Add a new devkit for p2p-trading wave2 which uses beckn aware ledger service intrerface

[ameetdesh]

Refs:

• 9 March: p2p arch with federated ledger
• Final P2P Ledger and Allocation Architecture
• Sequence diagrams in: Issue 166: Add alternate sequence diagrams without a centralized ledger #167

[ameetdesh]

• Goal: A new bootcamp + revamped p2p-interdiscom on beckn v2 LTS.
• Nice to have: minimal transition toil for discoms.
• Acronyms:
  LTSP: ledger TSP
  Changes:
  Ledger trade recording will not happen via ledger/record but via confirm from buyerTP to the buyerDiscomLedgerTSP and confirm from sellerTP to the sellerDiscomLedgerTSP. Each will acknowledge the trade with on_confirm.
  Will use beckn v2 LTS, not RC.
  Will use latest policy enforcer & onix & allowed networkId. (not p2p-multiarch-v6 image)
  On_status: sellerTP raises on_status to buyerTP after polling ledger/get and checking if both discoms have finished their allocations.
  This will change to
  sellerDiscomLedger will raise on_status to sellerTP once final allocation is done, and buyerDiscomLedger will raise on_status to buyerTP.
  buyerDiscomLegder will send on_status to buyerTP to sellerTP to sellerDiscomLedger.
  And vice versa .
  Once the final allocation is done then say buyerDiscomledger can raise another on-status to buyerTP.
  Discom interface:
  CURRENT: they use /get and /allocate to send meter data.

PROPOSED:
Pramod wants discoms to host a beckn node and send data using Data Exchange protocol.
Discoms will query ledger for existing trades and will be sending meter data for any meter + hour to their ledger TSP. Nice to have: ability to send batch data.
Getting the data form ledger about current trades, can be a confirm call for data request. Trades come on on_confirm from the ledger. We will need to create a context/attributes.yaml/tyep for ledger data row, and send it within the envelope of DatasetItem,
Work breakdown:
Keep discom interface the same. Only update the TP interface.
Each TP raises a confirm to the respective discom ledger TSP. We will need to have a mapping between DISCOM name & its LTSP’s beckn subscriber id. This will need to be a part of schema.
Devkit will have 3 personas. buyerTP, sellerTP, buyerDiscomLTSP, sellerDiscomLTSP, we will need to define example calls between those.
Name of new devkit: ‘p2p-trading-wave2’
Propose schema changes needed as we build example payloads. Tob e housed in DEG/specifications/schema
It will be nice to have automation of confirm calls, once the trade is recorded, similar to what onix plugin deg-recorder was doing.
After each on_confirm call, parse LTSP’s id & url and send a confirm request automatically to that LTSP.
Similarly for status call, we will need to define schemas that match /ledger/get output and send it over on_status.
Do we need a new ledger server? Probably not. Only needs new beckn-aware translation layer. The mapping from (discom to LTSPurl) will always point to ies.p2p-trading.beckn.io as LTSPurl.. But in future more such LTSP servers can emerge.