;;; titlesec.el --- AUCTeX style for `titlesec.sty' (v2.11)  -*- lexical-binding: t; -*-

;; Copyright (C) 2016--2024 Free Software Foundation, Inc.

;; Author: Arash Esbati <arash@gnu.org>
;; Maintainer: auctex-devel@gnu.org
;; Created: 2015-09-19
;; Keywords: tex

;; This file is part of AUCTeX.

;; AUCTeX is free software; you can redistribute it and/or modify it
;; under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; AUCTeX is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with AUCTeX; see the file COPYING.  If not, write to the Free
;; Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
;; 02110-1301, USA.

;;; Commentary:

;; This file adds support for `titlesec.sty' (v2.11) from
;; 2019/07/16.  `titlesec.sty' is part of TeXLive.

;;; Code:

(require 'tex)
(require 'latex)

;; Silence the compiler:
(declare-function font-latex-add-keywords
                  "font-latex"
                  (keywords class))

(defvar LaTeX-titlesec-key-val-options
  '(("page" ("even" "odd"))
    ("numberless"))
  "Key=value options for \"\\titleformat\" and \"\\titlespacing\"
macros provided by \"titlesec.sty\".")

(defvar LaTeX-titlesec-section-command-list
  '("part"
    "chapter"
    "section"
    "subsection"
    "subsubsection"
    "paragraph"
    "subparagraph")
  "List of sectioning commands available in \"titlesec.sty\".")

(defvar LaTeX-titlesec-section-shape-list
  '("hang"
    "block"
    "display"
    "runin"
    "leftmargin"
    "rightmargin"
    "drop"
    "wrap"
    "frame")
  "List of sectioning shapes available for \"\\titleformat\" command.")

(defun LaTeX-titlesec-section-command-list ()
  "Return a list of appropriate sectioning commands.
Commands are collected from the variable
`LaTeX-titlesec-section-command-list' and selected based on the
return value of function `LaTeX-largest-level'.  Commands
returned are prefixed with `TeX-esc'."
  (mapcar (lambda (elt) (concat TeX-esc elt))
          (if (< (LaTeX-largest-level) 2)
              LaTeX-titlesec-section-command-list
            (remove "chapter" LaTeX-titlesec-section-command-list))))

(defun LaTeX-titlesec-titlespec-key-val-options ()
  "Return key=val's for the 1st arg of titlesec macros.
Macros are \"\\titleformat\" and \"\\titlespacing\".  Depending
on the returned value of the function `LaTeX-largest-level',
append a \"name\" key with corresponding values to
`LaTeX-titlesec-key-val-options'.  The values are retrieved from
the variable `LaTeX-titlesec-section-command-list'.  The values
of this list are also added stand-alone as keys."
  (append
   `(("name"
      ,(mapcar (lambda (elt) (concat TeX-esc elt))
               (if (< (LaTeX-largest-level) 2)
                   LaTeX-titlesec-section-command-list
                 (remove "chapter" LaTeX-titlesec-section-command-list)))))
   (mapcar #'list
           (mapcar (lambda (elt) (concat TeX-esc elt))
                   (if (< (LaTeX-largest-level) 2)
                       LaTeX-titlesec-section-command-list
                     (remove "chapter" LaTeX-titlesec-section-command-list))))
   LaTeX-titlesec-key-val-options))

(TeX-add-style-hook
 "titlesec"
 (lambda ()

   ;; Load "titleps.el" when "pagestyles" package option is given
   (when (LaTeX-provided-package-options-member "titlesec" "pagestyles")
     (TeX-run-style-hooks "titleps"))

   (TeX-add-symbols
    ;; 2.4. Tools
    '("titlelabel" t)

    ;; \titleformat*{<command>}{<format>}
    '("titleformat*" (TeX-arg-key-val (LaTeX-titlesec-titlespec-key-val-options)) t)

    ;; 3. Advanced Interface
    ;; \titleformat{<command>}[<shape>]{<format>}{<label>}{<sep>}{<before-code>}[<after-code>]
    '("titleformat"
      (TeX-arg-key-val (LaTeX-titlesec-titlespec-key-val-options))
      [TeX-arg-completing-read LaTeX-titlesec-section-shape-list "Shape"]
      (TeX-arg-conditional (y-or-n-p "With optional after-code? ")
          (4 [nil])
        (4)))

    '("chaptertitlename" 0)

    ;; 3.2. Spacing
    ;; \titlespacing{<command>}{<left>}{<before-sep>}{<after-sep>}[<right-sep>]
    '("titlespacing"
      (TeX-arg-key-val (LaTeX-titlesec-titlespec-key-val-options))
      (TeX-arg-length "Left margin")
      (TeX-arg-length "Before vertical space")
      (TeX-arg-length "Space between title and text")
      [TeX-arg-length "Right margin"])

    '("titlespacing*"
      (TeX-arg-key-val (LaTeX-titlesec-titlespec-key-val-options))
      (TeX-arg-length "Left margin")
      (TeX-arg-length "Before vertical space")
      (TeX-arg-length "Space between title and text")
      [TeX-arg-length "Right margin"])

    ;; 3.3. Spacing related tools
    '("filright"  0)
    '("filcenter" 0)
    '("filleft"   0)
    '("fillast"   0)
    '("filinner"  0)
    '("filouter"  0)
    '("wordsep"   0)
    '("nostruts"  0)

    ;; 3.4. Rules
    '("titleline"
      [TeX-arg-completing-read ("l" "r" "c") "Alignment"]
      t)

    '("titlerule" [TeX-arg-length "Rule height"])

    '("titlerule*" [TeX-arg-length "Box width"] "Text")

    '("iftitlemeasuring" 2)

    ;; 3.5. Page styles
    '("assignpagestyle"
      (TeX-arg-completing-read (LaTeX-titlesec-section-command-list)
                               "Sectioning command")
      (TeX-arg-pagestyle))

    ;; 3.9. Creating new levels and changing the class
    '("titleclass"
      (TeX-arg-completing-read (LaTeX-titlesec-section-command-list)
                               "Sectioning command")
      (TeX-arg-completing-read ("page" "top" "straight")
                               "Class")
      [TeX-arg-completing-read (LaTeX-titlesec-section-command-list)
                               "Super level command"]))

   ;; Don't increase indent at \iftitlemeasuring:
   (add-to-list 'LaTeX-indent-begin-exceptions-list "iftitlemeasuring" t)
   (LaTeX-indent-commands-regexp-make)

   ;; 3.4. Rules: A variant of \titleline to be used only with calcwidth
   (when (LaTeX-provided-package-options-member "titlesec" "calcwidth")
     (TeX-add-symbols
      '("titleline*"
        (TeX-arg-completing-read ("l" "r" "c") "Alignment")
        t)))

   ;; The length of the longest line is returned in \titlewidth
   (LaTeX-add-lengths "titlewidth"
                      "titlewidthlast"
                      "titlewidthfirst")

   ;; Fontification: We only add macros which are used at top level;
   ;; most of macros definded above are intended to be used in
   ;; arguments of \titleformat
   (when (and (featurep 'font-latex)
              (eq TeX-install-font-lock 'font-latex-setup))
     (font-latex-add-keywords '(("titlelabel"        "{")
                                ;;
                                ;; \titleformat comes in 2 flavors:
                                ;; with *, it takes only 2 mandatory
                                ;; argument; w/o *, a lot more.  It is
                                ;; not (yet) possible to realize this
                                ;; behaviour within font-latex.  Hence
                                ;; we reduce the fontification to the
                                ;; first 2 mandatory arguments and
                                ;; ignore the rest.  *[ are optional anyway.
                                ("titleformat"       "*{[{")
                                ("titlespacing"      "*{{{{[")
                                ("iftitlemeasuring"  "{{")
                                ("assignpagestyle"   "{{")
                                ("titleclass"        "{[{["))
                              'function)))
 TeX-dialect)

(defvar LaTeX-titlesec-package-options
  '(;; 2.1. Format
    "rm" "sf" "tt" "md" "bf" "up" "it" "sl" "sc"
    "big" "medium" "small" "tiny"
    "raggedleft" "center" "raggedright"

    ;; 2.2. Spacing
    "compact"

    ;; 2.3. Uppercase
    "uppercase"

    ;; 3.3. Spacing related tools
    "indentafter"   "noindentafter"
    "rigidchapters" "rubberchapters"
    "bottomtitles"  "nobottomtitles" "nobottomtitles*"
    "aftersep"      "largestsep"     "pageatnewline"
    "nostruts"

    ;; 3.4. Rules
    "calcwidth"

    ;; 3.7. Other Package Options
    "explicit"
    "newparttoc"
    "oldparttoc"
    "clearempty"
    "toctitles"
    "newlinetospace"
    "loadonly"

    ;; 5. titleps and Page Styles
    "pagestyles")
  "Package options for the titlesec package.")

;;; titlesec.el ends here
