% Copyright 2026 Open-Guji (https://github.com/open-guji)
%
% Licensed under the Apache License, Version 2.0 (the "License");
% you may not use this file except in compliance with the License.
% You may obtain a copy of the License at
%
%     http://www.apache.org/licenses/LICENSE-2.0
%
% Unless required by applicable law or agreed to in writing, software
% distributed under the License is distributed on an "AS IS" BASIS,
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
% See the License for the specific language governing permissions and
% limitations under the License.

% luatex-cn-guji-titlepage.sty
% Book title page (书名页) support for vertical typesetting
% Wraps content in SinglePage with border options.
% Columns use \Column (列) with width parameter for flexible layout.

\RequirePackage{expl3}
\RequirePackage{xparse}
\RequirePackage{environ}
\ProvidesExplPackage {guji/luatex-cn-guji-titlepage} {2026/02/18} {0.3.0} {Book Title Page Support}

% ============================================================================
% Variables
% ============================================================================

\bool_new:N \l__luatexcn_titlepage_border_bool
\bool_new:N \l__luatexcn_titlepage_outer_border_bool
\tl_new:N \l__luatexcn_titlepage_body_tl

% ============================================================================
% Key-value Configuration
% ============================================================================

\keys_define:nn { luatexcn / titlepage }
  {
    border .bool_set:N = \l__luatexcn_titlepage_border_bool,
    border .initial:n = false,
    outer-border .bool_set:N = \l__luatexcn_titlepage_outer_border_bool,
    outer-border .initial:n = false,
  }

% ============================================================================
% TitlePage Environment (uses \NewEnviron to capture BODY)
% Usage:
%   \begin{书名页}[border=true, outer-border=true]
%     \行[width=2cm, align=top]{光緒九年仲春}
%     \行[width=6cm, align=center]{\TextBox[font-size=32pt]{童蒙必讀書}}
%     \行[width=2cm, align=bottom]{武昌書局校刊}
%   \end{书名页}
% ============================================================================
\NewEnviron{TitlePage}[1][]{%
  % Save BODY to a unique name before nested \NewEnviron environments
  % (SinglePage uses \NewEnviron, which redefines \BODY)
  \tl_set_eq:NN \l__luatexcn_titlepage_body_tl \BODY
  % Initialize col_widths array (columns will register their widths here)
  \lua_now:n { require('core.luatex-cn-core-content').init_col_widths() }%
  % Apply options
  \keys_set:nn { luatexcn / titlepage } { #1 }%
  % Wrap in SinglePage + Content
  \begin{单页}
    \bool_if:NT \l__luatexcn_titlepage_border_bool
      { \keys_set:nn { luatexcn / content } { border = true } }
    \bool_if:NT \l__luatexcn_titlepage_outer_border_bool
      { \keys_set:nn { luatexcn / content } { outer-border = true } }
    \begin{正文}
      \l__luatexcn_titlepage_body_tl
    \end{正文}
    % Set page-columns from the number of registered column widths
    \lua_now:n { require('core.luatex-cn-core-content').sync_page_columns_from_col_widths() }
  \end{单页}
  % Clear col_widths after page is shipped (clearpage runs inside 单页)
  \lua_now:n { require('core.luatex-cn-core-content').clear_col_widths() }%
}

% ============================================================================
% CJK Key Aliases (中文键值别名)
% ============================================================================
\keys_define:nn { luatexcn / titlepage }
  {
    边框 .bool_set:N = \l__luatexcn_titlepage_border_bool,
    邊框 .bool_set:N = \l__luatexcn_titlepage_border_bool,
    外框 .bool_set:N = \l__luatexcn_titlepage_outer_border_bool,
  }

% ============================================================================
% CJK Aliases (中文别名)
% ============================================================================
% Simplified Chinese / 简体
\NewEnvironmentCopy{书名页}{TitlePage}
% Traditional Chinese / 繁体
\NewEnvironmentCopy{書名頁}{TitlePage}

\endinput