-module(l4u@bif_template).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([bif_template_def/0]).

-spec bif_template_compile(list(l4u@l4u_type:expr()), l4u@l4u_type:env()) -> l4u@l4u_type:expr().
bif_template_compile(Exprs, Env) ->
    [{string, Template}] = case Exprs of
        [{string, _}] -> Exprs;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"l4u/bif_template"/utf8>>,
                        function => <<"bif_template_compile"/utf8>>,
                        line => 36})
    end,
    Compiled = l4u@bbmustache_js:compile(Template),
    {with_env,
        {native_value, <<"bbmustache"/utf8>>, gleam@dynamic:from(Compiled)},
        Env}.

-spec assoc_list_to_plist(
    list(l4u@l4u_type:expr()),
    list({l4u@l4u_type:expr(), l4u@l4u_type:expr()})
) -> list({l4u@l4u_type:expr(), l4u@l4u_type:expr()}).
assoc_list_to_plist(Assoc_list, Acc) ->
    case Assoc_list of
        [] ->
            Acc;

        [Key, Value | Rest] ->
            assoc_list_to_plist(Rest, [{Key, Value} | Acc]);

        Unhandable ->
            l4u@sys_bridge_ffi:throw_err(
                <<"assoc_list_to_plist: unhandable pattern"/utf8>>
            ),
            []
    end.

-spec to_mustache_param(list(l4u@l4u_type:expr())) -> list({binary(),
    gleam@bbmustache:argument()}).
to_mustache_param(Assoc_list) ->
    Plist = assoc_list_to_plist(Assoc_list, []),
    gleam@list:map(
        Plist,
        fun(Item) ->
            {Key, Value} = case Item of
                {_, _} -> Item;
                _assert_fail ->
                    erlang:error(#{gleam_error => let_assert,
                                message => <<"Assertion pattern match failed"/utf8>>,
                                value => _assert_fail,
                                module => <<"l4u/bif_template"/utf8>>,
                                function => <<"to_mustache_param"/utf8>>,
                                line => 61})
            end,
            {l4u@l4u_core:pstr(Key),
                l4u@bbmustache_js:string(l4u@l4u_core:pstr(Value))}
        end
    ).

-spec bif_template_render(list(l4u@l4u_type:expr()), l4u@l4u_type:env()) -> l4u@l4u_type:expr().
bif_template_render(Exprs, Env) ->
    [{native_value, <<"bbmustache"/utf8>>, Compiled}, {dict, Assoc_list}] = case Exprs of
        [{native_value, <<"bbmustache"/utf8>>, _}, {dict, _}] -> Exprs;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"l4u/bif_template"/utf8>>,
                        function => <<"bif_template_render"/utf8>>,
                        line => 68})
    end,
    Rendered = l4u@bbmustache_js:render(
        l4u_ffi:unsafe_corece(Compiled),
        to_mustache_param(Assoc_list)
    ),
    {with_env, {string, Rendered}, Env}.

-spec bif_template_def() -> list({binary(), l4u@l4u_type:expr()}).
bif_template_def() ->
    Bif = fun(Name, F) -> {Name, {bif, l4u@l4u_core:description(Name), F}} end,
    Bsf = fun(Name@1, F@1) ->
        {Name@1, {bispform, l4u@l4u_core:description(Name@1), F@1}}
    end,
    [Bif(<<"template-compile"/utf8>>, fun bif_template_compile/2),
        Bif(<<"template-render"/utf8>>, fun bif_template_render/2)].