-module(lightspeed@ops@telemetry).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/lightspeed/ops/telemetry.gleam").
-export([from_session_event/1, receive_span/5, span_status_label/1, metric_line/1]).
-export_type([tag/0, metric/0, span_status/0, span/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.

?MODULEDOC(" Metrics and tracing primitives for production observability.\n").

-type tag() :: {tag, binary(), binary()}.

-type metric() :: {counter, binary(), integer(), list(tag())} |
    {gauge, binary(), integer(), list(tag())}.

-type span_status() :: span_ok | {span_error, binary()}.

-type span() :: {span,
        binary(),
        binary(),
        integer(),
        integer(),
        span_status(),
        list(tag())}.

-file("src/lightspeed/ops/telemetry.gleam", 36).
?DOC(" Translate one session telemetry event into metric points.\n").
-spec from_session_event(lightspeed@agent@session:telemetry_event()) -> list(metric()).
from_session_event(Event) ->
    case Event of
        {session_mounted, Session_id, Route} ->
            [{counter,
                    <<"lightspeed.session.mounted_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id},
                        {tag, <<"route"/utf8>>, Route}]}];

        {session_rehydrated, Session_id@1, Route@1} ->
            [{counter,
                    <<"lightspeed.session.rehydrated_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@1},
                        {tag, <<"route"/utf8>>, Route@1}]}];

        {session_remounted, Session_id@2, Route@2} ->
            [{counter,
                    <<"lightspeed.session.remounted_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@2},
                        {tag, <<"route"/utf8>>, Route@2}]}];

        {counter_updated, Session_id@3, Value} ->
            [{counter,
                    <<"lightspeed.session.counter_updates_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@3}]},
                {gauge,
                    <<"lightspeed.session.counter_value"/utf8>>,
                    Value,
                    [{tag, <<"session_id"/utf8>>, Session_id@3}]}];

        {patch_queued, Session_id@4, _} ->
            [{counter,
                    <<"lightspeed.session.patch_queued_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@4}]}];

        {patch_acked, Session_id@5, _} ->
            [{counter,
                    <<"lightspeed.session.patch_acked_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@5}]}];

        {heartbeat_received, Session_id@6, _} ->
            [{counter,
                    <<"lightspeed.session.heartbeat_received_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@6}]}];

        {heartbeat_timed_out, Session_id@7, _} ->
            [{counter,
                    <<"lightspeed.session.heartbeat_timeout_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@7}]}];

        {session_crashed, Session_id@8, _} ->
            [{counter,
                    <<"lightspeed.session.crashed_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@8}]}];

        {session_restarted, Session_id@9} ->
            [{counter,
                    <<"lightspeed.session.restarted_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@9}]}];

        {session_shutdown, Session_id@10, _} ->
            [{counter,
                    <<"lightspeed.session.shutdown_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@10}]}];

        {ownership_rejected, Session_id@11, _} ->
            [{counter,
                    <<"lightspeed.session.ownership_rejected_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@11}]}];

        {event_ignored, Session_id@12, Event_name} ->
            [{counter,
                    <<"lightspeed.session.event_ignored_total"/utf8>>,
                    1,
                    [{tag, <<"session_id"/utf8>>, Session_id@12},
                        {tag, <<"event_name"/utf8>>, Event_name}]}]
    end.

-file("src/lightspeed/ops/telemetry.gleam", 132).
?DOC(" Build a receive span for transport traces.\n").
-spec receive_span(binary(), binary(), integer(), integer(), span_status()) -> span().
receive_span(Session_id, Frame_tag, Start_ms, End_ms, Status) ->
    {span,
        <<"lightspeed.transport.receive"/utf8>>,
        Session_id,
        Start_ms,
        End_ms,
        Status,
        [{tag, <<"frame_tag"/utf8>>, Frame_tag}]}.

-file("src/lightspeed/ops/telemetry.gleam", 150).
?DOC(" Convert span status to a stable label.\n").
-spec span_status_label(span_status()) -> binary().
span_status_label(Status) ->
    case Status of
        span_ok ->
            <<"ok"/utf8>>;

        {span_error, _} ->
            <<"error"/utf8>>
    end.

-file("src/lightspeed/ops/telemetry.gleam", 177).
-spec render_tags(list(tag())) -> binary().
render_tags(Tags) ->
    case Tags of
        [] ->
            <<""/utf8>>;

        [{tag, Key, Value}] ->
            <<<<Key/binary, "="/utf8>>/binary, Value/binary>>;

        [{tag, Key@1, Value@1} | Rest] ->
            <<<<<<<<Key@1/binary, "="/utf8>>/binary, Value@1/binary>>/binary,
                    ","/utf8>>/binary,
                (render_tags(Rest))/binary>>
    end.

-file("src/lightspeed/ops/telemetry.gleam", 158).
?DOC(" Render one metric as a log-friendly line.\n").
-spec metric_line(metric()) -> binary().
metric_line(Metric) ->
    case Metric of
        {counter, Name, Value, Tags} ->
            <<<<<<<<<<"counter "/utf8, Name/binary>>/binary, " "/utf8>>/binary,
                        (erlang:integer_to_binary(Value))/binary>>/binary,
                    " "/utf8>>/binary,
                (render_tags(Tags))/binary>>;

        {gauge, Name@1, Value@1, Tags@1} ->
            <<<<<<<<<<"gauge "/utf8, Name@1/binary>>/binary, " "/utf8>>/binary,
                        (erlang:integer_to_binary(Value@1))/binary>>/binary,
                    " "/utf8>>/binary,
                (render_tags(Tags@1))/binary>>
    end.