start grids qr demo

src/fd_gridsd.erl

@@ -0,0 +1,122 @@
+% @doc grids cache
+-module(fd_gridsd).
+-vsn("0.2.0").
+
+-behavior(gen_server).
+
+-export_type([
+]).
+
+-export([
+    %% caller context
+    get_url/2,
+
+    %% api
+    start_link/0,
+
+    %% process context
+    init/1, handle_call/3, handle_cast/2, handle_info/2,
+    code_change/3, terminate/2
+]).
+
+-include("$zx_include/zx_logger.hrl").
+
+-type mh_str()         :: string().
+
+%% for craig's autism
+-record(sp,
+        {recipient :: string(),
+         amount    :: non_neg_integer(),
+         payload   :: binary()}).
+
+-type search_pattern() :: #sp{}.
+
+-record(s,
+        {current_gen_height         :: pos_integer(),
+         current_gen_hash           :: string(),
+         current_gen_seen_mb_hashes :: [mh_str()],
+         past_gen_seen_mb_hashes    :: [mh_str()],
+         looking_for                :: [search_pattern()]}).
+-type state() :: #s{}.
+
+
+%%-----------------------------------------------------------------------------
+%% caller context
+%%-----------------------------------------------------------------------------
+
+-spec get_url(Amount, Payload) -> {ok, URL, QR_PNG} | {error, term()}
+    when Amount  :: none | pos_integer(),
+         Payload :: none | binary(),
+         URL     :: string(),
+         QR_PNG  :: binary().
+
+get_url(Amount, Payload) ->
+    gen_server:call(?MODULE, {get_url, Amount, Payload}).
+
+
+%% gen_server callbacks
+start_link() ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, none, []).
+
+
+%%-----------------------------------------------------------------------------
+%% process context below this line
+%%-----------------------------------------------------------------------------
+
+%% gen_server callbacks
+
+init(none) ->
+    tell("starting fd_gridsd"),
+    InitState = #s{},
+    {ok, InitState}.
+
+
+handle_call({get_url, Amount, Payload}, From, State) ->
+    case i_get_url(Amount, Payload, From, State) of
+        {ok, URL, PNG, NewState} ->
+            {reply, {ok, URL, PNG}, NewState};
+        Error ->
+            {reply, Error, State}
+    end;
+handle_call(Unexpected, From, State) ->
+    tell("~tp: unexpected call from ~tp: ~tp", [?MODULE, Unexpected, From]),
+    {noreply, State}.
+
+
+handle_cast(Unexpected, State) ->
+    tell("~tp: unexpected cast: ~tp", [?MODULE, Unexpected]),
+    {noreply, State}.
+
+
+handle_info(Unexpected, State) ->
+    tell("~tp: unexpected info: ~tp", [?MODULE, Unexpected]),
+    {noreply, State}.
+
+
+code_change(_, State, _) ->
+    {ok, State}.
+
+terminate(_, _) ->
+    ok.
+
+
+%%-----------------------------------------------------------------------------
+%% internals
+%%-----------------------------------------------------------------------------
+
+-spec i_get_url(Amount, Payload, From, State) -> Result
+    when Amount  :: none | pos_integer(),
+         Payload :: none | binary(),
+         From    :: {pid(), reference()},
+         State   :: state(),
+         URL     :: string(),
+         QR_PNG  :: binary().
+         Result  :: {ok, URL, QR_PNG, NewState}
+                  | {error, term()}.
+
+i_get_url(Amount, Payload, From, State) ->
+    NetworkId = fewd:network_id(),
+    Pubkey    = fewd:pubkey(),
+    URL       = gmgrids:encode({spend, NetworkId, Pubkey},
+                               [{amount, Amount}, {payload, Payload}]),
+