More sensible signature functions

Remove all of the older functions. Bind git_signature_default() and
implement the _now() equivalent in erlang.

c_src/geef.c

@@ -184,8 +184,7 @@ static ErlNifFunc geef_funcs[] =
 	{"index_nth",        2, geef_index_nth},
 	{"index_clear",      1, geef_index_clear},
 	{"index_read_tree",  2, geef_index_read_tree},
-	{"signature_new", 2, geef_signature_new},
-	{"signature_new", 3, geef_signature_new},
+	{"signature_default", 1, geef_signature_default},
 };
 
 ERL_NIF_INIT(geef_nif, geef_funcs, load, NULL, upgrade, unload)

c_src/signature.c

@@ -1,7 +1,53 @@
 #include "geef.h"
+#include "repository.h"
 #include <string.h>
 #include <git2.h>
 
+static int geef_string_to_bin(ErlNifBinary *bin, const char *str)
+{
+	size_t len;
+
+	len = strlen(str);
+	if (!enif_alloc_binary(len, bin))
+		return -1;
+
+	memcpy(bin->data, str, len);
+	return 0;
+}
+
+ERL_NIF_TERM
+geef_signature_default(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
+{
+	git_signature *sig;
+	geef_repository *repo;
+	ErlNifBinary name, email;
+
+	if (!enif_get_resource(env, argv[0], geef_repository_type, (void **) &repo))
+		return enif_make_badarg(env);
+
+	memset(&name, 0, sizeof(ErlNifBinary));
+	memset(&email, 0, sizeof(ErlNifBinary));
+
+	if (git_signature_default(&sig, repo->repo) < 0)
+		return geef_error(env);
+
+	if (geef_string_to_bin(&name, sig->name) < 0)
+		goto oom;
+
+	if (geef_string_to_bin(&email, sig->email) < 0)
+		goto oom;
+
+	return enif_make_tuple5(env, atoms.ok,
+	         enif_make_binary(env, &name), enif_make_binary(env, &email),
+		 enif_make_ulong(env, sig->when.time), enif_make_uint(env, sig->when.offset));
+oom:
+	git_signature_free(sig);
+	enif_release_binary(&name);
+	enif_release_binary(&email);
+
+	return geef_oom(env);
+}
+
 ERL_NIF_TERM
 geef_signature_new(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[])
 {

c_src/signature.h

@@ -1,3 +1,4 @@
 #include "geef.h"
 
 ERL_NIF_TERM geef_signature_new(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+ERL_NIF_TERM geef_signature_default(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);

lib/geef/signature.ex

@@ -1,9 +1,12 @@
 defrecord Geef.Signature, Record.extract(:geef_signature, from: "src/geef_records.hrl") do
 
-  def new(name, email), do: :geef_sig.new(name, email) |> maybe_sig
-  def new(name, email, time), do: :geef_sig.new(name, email, time) |> maybe_sig
+  def now(name, email), do: :geef_sig.now(name, email) |> from_erl
 
-  defp maybe_sig({:ok, sig}), do: Geef.Signature.new(sig)
-  defp maybe_sig({:error, error}), do: raise error
+  def default(repo), do: :geef_sig.default(repo) |> maybe_sig
+
+  defp maybe_sig({:ok, sig}), do: from_erl(sig)
+  defp maybe_sig(error = {:error, _}), do: error
+
+  defp from_erl(sig), do: set_elem(sig, 0, Geef.Signature)
 
 end

src/geef_nif.erl

@@ -172,6 +172,10 @@ index_add(_Handle, _Entry) ->
 index_clear(_Handle) ->
     ?NIF_FN.
 
+-spec signature_default(term()) -> {ok, geef_sig:signature()} | {error, term()}.
+signature_default(_Repo) ->
+    ?NIF_FN.
+
 signature_new(_Name, _Email) ->
     ?NIF_FN.
 

src/geef_sig.erl

@@ -6,23 +6,29 @@
 -type signature() :: #geef_signature{}.
 -export_type([time/0, signature/0]).
 
--export([new/2, new/3]).
+-export([default/1, now/2]).
 
--spec new(iolist(), iolist()) -> {ok, signature()} | {error, term()}.
-new(Name0, Email0) ->
-    case geef_nif:signature_new(Name0, Email0) of
-        {ok, Name, Email, Time0, Offset} ->
-            Time = {{Time0 div 1000000, Time0 rem 1000000, 0}, Offset},
-            {ok, #geef_signature{name=Name, email=Email, time=Time}};
-        Err ->
+%% @doc Create a signature for the repository's configured username and
+%% email, with a timestamp of now.
+-spec default(pid()) -> {ok, signature()} | {error, term()}.
+default(Repo) ->
+    RepoHandle = geef_repo:handle(Repo),
+    case geef_nif:signature_default(RepoHandle) of
+        {ok, Name, Email, Timestamp, Offset} ->
+            Time = {{Timestamp div 1000000, Timestamp rem 1000000, 0}, Offset},
+            Sig = #geef_signature{name=Name, email=Email, time=Time},
+            {ok, Sig};
+        Err = {error, _} ->
             Err
     end.
 
--spec new(iolist(), iolist(), time()) ->  {ok, signature()} | {error, term()}.
-new(Name0, Email0, Time) ->
-    case geef_nif:signature_new(Name0, Email0, 0) of
-        {ok, Name, Email} ->
-            {ok, #geef_signature{name=Name, email=Email, time=Time}};
-        Err ->
-            Err
-    end.
+%% @doc Create a signature with the specified username and email, with
+%% a timestamp of now
+now(Name, Email) ->
+    Now = now(),
+    %% We ask two questions "what's the time here?" and "what's the
+    %% time in UTC-Land?". The difference in minutes is our offset.
+    Local = calendar:datetime_to_gregorian_seconds(calendar:now_to_local_time(Now)),
+    UTC = calendar:datetime_to_gregorian_seconds(calendar:now_to_universal_time(Now)),
+    Offset = (Local - UTC) div 60,
+    #geef_signature{name=Name, email=Email, time={Now, Offset}}.