-- This should be its own package!

module Exercise3.Solutions.Currency.Cash where

import Exercise3.Solutions.Modularized.Interfaces

template Cash
  with
    issuer : Party
    owner : Party
    quantity : Decimal
    currency : Text
    obs : [Party]
  where
    signatory [issuer, owner]
    observer obs



    -- Make new cash backwards compatible in case currency is USD.
    interface instance IAsset for Cash where
      view = VAsset with
        assetType = if currency == "USD" then "Cash" else "V2_Cash " <> currency
        ..
      set_obs newObs = toInterface (this with obs = newObs)
      set_owner newOwner = toInterface (this with owner = newOwner)
      set_quantity newQuantity = toInterface (this with quantity = newQuantity)
      transfer_for newOwner = toInterface $ CashTransferProposal with cash = this; ..

-- Workaround for https://github.com/digital-asset/daml/issues/15459
myView = view

template CashTransferProposal
  with
    newOwner : Party
    cash : Cash
  where
    signatory (signatory cash)
    observer newOwner
    
    -- Make new transfer proposals backwards compatible in case currency is USD.
    interface instance IAssetTransferProposal for CashTransferProposal where
      view = VAssetTransferProposal with
        newOwner = newOwner
        vasset = myView (toInterface @IAsset cash)
      asset = toInterface @IAsset cash