distribute

-module(distribute@cluster@gossip).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/distribute/cluster/gossip.gleam").
-export([local_view/0, send_to/2, receive_and_merge/1, merge_single/1, pick_random_peers/2]).
-export_type([node_status/0, gossip_entry/0, gossip_message/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-type node_status() :: alive | suspect | dead.

-type gossip_entry() :: {gossip_entry,
        binary(),
        node_status(),
        integer(),
        integer()}.

-type gossip_message() :: {gossip_message, list(gossip_entry())}.

-file("src/distribute/cluster/gossip.gleam", 60).
?DOC(" Get the local gossip view as a list of entries.\n").
-spec local_view() -> list(gossip_entry()).
local_view() ->
    Raw = gossip_ffi:local_view(),
    gleam@list:map(
        Raw,
        fun(Item) ->
            {Node, Status_str, Inc, Ts} = Item,
            Status = case Status_str of
                <<"alive"/utf8>> ->
                    alive;

                <<"suspect"/utf8>> ->
                    suspect;

                _ ->
                    dead
            end,
            {gossip_entry, Node, Status, Inc, Ts}
        end
    ).

-file("src/distribute/cluster/gossip.gleam", 74).
?DOC(" Convert a status to string for FFI.\n").
-spec status_to_string(node_status()) -> binary().
status_to_string(Status) ->
    case Status of
        alive ->
            <<"alive"/utf8>>;

        suspect ->
            <<"suspect"/utf8>>;

        dead ->
            <<"dead"/utf8>>
    end.

-file("src/distribute/cluster/gossip.gleam", 83).
?DOC(" Send gossip to a specific node.\n").
-spec send_to(binary(), list(gossip_entry())) -> nil.
send_to(Node, Entries) ->
    Raw = gleam@list:map(
        Entries,
        fun(E) ->
            {erlang:element(2, E),
                status_to_string(erlang:element(3, E)),
                erlang:element(4, E),
                erlang:element(5, E)}
        end
    ),
    gossip_ffi:send_gossip(Node, Raw).

-file("src/distribute/cluster/gossip.gleam", 92).
?DOC(" Receive and merge gossip from a peer.\n").
-spec receive_and_merge(list(gossip_entry())) -> nil.
receive_and_merge(Entries) ->
    Raw = gleam@list:map(
        Entries,
        fun(E) ->
            {erlang:element(2, E),
                status_to_string(erlang:element(3, E)),
                erlang:element(4, E),
                erlang:element(5, E)}
        end
    ),
    gossip_ffi:receive_gossip(Raw).

-file("src/distribute/cluster/gossip.gleam", 102).
?DOC(
    " Merge a single entry into the local view.\n"
    " Uses the rule: higher incarnation wins; on tie, alive > suspect > dead.\n"
).
-spec merge_single(gossip_entry()) -> nil.
merge_single(Entry) ->
    gossip_ffi:merge_entry(
        erlang:element(2, Entry),
        status_to_string(erlang:element(3, Entry)),
        erlang:element(4, Entry),
        erlang:element(5, Entry)
    ).

-file("src/distribute/cluster/gossip.gleam", 112).
?DOC(" Pick random peers from a list of nodes.\n").
-spec pick_random_peers(list(binary()), integer()) -> list(binary()).
pick_random_peers(Nodes, Count) ->
    gleam@list:take(Nodes, Count).