Mint: some fixes

config/dev.exs

@@ -24,6 +24,9 @@ config :cashubrew, dev_routes: true
 # Do not include metadata nor timestamps in development logs
 config :logger, :console, format: "[$level] $message\n"
 
+# Use mock
+config :cashubrew, :lightning_service, Cashubrew.LightningMock
+
 # Set a higher stacktrace during development. Avoid configuring such
 # in production as building large stacktraces may be expensive.
 config :phoenix, :stacktrace_depth, 20

lib/cashubrew/NUTs/NUT-04/impl.ex

@@ -10,20 +10,24 @@ defmodule Cashubrew.Nuts.Nut04.Impl do
 
   def create_mint_quote!(amount, unit) do
     repo = Application.get_env(:cashubrew, :repo)
-
-    {payment_request, _payment_hash} = LightningNetworkService.create_invoice!(amount, unit)
+    # Mock for dev
+    lightning_service = Application.get_env(:cashubrew, :lightning_service, LightningNetworkService)
+    {:ok, payment_request} = lightning_service.create_invoice!(amount, unit)
+    amount = if is_integer(amount), do: amount, else: String.to_integer(amount)
 
     # Note: quote is a unique and random id generated by the mint to internally look up the payment state.
     # quote MUST remain a secret between user and mint and MUST NOT be derivable from the payment request.
     # A third party who knows the quote ID can front-run and steal the tokens that this operation mints.
-    quote_id = Ecto.UUID.bingenerate()
+    quote_id = :os.system_time(:millisecond)
 
     # 1 hour expiry
     expiry = :os.system_time(:second) + 3600
 
     Schema.MintQuote.create!(repo, %{
       id: quote_id,
       payment_request: payment_request,
+      amount: amount,
+      unit: unit,
       expiry: expiry,
       # Unpaid
       state: <<0>>

lib/cashubrew/NUTs/NUT-04/serde.ex

@@ -36,5 +36,6 @@ defmodule Cashubrew.Nuts.Nut04.Serde.PostMintBolt11Response do
   The body of the post mint response
   """
   @enforce_keys [:signatures]
+  @derive [Jason.Encoder]
   defstruct [:signatures]
 end

lib/cashubrew/lightning/lightning_network_service.ex

@@ -19,7 +19,7 @@ defmodule Cashubrew.Lightning.LightningNetworkService do
         {payment_request, payment_hash}
 
       {:error, reason} ->
-        raise reason
+        raise RuntimeError, "Failed to create invoice: #{inspect(reason)}"
     end
   end
 

lib/cashubrew/mocks/lightning_mock.ex

@@ -0,0 +1,5 @@
+defmodule Cashubrew.LightningMock do
+  def create_invoice!(amount, unit) do
+    {:ok, "mock_payment_request_#{amount}_#{unit}"}
+  end
+end

lib/cashubrew/schema/mint_quote.ex

@@ -5,7 +5,7 @@ defmodule Cashubrew.Schema.MintQuote do
   use Ecto.Schema
   import Ecto.Changeset
 
-  @primary_key {:id, :binary_id, autogenerate: false}
+  @primary_key {:id, :id, autogenerate: false}
   schema "mint_quotes" do
     field(:payment_request, :string)
     field(:amount, :integer)
@@ -23,7 +23,7 @@ defmodule Cashubrew.Schema.MintQuote do
   def changeset(quote, attrs) do
     quote
     |> cast(attrs, [:id, :payment_request, :amount, :unit, :expiry, :state])
-    |> validate_required([:id, :payment_request, :amout, :unit, :expiry, :state])
+    |> validate_required([:id, :payment_request, :amount, :unit, :expiry, :state])
     |> validate_inclusion(:state, [<<0>>, <<1>>, <<2>>, <<128>>, <<129>>, <<130>>])
   end
 

lib/cashubrew/web/controllers/mint_controller.ex

@@ -57,16 +57,25 @@ defmodule Cashubrew.Web.MintController do
       raise "UnsuportedMethod"
     end
 
-    %Nut04.Serde.PostMintQuoteBolt11Request{
-      amount: amount,
-      unit: unit,
-      description: _description
-    } = params["body"]
+    unit = params["unit"]
+
+    if !unit do
+      raise "NoUnit"
+    end
+
+    amount = params["amount"]
+
+    if !amount do
+      raise "NoUnit"
+    end
 
     res = Nut04.Impl.create_mint_quote!(amount, unit)
-    json(conn, struct(Nut04.Serde.PostMintBolt11Response, Map.put(res, :state, "UNPAID")))
+    json(conn, struct(Nut04.Serde.PostMintBolt11Response, Map.merge(res, %{signatures: [], state: "UNPAID"})))
   rescue
-    e in RuntimeError -> conn |> put_status(:bad_request) |> json(Nut00.Error.new_error(0, e))
+    e in RuntimeError ->
+      conn
+      |> put_status(:bad_request)
+      |> json(%{error: e.message})
   end
 
   def get_mint_quote(conn, %{"quote_id" => quote_id, "method" => method}) do

priv/repo/migrations/20240918113122_create_mint_quote.exs

@@ -5,10 +5,11 @@ defmodule Cashubrew.Repo.Migrations.CreateMintQuote do
     create table(:mint_quotes) do
       add :amount, :integer, null: false
       add :payment_request, :text, null: false
-      add :state, :string, default: "UNPAID", null: false
+      add :state, :binary, null: false, default: fragment("decode('00', 'hex')")
       add :expiry, :integer, null: false
       add :description, :string
       add :payment_hash, :string
+      add :unit, :string
 
       timestamps()
     end