ssevents

-module(ssevents@encoder).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/ssevents/encoder.gleam").
-export([default_line_ending/0, encode_with_line_ending/2, encode/1, encode_bytes/1, encode_item_with_line_ending/2, encode_item/1, encode_item_bytes/1, encode_items_with_line_ending/2, encode_items/1, encode_items_bytes/1]).
-export_type([line_ending/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(
    " Deterministic Server-Sent Events encoding.\n"
    "\n"
    " The default line ending is LF. Call the `*_with_line_ending`\n"
    " variants to emit CRLF instead.\n"
).

-type line_ending() :: lf | crlf.

-file("src/ssevents/encoder.gleam", 18).
-spec default_line_ending() -> line_ending().
default_line_ending() ->
    lf.

-file("src/ssevents/encoder.gleam", 179).
-spec comment_line(binary()) -> binary().
comment_line(Text) ->
    case Text of
        <<""/utf8>> ->
            <<":"/utf8>>;

        _ ->
            <<": "/utf8, Text/binary>>
    end.

-file("src/ssevents/encoder.gleam", 186).
-spec prefixed_line(binary(), binary()) -> binary().
prefixed_line(Field, Value) ->
    case Value of
        <<""/utf8>> ->
            <<Field/binary, ":"/utf8>>;

        _ ->
            <<<<Field/binary, ": "/utf8>>/binary, Value/binary>>
    end.

-file("src/ssevents/encoder.gleam", 146).
-spec prepend_optional(list(binary()), binary(), gleam@option:option(binary())) -> list(binary()).
prepend_optional(Lines, Field, Maybe_value) ->
    case Maybe_value of
        {some, Value} ->
            [prefixed_line(Field, Value) | Lines];

        none ->
            Lines
    end.

-file("src/ssevents/encoder.gleam", 157).
-spec prepend_optional_int(
    list(binary()),
    binary(),
    gleam@option:option(integer())
) -> list(binary()).
prepend_optional_int(Lines, Field, Maybe_value) ->
    case Maybe_value of
        {some, Value} ->
            [prefixed_line(Field, erlang:integer_to_binary(Value)) | Lines];

        none ->
            Lines
    end.

-file("src/ssevents/encoder.gleam", 193).
-spec line_ending_to_string(line_ending()) -> binary().
line_ending_to_string(Line_ending) ->
    case Line_ending of
        lf ->
            <<"\n"/utf8>>;

        crlf ->
            <<"\r\n"/utf8>>
    end.

-file("src/ssevents/encoder.gleam", 168).
-spec encode_comment_with_line_ending(binary(), line_ending()) -> binary().
encode_comment_with_line_ending(Text, Line_ending) ->
    Newline = line_ending_to_string(Line_ending),
    <<(comment_line(Text))/binary, Newline/binary>>.

-file("src/ssevents/encoder.gleam", 220).
-spec walk_normalise_newlines(bitstring(), bitstring()) -> bitstring().
walk_normalise_newlines(Input, Acc) ->
    case Input of
        <<>> ->
            Acc;

        <<13, 10, Rest/binary>> ->
            walk_normalise_newlines(Rest, <<Acc/bitstring, 10>>);

        <<13, Rest@1/binary>> ->
            walk_normalise_newlines(Rest@1, <<Acc/bitstring, 10>>);

        <<Byte, Rest@2/binary>> ->
            walk_normalise_newlines(Rest@2, <<Acc/bitstring, Byte>>);

        _ ->
            Acc
    end.

-file("src/ssevents/encoder.gleam", 200).
-spec normalise_newlines(binary()) -> binary().
normalise_newlines(Text) ->
    S@1 = case begin
        _pipe = Text,
        _pipe@1 = gleam_stdlib:identity(_pipe),
        _pipe@2 = walk_normalise_newlines(_pipe@1, <<>>),
        gleam@bit_array:to_string(_pipe@2)
    end of
        {ok, S} -> S;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                        file => <<?FILEPATH/utf8>>,
                        module => <<"ssevents/encoder"/utf8>>,
                        function => <<"normalise_newlines"/utf8>>,
                        line => 212,
                        value => _assert_fail,
                        start => 6610,
                        'end' => 6730,
                        pattern_start => 6621,
                        pattern_end => 6626})
    end,
    S@1.

-file("src/ssevents/encoder.gleam", 129).
-spec chunk_data_line_loop(binary(), list(binary())) -> list(binary()).
chunk_data_line_loop(Remaining, Acc) ->
    case string:length(Remaining) =< 2000 of
        true ->
            lists:reverse([Remaining | Acc]);

        false ->
            Head = gleam@string:slice(Remaining, 0, 2000),
            Rest = gleam@string:slice(
                Remaining,
                2000,
                string:length(Remaining) - 2000
            ),
            chunk_data_line_loop(Rest, [Head | Acc])
    end.

-file("src/ssevents/encoder.gleam", 122).
-spec chunk_data_line(binary()) -> list(binary()).
chunk_data_line(Line) ->
    case erlang:byte_size(Line) =< (2000 * 4) of
        true ->
            [Line];

        false ->
            chunk_data_line_loop(Line, [])
    end.

-file("src/ssevents/encoder.gleam", 86).
-spec event_lines(ssevents@event:event()) -> list(binary()).
event_lines(Ev) ->
    Prefix_lines = begin
        _pipe = [],
        _pipe@1 = prepend_optional(
            _pipe,
            <<"event"/utf8>>,
            ssevents@event:name_of(Ev)
        ),
        _pipe@2 = prepend_optional(
            _pipe@1,
            <<"id"/utf8>>,
            ssevents@event:id_of(Ev)
        ),
        _pipe@3 = prepend_optional_int(
            _pipe@2,
            <<"retry"/utf8>>,
            ssevents@event:retry_of(Ev)
        ),
        lists:reverse(_pipe@3)
    end,
    Data_lines = begin
        _pipe@4 = ssevents@event:data_of(Ev),
        _pipe@5 = normalise_newlines(_pipe@4),
        _pipe@6 = gleam@string:split(_pipe@5, <<"\n"/utf8>>),
        _pipe@7 = gleam@list:flat_map(_pipe@6, fun chunk_data_line/1),
        gleam@list:map(
            _pipe@7,
            fun(Line) -> prefixed_line(<<"data"/utf8>>, Line) end
        )
    end,
    lists:append(Prefix_lines, Data_lines).

-file("src/ssevents/encoder.gleam", 57).
-spec encode_with_line_ending(ssevents@event:event(), line_ending()) -> binary().
encode_with_line_ending(Event, Line_ending) ->
    Newline = line_ending_to_string(Line_ending),
    Lines = event_lines(Event),
    <<(erlang:list_to_binary(
            gleam@list:map(
                Lines,
                fun(Line) -> <<Line/binary, Newline/binary>> end
            )
        ))/binary,
        Newline/binary>>.

-file("src/ssevents/encoder.gleam", 33).
?DOC(
    " Encode one semantic SSE `Event` to its wire-format `String` (LF\n"
    " line ending).\n"
    "\n"
    " **Determinism invariant** (#72): the encoded bytes depend only on\n"
    " the *value* of the `Event`, not on the builder call sequence used to\n"
    " construct it. For any two structurally equal `Event` values\n"
    " (`Event.from_parts(...)` with the same fields, or any sequence of\n"
    " builder calls that ends in the same field assignment),\n"
    " `encode(a) == encode(b)` byte-for-byte. The same invariant holds\n"
    " across the BEAM and JavaScript targets, so caches, signatures, and\n"
    " content-addressable storage on the wire are stable across runtimes.\n"
).
-spec encode(ssevents@event:event()) -> binary().
encode(Event) ->
    encode_with_line_ending(Event, lf).

-file("src/ssevents/encoder.gleam", 37).
-spec encode_bytes(ssevents@event:event()) -> bitstring().
encode_bytes(Event) ->
    _pipe = encode(Event),
    gleam_stdlib:identity(_pipe).

-file("src/ssevents/encoder.gleam", 66).
-spec encode_item_with_line_ending(ssevents@event:item(), line_ending()) -> binary().
encode_item_with_line_ending(Item, Line_ending) ->
    case Item of
        {event_item, Ev} ->
            encode_with_line_ending(Ev, Line_ending);

        {comment_item, C} ->
            encode_comment_with_line_ending(
                ssevents@event:comment_text_of(C),
                Line_ending
            )
    end.

-file("src/ssevents/encoder.gleam", 41).
-spec encode_item(ssevents@event:item()) -> binary().
encode_item(Item) ->
    encode_item_with_line_ending(Item, lf).

-file("src/ssevents/encoder.gleam", 45).
-spec encode_item_bytes(ssevents@event:item()) -> bitstring().
encode_item_bytes(Item) ->
    _pipe = encode_item(Item),
    gleam_stdlib:identity(_pipe).

-file("src/ssevents/encoder.gleam", 77).
-spec encode_items_with_line_ending(list(ssevents@event:item()), line_ending()) -> binary().
encode_items_with_line_ending(Items, Line_ending) ->
    _pipe = Items,
    _pipe@1 = gleam@list:map(
        _pipe,
        fun(Item) -> encode_item_with_line_ending(Item, Line_ending) end
    ),
    erlang:list_to_binary(_pipe@1).

-file("src/ssevents/encoder.gleam", 49).
-spec encode_items(list(ssevents@event:item())) -> binary().
encode_items(Items) ->
    encode_items_with_line_ending(Items, lf).

-file("src/ssevents/encoder.gleam", 53).
-spec encode_items_bytes(list(ssevents@event:item())) -> bitstring().
encode_items_bytes(Items) ->
    _pipe = encode_items(Items),
    gleam_stdlib:identity(_pipe).