%% dbshow.sty
%% Copyright 2022 Li Changkai <lichangkai225@qq.com>
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3
% of this license or (at your option) any later version.
% The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.3 or later is part of all distributions of LaTeX
% version 2005/12/01 or later.
%
% This work has the LPPL maintenance status `maintained'.
% 
% The Current Maintainer of this work is Li Changkai.
%
% This work consists of the files dbshow.sty, dbshow-doc.tex.
\def\myfileversion{1.0}
\def\myfiledate{2022/01/02}
\RequirePackage{expl3, xparse}
\RequirePackage[calc]{datetime2}
\ProvidesExplPackage
  {dbshow}
  {\myfiledate}
  {\myfileversion}
  {database to store and show data}

\DTMsetdatestyle{iso}

\msg_new:nnn { dbshow } { non-existent-database } {
  Database~'#1'~does~not~exist~\msg_line_context:.
}

% #1 database
\cs_new:Nn \dbshow_check_database:n {
  \prop_if_exist:cF { g__dbshow_type_map_#1 }
    { \msg_fatal:nnn { dbshow } { non-existent-database } { #1 } }
}

\msg_new:nnn { dbshow } { non-existent-attr } {
  Attribute~'#2'~of~database~'#1'~does~not~exist~\msg_line_context:.
}

% #1 database #2 attr
\cs_new:Nn \dbshow_check_attr:nn {
  \prop_if_in:cnF { g__dbshow_type_map_#1 } { #2 }
    { \msg_fatal:nnnn { dbshow } { non-existent-attr } { #1 } { #2 } }
}

\msg_new:nnn { dbshow } { non-existent-style } {
  Style~'#1'~of~database~'#2'~does~not~exist~\msg_line_context:.
}

% #1 style #2 database
\cs_new:Nn \dbshow_check_style:nn {
  \tl_if_exist:cF { g__dbshow_style_opts_#1_#2 }
    { \msg_warning:nnnn { dbshow } { non-existent-style } { #1 } { #2 } }
}

\msg_new:nnn { dbshow } { non-existent-cond } {
  Conditional~'#2'~of~database~'#1'~does~not~exist~\msg_line_context:.
}

% #1 database #2 cond
\cs_new:Nn \dbshow_check_cond:nnn {
  \tl_if_exist:cF { g__dbshow_filter_attr_#1_#2 }
    { \msg_fatal:nnnn { dbshow } { non-existent-cond } { #1 } { #2 } }
}

\msg_new:nnn { dbshow } { non-existent-filter } {
  Filter~'#2'~of~database~'#1'~does~not~exist~and~is~ignored~\msg_line_context:.
}

\cs_generate_variant:Nn \msg_warning:nnnn { nnnx }
% #1 database #2 filter
\cs_new:Nn \dbshow_check_filter:nn {
  \seq_if_exist:cF { g__dbshow_filter_run_seq_#1_#2 } {
    \str_if_eq:eeF { #2 } { -none- } {
      \msg_warning:nnnx { dbshow } { non-existent-filter } { #1 } { #2 }
    }
  }
}

\msg_new:nnn { dbshow } { non-existent-type } {
  Type~'#1'~does~not~exist,~the~type~of~attribute~should~be~one~of~
  \{date,~str,~tl,~clist,~int,~fp\}~\msg_line_context:.
}

% #1 type
\cs_new:Nn \dbshow_check_type:n {
  \clist_if_in:NnF \dbshow_type_clist { #1 }
    { \msg_fatal:nnn { dbshow } { non-existent-type } { #1 } }
}

% #1 count #2 content
\msg_new:nnn { dbshow } { wrong-seperator } {
  option~sep~should~contain~1~or~3~items~but~only~#1~items~was~given,~
  sep~=~\{#2\}~\msg_line_context:.
}

\msg_new:nnn { dbshow } { unsupported-sort-type } {
  unsupported~sort~type:~'#1'~\msg_line_context:.~The~type~should~be~one~of~
  \{str,~date,~int,~fp\}.
}

\cs_new:Nn \dbshow_sep_error:nn {
  \msg_error:nnnn { dbshow } { wrong-seperator } { #1 } { #2 }
}
\cs_generate_variant:Nn \dbshow_sep_error:nn { xx }

\clist_const:Nn \dbshow_type_clist { date, str, tl, clist, int, fp }

\prop_const_from_keyval:Nn \dbshow_new_cs_map {
  date = str_clear_new:c,
  str = str_clear_new:c,
  tl = tl_gclear_new:c,
  clist = clist_gclear_new:c,
  int = int_gzero_new:c,
  fp = fp_gzero_new:c
}

\prop_const_from_keyval:Nn \dbshow_set_cs_map {
  date = str_gset:cn,
  str = str_gset:cn,
  tl = tl_gset:cn,
  clist = clist_gset:cn,
  int = int_gset:cn,
  fp = fp_gset:cn
}

\prop_const_from_keyval:Nn \dbshow_use_cs_map {
  date = str_use:c,
  str = str_use:c,
  tl = tl_use:c,
  clist = dbshow_clist_use:c,
  int = int_use:c,
  fp = fp_use:c
}

\prop_const_from_keyval:Nn \dbshow_default_value {
  date = \Today,
  str = ,
  tl = ,
  clist = ,
  int = 0,
  fp = 0
}

\newcount\l_dbshow_date_diff

% #1 database #2 attr #3 type #4 default value
\cs_new:Npn \dbshow_process_default_value:w #1|#2=#3|#4\scan_stop {
  \dbshow_check_type:n { #3 }
  \prop_gput:cxx { g__dbshow_type_map_#1 } { #2 } { #3 }
  \prop_gput:cxx { g__dbshow_default_map_#1 } { #2 } { #4 }
}

\cs_new_protected:Nn \dbshow_process_type_map:n {
  \prop_gclear_new:c { g__dbshow_default_map_#1 }
  \prop_map_inline:cn { g__dbshow_type_map_#1 } {
    \str_if_in:nnTF { ##2 } { | }
      { \dbshow_process_default_value:w #1|##1=##2\scan_stop }
      {
        \prop_get:NnN \dbshow_default_value { ##2 } \l_tmp_default
        \dbshow_process_default_value:w #1|##1=##2|\l_tmp_default\scan_stop
      }
  }
}

% #1 database_name, #2 clist, attr=type
\cs_new_protected:Nn \dbshow_database_new:nn {
  \int_gzero_new:c { g__dbshow_counter_#1 }
  \prop_gset_from_keyval:cn { g__dbshow_type_map_#1 } { #2 }
}

% #1 database_name, #2 clist
\cs_new_protected:Nn \dbshow_database_new_append:nn {
  \int_gzero_new:c { g__dbshow_counter_#1 }
  \prop_if_exist:cF { g__dbshow_type_map_#1 }
    { \prop_new:c { g__dbshow_type_map_#1 } }
  \prop_gset_from_keyval:Nn \l_tmpa_prop { #2 }
  \prop_concat:ccc { g__dbshow_type_map_#1 } { g__dbshow_type_map_#1 } { l_tmpa_prop }
}

% #1 database_name, #2 database inherit from #3 clist
\cs_new_protected:Nn \dbshow_database_new_inherit:nnn {
  \dbshow_check_database:n { #2 }
  \str_if_eq:nnTF { #1 } { #2 } {
    \dbshow_database_new_append:nn { #1 } { #3 }
  } {
    \int_gzero_new:c { g__dbshow_counter_#1 }
    \prop_gset_from_keyval:cn { g__dbshow_type_map_#1 } { #3 }
    \prop_concat:ccc { g__dbshow_type_map_#1 } { g__dbshow_type_map_#2 } { g__dbshow_type_map_#1 }
  }
}

% #1 database_name, #2 attr
\cs_new:Nn \dbshow_get_type:nn {
  \prop_item:cn { g__dbshow_type_map_#1 } { #2 }
}

% #1 database_name
\cs_new:Nn \dbshow_get_counter:n {
  \int_use:c { g__dbshow_counter_#1 }
}

% #1 database_name
\cs_new:Nn \dbshow_step_counter:n {
  \int_gincr:c { g__dbshow_counter_#1 }
}

% #1 database #2 attr #3 content
\cs_new:Nn \dbshow_save_data:nnn {
  \dbshow_check_attr:nn { #1 } { #2 }
  \str_set:Nx \l_tmp_type { \dbshow_get_type:nn { #1 } { #2 } }
  \prop_get:NVN \dbshow_new_cs_map \l_tmp_type \l_tmp_cs_new
  \prop_get:NVN \dbshow_set_cs_map \l_tmp_type \l_tmp_cs_set
  \use:c { \l_tmp_cs_new }
    { g__dbshow_data_#1_#2_\dbshow_get_counter:n { #1 } }
  \use:c { \l_tmp_cs_set }
    { g__dbshow_data_#1_#2_\dbshow_get_counter:n { #1 } } { #3 }
}
\cs_generate_variant:Nn \dbshow_save_data:nnn { nnx }

\cs_new:Nn \dbshow_clist_use:N {
  \clist_clear:N \l_tmpa_clist

  \clist_map_inline:Nn #1 {
    \prg_set_conditional:Nnn \dbshow_clist_item_if_empty: { T, F, TF } {
      \tl_if_empty:nTF { ##1 }
        { \prg_return_true: }
        { \prg_return_false: }
    }
    \cs_set_eq:NN \dbClistItemIfEmptyT\dbshow_clist_item_if_empty:T
    \cs_set_eq:NN \dbClistItemIfEmptyF\dbshow_clist_item_if_empty:F
    \cs_set_eq:NN \dbClistItemIfEmptyTF\dbshow_clist_item_if_empty:TF

    \clist_put_right:Nn \l_tmpa_clist {
      \l_style_item_before_code
      ##1
      \l_style_item_after_code
    }
  }

  \tl_clear:N \l_tmpa_tl
  \clist_map_inline:Nn \l_style_sep_clist {
    \tl_put_right:Nn \l_tmpa_tl { { ##1 } }
  }

  \int_set:Nn \l_tmpa_int { \clist_count:N \l_style_sep_clist }
  \int_case:nnF { \l_tmpa_int } {
    { 1 } {
      \exp_after:wN \clist_use:Nn \exp_after:wN \l_tmpa_clist \l_tmpa_tl
    }
    { 3 } {
      \exp_after:wN \clist_use:Nnnn \exp_after:wN \l_tmpa_clist \l_tmpa_tl
    }
  }
  {
    \dbshow_sep_error:xx
      { \int_use:N \l_tmpa_int }
      { \clist_use:Nn \l_style_sep_clist { , } }
  }
}
\cs_generate_variant:Nn \dbshow_clist_use:N { c }

% #1 database #2 attr #3 index
\cs_new:Nn \dbshow_use_data:nnn {
  \str_set:Nx \l_tmp_type { \dbshow_get_type:nn { #1 } { #2 } }
  \prop_get:NVN \dbshow_use_cs_map \l_tmp_type \l_tmp_cs
  \use:c { \l_tmp_cs } { g__dbshow_data_#1_#2_#3 }
}

% #1 database
\cs_new_protected:Nn \dbshow_set_database_keys:n {
  \prop_map_inline:cn { g__dbshow_type_map_#1 } {
    \keys_define:nn { dbshow/database/#1 } {
      ##1 .code:n = \dbshow_save_data:nnn { #1 } { ##1 } { ####1 },
    }
  }
}

% #1 append or not #2 inherit #3 database #4 attrs
\NewDocumentCommand { \dbNewDatabase } { s o m m } {
  \IfNoValueTF { #2 } {
    \IfBooleanTF { #1 }
      { \dbshow_database_new_append:nn { #3 } { #4 } }
      { \dbshow_database_new:nn { #3 } { #4 } }
  } { \dbshow_database_new_inherit:nnn { #3 } { #2 } { #4 } }
  \dbshow_database_new_append:nn { #3 } { id=int }
  \dbshow_process_type_map:n { #3 }
  \dbshow_set_database_keys:n { #3 }
  \dbNewStyle{default}{#3}{}
}

% #1 database #2 attr-content map
\NewDocumentEnvironment { dbitem } { m O{} +b } {
  \dbshow_check_database:n { #1 }
  \dbshow_step_counter:n { #1 }
  \cs_set:Nn \dbshow_set_default:nn {
    \dbshow_save_data:nnx { #1 } { ##1 } {
      \prop_item:cn { g__dbshow_default_map_#1 } { ##1 }
    }
  }
  \prop_map_function:cN { g__dbshow_type_map_#1 } \dbshow_set_default:nn
  \dbshow_save_data:nnx { #1 } { id } { \dbshow_get_counter:n { #1 } }
  \keys_set:nn { dbshow/database/#1 } { #2 }
  % #2 attr #3 content
  \NewDocumentCommand { \dbsave } { m m } {
    \dbshow_save_data:nnn { #1 } { ##1 } { ##2 }
  }
} { #3 }

\cs_new:Nn \dbshow_if_int: {
  \int_compare:nTF { \l_dbshow_rela }
    { \dbshow_set_true: }
    { \dbshow_set_false: }
}

\cs_new:Nn \dbshow_if_fp: {
  \fp_compare:nTF { \l_dbshow_rela }
    { \dbshow_set_true: }
    { \dbshow_set_false: }
}

% star: all in
% no star: one in
\cs_new:Nn \dbshow_if_clist: {
  \bool_if:NTF \l_star_bool { % and
    \dbshow_set_true:
    \exp_args:Nx
    \clist_map_inline:nn { \l_dbshow_rela } {
      \clist_if_in:NnF \dbval { ##1 } {
        \dbshow_set_false:
        \clist_map_break:
      }
    }
  }
  { % or
    \dbshow_set_false:
    \exp_args:Nx
    \clist_map_inline:nn { \l_dbshow_rela } {
      \clist_if_in:NnT \dbval { ##1 } {
        \dbshow_set_true:
        \clist_map_break:
      }
    }
  }
}

% star: match full
% no star: match part
\cs_new:Nn \dbshow_if_str: {
  \bool_if:NT \l_star_bool {
    \tl_put_left:Nn \l_dbshow_rela { \A }
    \tl_put_right:Nn \l_dbshow_rela { \Z }
  }
  \regex_match:VVTF \l_dbshow_rela \dbval
    { \dbshow_set_true: }
    { \dbshow_set_false: }
}
\cs_set_eq:NN \dbshow_if_tl: \dbshow_if_str:

\cs_new:Npn \dbshow_parse_date:w #1|#2\dbshow_stop {
  \clist_set_eq:Nc \l_point_clist { g__review_points_#1 }
  \tl_set:Nn \l_date_tl { #2 }
}

\cs_new:Nn \dbshow_if_date: {
  \bool_if:NTF \l_star_bool {
    \regex_extract_once:nVNF { \A(.*)([!<>=]+)(.*)\Z }
      \l_dbshow_rela \l_tmpa_seq { }
    \exp_args:Nnx \DTMsavedate{day1}{ \seq_item:Nn \l_tmpa_seq { 2 } }
    \tl_set:Nx \l_rela { \seq_item:Nn \l_tmpa_seq { 3 } }
    \exp_args:Nnx \DTMsavedate{day2}{ \seq_item:Nn \l_tmpa_seq { 4 } }
    \DTMsaveddatediff{day1}{day2}{\l_dbshow_date_diff}% specious blank
    \exp_args:NnV \int_compare:nNnTF
      { \the\l_dbshow_date_diff } \l_rela { 0 }
      { \dbshow_set_true: }
      { \dbshow_set_false: }
  }
  {
    \exp_after:wN \dbshow_parse_date:w \l_dbshow_rela\dbshow_stop
    \exp_args:Nnx \DTMsavedate{day1}{ \l_date_tl }
    \exp_args:Nnx \DTMsavedate{day2}{ \dbval }
    \DTMsaveddatediff{day1}{day2}{\l_dbshow_date_diff}% specious blank
    \clist_if_in:NoTF \l_point_clist { \the\l_dbshow_date_diff }
      { \dbshow_set_true: }
      { \dbshow_set_false: }
  }
}

\cs_generate_variant:Nn \prop_get:NnN { cVN }
\prg_generate_conditional_variant:Nnn \regex_extract_once:nnN { nVN } { T, F, TF, p }
\prg_generate_conditional_variant:Nnn \regex_match:nn { VV } { T, F, TF, p }
% #1 database name #2 cond name #3 index
\cs_set:Nn \dbshow_if:nnn {
  \tl_set_eq:Nc \l_dbshow_attr { g__dbshow_filter_attr_#1_#2 }
  \tl_set_eq:Nc \l_dbshow_rela { g__dbshow_filter_rela_#1_#2 }
  \cs_set_eq:Nc \dbval { g__dbshow_data_#1_\l_dbshow_attr _#3 }
  \cs_set:Nn \dbshow_set_true:
    { \bool_gset_true:c { g__dbshow_filter_bool_#1_#2 } }
  \cs_set:Nn \dbshow_set_false:
    { \bool_gset_false:c { g__dbshow_filter_bool_#1_#2 } }
  \prop_get:cVN { g__dbshow_type_map_#1 } \l_dbshow_attr \l_tmp_type
  \bool_set_eq:Nc \l_star_bool { g__dbshow_cond_star_#1_#2 }
  \use:c { dbshow_if_\l_tmp_type : }
}

% 将cond->attr, cond->rela, cond->bool关联起来
% #1 database name #2 cond name #3 attr #4 rela #5 star
\cs_new_protected:Nn \dbshow_new_conditional:nnnnn {
  \tl_gset:cn { g__dbshow_filter_attr_#1_#2 } { #3 }
  \tl_gset:cn { g__dbshow_filter_rela_#1_#2 } { #4 }
  \bool_if_exist:cF { g__dbshow_filter_bool_#1_#2 }
    { \bool_new:c { g__dbshow_filter_bool_#1_#2 } }
  \bool_if_exist:cF { g__dbshow_cond_star_#1_#2 }
    { \bool_new:c { g__dbshow_cond_star_#1_#2 } }
  \IfBooleanTF { #5 }
    { \bool_gset_true:c { g__dbshow_cond_star_#1_#2 } }
    { \bool_gset_false:c { g__dbshow_cond_star_#1_#2 } }
  \cs_gset:cn { g__dbshow_filter_cs_#1_#2:n } {
    \dbshow_if:nnn { #1 } { #2 } { ##1 }
  }
  \seq_gput_right:cn { g__dbshow_cond_list_#1 } { #2 }
}

% 将组合条件cond1, cond2, ..., 替换成cond1->bool, cond2->bool, ...
% #1 database name #2 filter name #3 filters
\cs_new_protected:Nn \dbshow_combine_conditional:nnn {
  \tl_gset_eq:cN { g__dbshow_filter_bool_tl_#1_#2 } \c_true_bool
  \seq_gclear_new:c { g__dbshow_filter_run_seq_#1_#2 }
  \regex_extract_all:nnN { \w+ } { #3 } \l_tmpa_seq
  \seq_map_inline:Nn \l_tmpa_seq {
    % ##1 cond name
    \seq_if_in:cnT { g__dbshow_cond_list_#1 } { ##1 } {
      \seq_gput_right:cn { g__dbshow_filter_run_seq_#1_#2 }
        { g__dbshow_filter_cs_#1_##1:n }
    }
  }
  \tl_set:Nn \l_tmpa_tl { #3 }
  \regex_replace_all:nnN
    { \w+ } { \c{ g__dbshow_filter_bool_#1_\0 } }
    \l_tmpa_tl
  \tl_gset_eq:cN { g__dbshow_filter_bool_tl_#1_#2 } \l_tmpa_tl
}

\cs_generate_variant:Nn \regex_replace_all:nnN { nnc }
% #1 database #2 content
\NewDocumentEnvironment { dbFilters } { m +b } {
  \seq_gclear_new:c { g__dbshow_cond_list_#1 }
  % #1 star #2 cond name #3 attr #4 rela
  \DeclareDocumentCommand { \dbNewConditional } { s m m m } {
    \dbshow_new_conditional:nnnnn
      { #1 } { ##2 } { ##3 } { ##4 } { ##1 }
  }
  % ##1 filter name ##2 filters ##3 info
  \DeclareDocumentCommand { \dbCombineConditionals } { m m O{} } {
    \tl_gset:cn { g__dbshow_filter_info_#1_##1 } { ##3 }
    \dbshow_combine_conditional:nnn { #1 } { ##1 } { ##2 }
  }
  #2
} {  }

% #1 name #2 points
\NewDocumentCommand { \dbNewReviewPoints } { m m } {
  \clist_set:cn { g__review_points_#1 } { #2 }
}

% #1 style name #2 database name #3 attr
\cs_new_protected:Nn \dbshow_new_attr_style:nnn {
  \dbshow_check_attr:nn { #2 } { #3 }
  \keys_define:nn { dbshow/style/#1/#3 } {
    before-code .tl_gset:c = { g__dbshow_style_before_#1_#2_#3 },
    before-code .initial:n = ,
    after-code .tl_gset:c = { g__dbshow_style_after_#1_#2_#3 },
    after-code .initial:n = ,
  }
  \prop_get:cnN { g__dbshow_type_map_#2 } { #3 } \l_tmp_type
  \str_if_eq:eeT { \l_tmp_type } { clist } {
    \keys_define:nn { dbshow/style/#1/#3 } {
      sep .clist_gset:c = { g__dbshow_style_sep_#1_#2_#3 },
      sep .initial:n = { { ,~ } },
      item-before-code .tl_gset:c = { g__dbshow_style_item_before_#1_#2_#3 },
      item-before-code .initial:n = ,
      item-after-code .tl_gset:c = { g__dbshow_style_item_after_#1_#2_#3 },
      item-after-code .initial:n = ,
    }
  }
}

% #1 style name #2 database name
\cs_new_protected:Nn \dbshow_new_database_style:nn {
  \dbshow_check_database:n { #2 }
  \keys_define:nn { dbshow/style/#1 } {
    filter .tl_gset:c = { g__dbshow_filter_#1_#2 },
    filter .initial:n = -none-,
    sort .clist_gset:c = { g__dbshow_sort_#1_#2 },
    before-code .tl_gset:c = { g__dbshow_style_before_#1_#2 },
    before-code .initial:n = ,
    item-code .tl_gset:c = { g__dbshow_style_database_item_#1_#2 },
    item-code .initial:n = ,
    after-code .tl_gset:c = { g__dbshow_style_after_#1_#2 },
    after-code .initial:n = ,
  }
  \prop_map_inline:cn { g__dbshow_type_map_#2 } {
    \dbshow_new_attr_style:nnn { #1 } { #2 } { ##1 }
  }
}

% #1 base style #2 style #3 database #4 opt
\NewDocumentCommand { \dbNewStyle } { o m m +m } {
  \tl_gset:cn { g__dbshow_style_opts_#2_#3 } { #4, }
  \IfValueT { #1 } {
    \tl_gclear:N \g_tmpa_tl
    \clist_map_inline:nn { #1 } {
      \dbshow_check_style:nn { ##1 } { #3 }
      \tl_if_exist:cT { g__dbshow_style_opts_##1_#3 } {
        \tl_gconcat:ccc { g_tmpa_tl }
          { g_tmpa_tl } { g__dbshow_style_opts_##1_#3 }
      }
    }
    \tl_gconcat:ccc { g__dbshow_style_opts_#2_#3 }
      { g_tmpa_tl } { g__dbshow_style_opts_#2_#3 }
  }
  \dbshow_new_database_style:nn { #2 } { #3 }
  \exp_args:Nnv
  \keys_set:nn { dbshow/style/#2 } { g__dbshow_style_opts_#2_#3 }
}

\cs_new:Npn \dbshow_sort_parse_star:w #1* {
  \tl_set:Nx \l_op_same { > }
  \tl_set:Nx \l_op_swap { < }
  \str_set:Nn \l_tmpa_str { #1 }
}

% #1 database #2 index #3 style
\cs_new:Nn \dbshow_sort:nNn {
  \int_set:Nn \l_tmpb_int { \clist_count:c { g__dbshow_sort_#3_#1 } }
  \clist_sort:Nn #2 {
    \int_zero:N \l_tmpa_int
    \cs_set:Nn \dbshow_sort_single: {
      \int_incr:N \l_tmpa_int
      \str_set:Nx \l_tmpa_str
        { \clist_item:cn { g__dbshow_sort_#3_#1 } { \l_tmpa_int } }
      \str_if_in:NnTF \l_tmpa_str { * } {
        \exp_after:wN \dbshow_sort_parse_star:w \l_tmpa_str
      }
      {
        \tl_set:Nx \l_op_same { < }
        \tl_set:Nx \l_op_swap { > }
      }
      \exp_args:NnV \dbshow_check_attr:nn { #1 } \l_tmpa_str

      \cs_set_eq:Nc \l_tmpa_tl { g__dbshow_data_#1_\l_tmpa_str _##1 }
      \cs_set_eq:Nc \l_tmpb_tl { g__dbshow_data_#1_\l_tmpa_str _##2 }

      \prop_get:cVN { g__dbshow_type_map_#1 } \l_tmpa_str \l_tmp_type
      \clist_if_in:nVF { str, int, date, fp  } \l_tmp_type {
        \msg_error:nnx { dbshow } { unsupported-sort-type } { \l_tmp_type }
      }
      \str_if_eq:eeT { \l_tmp_type } { date }
        { \str_set:Nn \l_tmp_type { str } }
      \cs_set_eq:Nc \dbshow_compare { \l_tmp_type _compare:nNnTF }

      \exp_args:NnV
      \dbshow_compare { \l_tmpa_tl } \l_op_same { \l_tmpb_tl }
        { \sort_return_same: }
      {
        \exp_args:NnV
        \dbshow_compare { \l_tmpa_tl } \l_op_swap { \l_tmpb_tl }
          { \sort_return_swapped: }
        {
          \int_compare:nTF { \l_tmpa_int = \l_tmpb_int }
            { \sort_return_same: }
            { \dbshow_sort_single: }
        }
      }
    }
    \dbshow_sort_single:
  }
}

% #1 style #2 database #3 filter
\cs_new_protected:Nn \dbshow_init_iterator:nnn {
  \tl_set:Nn \dbDatabase { #2 }
  \tl_set:Nx \dbFilterName { #3 }
  \tl_set_eq:Nc \dbFilterInfo { g__dbshow_filter_info_#2_#3 }

  \clist_clear_new:N \l_index
  %% run filters
  % ##1 index
  \cs_set:Nn \dbshow_filter:n {
    \seq_if_exist:cTF { g__dbshow_filter_run_seq_#2_#3 } {
      \seq_map_inline:cn { g__dbshow_filter_run_seq_#2_#3 } {
        \use:c { ####1 } { ##1 }
      }
      \exp_args:Nv
      \bool_if:nT { g__dbshow_filter_bool_tl_#2_#3 }
        { \clist_put_right:Nn \l_index { ##1 } }
    } { \clist_put_right:Nn \l_index { ##1 } }
  }
  \int_step_function:nN { \dbshow_get_counter:n { #2 } } \dbshow_filter:n
  \clist_if_empty:cF { g__dbshow_sort_#1_#2 }
    { \dbshow_sort:nNn { #2 } \l_index { #1 } }

  % ##1 index
  \cs_set:Nn \dbshow_iter:n {
    % ####1 attr
    \cs_set:Npn \dbuse ####1 {
      \dbshow_check_attr:nn { #2 } { ####1 }
      \clist_set_eq:Nc \l_style_sep_clist
        { g__dbshow_style_sep_#1_#2_####1 }
      \tl_set_eq:Nc \l_style_item_before_code
        { g__dbshow_style_item_before_#1_#2_####1 }
      \tl_set_eq:Nc \l_style_item_after_code
        { g__dbshow_style_item_after_#1_#2_####1 }
      \tl_set:Nn \dbIndex { ##1 }

      \prop_get:cnN { g__dbshow_type_map_#2 } { ####1 } \l_tmp_type
      % \tl_show:N \l_tmp_type
      \str_if_eq:eeT { \l_tmp_type } { date }
        { \tl_set:Nn \l_tmp_type { str } }
      \prg_set_conditional:Nnn \dbshow_item_if_empty: { T, F, TF } {
        \use:c { \l_tmp_type _if_empty:cTF }
          { g__dbshow_data_#2_####1_##1 }
          { \prg_return_true: }
          { \prg_return_false: }
      }
      \cs_set_eq:NN \dbItemIfEmptyT\dbshow_item_if_empty:T
      \cs_set_eq:NN \dbItemIfEmptyF\dbshow_item_if_empty:F
      \cs_set_eq:NN \dbItemIfEmptyTF\dbshow_item_if_empty:TF

      \tl_use:c { g__dbshow_style_before_#1_#2_####1 }
      \dbshow_use_data:nnn { #2 } { ####1 } { ##1 }
      \tl_use:c { g__dbshow_style_after_#1_#2_####1 }
    }
    \tl_use:c { g__dbshow_style_database_item_#1_#2 }
  }
  \prg_set_conditional:Nnn \dbshow_if_empty: { T, F, TF } {
    \clist_if_empty:NTF \l_index
      { \prg_return_true: }
      { \prg_return_false: }
  }
  \cs_set_eq:NN \dbIfEmptyT\dbshow_if_empty:T
  \cs_set_eq:NN \dbIfEmptyF\dbshow_if_empty:F
  \cs_set_eq:NN \dbIfEmptyTF\dbshow_if_empty:TF

  \tl_use:c { g__dbshow_style_before_#1_#2 }
  \clist_map_function:NN \l_index \dbshow_iter:n
  \tl_use:c { g__dbshow_style_after_#1_#2 }
}

% #1 style #2 database
\NewDocumentCommand { \dbshow } { m m } {
  \dbshow_check_database:n { #2 }
  \tl_set_eq:Nc \l_dbshow_filter { g__dbshow_filter_#1_#2 }
  \dbshow_check_filter:nn  { #2 } { \l_dbshow_filter }
  \dbshow_init_iterator:nnn { #1 } { #2 } { \l_dbshow_filter }
}

\endinput