-module(coinglecko@request).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/coinglecko/request.gleam").
-export([optional_params/1, flexible_float/0, optional_flexible_float/0, bool_to_string/1, build_get_request/3, handle_response/2, send_and_decode/3]).
-export_type([query_param/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(
    " Request building and response handling for the CoinGecko API.\n"
    "\n"
    " This module is transport-agnostic. It builds HTTP requests and decodes\n"
    " responses, but does NOT perform HTTP calls. Users provide their own\n"
    " sender function (e.g., httpc.send on Erlang, fetch.send on JavaScript).\n"
).

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

-file("src/coinglecko/request.gleam", 38).
?DOC(
    " Convert a list of optional query params to actual params,\n"
    " filtering out None values.\n"
).
-spec optional_params(list({binary(), gleam@option:option(binary())})) -> list(query_param()).
optional_params(Params) ->
    gleam@list:filter_map(Params, fun(Param) -> case erlang:element(2, Param) of
                {some, Value} ->
                    {ok, {query_param, erlang:element(1, Param), Value}};

                none ->
                    {error, nil}
            end end).

-file("src/coinglecko/request.gleam", 51).
?DOC(
    " A decoder that accepts both floats and ints, converting ints to floats.\n"
    " CoinGecko sometimes returns integers where floats are expected.\n"
).
-spec flexible_float() -> gleam@dynamic@decode:decoder(float()).
flexible_float() ->
    gleam@dynamic@decode:one_of(
        {decoder, fun gleam@dynamic@decode:decode_float/1},
        [begin
                _pipe = {decoder, fun gleam@dynamic@decode:decode_int/1},
                gleam@dynamic@decode:map(_pipe, fun erlang:float/1)
            end]
    ).

-file("src/coinglecko/request.gleam", 56).
?DOC(" A decoder for optional flexible floats (handles null, missing, int, or float).\n").
-spec optional_flexible_float() -> gleam@dynamic@decode:decoder(gleam@option:option(float())).
optional_flexible_float() ->
    gleam@dynamic@decode:optional(flexible_float()).

-file("src/coinglecko/request.gleam", 61).
?DOC(" Convert a Bool to a lowercase string for query parameters.\n").
-spec bool_to_string(boolean()) -> binary().
bool_to_string(B) ->
    case B of
        true ->
            <<"true"/utf8>>;

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

-file("src/coinglecko/request.gleam", 70).
?DOC(
    " Build a GET request for the CoinGecko API.\n"
    " Returns a fully configured Request with auth headers and query params.\n"
).
-spec build_get_request(
    coinglecko@client:client(),
    binary(),
    list(query_param())
) -> {ok, gleam@http@request:request(binary())} |
    {error, coinglecko@error:coin_gecko_error()}.
build_get_request(Client, Path, Query) ->
    Url = <<(coinglecko@client:base_url(Client))/binary, Path/binary>>,
    Query_pairs = gleam@list:map(
        Query,
        fun(Q) -> {erlang:element(2, Q), erlang:element(3, Q)} end
    ),
    gleam@result:'try'(
        begin
            _pipe = gleam@http@request:to(Url),
            gleam@result:map_error(
                _pipe,
                fun(_) ->
                    {request_error,
                        <<"Failed to construct request for: "/utf8, Url/binary>>}
                end
            )
        end,
        fun(Req) ->
            Auth_header = case coinglecko@client:api_tier(Client) of
                demo ->
                    <<"x-cg-demo-api-key"/utf8>>;

                pro ->
                    <<"x-cg-pro-api-key"/utf8>>
            end,
            {ok,
                begin
                    _pipe@1 = Req,
                    _pipe@2 = gleam@http@request:set_query(_pipe@1, Query_pairs),
                    _pipe@3 = gleam@http@request:prepend_header(
                        _pipe@2,
                        Auth_header,
                        coinglecko@client:api_key(Client)
                    ),
                    gleam@http@request:prepend_header(
                        _pipe@3,
                        <<"accept"/utf8>>,
                        <<"application/json"/utf8>>
                    )
                end}
        end
    ).

-file("src/coinglecko/request.gleam", 100).
?DOC(
    " Handle an HTTP response: check status code and decode JSON body.\n"
    " On non-200 status, tries to parse CoinGecko's error JSON for a message.\n"
).
-spec handle_response(
    gleam@http@response:response(binary()),
    gleam@dynamic@decode:decoder(ESL)
) -> {ok, ESL} | {error, coinglecko@error:coin_gecko_error()}.
handle_response(Resp, Decoder) ->
    case erlang:element(2, Resp) of
        200 ->
            _pipe = gleam@json:parse(erlang:element(4, Resp), Decoder),
            gleam@result:map_error(
                _pipe,
                fun(Field@0) -> {decode_error, Field@0} end
            );

        Status ->
            {error,
                {api_error,
                    Status,
                    erlang:element(4, Resp),
                    coinglecko@error:parse_error_body(erlang:element(4, Resp))}}
    end.

-file("src/coinglecko/request.gleam", 119).
?DOC(
    " Send a request using the provided sender and decode the response.\n"
    " Convenience function that chains build -> send -> decode.\n"
).
-spec send_and_decode(
    gleam@http@request:request(binary()),
    gleam@dynamic@decode:decoder(ESQ),
    fun((gleam@http@request:request(binary())) -> {ok,
            gleam@http@response:response(binary())} |
        {error, binary()})
) -> {ok, ESQ} | {error, coinglecko@error:coin_gecko_error()}.
send_and_decode(Req, Decoder, Sender) ->
    gleam@result:'try'(
        begin
            _pipe = Sender(Req),
            gleam@result:map_error(
                _pipe,
                fun(Field@0) -> {http_error, Field@0} end
            )
        end,
        fun(Resp) -> handle_response(Resp, Decoder) end
    ).