-module(webls@sitemap).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([to_string/1, item/1, with_frequency/2, with_priority/2, with_modified/2]).
-export_type([sitemap/0, sitemap_item/0, change_frequency/0]).

-type sitemap() :: {sitemap,
        binary(),
        gleam@option:option(birl:time()),
        list(sitemap_item())}.

-type sitemap_item() :: {sitemap_item,
        binary(),
        gleam@option:option(birl:time()),
        gleam@option:option(change_frequency()),
        gleam@option:option(float())}.

-type change_frequency() :: always |
    hourly |
    daily |
    weekly |
    monthly |
    yearly |
    never.

-spec sitemap_item_to_string(sitemap_item()) -> binary().
sitemap_item_to_string(Item) ->
    <<<<<<<<<<<<<<"<url>\n"/utf8, "<loc>"/utf8>>/binary,
                            (erlang:element(2, Item))/binary>>/binary,
                        "</loc>\n"/utf8>>/binary,
                    (case erlang:element(3, Item) of
                        {some, Date} ->
                            <<<<"<lastmod>"/utf8,
                                    (begin
                                        _pipe = Date,
                                        birl:to_iso8601(_pipe)
                                    end)/binary>>/binary,
                                "</lastmod>\n"/utf8>>;

                        _ ->
                            <<""/utf8>>
                    end)/binary>>/binary,
                (case erlang:element(4, Item) of
                    {some, Freq} ->
                        <<<<"<changefreq>"/utf8, (case Freq of
                                    always ->
                                        <<"always"/utf8>>;

                                    hourly ->
                                        <<"hourly"/utf8>>;

                                    daily ->
                                        <<"daily"/utf8>>;

                                    weekly ->
                                        <<"weekly"/utf8>>;

                                    monthly ->
                                        <<"monthly"/utf8>>;

                                    yearly ->
                                        <<"yearly"/utf8>>;

                                    never ->
                                        <<"never"/utf8>>
                                end)/binary>>/binary, "</changefreq>\n"/utf8>>;

                    _ ->
                        <<""/utf8>>
                end)/binary>>/binary,
            (case erlang:element(5, Item) of
                {some, Priority} ->
                    <<<<"<priority>"/utf8,
                            (begin
                                _pipe@1 = Priority,
                                _pipe@2 = gleam@float:clamp(_pipe@1, +0.0, 1.0),
                                gleam@float:to_string(_pipe@2)
                            end)/binary>>/binary,
                        "</priority>\n"/utf8>>;

                _ ->
                    <<""/utf8>>
            end)/binary>>/binary,
        "</url>"/utf8>>.

-spec to_string(sitemap()) -> binary().
to_string(Sitemap) ->
    Channel_content = begin
        _pipe = erlang:element(4, Sitemap),
        _pipe@2 = gleam@list:map(_pipe, fun(Item) -> _pipe@1 = Item,
                sitemap_item_to_string(_pipe@1) end),
        _pipe@3 = gleam@list:reduce(
            _pipe@2,
            fun(Acc, Item_string) ->
                <<<<Acc/binary, "\n"/utf8>>/binary, Item_string/binary>>
            end
        ),
        gleam@result:unwrap(_pipe@3, <<""/utf8>>)
    end,
    <<<<"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n"/utf8,
            Channel_content/binary>>/binary,
        "\n</urlset>"/utf8>>.

-spec item(binary()) -> sitemap_item().
item(Loc) ->
    {sitemap_item, Loc, none, none, none}.

-spec with_frequency(sitemap_item(), change_frequency()) -> sitemap_item().
with_frequency(Item, Frequency) ->
    erlang:setelement(4, Item, {some, Frequency}).

-spec with_priority(sitemap_item(), float()) -> sitemap_item().
with_priority(Item, Priority) ->
    erlang:setelement(5, Item, {some, Priority}).

-spec with_modified(sitemap_item(), birl:time()) -> sitemap_item().
with_modified(Item, Modified) ->
    erlang:setelement(3, Item, {some, Modified}).