1 files changed, 103 insertions, 0 deletions
diff --git a/apps/dreki/src/dreki_node.erl b/apps/dreki/src/dreki_node.erl
new file mode 100644
index 0000000..87dbc73
--- /dev/null
+++ b/apps/dreki/src/dreki_node.erl
@@ -0,0 +1,103 @@
+-module(dreki_node).
+-include("dreki.hrl").
+-include_lib("opentelemetry_api/include/otel_tracer.hrl").
+-behaviour(partisan_gen_fsm).
+-compile({no_auto_import,[get/0]}).
+-export([get/0, urn/0, stores/0]).
+-export([rpc/4, rpc/5]).
+-export([uri/0]). % deprecated
+-export([parents/0, parents/1, parent/0, parent/1]).
+-export([neighbours/0, neighbours/1]).
+-export([descendants/0, descendants/1]).
+-export([ensure_local_node/0]).
+
+-type rpc_error() :: {rpc_error, dreki_urn(), timeout | any()}.
+
+rpc(Path, Mod, Fun, Args) ->
+  rpc(Path, Mod, Fun, Args, #{timeout => 1000}).
+
+-spec rpc(dreki_urn(), module(), function(), Args :: [], #{timeout => non_neg_integer()}) -> {ok, any()} | {error, rpc_error()}.
+rpc(Path, Mod, Fun, Args, #{timeout := Timeout}) ->
+    ?with_span(<<"dreki_node:rpc">>, #{}, fun(ChildSpanCtx) ->
+        case dreki_world_dns:node_param(dreki_world:path_to_domain(Path), node_name) of
+          {ok, NodeName} ->
+            case partisan_rpc_backend:call(NodeName, Mod, Fun, Args, Timeout) of
+              {badrpc, Error} -> {error, {rpc_error, Path, Error}};
+              Result -> Result
+            end;
+          Error -> Error
+      end
+    end).
+
+get() ->
+  {ok, Node} = dreki_world:get_node(dreki_world:node()),
+  Node.
+
+urn() -> dreki_world:path().
+
+uri() -> urn().
+
+stores() -> dreki_world:stores(uri()).
+
+parents() ->
+    parents(urn()).
+
+parents(Node) ->
+    {ok, #{node := NodeUrn}} = dreki_world:get_node(Node),
+    NodeDomain = dreki_world:path_to_domain(NodeUrn),
+    Vertices0 = dreki_world_dns:get_path({root, dreki_world:internal_domain()}, {node, NodeDomain}),
+    Vertices = lists:map(fun get_from_vertex/1, Vertices0),
+    [_Me | Parents] = lists:reverse(Vertices),
+    Parents.
+
+parent() ->
+    parent(urn()).
+
+parent(Node) ->
+    {ok, #{node := NodeUrn}} = dreki_world:get_node(Node),
+    NodeDomain = dreki_world:path_to_domain(NodeUrn),
+    [Parent] = dreki_world_dns:in_neighbours({node, NodeDomain}),
+    get_from_vertex(Parent).
+
+neighbours() ->
+    neighbours(urn()).
+
+neighbours(Node) ->
+    {ok, #{node := NodeUrn}} = dreki_world:get_node(Node),
+    NodeDomain = dreki_world:path_to_domain(NodeUrn),
+    [Parent] = dreki_world_dns:in_neighbours({node, NodeDomain}),
+    Neighbours = dreki_world_dns:out_neighbours(Parent),
+    lists:map(fun get_from_vertex/1, Neighbours -- [{node, NodeDomain}]).
+
+descendants() ->
+    descendants(urn()).
+
+descendants(Node) ->
+    {ok, #{node := NodeUrn}} = dreki_world:get_node(Node),
+    NodeDomain = dreki_world:path_to_domain(NodeUrn),
+    Descendants0 = dreki_world_dns:out_neighbours({node, NodeDomain}),
+    Descendants = case Descendants0 of
+      [{region, NodeDomain}] -> dreki_world_dns:out_neighbours({region, NodeDomain});
+      D -> D
+    end,
+    lists:map(fun get_from_vertex/1, Descendants).
+
+get_from_vertex({root, Domain}) ->
+  {ok, Region} = dreki_world:get_region_from_dns_name(Domain),
+  Region;
+get_from_vertex({region, Domain}) ->
+  {ok, Region} = dreki_world:get_region_from_dns_name(Domain),
+  Region;
+get_from_vertex({node, Domain}) ->
+  {ok, Node} = dreki_world:get_node_from_dns_name(Domain),
+  Node.
+
+ensure_local_node() ->
+    case dreki_world:get_node(uri()) of
+      {ok, _} -> ok;
+      {error, {not_found, _}} -> create_local_node()
+    end.
+
+create_local_node() ->
+    dreki_world:create_node(uri(), #{}).
+