;;; php-ts-mode.el --- Major mode for editing PHP files using tree-sitter -*- lexical-binding: t; -*-

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

;; Author: Vincenzo Pupillo <v.pupillo@gmail.com>
;; Maintainer: Vincenzo Pupillo <v.pupillo@gmail.com>
;; Created: Jun 2024
;; Keywords: PHP language tree-sitter

;; This file is part of GNU Emacs.

;; GNU Emacs 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 of the License, or
;; (at your option) any later version.

;; GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:
;;
;; This package provides `php-ts-mode' which is a major mode
;; for editing PHP files with embedded HTML, JavaScript, CSS and phpdoc.
;; Tree Sitter is used to parse each of these languages.
;;
;; Please note that this package requires `html-ts-mode', which
;; registers itself as the major mode for editing HTML.
;;
;; This package is compatible and has been tested with the following
;; tree-sitter grammars:
;; * https://github.com/tree-sitter/tree-sitter-php
;; * https://github.com/tree-sitter/tree-sitter-html
;; * https://github.com/tree-sitter/tree-sitter-javascript
;; * https://github.com/tree-sitter/tree-sitter-jsdoc
;; * https://github.com/tree-sitter/tree-sitter-css
;; * https://github.com/claytonrcarter/tree-sitter-phpdoc
;;
;; Features
;;
;; * Indent
;; * IMenu
;; * Navigation
;; * Which-function
;; * Flymake
;; * Tree-sitter parser installation helper
;; * PHP built-in server support
;; * Shell interaction: execute PHP code in a inferior PHP process

;;; Code:

(require 'treesit)
(require 'c-ts-common) ;; For comment indent and filling.
(require 'css-mode) ;; for embed css into html
(require 'js) ;; for embed javascript into html
(require 'comint)

(eval-when-compile
  (require 'cl-lib)
  (require 'rx)
  (require 'subr-x))

(declare-function treesit-node-child "treesit.c")
(declare-function treesit-node-child-by-field-name "treesit.c")
(declare-function treesit-node-end "treesit.c")
(declare-function treesit-node-parent "treesit.c")
(declare-function treesit-node-start "treesit.c")
(declare-function treesit-node-string "treesit.c")
(declare-function treesit-node-type "treesit.c")
(declare-function treesit-parser-add-notifier "treesit.c")
(declare-function treesit-parser-buffer "treesit.c")
(declare-function treesit-parser-create "treesit.c")
(declare-function treesit-parser-included-ranges "treesit.c")
(declare-function treesit-parser-list "treesit.c")
(declare-function treesit-parser-language "treesit.c")
(declare-function treesit-query-compile "treesit.c")
(declare-function treesit-search-forward "treesit.c")
(declare-function treesit-node-prev-sibling "treesit.c")
(declare-function treesit-node-first-child-for-pos "treesit.c")

;;; Install treesitter language parsers
(defvar php-ts-mode--language-source-alist
  '((php . ("https://github.com/tree-sitter/tree-sitter-php" "v0.23.11" "php/src"))
    (phpdoc . ("https://github.com/claytonrcarter/tree-sitter-phpdoc"))
    (html . ("https://github.com/tree-sitter/tree-sitter-html"  "v0.23.0"))
    (javascript . ("https://github.com/tree-sitter/tree-sitter-javascript" "v0.23.0"))
    (jsdoc . ("https://github.com/tree-sitter/tree-sitter-jsdoc" "v0.23.0"))
    (css . ("https://github.com/tree-sitter/tree-sitter-css" "v0.23.0")))
  "Treesitter language parsers required by `php-ts-mode'.
You can customize this variable if you want to stick to a specific
commit and/or use different parsers.")

(defun php-ts-mode-install-parsers ()
  "Install all the required treesitter parsers.
`php-ts-mode--language-source-alist' defines which parsers to install."
  (interactive)
  (let ((treesit-language-source-alist php-ts-mode--language-source-alist))
    (dolist (item php-ts-mode--language-source-alist)
      (treesit-install-language-grammar (car item)))))

;;; Custom variables

(defgroup php-ts-mode nil
  "Major mode for editing PHP files."
  :prefix "php-ts-mode-"
  :group 'languages)

(defcustom php-ts-mode-indent-offset 4
  "Number of spaces for each indentation step in `php-ts-mode'."
  :tag "PHP indent offset"
  :version "30.1"
  :type 'integer
  :safe 'integerp)

(defcustom php-ts-mode-js-css-indent-offset 2
  "JavaScript and CSS indent spaces related to the <script> and <style> HTML tags.
By default should have same value as `html-ts-mode-indent-offset'."
  :tag "PHP javascript or css indent offset"
  :version "30.1"
  :type 'integer
  :safe 'integerp)

(defcustom php-ts-mode-css-fontify-colors t
  "Whether CSS colors should be fontified using the color as the background.
If non-nil, text representing a CSS color will be fontified
such that its background is the color itself.
Works like `css--fontify-region'."
  :tag "PHP colors the CSS properties values."
  :version "30.1"
  :type 'boolean
  :safe 'booleanp)

(defcustom php-ts-mode-php-executable (or (executable-find "php") "/usr/bin/php")
  "The location of PHP executable."
  :tag "PHP Executable"
  :version "30.1"
  :type 'file)

(defcustom php-ts-mode-php-config nil
  "The location of php.ini file.
If nil the default one is used to run the embedded webserver or
inferior PHP process."
  :tag "PHP Init file"
  :version "30.1"
  :type '(choice (const :tag "Default init file" nil) file))

(defcustom php-ts-mode-ws-hostname "localhost"
  "The hostname that will be served by the PHP built-in webserver.
If nil then `php-ts-mode-run-php-webserver' will ask you for the hostname.
See `https://www.php.net/manual/en/features.commandline.webserver.php'."
  :tag "PHP built-in web server hostname"
  :version "30.1"
  :type 'string
  :safe 'stringp)

(defcustom php-ts-mode-ws-port nil
  "The port on which the PHP built-in webserver will listen.
If nil `php-ts-mode-run-php-webserver' will ask you for the port number."
  :tag "PHP built-in web server port"
  :version "30.1"
  :type '(choice (const :tag "Ask which port to use" nil) integer)
  :safe 'integer-or-null-p)

(defcustom php-ts-mode-ws-document-root nil
  "The root of the documents that the PHP built-in webserver will serve.
If nil `php-ts-mode-run-php-webserver' will ask you for the document root."
  :tag "PHP built-in web server document root"
  :version "30.1"
  :type '(choice (const :tag "Ask for document root" nil) directory))

(defcustom php-ts-mode-ws-workers nil
  "The number of workers the PHP built-in webserver will fork.
Useful for testing code against multiple simultaneous requests."
  :tag "PHP built-in number of workers"
  :version "30.1"
  :type '(choice (const :tag "No workers" nil) integer)
  :safe 'integer-or-null-p)

(defcustom php-ts-mode-inferior-php-buffer "*PHP*"
  "Name of the inferior PHP buffer."
  :tag "PHP inferior process buffer name"
  :version "30.1"
  :type 'string
  :safe 'stringp)

(defcustom php-ts-mode-inferior-history nil
  "File used to save command history of the inferior PHP process."
  :tag "PHP inferior process history file."
  :version "30.1"
  :type '(choice (const :tag "None" nil) file)
  :safe 'string-or-null-p)

(defvar php-ts-mode--inferior-prompt "php >"
  "Prompt used by PHP inferior process.")

(defun php-ts-mode--indent-style-setter (sym val)
  "Custom setter for `php-ts-mode-set-style'.

Apart from setting the default value of SYM to VAL, also change
the value of SYM in `php-ts-mode' buffers to VAL.
SYM should be `php-ts-mode-indent-style', and VAL should be a style
symbol."
  (set-default sym val)
  (dolist (buffer (buffer-list))
      (with-current-buffer buffer
        (when (derived-mode-p 'php-ts-mode)
          (php-ts-mode-set-style val)))))

;; taken from c-ts-mode
(defun php-ts-indent-style-safep (style)
  "Non-nil if STYLE's value is safe for file-local variables."
  (and (symbolp style) (not (functionp style))))

(defcustom php-ts-mode-indent-style 'psr2
  "Style used for indentation.
The selected style could be one of:
`PSR-2/PSR-12' - use PSR standards (PSR-2, PSR-12), this is the default.
`PEAR' - use coding styles preferred for PEAR code and modules.
`Drupal' - use coding styles preferred for working with Drupal projects.
`WordPress' - use coding styles preferred for working with WordPress projects.
`Symfony' - use coding styles preferred for working with Symfony projects.
`Zend' - use coding styles preferred for working with Zend projects.

If one of the supplied styles doesn't suffice, a function could be
set instead.  This function is expected return a list that
follows the form of `treesit-simple-indent-rules'."
  :tag "PHP indent style"
  :version "30.1"
  :type '(choice (const :tag "PSR-2/PSR-12" psr2)
                 (const :tag "PEAR" pear)
                 (const :tag "Drupal" drupal)
                 (const :tag "WordPress" wordpress)
                 (const :tag "Symfony" symfony)
                 (const :tag "Zend" zend)
                 (function :tag "A function for user customized style" ignore))
  :set #'php-ts-mode--indent-style-setter
  :safe #'php-ts-indent-style-safep)

\f
;;; Flymake integration

;; based on lua-ts-mode
(defvar-local php-ts-mode--flymake-process nil
  "Store the Flymake process.")

;; TODO: add phpmd and phpcs
(defun php-ts-mode-flymake-php (report-fn &rest _args)
  "PHP backend for Flymake.
Calls REPORT-FN directly."
  (when (process-live-p php-ts-mode--flymake-process)
    (kill-process php-ts-mode--flymake-process))
  (let ((source (current-buffer))
        (diagnostics-pattern (eval-when-compile
                               (rx bol (? "PHP ") ;; every diagnostic line start with PHP
                                   (group (or "Fatal" "Parse")) ;; 1: type
                                   " error:" (+ (syntax whitespace))
                                   (group (+? nonl)) ;; 2: msg
                                   " in " (group (+? nonl)) ;; 3: file
                                   " on line " (group (+ num)) ;; 4: line
                                   eol))))
    (save-restriction
      (widen)
      (setq php-ts-mode--flymake-process
            (make-process
             :name "php-ts-mode-flymake"
             :noquery t
             :connection-type 'pipe
             :buffer (generate-new-buffer " *php-ts-mode-flymake*")
             :command `(,php-ts-mode-php-executable
                        "-l" "-d" "display_errors=0")
             :sentinel
             (lambda (proc _event)
               (when (eq 'exit (process-status proc))
                 (unwind-protect
                     (if (with-current-buffer source
                           (eq proc php-ts-mode--flymake-process))
                         (with-current-buffer (process-buffer proc)
                           (goto-char (point-min))
                           (let (diags)
                             (while (search-forward-regexp
                                     diagnostics-pattern
                                     nil t)
                               (let* ((beg
                                       (car (flymake-diag-region
                                             source
                                             (string-to-number (match-string 4)))))
                                      (end
                                       (cdr (flymake-diag-region
                                             source
                                             (string-to-number (match-string 4)))))
                                      (msg (match-string 2))
                                      (type :error))
                                 (push (flymake-make-diagnostic
                                        source beg end type msg)
                                       diags)))
                             (funcall report-fn diags)))
                       (flymake-log :warning "Canceling obsolete check %s" proc))
                   (kill-buffer (process-buffer proc)))))))
      (process-send-region php-ts-mode--flymake-process (point-min) (point-max))
      (process-send-eof php-ts-mode--flymake-process))))

\f
;;; Utils

(defun php-ts-mode--get-indent-style ()
  "Helper function to set indentation style.
MODE can be `psr2', `pear', `drupal', `wordpress', `symfony', `zend'."
  (let ((style
         (if (functionp php-ts-mode-indent-style)
             (funcall php-ts-mode-indent-style)
           (cl-case php-ts-mode-indent-style
             (psr2 (alist-get 'psr2 (php-ts-mode--indent-styles)))
             (pear (alist-get 'pear (php-ts-mode--indent-styles)))
             (drupal (alist-get 'drupal (php-ts-mode--indent-styles)))
             (wordpress (alist-get 'wordpress (php-ts-mode--indent-styles)))
             (symfony (alist-get 'symfony (php-ts-mode--indent-styles)))
             (zend (alist-get 'zend (php-ts-mode--indent-styles)))
             (t (alist-get 'psr2 (php-ts-mode--indent-styles)))))))
    `((php ,@style))))

(defun php-ts-mode--prompt-for-style ()
  "Prompt for an indent style and return the symbol for it."
  (intern
   (completing-read
    "Style: "
    (mapcar #'car (php-ts-mode--indent-styles))
    nil t nil nil "default")))

(defun php-ts-mode-set-global-style (style)
  "Set the indent style of PHP modes globally to STYLE.

This changes the current indent style of every PHP buffer and
the default PHP indent style for `php-ts-mode'
in this Emacs session."
  (interactive (list (php-ts-mode--prompt-for-style)))
  (php-ts-mode--indent-style-setter 'php-ts-mode-indent-style style))

(defun php-ts-mode--set-indent-property (style)
  "Set the offset, tab, etc. according to STYLE."
  (cl-case style
    (psr2 (setq php-ts-mode-indent-offset 4
                tab-width 4
                indent-tabs-mode nil))
    (pear (setq php-ts-mode-indent-offset 4
                tab-width 4
                indent-tabs-mode nil))
    (drupal (setq php-ts-mode-indent-offset 2
                  tab-width 2
                  indent-tabs-mode nil))
    (wordpress (setq php-ts-mode-indent-offset 4
                     tab-width 4
                     indent-tabs-mode t))
    (symfony (setq php-ts-mode-indent-offset 4
                   tab-width 4
                   indent-tabs-mode nil))
    (zend (setq php-ts-mode-indent-offset 4
                tab-width 4
                indent-tabs-mode nil))))

(defun php-ts-mode-set-style (style)
  "Set the PHP indent style of the current buffer to STYLE.
To set the default indent style globally, use
`php-ts-mode-set-global-style'."
  (interactive (list (php-ts-mode--prompt-for-style)))
  (cond
   ((not (derived-mode-p 'php-ts-mode))
    (user-error "The current buffer is not in `php-ts-mode'"))
   ((equal php-ts-mode-indent-style style)
    (message "The style is already %s" style));; nothing to do
   (t (progn
        (setq-local php-ts-mode-indent-style style)
        (php-ts-mode--set-indent-property style)
        (let ((rules (assq-delete-all 'php treesit-simple-indent-rules))
              (new-style (car (treesit--indent-rules-optimize
                               (php-ts-mode--get-indent-style)))))
          (setq treesit-simple-indent-rules (cons new-style rules))
          (message "Switch to %s style" style))))))

(defun php-ts-mode--get-parser-ranges ()
  "Return the ranges covered by the parsers.

`php-ts-mode' use five parsers, this function returns, for the
current buffer, the ranges covered by each parser.
Useful for debugging."
  (let ((ranges)
        (parsers (treesit-parser-list nil nil t)))
    (if (not parsers)
        (message "At least one parser must be initialized"))
    (cl-loop
     for parser in parsers
     do (push (list parser (treesit-parser-included-ranges parser)) ranges)
     finally return ranges)))

\f
;;; Syntax table

(defvar php-ts-mode--syntax-table
  (let ((table (make-syntax-table)))
    (modify-syntax-entry ?\\ "\\"     table)
    (modify-syntax-entry ?+  "."      table)
    (modify-syntax-entry ?-  "."      table)
    (modify-syntax-entry ?=  "."      table)
    (modify-syntax-entry ?%  "."      table)
    (modify-syntax-entry ?<  "."      table)
    (modify-syntax-entry ?>  "."      table)
    (modify-syntax-entry ?&  "."      table)
    (modify-syntax-entry ?|  "."      table)
    (modify-syntax-entry ?\' "\""     table)
    (modify-syntax-entry ?\240 "."    table)
    (modify-syntax-entry ?/  ". 124b" table)
    (modify-syntax-entry ?*  ". 23"   table)
    (modify-syntax-entry ?\n "> b"    table)
    (modify-syntax-entry ?\^m "> b"   table)
    ;; php specific syntax
    (modify-syntax-entry ?_  "w"      table)
    (modify-syntax-entry ?`  "\""     table)
    (modify-syntax-entry ?\" "\""     table)
    (modify-syntax-entry ?\r "> b"    table)
    (modify-syntax-entry ?#  "< b"    table)
    (modify-syntax-entry ?$  "_"      table)
    table)
  "Syntax table for `php-ts-mode'.")

\f
;;; Indent

(defconst php-ts-mode--possibly-braceless-keyword-re
  (regexp-opt '("if" "for" "foreach" "while" "do") 'symbols)
  "Regexp matching keywords optionally followed by an opening brace.")

(defun php-ts-mode--open-statement-group-heuristic (node _parent bol &rest _)
  "Heuristic matcher for statement-group without closing bracket.

Return `php-ts-mode-indent-offset' plus 1 when BOL is after
`php-ts-mode--possibly-braceless-keyword-re', otherwise return 0.  It's
useful for matching incomplete compound_statement or colon_block.
PARENT is NODE's parent, BOL is the beginning of non-whitespace
characters of the current line."
  (and (null node)
       (save-excursion
	   (forward-line -1)
	   (if (re-search-forward
		php-ts-mode--possibly-braceless-keyword-re
		bol t)
	       (+ 1 php-ts-mode-indent-offset)
	     0))))

;; taken from c-ts-mode
(defun php-ts-mode--else-heuristic (node parent bol &rest _)
  "Heuristic matcher for when \"else\" is followed by a closing bracket.

PARENT is NODE's parent, BOL is the beginning of non-whitespace
characters of the current line."
  (and (null node)
       (save-excursion
         (forward-line -1)
         (looking-at (rx (* whitespace) "else" (* whitespace) eol)))
       (let ((next-node (treesit-node-first-child-for-pos parent bol)))
         (equal (treesit-node-type next-node) "}"))))

;; taken from c-ts-mode
(defun php-ts-mode--first-sibling (node parent &rest _)
  "Matches when NODE is the \"first sibling\".

\"First sibling\" is defined as: the first child node of PARENT
such that it's on its own line.  NODE is the node to match and
PARENT is its parent."
  (let ((prev-sibling (treesit-node-prev-sibling node t)))
    (or (null prev-sibling)
        (save-excursion
          (goto-char (treesit-node-start prev-sibling))
          (<= (line-beginning-position)
              (treesit-node-start parent)
              (line-end-position))))))

(defun php-ts-mode--js-css-tag-bol (_node parent &rest _)
  "Find the first non-space characters of html tags <script> or <style>.

Return `line-beginning-position' when `treesit-node-at' is HTML or PHP.
Otherwise go to the PARENT and search backward for <script> or <style> tags.
Should be used only for Javascript or CSS indenting rules.
NODE, ignored, is the node to match and PARENT is its parent."
  (let ((lang (treesit-language-at (point))))
    (if (or (eq lang 'javascript)
	    (eq lang 'css))
	(save-excursion
	  (goto-char (treesit-node-start parent))
	  (re-search-backward "<script>\\|<style>" nil t))
      (line-beginning-position))))

(defun php-ts-mode--parent-eol (_node parent &rest _)
  "Find the last non-space characters of the PARENT of the current NODE.

NODE is the node to match and PARENT is its parent."
  (save-excursion
    (goto-char (treesit-node-start parent))
    (line-end-position)))

(defun php-ts-mode--parent-html-bol (node parent bol &rest _)
  "Find the first non-space characters of the HTML tags before NODE.

When NODE is nil call `php-ts-mode--open-statement-group-heuristic'.
PARENT is NODE's parent, BOL is the beginning of non-whitespace
characters of the current line."
  (if (null node)
      ;; If NODE is nil it could be an open statement-group.
      (php-ts-mode--open-statement-group-heuristic node parent bol)
    (save-excursion
      (let ((html-node (treesit-search-forward node "text" t)))
	(if html-node
            (let ((end-html (treesit-node-end html-node)))
              (goto-char end-html)
              (backward-word)
              (back-to-indentation)
              (point))
          (treesit-node-start parent))))))

(defun php-ts-mode--parent-html-heuristic (node parent bol &rest _)
  "Return position based on html indentation.

Returns 0 if the NODE is after the </html>, otherwise returns the
indentation point of the last word before the NODE, plus the indentation
offset.  If there is no HTML tag, it returns the beginning of the
parent.  When NODE is nil call `php-ts-mode--open-statement-group-heuristic'.
It can be used when you want to indent PHP code relative to the HTML.
PARENT is NODE's parent, BOL is the beginning of non-whitespace
characters of the current line."
  (if (null node)
      ;; If NODE is nil it could be an open statement-group.
      (php-ts-mode--open-statement-group-heuristic node parent bol)
    (let ((html-node (treesit-search-forward node "text" t)))
      (if html-node
          (let ((end-html (treesit-node-end html-node)))
            (save-excursion
	      (goto-char end-html)
	      (backward-word)
	      (back-to-indentation)
	      (if (search-forward "</html>" end-html t 1)
                  0
		(+ (point) php-ts-mode-indent-offset))))
	;; Maybe it's better to use bol?
	(treesit-node-start parent)))))

(defun php-ts-mode--array-element-heuristic (_node parent _bol &rest _)
  "Return of the position of the first element of the array.

PARENT is NODE's parent, BOL is the beginning of non-whitespace
characters of the current line."
  (let ((parent-start
         (treesit-node-start parent))
        (parent-first-child-start
         (treesit-node-start (treesit-node-child parent 2))))
    (if (equal
         (line-number-at-pos parent-start)
         (line-number-at-pos parent-first-child-start))
        ;; if array_creation_expression and the first
        ;; array_element_initializer are on the same same line
        parent-first-child-start
      ;; else return parent-bol plus the offset
      (save-excursion
        (goto-char (treesit-node-start parent))
        (back-to-indentation)
        (+ (point) php-ts-mode-indent-offset)))))


(defun php-ts-mode--anchor-first-sibling (_node parent _bol &rest _)
  "Return the start of the first child of a sibling of PARENT.

If the fist sibling of PARENT and the first child of the sibling are
on the same line return the start position of the first child of the
sibling.  Otherwise return the start of the first sibling.
PARENT is NODE's parent, BOL is the beginning of non-whitespace
characters of the current line."
  (let ((first-sibling-start
         (treesit-node-start (treesit-node-child parent 0)))
        (first-sibling-child-start
         (treesit-node-start (treesit-node-child parent 1))))
    (if (equal
         (line-number-at-pos first-sibling-start)
         (line-number-at-pos first-sibling-child-start))
        ;; if are on the same line return the child start
        first-sibling-child-start
      first-sibling-start)))

;; adapted from c-ts-mode--anchor-prev-sibling
(defun php-ts-mode--anchor-prev-sibling (node parent bol &rest _)
  "Return the start of the previous named sibling of NODE.

Return nil if a) there is no prev-sibling, or b) prev-sibling
doesn't have a child.

PARENT is NODE's parent, BOL is the beginning of non-whitespace
characters of the current line."
  (when-let ((prev-sibling
              (or (treesit-node-prev-sibling node t)
                  (treesit-node-prev-sibling
                   (treesit-node-first-child-for-pos parent bol) t)
                  (treesit-node-child parent -1 t)))
             (continue t))
    (save-excursion
      (while (and prev-sibling continue)
        (goto-char (treesit-node-start prev-sibling))
        (if (looking-back (rx bol (* whitespace))
                          (line-beginning-position))
            (setq continue nil)
          (setq prev-sibling
                (treesit-node-prev-sibling prev-sibling)))))
    (treesit-node-start prev-sibling)))

(defun php-ts-mode--indent-styles ()
  "Indent rules supported by `php-ts-mode'."
  (let ((common
         `((php-ts-mode--else-heuristic prev-line php-ts-mode-indent-offset)

           ((query "(ERROR (ERROR)) @indent") column-0 0)

           ((node-is ")") parent-bol 0)
           ((node-is "]") parent-bol 0)
           ((node-is "else_clause") parent-bol 0)
           ((node-is "case_statement") parent-bol php-ts-mode-indent-offset)
           ((node-is "default_statement") parent-bol php-ts-mode-indent-offset)
           ((parent-is "default_statement") parent-bol php-ts-mode-indent-offset)
           ((and
             (parent-is "expression_statement")
             (node-is ";"))
            parent-bol 0)
           ((parent-is "expression_statement") parent-bol php-ts-mode-indent-offset)
           ;; `c-ts-common-looking-at-star' has to come before
           ;; `c-ts-common-comment-2nd-line-matcher'.
           ((and (parent-is "comment") c-ts-common-looking-at-star)
            c-ts-common-comment-start-after-first-star -1)
           (c-ts-common-comment-2nd-line-matcher
            c-ts-common-comment-2nd-line-anchor
            1)
           ((parent-is "comment") prev-adaptive-prefix 0)

           ((parent-is "method_declaration") parent-bol 0)
           ((node-is "class_interface_clause") parent-bol php-ts-mode-indent-offset)
           ((query "(class_interface_clause (name) @indent)") php-ts-mode--parent-eol 1)
           ((query "(class_interface_clause (qualified_name) @indent)")
            parent-bol php-ts-mode-indent-offset)
           ((parent-is "class_declaration") parent-bol 0)
	   ((parent-is "namespace_use_declaration") parent-bol php-ts-mode-indent-offset)
           ((parent-is "namespace_use_group") parent-bol php-ts-mode-indent-offset)
           ((parent-is "function_definition") parent-bol 0)
           ((parent-is "member_call_expression") first-sibling php-ts-mode-indent-offset)
           ((parent-is "conditional_expression") parent-bol php-ts-mode-indent-offset)
           ((parent-is "assignment_expression") parent-bol php-ts-mode-indent-offset)
           ((parent-is "array_creation_expression") parent-bol php-ts-mode-indent-offset)
           ((parent-is "parenthesized_expression") first-sibling 1)
           ((parent-is "binary_expression") parent 0)
           ((or (parent-is "arguments")
                (parent-is "formal_parameters"))
            parent-bol php-ts-mode-indent-offset)

           ((query "(for_statement (assignment_expression left: (_)) @indent)")
            parent-bol php-ts-mode-indent-offset)
           ((query "(for_statement (binary_expression left: (_)) @indent)")
            parent-bol php-ts-mode-indent-offset)
           ((query "(for_statement (update_expression (_)) @indent)")
            parent-bol php-ts-mode-indent-offset)
           ((query "(function_call_expression arguments: (_) @indent)")
            parent php-ts-mode-indent-offset)
           ((query "(member_call_expression arguments: (_) @indent)")
            parent php-ts-mode-indent-offset)
           ((query "(scoped_call_expression name: (_) @indent)")
            parent php-ts-mode-indent-offset)
           ((parent-is "scoped_property_access_expression")
            parent php-ts-mode-indent-offset)

           ;; Closing bracket. Must stay here, the rule order matter.
           ((node-is "}") standalone-parent 0)
           ;; handle multiple single line comment that start at the and of a line
           ((match "comment" "declaration_list") php-ts-mode--anchor-prev-sibling 0)
           ((parent-is "declaration_list") column-0 php-ts-mode-indent-offset)

           ((parent-is "initializer_list") parent-bol php-ts-mode-indent-offset)

           ;; Statement in {} blocks.
           ((or (and (or (parent-is "compound_statement")
			 (parent-is "colon_block"))
                     ;; If the previous sibling(s) are not on their
                     ;; own line, indent as if this node is the first
                     ;; sibling
                     php-ts-mode--first-sibling)
                (or (match null "compound_statement")
		    (match null "colon_block")))
            standalone-parent php-ts-mode-indent-offset)
           ((or (parent-is "compound_statement")
		(parent-is "colon_block"))
	    parent-bol php-ts-mode-indent-offset)
           ;; Opening bracket.
           ((or (node-is "compound_statement")
                (node-is "colon_block"))
                standalone-parent php-ts-mode-indent-offset)

           ((parent-is "match_block") parent-bol php-ts-mode-indent-offset)
           ((parent-is "switch_block") parent-bol 0)

           ;; These rules are for cases where the body is bracketless.
           ((match "while" "do_statement") parent-bol 0)
           ;; rule for PHP alternative syntax
           ((or (node-is "else_if_clause")
                (node-is "endif")
                (node-is "endfor")
                (node-is "endforeach")
                (node-is "endwhile"))
            parent-bol 0)
           ((or (parent-is "if_statement")
                (parent-is "else_clause")
                (parent-is "for_statement")
                (parent-is "foreach_statement")
                (parent-is "while_statement")
                (parent-is "do_statement")
                (parent-is "switch_statement")
                (parent-is "case_statement")
                (parent-is "empty_statement"))
            parent-bol php-ts-mode-indent-offset)

	   ;; Workaround: handle "for" open statement group. Currently
           ;; the grammar handles it differently than other control structures.
	   (no-node php-ts-mode--open-statement-group-heuristic 0))))
    `((psr2
       ((parent-is "program") php-ts-mode--open-statement-group-heuristic 0)
       ((parent-is "text_interpolation") column-0 0)
       ((parent-is "function_call_expression") parent-bol php-ts-mode-indent-offset)
       ,@common)
      (pear
       ((parent-is "program") php-ts-mode--parent-html-heuristic 0)
       ((parent-is "text_interpolation") php-ts-mode--parent-html-heuristic 0)
       ((or (node-is "case_statement")
            (node-is "default_statement"))
        parent-bol 0)
       ((parent-is "binary_expression") parent-bol php-ts-mode-indent-offset)
       ,@common)
      (drupal
       ((parent-is "program") php-ts-mode--parent-html-heuristic 0)
       ((parent-is "text_interpolation") php-ts-mode--parent-html-bol 0)
       ((parent-is "if_statement") parent-bol 0)
       ((parent-is "binary_expression") parent-bol php-ts-mode-indent-offset)
       ((parent-is "function_call_expression") parent-bol php-ts-mode-indent-offset)
       ,@common)
      (symfony
       ((parent-is "function_call_expression") parent-bol php-ts-mode-indent-offset)
       ,@common)
      (wordpress
       ((parent-is "program") php-ts-mode--parent-html-bol 0)
       ((parent-is "text_interpolation") php-ts-mode--parent-html-bol 0)
       ,@common)
      (zend
       ((parent-is "class_interface_clause") php-ts-mode--anchor-first-sibling 0)
       ((parent-is "function_call_expression") first-sibling 0)
       ((parent-is "array_creation_expression") php-ts-mode--array-element-heuristic 0)
       ,@common))))

(defvar php-ts-mode--phpdoc-indent-rules
  '((phpdoc
     ((and (parent-is "document") c-ts-common-looking-at-star)
      c-ts-common-comment-start-after-first-star -1)
     (c-ts-common-comment-2nd-line-matcher
      c-ts-common-comment-2nd-line-anchor
      1)))
  "Tree-sitter indentation rules for `phpdoc'.")

\f
;;; Font-lock

(defconst php-ts-mode--keywords
  '("abstract" "and" "array" "as" "break" "callable" "case" "catch"
    "class" "clone" "const" "continue" "declare" "default" "do" "echo"
    "else" "elseif" "enddeclare" "endfor" "endforeach" "endif"
    "endswitch" "endwhile" "enum" "exit" "extends" "final" "finally" "fn"
    "for" "foreach" "from" "function" "global" "goto" "if" "implements"
    "include" "include_once" "instanceof" "insteadof" "interface"
    "list" "match" "namespace" "new" "null" "or" "print" "private"
    "protected" "public" "readonly" "require" "require_once" "return"
    "static" "switch" "throw" "trait" "try" "unset" "use" "while" "xor"
    "yield")
  "PHP keywords for tree-sitter font-locking.")

(defconst php-ts-mode--operators
  '("--" "**=" "*=" "/=" "%=" "+=" "-=" ".=" "<<=" ">>=" "&=" "^="
    "|=" "??"  "??=" "||" "&&" "|" "^" "&" "==" "!=" "<>" "===" "!=="
    "<" ">" "<=" ">=" "<=>" "<<" ">>" "+" "-" "." "*" "**" "/" "%"
    "->" "?->" "...")
  "PHP operators for tree-sitter font-locking.")

(defconst php-ts-mode--predefined-constant
  '(;; predefined constant
    "PHP_VERSION" "PHP_MAJOR_VERSION" "PHP_MINOR_VERSION"
    "PHP_RELEASE_VERSION" "PHP_VERSION_ID" "PHP_EXTRA_VERSION"
    "ZEND_THREAD_SAFE" "ZEND_DEBUG_BUILD" "PHP_ZTS" "PHP_DEBUG"
    "PHP_MAXPATHLEN" "PHP_OS" "PHP_OS_FAMILY" "PHP_SAPI" "PHP_EOL"
    "PHP_INT_MAX" "PHP_INT_MIN" "PHP_INT_SIZE" "PHP_FLOAT_DIG"
    "PHP_FLOAT_EPSILON" "PHP_FLOAT_MIN" "PHP_FLOAT_MAX"
    "PHP_WINDOWS_EVENT_CTRL_C" "PHP_WINDOWS_EVENT_CTRL_BREAK"
    "DEFAULT_INCLUDE_PATH" "PEAR_INSTALL_DIR" "PEAR_EXTENSION_DIR"
    "PHP_EXTENSION_DIR" "PHP_PREFIX" "PHP_BINDIR" "PHP_BINARY"
    "PHP_MANDIR" "PHP_LIBDIR" "PHP_DATADIR" "PHP_SYSCONFDIR"
    "PHP_LOCALSTATEDIR" "PHP_CONFIG_FILE_PATH" "PHP_CONFIG_FILE_SCAN_DIR"
    "PHP_SHLIB_SUFFIX" "PHP_FD_SETSIZE" "E_ERROR" "E_WARNING" "E_PARSE"
    "E_NOTICE" "E_CORE_ERROR" "E_CORE_WARNING" "E_COMPILE_ERROR"
    "E_COMPILE_WARNING" "E_USER_ERROR" "E_USER_WARNING"
    "E_USER_NOTICE" "E_DEPRECATED" "E_USER_DEPRECATED"
    "E_ALL" "E_STRICT"
    ;; math constant
    "M_PI" "M_E" "M_LOG2E" "M_LOG10E" "M_LN2" "M_LN10" "M_PI_2"
    "M_PI_4" "M_1_PI" "M_2_PI" "M_SQRTPI" "M_2_SQRTPI" "M_SQRT2"
    "M_SQRT3" "M_SQRT1_2" "M_LNPI" "M_EULER" "PHP_ROUND_HALF_UP"
    "PHP_ROUND_HALF_DOWN" "PHP_ROUND_HALF_EVEN" "PHP_ROUND_HALF_ODD"
    "NAN" "INF"
    ;; magic constant
    "__COMPILER_HALT_OFFSET__" "__CLASS__" "__DIR__" "__FILE__"
    "__FUNCTION__" "__LINE__" "__METHOD__" "__NAMESPACE__" "__TRAIT__")
  "PHP predefined constant.")

(defconst php-ts-mode--class-magic-methods
  '("__construct" "__destruct" "__call" "__callStatic" "__get" "__set"
    "__isset" "__unset" "__sleep" "__wakeup" "__serialize" "__unserialize"
    "__toString" "__invoke" "__set_state" "__clone" "__debugInfo")
  "PHP predefined magic methods.")

(defun php-ts-mode--test-namespace-name-as-prefix-p ()
  "Return t if namespace_name_as_prefix is a named node, nil otherwise."
  (ignore-errors
    (progn (treesit-query-compile 'php "(namespace_name_as_prefix)" t) t)))

(defun php-ts-mode--test-namespace-aliasing-clause-p ()
  "Return t if namespace_aliasing_clause is a named node, nil otherwise."
  (ignore-errors
    (progn (treesit-query-compile 'php "(namespace_aliasing_clause)" t) t)))

(defun php-ts-mode--test-namespace-use-group-clause-p ()
  "Return t if namespace_use_group_clause is a named node, nil otherwise."
  (ignore-errors
    (progn (treesit-query-compile 'php "(namespace_use_group_clause)" t) t)))

(defun php-ts-mode--test-visibility-modifier-operation-clause-p ()
  "Return t if (visibility_modifier (operation)) is defined, nil otherwise."
  (ignore-errors
    (progn (treesit-query-compile 'php "(visibility_modifier (operation))" t) t)))

(defun php-ts-mode--test-property-hook-clause-p ()
  "Return t if property_hook is a named node, nil otherwise."
  (ignore-errors
    (progn (treesit-query-compile 'php "(property_hook)" t) t)))

(defun php-ts-mode--font-lock-settings ()
  "Tree-sitter font-lock settings."
  (treesit-font-lock-rules

   :language 'php
   :feature 'keyword
   :override t
   `([,@php-ts-mode--keywords] @font-lock-keyword-face
     ,@(when (php-ts-mode--test-visibility-modifier-operation-clause-p)
	 '((visibility_modifier (operation) @font-lock-builtin-face)))
     (var_modifier) @font-lock-builtin-face)

   :language 'php
   :feature 'comment
   :override t
   '((comment) @font-lock-comment-face)

   :language 'php
   :feature 'constant
   `((boolean) @font-lock-constant-face
     (null) @font-lock-constant-face
     ;; predefined constant or built in constant (part of PHP core)
     ((name) @font-lock-builtin-face
      (:match ,(rx-to-string
                `(: bos (or ,@php-ts-mode--predefined-constant) eos))
              @font-lock-builtin-face))
     ;; user defined constant
     ((name) @font-lock-constant-face
      (:match "\\`_*[A-Z][0-9A-Z_]+\\'" @font-lock-constant-face))
     (const_declaration
      (const_element (name) @font-lock-constant-face))
     ;; declare directive
     (declare_directive ["strict_types" "encoding" "ticks"] @font-lock-constant-face))

   :language 'php
   :feature 'name
   '((goto_statement (name) @font-lock-constant-face)
     (named_label_statement (name) @font-lock-constant-face))

   :language 'php
   :feature 'delimiter
   `((["," ":" ";" "\\"]) @font-lock-delimiter-face)

   :language 'php
   :feature 'operator
   `((error_suppression_expression "@" @font-lock-keyword-face)
     [,@php-ts-mode--operators] @font-lock-operator-face)

   :language 'php
   :feature 'variable-name
   :override t
   '(((name) @font-lock-keyword-face (:equal "this" @font-lock-keyword-face))
     (variable_name (name) @font-lock-variable-name-face)
     (relative_scope ["parent" "self" "static"] @font-lock-builtin-face)
     (relative_scope) @font-lock-constant-face
     (dynamic_variable_name (name) @font-lock-variable-name-face)
     (member_access_expression
      name: (_) @font-lock-variable-name-face)
     (scoped_property_access_expression
      scope: (name) @font-lock-constant-face))

   :language 'php
   :feature 'string
   `(("\"") @font-lock-string-face
     (encapsed_string) @font-lock-string-face
     (string_content) @font-lock-string-face
     (string) @font-lock-string-face)

   :language 'php
   :feature 'literal
   '((integer) @font-lock-number-face
     (float) @font-lock-number-face
     (heredoc identifier: (heredoc_start) @font-lock-constant-face)
     (heredoc_body (string_content) @font-lock-string-face)
     (heredoc end_tag: (heredoc_end) @font-lock-constant-face)
     (nowdoc identifier: (heredoc_start) @font-lock-constant-face)
     (nowdoc_body (nowdoc_string) @font-lock-string-face)
     (nowdoc end_tag: (heredoc_end) @font-lock-constant-face)
     (shell_command_expression) @font-lock-string-face)

   :language 'php
   :feature 'type
   :override t
   '((union_type "|" @font-lock-operator-face)
     (union_type) @font-lock-type-face
     (bottom_type) @font-lock-type-face
     (primitive_type) @font-lock-type-face
     (cast_type) @font-lock-type-face
     (named_type) @font-lock-type-face
     (optional_type) @font-lock-type-face)

   :language 'php
   :feature 'definition
   :override t
   `((php_tag) @font-lock-preprocessor-face
     ("?>") @font-lock-preprocessor-face
     ;; Highlights identifiers in declarations.
     (class_declaration
      name: (_) @font-lock-type-face)
     (class_interface_clause (name) @font-lock-type-face)
     (interface_declaration
      name: (_) @font-lock-type-face)
     (trait_declaration
      name: (_) @font-lock-type-face)
     (enum_declaration
      name: (_) @font-lock-type-face)
     (function_definition
      name: (_) @font-lock-function-name-face)
     ,@(when (php-ts-mode--test-property-hook-clause-p)
	 '((property_hook (name) @font-lock-function-name-face)))
     (method_declaration
      name: (_) @font-lock-function-name-face)
     (method_declaration
      name: (name) @font-lock-builtin-face
      (:match ,(rx-to-string
                `(: bos (or ,@php-ts-mode--class-magic-methods) eos))
              @font-lock-builtin-face))
     ("=>") @font-lock-keyword-face
     (object_creation_expression
      (name) @font-lock-type-face)
     ,@(when (php-ts-mode--test-namespace-name-as-prefix-p)
           '((namespace_name_as_prefix "\\" @font-lock-delimiter-face)
             (namespace_name_as_prefix
              (namespace_name (name)) @font-lock-type-face)))
     ,@(if (php-ts-mode--test-namespace-aliasing-clause-p)
           '((namespace_aliasing_clause (name) @font-lock-type-face))
         '((namespace_use_clause alias: (name) @font-lock-type-face)))
     ,@(when (not (php-ts-mode--test-namespace-use-group-clause-p))
         '((namespace_use_group
            (namespace_use_clause (name) @font-lock-type-face))))
     (namespace_use_clause (name) @font-lock-type-face)
     (namespace_name "\\" @font-lock-delimiter-face)
     (namespace_name (name) @font-lock-type-face)
     (use_declaration (name) @font-lock-property-use-face)
     (use_instead_of_clause (name) @font-lock-type-face)
     (binary_expression
      operator: "instanceof"
      right: (name) @font-lock-type-face))

   :language 'php
   :feature 'function-scope
   :override t
   '((scoped_call_expression
      scope: (name) @font-lock-constant-face)
     (class_constant_access_expression (name) @font-lock-constant-face))

   :language 'php
   :feature  'function-call
   :override t
   '((function_call_expression
      function: (name) @font-lock-function-call-face)
     (scoped_call_expression
      name: (_) @font-lock-function-call-face)
     (member_call_expression
      name: (_) @font-lock-function-call-face)
     (nullsafe_member_call_expression
      name: (_) @font-lock-function-call-face))

   :language 'php
   :feature 'argument
   '((argument
      name: (_) @font-lock-constant-face))

   :language 'php
   :feature 'escape-sequence
   :override t
   '((string (escape_sequence) @font-lock-escape-face)
     (encapsed_string (escape_sequence) @font-lock-escape-face)
     (heredoc_body (escape_sequence) @font-lock-escape-face))

   :language 'php
   :feature 'base-clause
   :override t
   `((base_clause (name) @font-lock-type-face)
     (use_as_clause (name) @font-lock-property-use-face)
     ,@(when (not (php-ts-mode--test-namespace-name-as-prefix-p))
	 '((qualified_name prefix: "\\" @font-lock-delimiter-face)))
     (qualified_name (name) @font-lock-constant-face))

   :language 'php
   :feature 'property
   '((enum_case
      name: (_) @font-lock-type-face))

   :language 'php
   :feature 'attribute
   '((((attribute (_) @attribute_name) @font-lock-preprocessor-face)
      (:equal "Deprecated" @attribute_name))
     (attribute_group (attribute (name) @font-lock-constant-face)))

   :language 'php
   :feature 'bracket
   '((["(" ")" "[" "]" "{" "}"]) @font-lock-bracket-face)

   :language 'php
   :feature 'error
   :override t
   '((ERROR) @php-ts-mode--fontify-error)))

\f
;;; Font-lock helpers

(defconst php-ts-mode--custom-html-font-lock-settings
  (treesit-font-lock-rules
   :language 'html
   :override t
   :feature 'comment
   `((comment) @font-lock-comment-face
     ;; handle shebang path and others type of comment
     (document (text) @font-lock-comment-face))

   :language 'html
   :override t
   :feature 'keyword
   `("doctype" @font-lock-keyword-face)

   :language 'html
   :override t
   :feature 'definition
   `((tag_name) @font-lock-function-name-face)

   :language 'html
   :override 'append
   :feature 'string
   `((quoted_attribute_value) @font-lock-string-face)

   :language 'html
   :override t
   :feature 'property
   `((attribute_name) @font-lock-variable-name-face))
  "Tree-sitter Font-lock settings for HTML when embedded in PHP.
Like `html-ts-mode--font-lock-settings' but adapted for `php-ts-mode'.")

(defvar php-ts-mode--phpdoc-font-lock-settings
  (treesit-font-lock-rules
   :language 'phpdoc
   :feature 'document
   :override t
   '((document) @font-lock-doc-face)

   :language 'phpdoc
   :feature 'type
   :override t
   '((union_type
      [(array_type) (primitive_type) (named_type) (optional_type)] @font-lock-type-face)
     ([(array_type) (primitive_type) (named_type) (optional_type)] @font-lock-type-face)
     (fqsen (name) @font-lock-function-name-face))

   :language 'phpdoc
   :feature 'attribute
   :override t
   `((tag_name) @font-lock-constant-face
     (uri) @font-lock-doc-markup-face
     (tag
      [(version) (email_address)] @font-lock-doc-markup-face)
     (tag (author_name) @font-lock-property-name-face))

   :language 'phpdoc
   :feature 'variable
   :override t
   '((variable_name (name) @font-lock-variable-name-face)))
  "Tree-sitter font-lock settings for phpdoc.")

(defun php-ts-mode--colorize-css-value (node override start end &rest _)
  "Colorize CSS property value like `css--fontify-region'.
For NODE, OVERRIDE, START, and END, see `treesit-font-lock-rules'."
  (if (and php-ts-mode-css-fontify-colors
           (string-equal "plain_value" (treesit-node-type node)))
      (let ((color (css--compute-color start (treesit-node-text node t))))
        (when color
	  (with-silent-modifications
	    (add-text-properties
	     (treesit-node-start node) (treesit-node-end node)
	     (list 'face (list :background color
			       :foreground (readable-foreground-color
                                            color)
			       :box '(:line-width -1)))))))
    (treesit-fontify-with-override
     (treesit-node-start node) (treesit-node-end node)
     'font-lock-variable-name-face
     override start end)))

(defun php-ts-mode--fontify-error (node override start end &rest _)
  "Fontify the error nodes.
For NODE, OVERRIDE, START, and END, see `treesit-font-lock-rules'."
  (treesit-fontify-with-override
   (treesit-node-start node) (treesit-node-end node)
   'font-lock-warning-face
   override start end))

(defun php-ts-mode--html-language-at-point (point)
  "Return the language at POINT assuming the point is within a HTML region."
  (let* ((node (treesit-node-at point 'html))
         (parent (treesit-node-parent node))
         (node-query (format "(%s (%s))"
                             (treesit-node-type parent)
                             (treesit-node-type node))))
    (cond
     ((string-equal "(script_element (raw_text))" node-query) 'javascript)
     ((string-equal "(style_element (raw_text))" node-query) 'css)
     (t 'html))))

(defun php-ts-mode--language-at-point (point)
  "Return the language at POINT."
  (let* ((node (treesit-node-at point 'php))
         (node-type (treesit-node-type node))
         (parent (treesit-node-parent node))
         (node-query (format "(%s (%s))" (treesit-node-type parent) node-type)))
    (save-excursion
      (goto-char (treesit-node-start node))
      (cond
       ((not (member node-query '("(program (text))"
                                  "(text_interpolation (text))")))
        'php)
       (t (php-ts-mode--html-language-at-point point))))))

\f
;;; Imenu

(defun php-ts-mode--parent-object (node)
  "Return the name of the object that own NODE."
  (treesit-parent-until
   node
   (lambda (n)
     (member (treesit-node-type n)
             '("class_declaration"
               "enum_declaration"
               "function_definition"
               "interface_declaration"
               "method_declaration"
               "namespace_definition"
               "trait_declaration")))))

(defun php-ts-mode--defun-name-separator (node)
  "Return a separator to connect object name, based on NODE type."
  (let ((node-type (treesit-node-type node)))
    (cond ((member node-type '("function_definition" "method_declaration"))
           "()::")
          ((member node-type '("class_declaration" "enum_declaration" "trait_declaration"))
           "::")
          (t "\\"))))

(defun php-ts-mode--defun-object-name (node node-text)
  "Compose the full name of a NODE that is a PHP variable, method, class etc.
If the NODE has a parent, it recursively concat the parent names with NODE-TEXT,
otherwise it returns NODE-TEXT."
  (let* ((parent-node (php-ts-mode--parent-object node))
         (parent-node-text
          (treesit-node-text
           (treesit-node-child-by-field-name parent-node "name") t))
         (parent-node-separator (php-ts-mode--defun-name-separator parent-node)))
    (if parent-node
        (progn
          (setq parent-node-text
                (php-ts-mode--defun-object-name
                 parent-node
                 parent-node-text))
          (concat parent-node-text parent-node-separator node-text))
      node-text)))

(defun php-ts-mode--defun-name (node)
  "Return the defun name of NODE.
Return nil if the NODE has no field “name” or if NODE is not a defun node."
  (let ((child (treesit-node-child-by-field-name node "name")))
    (cl-case (intern (treesit-node-type node))
      (class_declaration (treesit-node-text child t))
      (trait_declaration (treesit-node-text child t))
      (interface_declaration (treesit-node-text child t))
      (namespace_definition (treesit-node-text child t))
      (enum_declaration (treesit-node-text child t))
      (function_definition (treesit-node-text child t))
      (method_declaration
       (php-ts-mode--defun-object-name node (treesit-node-text child t)))
      (variable_name
       (php-ts-mode--defun-object-name node (treesit-node-text node t)))
      (const_element
       (php-ts-mode--defun-object-name
        node
        (treesit-node-text (treesit-node-child node 0) t))))))

\f
;;; Defun navigation

(defun php-ts-mode--indent-defun ()
  "Indent the current top-level declaration syntactically.
`treesit-defun-type-regexp' defines what constructs to indent."
  (interactive "*")
  (when-let ((orig-point (point-marker))
             (node (treesit-defun-at-point)))
    (indent-region (treesit-node-start node)
                   (treesit-node-end node))
    (goto-char orig-point)))

(defun php-ts-mode--defun-valid-p (node)
  "Return non-nil if NODE is a valid defun node.
Ie, NODE is not nested."
  (not (and (member (treesit-node-type node)
                    '("variable_name"
                      "const_element"
                      "enum_declaration"
                      "union_declaration"
                      "declaration"))
            ;; If NODE's type is one of the above, make sure it is
            ;; top-level.
            (treesit-node-top-level
             node (rx (or "variable_name"
                          "const_element"
                          "function_definition"
                          "enum_declaration"
                          "union_declaration"
                          "declaration"))))))

\f
;;; Filling

(defun php-ts-mode--comment-indent-new-line (&optional soft)
  "Break line at point and indent, continuing comment if within one.
Like `c-ts-common-comment-indent-new-line', but handle the
less common PHP-style # comment.  SOFT works the same as in
`comment-indent-new-line'."
  (if (save-excursion
        ;; Line start with # or ## or ###...
        (beginning-of-line)
        (re-search-forward
         (rx "#" (group (* (any "#")) (* " ")))
         (line-end-position)
         t nil))
      (let ((offset (- (match-beginning 0) (line-beginning-position)))
            (comment-prefix (match-string 0))
	    (insert-line-break
             (lambda ()
	       (delete-horizontal-space)
	       (if soft
		   (insert-and-inherit ?\n)
		 (newline  1)))))
	(funcall insert-line-break)
        (delete-region (line-beginning-position) (point))
        (insert
         (make-string offset ?\s)
         comment-prefix))
    ;; other style of comments
    (c-ts-common-comment-indent-new-line soft)))

(defun php-ts-mode-comment-setup ()
  "Set up local variables for PHP comment.
Depends on `c-ts-common-comment-setup'."
  (c-ts-common-comment-setup)
  (setq-local c-ts-common--comment-regexp "comment"
              comment-line-break-function #'php-ts-mode--comment-indent-new-line
              comment-style 'extra-line
              comment-start-skip (rx (or (seq "#" (not (any "[")))
                                         (seq "/" (+ "/"))
                                         (seq "/" (+ "*")))
                                     (* (syntax whitespace)))))

\f
;;; Modes

(defun php-ts-mode-set-comment-style ()
  "Set a different comment style."
  (interactive)
  (setq-local comment-start
              (completing-read
               "Choose comment style: "
               '("/**" "//" "/*" "#") nil t nil nil "// "))
  (cond
   ((equal comment-start "/*") (setq-local comment-end "*/"))
   ((equal comment-start "//") (setq-local comment-end ""))
   ((equal comment-start "#") (setq-local comment-end ""))
   ((equal comment-start "/**") (setq-local comment-end "*/"))))

(defvar-keymap php-ts-mode-map
  :doc "Keymap for `php-ts-mode' buffers."
  :parent prog-mode-map
  "C-c C-q" #'php-ts-mode--indent-defun
  "C-c ."   #'php-ts-mode-set-style
  "C-c C-k" #'php-ts-mode-set-comment-style
  "C-c C-n" #'run-php
  "C-c C-c" #'php-ts-mode-send-buffer
  "C-c C-l" #'php-ts-mode-send-file
  "C-c C-r" #'php-ts-mode-send-region)

(easy-menu-define php-ts-mode-menu php-ts-mode-map
  "Menu bar entry for `php-ts-mode'."
  `("PHP"
    ["Comment Out Region" comment-region
     :enable mark-active
     :help "Comment out the region between the mark and point"]
    ["Uncomment Region" (comment-region (region-beginning)
                                        (region-end) '(4))
     :enable mark-active
     :help "Uncomment the region between the mark and point"]
    ["Indent Top-level Expression" php-ts-mode--indent-defun
     :help "Indent/reindent top-level function, class, etc."]
    ["Indent Line or Region" indent-for-tab-command
     :help "Indent current line or region, or insert a tab"]
    ["Forward Expression" forward-sexp
     :help "Move forward across one balanced expression"]
    ["Backward Expression" backward-sexp
     :help "Move back across one balanced expression"]
    ("Style..."
     ["Set Indentation Style..." php-ts-mode-set-style
      :help "Set PHP indentation style for current buffer"]
     ["Show Current Style Name"(message "Indentation Style: %s"
                                        php-ts-mode-indent-style)
      :help "Show the name of the PHP indentation style for current buffer"]
     ["Set Comment Style" php-ts-mode-set-comment-style
      :help "Choose PHP comment style between block and line comments"])
    "--"
    ["Start interpreter" run-php
     :help "Run inferior PHP process in a separate buffer"]
    ["Show interpreter buffer" php-ts-mode-show-process-buffer]
    ["Hide interpreter buffer" php-ts-mode-hide-process-buffer]
    ["Kill interpreter process" php-ts-mode-kill-process]
    ["Evaluate buffer" php-ts-mode-send-buffer]
    ["Evaluate file" php-ts-mode-send-file]
    ["Evaluate region" php-ts-mode-send-region]
    "--"
    ["Start built-in webserver" php-ts-mode-run-php-webserver
     :help "Run the built-in PHP webserver"]
    "--"
    ["Customize" (lambda () (interactive) (customize-group "php-ts-mode"))]))

(defvar php-ts-mode--feature-list
  '((;; common
     comment definition spell
     ;; CSS specific
     query selector
     ;; HTML specific
     text
     ;; PHPDOC specific
     document
     phpdoc-error)
    (keyword string property type name)
    (;; common
     attribute assignment constant escape-sequence function-scope
     base-clause literal variable-name variable
     ;; Javascript specific
     jsx number pattern string-interpolation)
    (;; common
     argument bracket delimiter error function-call operator
     ;; Javascript specific
     function)))

;;;###autoload
(define-derived-mode php-ts-mode prog-mode "PHP"
  "Major mode for editing PHP, powered by tree-sitter."
  :syntax-table php-ts-mode--syntax-table

  (if (not (and
            (treesit-ready-p 'php)
            (treesit-ready-p 'phpdoc)
            (treesit-ready-p 'html)
            (treesit-ready-p 'javascript)
            (treesit-ready-p 'jsdoc)
            (treesit-ready-p 'css)))
      (error "Tree-sitter for PHP isn't
    available.  You can install the parsers with M-x
    `php-ts-mode-install-parsers'")

    ;; Require html-ts-mode only when we load php-ts-mode
    ;; so that we don't get a tree-sitter compilation warning for
    ;; php-ts-mode.
    (defvar html-ts-mode--indent-rules)
    (require 'html-ts-mode)
    ;; For embed html

    ;; phpdoc is a local parser, don't create a parser for it
    (treesit-parser-create 'html)
    (treesit-parser-create 'css)
    (treesit-parser-create 'javascript)

    ;; define the injected parser ranges
    (setq-local treesit-range-settings
                (treesit-range-rules
                 :embed 'phpdoc
                 :host 'php
                 :local t
                 '(((comment) @cap
                    (:match "/\\*\\*" @cap)))

                 :embed 'html
                 :host 'php
                 '((program (text) @cap)
                   (text_interpolation (text) @cap))

                 :embed 'javascript
                 :host 'html
                 :offset '(1 . -1)
                 '((script_element
                    (start_tag (tag_name))
                    (raw_text) @cap))

                 :embed 'jsdoc
                 :host 'javascript
                 :local t
                 `(((comment) @cap
                    (:match ,js--treesit-jsdoc-beginning-regexp @cap)))

                 :embed 'css
                 :host 'html
                 :offset '(1 . -1)
                 '((style_element
                    (start_tag (tag_name))
                    (raw_text) @cap))))

    (setq-local treesit-language-at-point-function #'php-ts-mode--language-at-point)

    ;; Navigation.
    (setq-local treesit-defun-type-regexp
                (regexp-opt '("class_declaration"
                              "enum_declaration"
                              "function_definition"
                              "interface_declaration"
                              "method_declaration"
                              "namespace_definition"
                              "trait_declaration")))

    (setq-local treesit-defun-name-function #'php-ts-mode--defun-name)

    (setq-local treesit-thing-settings
                `((php
                   (defun ,treesit-defun-type-regexp)
                   (sexp (not ,(rx (or "{" "}" "[" "]" "(" ")" ","))))
                   (sentence  ,(regexp-opt
                                '("break_statement"
                                  "case_statement"
                                  "continue_statement"
                                  "declaration"
                                  "default_statement"
                                  "do_statement"
                                  "expression_statement"
                                  "for_statement"
                                  "if_statement"
                                  "return_statement"
                                  "switch_statement"
                                  "while_statement"
                                  "statement")))
                   (text ,(regexp-opt '("comment" "text"))))))

    ;; Indent.
    (when (eq php-ts-mode-indent-style 'wordpress)
      (setq-local indent-tabs-mode t))

    (setq-local c-ts-common-indent-offset 'php-ts-mode-indent-offset)
    (setq-local treesit-simple-indent-rules (php-ts-mode--get-indent-style))
    (setq-local treesit-simple-indent-rules
                (append treesit-simple-indent-rules
                        php-ts-mode--phpdoc-indent-rules
                        html-ts-mode--indent-rules
                        ;; Extended rules for js and css, to
                        ;; indent appropriately when injected
                        ;; into html
                        `((javascript ((parent-is "program")
                                       php-ts-mode--js-css-tag-bol
                                       php-ts-mode-js-css-indent-offset)
                                      ,@(cdr (car js--treesit-indent-rules))))
                        `((css ((parent-is "stylesheet")
                                php-ts-mode--js-css-tag-bol
                                php-ts-mode-js-css-indent-offset)
                               ,@(cdr (car css--treesit-indent-rules))))))

    ;; Comment
    (php-ts-mode-comment-setup)

    ;; PHP vars are case-sensitive
    (setq-local case-fold-search t)

    ;; Electric
    (setq-local electric-indent-chars
                (append "{}():;," electric-indent-chars))

    ;; Imenu/Which-function/Outline
    (setq-local treesit-simple-imenu-settings
                '(("Class" "\\`class_declaration\\'" nil nil)
                  ("Enum" "\\`enum_declaration\\'" nil nil)
                  ("Function" "\\`function_definition\\'" nil nil)
                  ("Interface" "\\`interface_declaration\\'" nil nil)
                  ("Method" "\\`method_declaration\\'" nil nil)
                  ("Namespace" "\\`namespace_definition\\'" nil nil)
                  ("Trait" "\\`trait_declaration\\'" nil nil)
                  ("Variable" "\\`variable_name\\'" nil nil)
                  ("Constant" "\\`const_element\\'" nil nil)))

    ;; Font-lock.
    (setq-local treesit-font-lock-settings
                (append (php-ts-mode--font-lock-settings)
                        php-ts-mode--custom-html-font-lock-settings
                        js--treesit-font-lock-settings
                        (append
                         ;; Rule for coloring CSS property values.
                         ;; Placed before `css--treesit-settings'
                         ;; to win against the same rule contained therein.
                         (treesit-font-lock-rules
                          :language 'css
                          :override t
                          :feature 'variable
                          '((plain_value) @php-ts-mode--colorize-css-value))
                         css--treesit-settings)
                        php-ts-mode--phpdoc-font-lock-settings))

    (setq-local treesit-font-lock-feature-list php-ts-mode--feature-list)

    ;; Align.
    (setq-local align-indent-before-aligning t)

    ;; should be the last one
    (setq-local treesit-primary-parser (treesit-parser-create 'php))
    (treesit-font-lock-recompute-features)
    (treesit-major-mode-setup)
    (add-hook 'flymake-diagnostic-functions #'php-ts-mode-flymake-php nil 'local)))

\f
;;;###autoload
(defun php-ts-mode-run-php-webserver (&optional port hostname document-root
                                                router-script num-of-workers)
  "Run PHP built-in web server.

PORT: Port number of built-in web server, default `php-ts-mode-ws-port'.
Prompt for the port if the default value is nil.
HOSTNAME: Hostname or IP address of Built-in web server,
default `php-ts-mode-ws-hostname'.  Prompt for the hostname if the
default value is nil.
DOCUMENT-ROOT: Path to Document root, default `php-ts-mode-ws-document-root'.
Prompt for the document-root if the default value is nil.
ROUTER-SCRIPT: Path of the router PHP script,
see `https://www.php.net/manual/en/features.commandline.webserver.php'
NUM-OF-WORKERS: Before run the web server set the
PHP_CLI_SERVER_WORKERS env variable useful for testing code against
multiple simultaneous requests.

Interactively, when invoked with prefix argument, always prompt
for PORT, HOSTNAME, DOCUMENT-ROOT and ROUTER-SCRIPT."
  (interactive (when current-prefix-arg
                 (php-ts-mode--webserver-read-args)))
  (let* ((port (or
                port
                php-ts-mode-ws-port
                (php-ts-mode--webserver-read-args 'port)))
         (hostname (or
                    hostname
                    php-ts-mode-ws-hostname
                    (php-ts-mode--webserver-read-args 'hostname)))
         (document-root (or
                         document-root
                         php-ts-mode-ws-document-root
                         (php-ts-mode--webserver-read-args 'document-root)))
         (host (format "%s:%d" hostname port))
         (name (format "PHP web server on: %s" host))
         (buf-name (format "*%s*" name))
         (args (delq
                nil
                (list "-S" host
                      "-t" document-root
                      router-script)))
         (process-environment
          (cons (cond
                 (num-of-workers (format "PHP_CLI_SERVER_WORKERS=%d" num-of-workers))
                 (php-ts-mode-ws-workers (format "PHP_CLI_SERVER_WORKERS=%d" php-ts-mode-ws-workers)))
                process-environment)))
    (if (get-buffer buf-name)
        (message "Switch to already running web server into buffer %s" buf-name)
      (message "Run PHP built-in web server with args %s into buffer %s"
               (string-join args " ")
               buf-name)
      (apply #'make-comint name php-ts-mode-php-executable nil args))
    (funcall
     (if (called-interactively-p 'interactive) #'display-buffer #'get-buffer)
     buf-name)))

(derived-mode-add-parents 'php-ts-mode '(php-mode))

(defun php-ts-mode--webserver-read-args (&optional type)
  "Helper for `php-ts-mode-run-php-webserver'.
The optional TYPE can be the symbol \"port\", \"hostname\", \"document-root\" or
\"router-script\", otherwise it requires all of them."
  (let ((ask-port (lambda ()
                    (read-number "Port: " 3000)))
        (ask-hostname (lambda ()
                        (read-string "Hostname: " "localhost")))
        (ask-document-root (lambda ()
                             (expand-file-name
                              (read-directory-name "Document root: "
                                                   (file-name-directory
                                                    (or (buffer-file-name)
                                                        default-directory))))))
        (ask-router-script (lambda ()
                             (expand-file-name
                              (read-file-name "Router script: "
                                              (file-name-directory
                                               (or (buffer-file-name)
                                                   default-directory)))))))
    (cl-case type
      (port (funcall ask-port))
      (hostname (funcall ask-hostname))
      (document-root (funcall ask-document-root))
      (router-script (funcall ask-router-script))
      (t (list
          (funcall ask-port)
          (funcall ask-hostname)
          (funcall ask-document-root)
          (funcall ask-router-script))))))

(define-derived-mode inferior-php-ts-mode comint-mode "Inferior PHP"
  "Major mode for PHP inferior process."
  (setq-local scroll-conservatively 1
              comint-input-ring-file-name php-ts-mode-inferior-history
              comint-input-ignoredups t
              comint-prompt-read-only t
              comint-use-prompt-regexp t
              comint-prompt-regexp (concat "^" php-ts-mode--inferior-prompt " "))
  (comint-read-input-ring t))

\f
;;; Inferior PHP process.

(defvar php-ts-mode--inferior-php-process nil
  "The PHP inferior process associated to `php-ts-mode-inferior-php-buffer'.")

;;;###autoload
(defun run-php (&optional cmd config)
  "Run an PHP interpreter as a inferior process.

Arguments CMD and CONFIG, default to `php-ts-mode-php-executable'
and `php-ts-mode-php-config' respectively, control which PHP interpreter is run.
Prompt for CMD if `php-ts-mode-php-executable' is nil.
Optional CONFIG, if supplied, is the php.ini file to use."
  (interactive (when current-prefix-arg
                 (list
                  (read-string "Run PHP: " php-ts-mode-php-executable)
                  (expand-file-name
                   (read-file-name "With config: " php-ts-mode-php-config)))))
  (let ((buffer (get-buffer-create php-ts-mode-inferior-php-buffer))
        (cmd (or
              cmd
              php-ts-mode-php-executable
              (read-string "Run PHP: " php-ts-mode-php-executable)))
        (config (or
                 config
                 (and php-ts-mode-php-config
                      (expand-file-name php-ts-mode-php-config)))))
    (unless (comint-check-proc buffer)
      (with-current-buffer buffer
        (inferior-php-ts-mode-startup cmd config)
        (inferior-php-ts-mode)))
    (when buffer
      (pop-to-buffer buffer))))

(defun inferior-php-ts-mode-startup (cmd &optional config)
  "Start an inferior PHP process with command CMD and init file CONFIG.
CMD is the command to run.  Optional CONFIG, if supplied, is the php.ini
file to use."
  (setq-local php-ts-mode--inferior-php-process
              (apply #'make-comint-in-buffer
                     (string-replace "*" "" php-ts-mode-inferior-php-buffer)
                     php-ts-mode-inferior-php-buffer
                     cmd
                     nil
                     (delq
                      nil
                      (list
                       (when config
                         (format "-c %s" config))
                       "-a"))))
  (add-hook 'comint-preoutput-filter-functions
            (lambda (string)
              (let ((prompt (concat php-ts-mode--inferior-prompt " ")))
                (if (member
                     string
                     (list prompt "php { " "php ( " "/* > " "Interactive shell\n\n"))
                    string
                  (let (;; Filter out prompts characters that accumulate when sending
                        ;; regions to the inferior process.
                        (clean-string
                         (replace-regexp-in-string
                          (rx-to-string `(or
                                          (+ "php >" (opt space))
                                          (+ "php {" (opt space))
                                          (+ "php (" (opt space))
                                          (+ "/*" (1+ space) (1+ ">") (opt space))))
                          "" string)))
                    ;; Re-add the prompt for the next line, if isn't empty.
                    (if (string= clean-string "")
                        ""
                      (concat (string-chop-newline clean-string) "\n" prompt))))))
            nil t)
  (when php-ts-mode-inferior-history
    (set-process-sentinel
     (get-buffer-process  php-ts-mode-inferior-php-buffer)
     'php-ts-mode-inferior--write-history)))

;; taken and adapted from lua-ts-mode
(defun php-ts-mode-inferior--write-history (process _)
  "Write history file for inferior PHP PROCESS."
  ;; Depending on how the process is killed the buffer may not be
  ;; around anymore; e.g. `kill-buffer'.
  (when-let* ((buffer (process-buffer process))
              ((buffer-live-p (process-buffer process))))
    (with-current-buffer buffer (comint-write-input-ring))))

(defun php-ts-mode-send-region (beg end)
  "Send region between BEG and END to the inferior PHP process."
  (interactive "r")
  (if (buffer-live-p php-ts-mode--inferior-php-process)
      (progn
        (php-ts-mode-show-process-buffer)
        (comint-send-string php-ts-mode--inferior-php-process "\n")
        (comint-send-string
         php-ts-mode--inferior-php-process
         (buffer-substring-no-properties beg end))
        (comint-send-string php-ts-mode--inferior-php-process "\n"))
    (message "Invoke run-php first!")))

(defun php-ts-mode-send-buffer ()
  "Send current buffer to the inferior PHP process."
  (interactive)
  (save-excursion
    (goto-char (point-min))
    (search-forward "<?php" nil t)
    (php-ts-mode-send-region (point) (point-max))))

(defun php-ts-mode-send-file (file)
  "Send contents of FILE to the inferior PHP process."
  (interactive "f")
  (with-temp-buffer
    (insert-file-contents-literally file)
    (search-forward "<?php" nil t)
    (php-ts-mode-send-region (point) (point-max))))

(defun php-ts-mode-show-process-buffer ()
  "Show the inferior PHP process buffer."
  (interactive)
  (display-buffer php-ts-mode-inferior-php-buffer))

(defun php-ts-mode-hide-process-buffer ()
  "Hide the inferior PHP process buffer."
  (interactive)
  (delete-windows-on php-ts-mode-inferior-php-buffer))

(defun php-ts-mode-kill-process ()
  "Kill the inferior PHP process."
  (interactive)
  (with-current-buffer php-ts-mode-inferior-php-buffer
    (kill-buffer-and-window)))

(when (treesit-ready-p 'php)
  (add-to-list
   'auto-mode-alist '("\\.\\(?:php[s345]?\\|phtml\\)\\'" . php-ts-mode))
  (add-to-list
   'auto-mode-alist '("\\.\\(?:php\\|inc\\|stub\\)\\'" . php-ts-mode))
  (add-to-list
   'auto-mode-alist '("/\\.php_cs\\(?:\\.dist\\)?\\'" . php-ts-mode))
  (add-to-list
   'interpreter-mode-alist
   (cons "php\\(?:-?[34578]\\(?:\\.[0-9]+\\)*\\)?" 'php-ts-mode)))

(provide 'php-ts-mode)
;;; php-ts-mode.el ends here