pig

-module(pig@ai@stop_reason).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/pig/ai/stop_reason.gleam").
-export([from_openai/1, to_string/1, from_string/1, to_json/1, decoder/0]).
-export_type([stop_reason/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(
    " A normalized stop reason across all LLM providers.\n"
    "\n"
    " Each provider maps its native finish/stop reason string to one of\n"
    " these variants. This gives the rest of the codebase a stable,\n"
    " provider-agnostic type to pattern-match on.\n"
    "\n"
    " Inspired by pi's `StopReason` type.\n"
).

-type stop_reason() :: stop | length | tool_use | error | {unknown, binary()}.

-file("src/pig/ai/stop_reason.gleam", 37).
?DOC(
    " Map an OpenAI native finish_reason string to a StopReason.\n"
    "\n"
    " | OpenAI value     | StopReason |\n"
    " |------------------|------------|\n"
    " | `\"stop\"`          | `Stop`     |\n"
    " | `\"tool_calls\"`    | `ToolUse`  |\n"
    " | `\"length\"`        | `Length`   |\n"
    " | `\"content_filter\"`| `Error`    |\n"
    " | anything else     | `Unknown`  |\n"
).
-spec from_openai(binary()) -> stop_reason().
from_openai(Raw) ->
    case Raw of
        <<"stop"/utf8>> ->
            stop;

        <<"tool_calls"/utf8>> ->
            tool_use;

        <<"length"/utf8>> ->
            length;

        <<"content_filter"/utf8>> ->
            error;

        Other ->
            {unknown, Other}
    end.

-file("src/pig/ai/stop_reason.gleam", 53).
?DOC(
    " Convert a StopReason to its canonical string representation.\n"
    "\n"
    " Used for JSONL serialization, telemetry, and display.\n"
    " `Unknown` values pass through the original provider string.\n"
).
-spec to_string(stop_reason()) -> binary().
to_string(Reason) ->
    case Reason of
        stop ->
            <<"stop"/utf8>>;

        length ->
            <<"length"/utf8>>;

        tool_use ->
            <<"tool_use"/utf8>>;

        error ->
            <<"error"/utf8>>;

        {unknown, V} ->
            V
    end.

-file("src/pig/ai/stop_reason.gleam", 67).
?DOC(
    " Parse a canonical string back into a StopReason.\n"
    "\n"
    " Inverse of `to_string` for known variants.\n"
    " Unrecognized strings become `Unknown`.\n"
).
-spec from_string(binary()) -> stop_reason().
from_string(S) ->
    case S of
        <<"stop"/utf8>> ->
            stop;

        <<"length"/utf8>> ->
            length;

        <<"tool_use"/utf8>> ->
            tool_use;

        <<"error"/utf8>> ->
            error;

        Other ->
            {unknown, Other}
    end.

-file("src/pig/ai/stop_reason.gleam", 80).
?DOC(" Serialize a StopReason as a JSON string value.\n").
-spec to_json(stop_reason()) -> gleam@json:json().
to_json(Reason) ->
    gleam@json:string(to_string(Reason)).

-file("src/pig/ai/stop_reason.gleam", 85).
?DOC(" Decode a StopReason from a JSON string value.\n").
-spec decoder() -> gleam@dynamic@decode:decoder(stop_reason()).
decoder() ->
    gleam@dynamic@decode:map(
        {decoder, fun gleam@dynamic@decode:decode_string/1},
        fun(Raw) -> from_string(Raw) end
    ).