FF-208: Implement GetAccountBalance operation (#285)

* Implement GetAccountBalance

* Fix wrong currency_ref marshaling

* Get all events

* Test getting account balance

* Move getting account balance from handler, introduce relevant types

* Get wallet from machine in handler

* Remove redundant return type

apps/ff_server/src/ff_wallet_codec.erl

@@ -69,6 +69,15 @@ marshal(wallet, Wallet) ->
         metadata = maybe_marshal(ctx, maps:get(metadata, Wallet, undefined))
     };
 
+marshal(wallet_account_balance, AccountBalance) ->
+    #account_AccountBalance{
+        id = marshal(id, maps:get(id, AccountBalance)),
+        currency = marshal(currency_ref, maps:get(currency, AccountBalance)),
+        expected_min = marshal(amount, maps:get(expected_min, AccountBalance)),
+        current = marshal(amount, maps:get(current, AccountBalance)),
+        expected_max = marshal(amount, maps:get(expected_max, AccountBalance))
+    };
+
 marshal(ctx, Ctx) ->
     marshal(context, Ctx);
 

apps/ff_server/src/ff_wallet_handler.erl

@@ -61,4 +61,15 @@ handle_function_('GetContext', [ID], _Opts) ->
             {ok, Response};
         {error, notfound} ->
             woody_error:raise(business, #fistful_WalletNotFound{})
+    end;
+
+handle_function_('GetAccountBalance', [ID], _Opts) ->
+    case ff_wallet_machine:get(ID) of
+        {ok, Machine} ->
+            Wallet = ff_wallet_machine:wallet(Machine),
+            {ok, AccountBalance} = ff_wallet:get_account_balance(Wallet),
+            Response = ff_wallet_codec:marshal(wallet_account_balance, AccountBalance),
+            {ok, Response};
+        {error, notfound} ->
+            woody_error:raise(business, #fistful_WalletNotFound{})
     end.

apps/ff_server/test/ff_wallet_handler_SUITE.erl

@@ -18,6 +18,7 @@
 -export([create_error_currency_not_found/1]).
 -export([create_error_party_blocked/1]).
 -export([create_error_party_suspended/1]).
+-export([get_account_balance/1]).
 
 -type config()         :: ct_helper:config().
 -type test_case_name() :: ct_helper:test_case_name().
@@ -38,7 +39,8 @@ groups() ->
             create_error_identity_not_found,
             create_error_currency_not_found,
             create_error_party_blocked,
-            create_error_party_suspended
+            create_error_party_suspended,
+            get_account_balance
         ]}
     ].
 
@@ -85,6 +87,7 @@ end_per_testcase(_Name, _C) ->
 -spec create_error_currency_not_found(config()) -> test_return().
 -spec create_error_party_blocked(config())      -> test_return().
 -spec create_error_party_suspended(config())    -> test_return().
+-spec get_account_balance(config())             -> test_return().
 
 create_ok(C) ->
     Party        = create_party(C),
@@ -147,6 +150,27 @@ create_error_party_suspended(C) ->
     Result     = call_service('Create', [Params, #{}]),
     ?assertMatch({exception, #fistful_PartyInaccessible{}}, Result).
 
+get_account_balance(C) ->
+    Party        = create_party(C),
+    Currency     = <<"RUB">>,
+    ID           = genlib:unique(),
+    ExternalID   = genlib:unique(),
+    IdentityID   = create_person_identity(Party, C),
+    Ctx          = #{<<"TEST_NS">> => {obj, #{ {str, <<"KEY">>} => {b, true}}}},
+    Metadata     = ff_entity_context_codec:marshal(#{<<"metadata">> => #{<<"some key">> => <<"some data">>}}),
+    Params       = construct_wallet_params(ID, IdentityID, Currency, ExternalID, Metadata),
+    {ok, Wallet}  = call_service('Create', [Params, Ctx]),
+    WalletID = Wallet#wlt_WalletState.id,
+    {ok, AccountBalance} = call_service('GetAccountBalance', [WalletID]),
+    CurrencyRef = AccountBalance#account_AccountBalance.currency,
+    Account   = Wallet#wlt_WalletState.account,
+    AccountID = Account#account_Account.id,
+    ?assertMatch(AccountID, AccountBalance#account_AccountBalance.id),
+    ?assertMatch(Currency,  CurrencyRef#'CurrencyRef'.symbolic_code),
+    ?assertMatch(0, AccountBalance#account_AccountBalance.expected_min),
+    ?assertMatch(0, AccountBalance#account_AccountBalance.current),
+    ?assertMatch(0, AccountBalance#account_AccountBalance.expected_max).
+
 %%-----------
 %%  Internal
 %%-----------

apps/fistful/src/ff_account.erl

@@ -20,6 +20,16 @@
     accounter_account_id := accounter_account_id()
 }.
 
+-type amount()   :: dmsl_domain_thrift:'Amount'().
+
+-type account_balance() :: #{
+    id           := id(),
+    currency     := ff_currency:id(),
+    expected_min := amount(),
+    current      := amount(),
+    expected_max := amount()
+}.
+
 -type event() ::
     {created, account()}.
 
@@ -32,6 +42,7 @@
 -export_type([account/0]).
 -export_type([event/0]).
 -export_type([create_error/0]).
+-export_type([account_balance/0]).
 
 -export([id/1]).
 -export([identity/1]).

apps/fistful/src/ff_wallet.erl

@@ -70,6 +70,7 @@
 -export([create/1]).
 -export([is_accessible/1]).
 -export([close/1]).
+-export([get_account_balance/1]).
 
 -export([apply_event/2]).
 
@@ -204,3 +205,18 @@ check_accessible(Wallet) ->
         blocked ->
             {error, blocked}
     end.
+
+-spec get_account_balance(wallet_state()) ->
+    {ok, ff_account:account_balance()}.
+
+get_account_balance(Wallet) ->
+    Account = ff_wallet:account(Wallet),
+    {ok, {Amounts, Currency}} = ff_transaction:balance(Account, ff_clock:latest_clock()),
+    AccountBalance = #{
+        id => ff_account:id(Account),
+        currency => Currency,
+        expected_min => ff_indef:expmin(Amounts),
+        current => ff_indef:current(Amounts),
+        expected_max => ff_indef:expmax(Amounts)
+    },
+    {ok, AccountBalance}.