fed-sx-m1: Step 6d-publish — outbox:publish/2 orchestration (construct+sign+validate+append) + 13 tests

next/kernel/outbox.erl

@@ -1,5 +1,5 @@
 -module(outbox).
--export([construct/4, sign/2, cid_of/1]).
+-export([construct/4, sign/2, cid_of/1, publish/2]).
 
 %% Outbox envelope construction + signing per design §3.1.
 %%
@@ -53,3 +53,53 @@ sign(Envelope, KeySpec) ->
 cid_of(Envelope) ->
     {ok, Id} = envelope:get_field(id, Envelope),
     Id.
+
+%% publish/2 — the outbound activity pipeline orchestrator.
+%%
+%% Request shape:   [{type, T}, {object, O}]
+%% Context shape:   [{actor_id, A}, {published, P}, {key_spec, KS},
+%%                   {actor_state, AS}, {log, L}]
+%%
+%% Returns:
+%%   {ok, [{cid, Cid}, {activity, Signed}], NewLog}   — happy path
+%%   {error, Reason, LogState}                         — validation halted
+%%
+%% Stages run in order: envelope shape, signature, replay. The
+%% replay check uses the log state pre-append, so if the caller
+%% publishes the same Request twice with the same Published
+%% timestamp the second call halts with {error, replay, _}.
+%%
+%% Projection-scheduler dispatch (the async fold the design calls
+%% for) is deferred to Step 7 — once the projection gen_server
+%% exists, this function will broadcast `Signed` to it.
+
+publish(Request, Context) ->
+    Type      = envelope_field(type, Request),
+    Object    = envelope_field(object, Request),
+    ActorId   = envelope_field(actor_id, Context),
+    Published = envelope_field(published, Context),
+    KeySpec   = envelope_field(key_spec, Context),
+    ActorState = envelope_field(actor_state, Context),
+    LogState   = envelope_field(log, Context),
+    Unsigned = construct(Type, ActorId, Published, Object),
+    Signed = sign(Unsigned, KeySpec),
+    Stages = [
+        fun (A) -> pipeline:stage_envelope(A) end,
+        pipeline:stage_signature(ActorState),
+        pipeline:stage_replay(LogState)
+    ],
+    case pipeline:run_stages(Signed, Stages) of
+        ok ->
+            {ok, NewLog, _Seq} = log:append(LogState, Signed),
+            Result = [{cid, cid_of(Signed)}, {activity, Signed}],
+            {ok, Result, NewLog};
+        {error, Reason} ->
+            {error, Reason, LogState}
+    end.
+
+envelope_field(K, PL) ->
+    case envelope:get_field(K, PL) of
+        {ok, V}   -> V;
+        not_found -> nil
+    end.
+