(* This file is part of the Catala compiler, a specification language for tax
   and social benefits computation rules. Copyright (C) 2020 Inria,
   contributors: Denis Merigoux <denis.merigoux@inria.fr>, Emile Rolley
   <emile.rolley@tuta.io>

   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. *)

(** This modules weaves the source code and the legislative text together into a
    document that law professionals can understand. *)

open Catala_utils
open Literate_common
module A = Surface.Ast
module C = Global

(** {1 Helpers} *)

let lines_of_code = ref 0

let update_lines_of_code c =
  lines_of_code :=
    !lines_of_code
    + Pos.get_end_line (Mark.get c)
    - Pos.get_start_line (Mark.get c)
    - 1

(** Escapes various LaTeX-sensitive characters *)
let pre_latexify (s : string) : string =
  (* Then we send to pandoc, to ensure the markdown features used in the
     original document are correctly printed! *)
  String.trim (run_pandoc s `Latex)

(** Usage: [wrap_latex source_files custom_pygments language fmt wrapped]

    Prints an LaTeX complete documùent structure around the [wrapped] content. *)
let wrap_latex
    (source_files : string list)
    (language : C.backend_lang)
    (fmt : Format.formatter)
    (wrapped : Format.formatter -> unit) =
  Format.fprintf fmt
    {latex|\documentclass[%s, 11pt, a4paper]{article}

\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{amssymb}
\usepackage{babel}
\usepackage{fontspec}
\usepackage[hidelinks]{hyperref}
%s
\usepackage{fancyvrb,fvextra}
\usepackage{color}
\usepackage{longtable}
\usepackage{booktabs,tabularx}
\usepackage{newunicodechar}
\usepackage{textcomp}
\usepackage[dvipsnames]{xcolor}
\usepackage[left=2cm,right=2cm,top=3cm,bottom=3cm,headheight=2cm]{geometry}
\usepackage[many]{tcolorbox}

\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\fancyhead[C]{\leftmark}
\fancyfoot[C]{\thepage}
\renewcommand{\headrulewidth}{0.5pt}
\renewcommand{\footrulewidth}{0.5pt}
\usepackage{titlesec}
\titleclass{\subsubsubsection}{straight}[\subsection]
\newcounter{subsubsubsection}[subsubsection]
\renewcommand\thesubsubsubsection{\thesubsubsection.\arabic{subsubsubsection}}
\titleformat{\subsubsubsection}{\normalfont\normalsize\bfseries}{\thesubsubsubsection}{1em}{}
\titlespacing*{\subsubsubsection}{0pt}{3.25ex plus 1ex minus .2ex}{1.5ex plus .2ex}
\titleclass{\subsubsubsubsection}{straight}[\subsubsection]
\newcounter{subsubsubsubsection}[subsubsubsection]
\renewcommand\thesubsubsubsubsection{\thesubsubsubsection.\arabic{subsubsubsubsection}}
\titleformat{\subsubsubsubsection}{\normalfont\normalsize\bfseries}{\thesubsubsubsubsection}{0.75em}{}
\titlespacing*{\subsubsubsubsection}{0pt}{2.75ex plus 1ex minus .2ex}{1.25ex plus .2ex}
\titleclass{\subsubsubsubsubsection}{straight}[\subsubsubsection]
\newcounter{subsubsubsubsubsection}[subsubsubsubsection]
\renewcommand\thesubsubsubsubsubsection{\thesubsubsubsubsection.\arabic{subsubsubsubsubsection}}
\titleformat{\subsubsubsubsubsection}{\normalfont\normalsize\bfseries}{\thesubsubsubsubsubsection}{0.7em}{}
\titlespacing*{\subsubsubsubsubsection}{0pt}{2.5ex plus 1ex minus .2ex}{1.1ex plus .2ex}
\titleclass{\subsubsubsubsubsubsection}{straight}[\subsubsubsubsection]
\newcounter{subsubsubsubsubsubsection}[subsubsubsubsubsection]
\renewcommand\thesubsubsubsubsubsubsection{\thesubsubsubsubsubsection.\arabic{subsubsubsubsubsubsection}}
\titleformat{\subsubsubsubsubsubsection}{\normalfont\normalsize\bfseries}{\thesubsubsubsubsubsubsection}{0.6em}{}
\titlespacing*{\subsubsubsubsubsubsection}{0pt}{2.25ex plus 1ex minus .2ex}{1ex plus .2ex}
\makeatletter
\def\toclevel@subsubsubsection{4}
\def\toclevel@subsubsubsubsection{5}
\def\toclevel@subsubsubsubsubsection{6}
\def\toclevel@subsubsubsubsubsubsection{7}
\def\toclevel@paragraph{8}
\def\toclevel@subparagraph{9}
\def\l@subsection{\@dottedtocline{1}{1em}{0.5em}}
\def\l@subsubsection{\@dottedtocline{2}{2em}{1em}}
\def\l@subsubsubsection{\@dottedtocline{3}{3em}{1.5em}}
\def\l@subsubsubsubsection{\@dottedtocline{5}{4em}{2em}}
\def\l@subsubsubsubsubsection{\@dottedtocline{6}{5em}{2.5em}}
\def\l@subsubsubsubsubsubsection{\@dottedtocline{7}{6em}{3em}}
\def\l@paragraph{\@dottedtocline{8}{7em}{3.5em}}
\def\l@subparagraph{\@dottedtocline{9}{8em}{4em}}
\makeatother
\setcounter{secnumdepth}{0}
\setcounter{tocdepth}{9}
\newunicodechar{÷}{$\div$}
\newunicodechar{×}{$\times$}
\newunicodechar{≤}{$\leqslant$}
\newunicodechar{≥}{$\geqslant$}
\newunicodechar{→}{$\rightarrow$}
\newunicodechar{≠}{$\neq$}

%s

\newcommand*\FancyVerbStartString{\PY{l+s}{```catala}}
\newcommand*\FancyVerbStopString{\PY{l+s}{```}}

%% We have to do that to enable line breaks in pygmentize outputs:
\let\oldPY\PY
\renewcommand{\PY}[2]{%%
  \oldPY{#1}{\FancyVerbBreakStart{}#2\FancyVerbBreakStop{}}}

\fvset{
numbers=left,
frame=lines,
framesep=3mm,
breaklines,
breakanywhere,
rulecolor=\color{gray!70},
firstnumber=last,
codes={\catcode`\$=3\catcode`\^=7}
}
\newcommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}

\title{
%s\\
%s Catala version %s
}
\begin{document}
\maketitle

%s

%s :
\begin{itemize}%s\end{itemize}

\clearpage
\tableofcontents

\[\star\star\star\]
\clearpage
|latex}
    (match language with Fr -> "french" | En -> "english" | Pl -> "polish")
    (match language with Fr -> "\\setmainfont{Marianne}" | _ -> "")
    (* for France, we use the official font of the French state design system
       https://gouvfr.atlassian.net/wiki/spaces/DB/pages/223019527/Typographie+-+Typography *)
    (call_pygmentize ["-f"; "latex"; "-S"; "default"])
    (literal_title language)
    (literal_generated_by language)
    Cli.version
    (pre_latexify (literal_disclaimer_and_link language))
    (literal_source_files language)
    (String.concat
       ((match language with Fr -> " ;" | En -> ";" | Pl -> ";") ^ "\n")
       (List.map
          (fun filename ->
            let mtime = (Unix.stat filename).Unix.st_mtime in
            let ltime = Unix.localtime mtime in
            let ftime =
              Printf.sprintf "%d-%02d-%02d %d:%02d"
                (1900 + ltime.Unix.tm_year)
                (ltime.Unix.tm_mon + 1) ltime.Unix.tm_mday ltime.Unix.tm_hour
                ltime.Unix.tm_min
            in
            Printf.sprintf "\\item\\texttt{%s}, %s %s"
              (pre_latexify (Filename.basename filename))
              (literal_last_modification language)
              ftime)
          source_files)
    ^ ".");
  wrapped fmt;
  Format.fprintf fmt "\n\n\\end{document}"

(** {1 Weaving} *)

let code_block ~meta lang fmt (code, pos) =
  (* Pygments does'nt allow to specify multiple 'verboptions' (escaping bug ?)
     so we call it with "nowrap" and write the FancyVrb wrapper ourselves. *)
  let pygmentized_code =
    let contents = String.concat "" ["```catala\n"; code; "```"] in
    let output =
      File.with_temp_file "catala_latex_pygments" "in" ~contents
      @@ fun temp_file_in ->
      call_pygmentize ~lang ["-f"; "latex"; "-O"; "\"nowrap\""; temp_file_in]
    in
    (* somehow even with the "nowrap" option on [pygmentize] still emits a
       wrapping [Verbatim] env. So we remove it with regexp finding. *)
    let env_rex =
      Re.compile
      @@ Re.seq
           [
             Re.char '\\';
             Re.alt [Re.str "begin"; Re.str "end"];
             Re.str "{Verbatim}";
             Re.opt
               (Re.seq
                  [
                    Re.char '[';
                    Re.rep (Re.diff Re.any (Re.char ']'));
                    Re.char ']';
                  ]);
             Re.char '\n';
           ]
    in
    Re.replace_string env_rex ~by:"" output
  in
  Format.fprintf fmt
    {latex|\begin{Verbatim}[commandchars=\\\{\},numbers=left,firstnumber=%d,stepnumber=1,label={\hspace*{\fill}\texttt{%s}}%s]|latex}
    (Pos.get_start_line pos + 1)
    (pre_latexify (Filename.basename (Pos.get_file pos)))
    (if meta then ",numbersep=9mm" else "");
  Format.pp_print_newline fmt ();
  Format.pp_print_string fmt pygmentized_code;
  Format.pp_print_string fmt "\\end{Verbatim}\n"

let rec law_structure_to_latex
    (language : C.backend_lang)
    (print_only_law : bool)
    (fmt : Format.formatter)
    (i : A.law_structure) : unit =
  match i with
  | A.LawHeading (heading, children) ->
    Format.fprintf fmt "\\%s{%s}\n\n"
      (match heading.law_heading_precedence with
      | 0 -> "section"
      | 1 -> "subsection"
      | 2 -> "subsubsection"
      | 3 -> "subsubsubsection"
      | 4 -> "subsubsubsubsection"
      | 5 -> "subsubsubsubsubsection"
      | 6 -> "subsubsubsubsubsubsection"
      | 7 -> "paragraph"
      | _ -> "subparagraph")
      (pre_latexify (Mark.remove heading.law_heading_name));
    Format.pp_print_list
      ~pp_sep:(fun fmt () -> Format.fprintf fmt "\n\n")
      (law_structure_to_latex language print_only_law)
      fmt children
  | A.LawInclude (A.PdfFile ((file, _), page)) ->
    let label =
      file
      ^ match page with None -> "" | Some p -> Format.sprintf "_page_%d," p
    in
    Format.fprintf fmt
      "\\begin{center}\\textit{Annexe incluse, retranscrite page \
       \\pageref{%s}}\\end{center} \
       \\begin{figure}[p]\\begin{center}\\includegraphics[%swidth=\\textwidth]{%s}\\label{%s}\\end{center}\\end{figure}"
      label
      (match page with None -> "" | Some p -> Format.sprintf "page=%d," p)
      file label
  | A.LawInclude (A.CatalaFile _ | A.LegislativeText _) -> ()
  | A.ModuleDef (id, extern) ->
    (match language with
    | Fr ->
      Format.fprintf fmt "\n\\textbf{Ceci définit le module %s \\texttt{%s}}"
        (if extern then "externe" else "catala")
    | _ ->
      Format.fprintf fmt "\n\\textbf{This defines the %s module \\texttt{%s}}"
        (if extern then "external" else "catala"))
      (pre_latexify (Mark.remove id))
  | A.ModuleUse (id, alias) -> (
    (match language with
    | Fr ->
      Format.fprintf fmt "\n\\textbf{Ce qui suit utilise le module \\texttt{%s}"
    | _ ->
      Format.fprintf fmt
        "\n\\textbf{The following makes use of the module \\texttt{%s}")
      (pre_latexify (Mark.remove id));
    match alias with
    | None -> Format.fprintf fmt "}"
    | Some al ->
      (match language with
      | Fr -> Format.fprintf fmt " sous le nom \\texttt{%s}}"
      | _ -> Format.fprintf fmt " under the name \\texttt{%s}}")
        (pre_latexify (Mark.remove al)))
  | A.LawText t -> Format.fprintf fmt "%s" (pre_latexify t)
  | A.CodeBlock (_, c, false) when not print_only_law ->
    let start_line = Pos.get_start_line (Mark.get c) + 1 in
    let filename = Pos.get_file (Mark.get c) in
    let block_content = Mark.remove c in
    check_exceeding_lines start_line filename block_content;
    update_lines_of_code c;
    code_block ~meta:false language fmt c
  | A.CodeBlock (_, c, true) when not print_only_law ->
    let metadata_title =
      match language with
      | Fr -> "Métadonnées"
      | En -> "Metadata"
      | Pl -> "Metadane"
    in
    let start_line = Pos.get_start_line (Mark.get c) + 1 in
    let filename = Pos.get_file (Mark.get c) in
    let block_content = Mark.remove c in
    check_exceeding_lines start_line filename block_content;
    update_lines_of_code c;
    Format.fprintf fmt
      "\\begin{tcolorbox}[colframe=OliveGreen, breakable, \
       title=\\textcolor{black}{\\texttt{%s}},title after \
       break=\\textcolor{black}{\\texttt{%s}},before skip=1em, after skip=1em, \
       left=0.6em, right=0.6em]\n\
       %a\n\
       \\end{tcolorbox}"
      metadata_title metadata_title
      (code_block ~meta:true language)
      c
  | A.CodeBlock _ -> ()

(** {1 API} *)

let ast_to_latex
    (language : C.backend_lang)
    ~(print_only_law : bool)
    (fmt : Format.formatter)
    (program : A.program) : unit =
  Format.pp_open_vbox fmt 0;
  List.iter
    (fun item ->
      law_structure_to_latex language print_only_law fmt item;
      Format.pp_print_cut fmt ())
    program.program_items;
  Format.pp_close_box fmt ();
  Message.debug "Lines of Catala inside literate source code: %d" !lines_of_code