-module(hanguleam@editor).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).
-define(FILEPATH, "src/hanguleam/editor.gleam").
-export([remove_last_character/1]).

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

-file("src/hanguleam/editor.gleam", 48).
-spec disassemble_complete_character(binary()) -> {ok,
        hanguleam@types:hangul_syllable()} |
    {error, nil}.
disassemble_complete_character(Char) ->
    case hanguleam@internal@character:get_character_type(Char) of
        empty ->
            {error, nil};

        non_hangul ->
            {error, nil};

        {incomplete_hangul, _} ->
            {error, nil};

        {complete_hangul, Char@1} ->
            {ok, Char@1}
    end.

-file("src/hanguleam/editor.gleam", 57).
-spec reduce_syllable(hanguleam@types:hangul_character()) -> binary().
reduce_syllable(Disassembled) ->
    case Disassembled of
        {simple_c_v, {choseong, Cho}, _} ->
            Cho;

        {compound_c_v, {choseong, Cho@1}, {jungseong, Jung}} ->
            hanguleam@composer:combine_character_unsafe(
                Cho@1,
                gleam@string:slice(Jung, 0, 1),
                <<""/utf8>>
            );

        {simple_c_v_c, {choseong, Cho@2}, {jungseong, Jung@1}, {jongseong, _}} ->
            hanguleam@composer:combine_character_unsafe(
                Cho@2,
                Jung@1,
                <<""/utf8>>
            );

        {compound_c_v_c, {choseong, Cho@3}, {jungseong, Jung@2}, {jongseong, _}} ->
            hanguleam@composer:combine_character_unsafe(
                Cho@3,
                Jung@2,
                <<""/utf8>>
            );

        {complex_batchim,
            {choseong, Cho@4},
            {jungseong, Jung@3},
            {jongseong, Jong}} ->
            hanguleam@composer:combine_character_unsafe(
                Cho@4,
                Jung@3,
                gleam@string:slice(Jong, 0, 1)
            );

        {compound_complex_batchim,
            {choseong, Cho@5},
            {jungseong, Jung@4},
            {jongseong, Jong@1}} ->
            hanguleam@composer:combine_character_unsafe(
                Cho@5,
                Jung@4,
                gleam@string:slice(Jong@1, 0, 1)
            )
    end.

-file("src/hanguleam/editor.gleam", 37).
-spec remove_character_component(binary(), binary()) -> binary().
remove_character_component(Text, Last_char) ->
    Prefix = gleam@string:drop_end(Text, 1),
    _pipe = Last_char,
    _pipe@1 = disassemble_complete_character(_pipe),
    _pipe@2 = gleam@result:map(
        _pipe@1,
        fun hanguleam@internal@character:parse_hangul_syllable/1
    ),
    _pipe@3 = gleam@result:map(_pipe@2, fun reduce_syllable/1),
    _pipe@4 = gleam@result:unwrap(_pipe@3, <<""/utf8>>),
    gleam@string:append(Prefix, _pipe@4).

-file("src/hanguleam/editor.gleam", 30).
?DOC(
    " Removes the last character component from a Korean string, intelligently handling Korean syllable decomposition.\n"
    " This function removes the last \"logical\" character unit from the input string. For complete Korean syllables,\n"
    " it removes the last jamo component (consonant or vowel part) rather than the entire character, allowing for\n"
    " fine-grained text editing that matches Korean input method behavior.\n"
    "\n"
    " ## Examples\n"
    "\n"
    " ```gleam\n"
    " remove_last_character(\"안녕하세요 값\")\n"
    " // -> \"안녕하세요 갑\"\n"
    "\n"
    " remove_last_character(\"전화\")\n"
    " // -> \"전호\"\n"
    "\n"
    " remove_last_character(\"Hello\")\n"
    " // -> \"Hell\"\n"
    "\n"
    " remove_last_character(\"\")\n"
    " // -> \"\"\n"
    " ```\n"
).
-spec remove_last_character(binary()) -> binary().
remove_last_character(Text) ->
    case gleam@string:last(Text) of
        {error, _} ->
            Text;

        {ok, Last_char} ->
            remove_character_component(Text, Last_char)
    end.