DDO. So i think we need to decide how we are going fwd with the database instance singleton or not and keep just one approach, in this case if singleton use the db only from indexer main thread otherwise do anything related to the db in the working threads.

As @paulo-ocean mentioned, this shouldn't be a show stopper. I decided to instantiate a new Database object to the event processor (for the moment I put only in metadata state, but we can declare it globally in that file as config was). If not, I've seen this message of yours @bogdanfazakas:

maybe keeping the necessary logic in the indexer main thread I'd say

Can you give more details about this approach, please?
In other words, for the moment I want to see if this change with database instance is more like an enhancement issue or it will actually break the functionality for POC. Can I have an answer to this statement, please? Because if it's not impacting the functionality for POC (and we decide it that way), maybe we can put these details to a separate issue to tackle it afterwards. What do you think @paulo-ocean @alexcos20 @bogdanfazakas @jamiehewitt15 ?

[jamiehewitt15]

I agree with paulo's comment on the DB, creating a new instance shouldn't necessarily be a showstopper

not going into details here, but if the issue is having 'DB access', i think that should not be a show stopper. We can always get the DB config and create a new Database instance if needed, anywhere. Its always the same DB everywhere, anyway

[mariacarmina]

Created issue for additional comments that could be tackled after the POC: #149

[jamiehewitt15]

The concerns mentioned above have been moved to separate issues, so we can proceed to merge this PR and deal with them separately.