clojure-ts-mode.el

;;; clojure-ts-mode.el --- Major mode for Clojure code -*- lexical-binding: t; -*-

;; Copyright © 2022-2025 Danny Freeman
;;
;; Authors: Danny Freeman <danny@dfreeman.email>
;; Maintainer: Danny Freeman <danny@dfreeman.email>
;; URL: http://github.com/clojure-emacs/clojure-ts-mode
;; Keywords: languages clojure clojurescript lisp
;; Version: 0.2.3
;; Package-Requires: ((emacs "29.1"))

;; This file is not part of GNU Emacs.

;;; Commentary:

;; Provides font-lock, indentation, and navigation for the
;; Clojure programming language (http://clojure.org).

;; For the tree-sitter grammar this mode is based on,
;; see https://github.com/sogaiu/tree-sitter-clojure.

;; Using clojure-ts-mode with paredit or smartparens is highly recommended.

;; Here are some example configurations:

;;   ;; require or autoload paredit-mode
;;   (add-hook 'clojure-ts-mode-hook #'paredit-mode)

;;   ;; require or autoload smartparens
;;   (add-hook 'clojure-ts-mode-hook #'smartparens-strict-mode)

;; See inf-clojure (http://github.com/clojure-emacs/inf-clojure) for
;; basic interaction with Clojure subprocesses.

;; See CIDER (http://github.com/clojure-emacs/cider) for
;; better interaction with subprocesses via nREPL.

;;; License:

;; This program 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.
;;
;; This program 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Code:

(require 'treesit)

(declare-function treesit-parser-create "treesit.c")
(declare-function treesit-node-eq "treesit.c")
(declare-function treesit-node-type "treesit.c")
(declare-function treesit-node-parent "treesit.c")
(declare-function treesit-node-child "treesit.c")
(declare-function treesit-node-child-by-field-name "treesit.c")

(defgroup clojure-ts nil
  "Major mode for editing Clojure code with tree-sitter."
  :prefix "clojure-ts-"
  :group 'languages
  :link '(url-link :tag "GitHub" "https://github.com/clojure-emacs/clojure-ts-mode")
  :link '(emacs-commentary-link :tag "Commentary" "clojure-mode"))

(defconst clojure-ts-mode-version
  "0.2.3"
  "The current version of `clojure-ts-mode'.")

(defcustom clojure-ts-comment-macro-font-lock-body nil
  "Highlight the entire body of a comment macro as a comment.

When set to a non-nil value, applies the comment font-locking face to the entire
body of comment macros.
When nil (the default), the body of comment macros uses default font-locking
rules for whatever expressions are in the body, except for the comment symbol
itself."
  :safe #'booleanp
  :type 'boolean
  :package-version '(clojure-ts-mode . "0.1.3"))

(defcustom clojure-ts-ensure-grammars t
  "When non-nil, ensure required tree-sitter grammars are installed."
  :safe #'booleanp
  :type 'boolean
  :package-version '(clojure-ts-mode . "0.2.0"))

(defcustom clojure-ts-toplevel-inside-comment-form nil
  "Eval top level forms inside comment forms instead of the comment form itself."
  :type 'boolean
  :safe #'booleanp
  :package-version '(clojure-ts-mode . "0.2.1"))

(defcustom clojure-ts-docstring-fill-column fill-column
  "Value of `fill-column' to use when filling a docstring."
  :type 'integer
  :safe #'integerp
  :package-version '(clojure-ts-mode . "0.2.3"))

(defcustom clojure-ts-docstring-fill-prefix-width 2
  "Width of `fill-prefix' when filling a docstring.
The default value conforms with the de facto convention for
Clojure docstrings, aligning the second line with the opening
double quotes on the third column."
  :type 'integer
  :safe #'integerp
  :package-version '(clojure-ts-mode . "0.2.3"))

(defcustom clojure-ts-use-markdown-inline t
  "When non-nil, use Markdown inline grammar for docstrings."
  :type 'boolean
  :safe #'booleanp
  :package-version '(clojure-ts-mode . "0.2.3"))

(defvar clojure-ts--debug nil
  "Enables debugging messages, shows current node in mode-line.
Only intended for use at development time.")

(defvar clojure-ts-mode-syntax-table
  (let ((table (make-syntax-table)))
    ;; Initialize ASCII charset as symbol syntax
    (modify-syntax-entry '(0 . 127) "_" table)

    ;; Word syntax
    (modify-syntax-entry '(?0 . ?9) "w" table)
    (modify-syntax-entry '(?a . ?z) "w" table)
    (modify-syntax-entry '(?A . ?Z) "w" table)

    ;; Whitespace
    (modify-syntax-entry ?\s " " table)
    (modify-syntax-entry ?\xa0 " " table) ; non-breaking space
    (modify-syntax-entry ?\t " " table)
    (modify-syntax-entry ?\f " " table)
    ;; Setting commas as whitespace makes functions like `delete-trailing-whitespace' behave unexpectedly (#561)
    (modify-syntax-entry ?, "." table)

    ;; Delimiters
    (modify-syntax-entry ?\( "()" table)
    (modify-syntax-entry ?\) ")(" table)
    (modify-syntax-entry ?\[ "(]" table)
    (modify-syntax-entry ?\] ")[" table)
    (modify-syntax-entry ?\{ "(}" table)
    (modify-syntax-entry ?\} "){" table)

    ;; Prefix chars
    (modify-syntax-entry ?` "'" table)
    (modify-syntax-entry ?~ "'" table)
    (modify-syntax-entry ?^ "'" table)
    (modify-syntax-entry ?@ "'" table)
    (modify-syntax-entry ?? "_ p" table) ; ? is a prefix outside symbols
    (modify-syntax-entry ?# "_ p" table) ; # is allowed inside keywords (#399)
    (modify-syntax-entry ?' "_ p" table) ; ' is allowed anywhere but the start of symbols

    ;; Others
    (modify-syntax-entry ?\; "<" table) ; comment start
    (modify-syntax-entry ?\n ">" table) ; comment end
    (modify-syntax-entry ?\" "\"" table) ; string
    (modify-syntax-entry ?\\ "\\" table) ; escape

    table)
  "Syntax table for `clojure-ts-mode'.")


(defconst clojure-ts--builtin-dynamic-var-regexp
  (eval-and-compile
    (concat "^"
            (regexp-opt
             '("*1" "*2" "*3" "*agent*"
               "*allow-unresolved-vars*" "*assert*" "*clojure-version*"
               "*command-line-args*" "*compile-files*"
               "*compile-path*" "*data-readers*" "*default-data-reader-fn*"
               "*e" "*err*" "*file*" "*flush-on-newline*"
               "*in*" "*macro-meta*" "*math-context*" "*ns*" "*out*"
               "*print-dup*" "*print-length*" "*print-level*"
               "*print-meta*" "*print-readably*"
               "*read-eval*" "*source-path*"
               "*unchecked-math*"
               "*use-context-classloader*" "*warn-on-reflection*"))
            "$")))

(defconst clojure-ts--builtin-symbol-regexp
  (eval-and-compile
    (concat "^"
            (regexp-opt
             '("do" "if" "let*" "var"
               "fn" "fn*" "loop*" "recur"
               "throw" "try" "catch" "finally"
               "set!" "new"
               "monitor-enter" "monitor-exit"
               "quote"

               "->" "->>" ".." "."
               "amap" "and" "areduce" "as->" "assert"
               "binding" "bound-fn"
               "case" "comment" "cond" "cond->" "cond->>" "condp"
               "declare" "def" "definline" "definterface" "defmacro" "defmethod"
               "defmulti" "defn" "defn-" "defonce" "defprotocol" "defrecord"
               "defstruct" "deftype"
               "delay" "doall" "dorun" "doseq" "dosync" "dotimes" "doto"
               "extend-protocol" "extend-type"
               "for" "future"
               "gen-class" "gen-interface"
               "if-let" "if-not" "if-some" "import" "in-ns""io!"
               "lazy-cat" "lazy-seq" "let" "letfn" "locking" "loop"
               "memfn" "ns" "or"
               "proxy" "proxy-super" "pvalues"
               "refer-clojure" "reify"
               "some->" "some->>""sync"
               "time" "vswap!"
               "when" "when-first" "when-let" "when-not" "when-some" "while"
               "with-bindings" "with-in-str" "with-loading-context"
               "with-local-vars" "with-open" "with-out-str" "with-precision"
               "with-redefs" "with-redefs-fn"
               ;; Commonly used clojure.test functions
               "deftest" "deftest-" "is" "are" "testing"))
            "$")))

(defface clojure-ts-keyword-face
  '((t (:inherit font-lock-constant-face)))
  "Face used to font-lock Clojure keywords (:something).")

(defface clojure-ts-character-face
  '((t (:inherit font-lock-string-face)))
  "Face used to font-lock Clojure character literals.")

(defun clojure-ts-symbol-regexp (symbols)
  "Return a regular expression that matches one of SYMBOLS exactly."
  (concat "^" (regexp-opt symbols) "$"))

(defvar clojure-ts-function-docstring-symbols
  '("definline"
    "defmulti"
    "defmacro"
    "defn"
    "defn-"
    "defprotocol"
    "ns")
  "Symbols that accept an optional docstring as their second argument.")

(defvar clojure-ts-definition-docstring-symbols
  '("def")
  "Symbols that accept an optional docstring as their second argument.
Any symbols added here should only treat their second argument as a docstring
if a third argument (the value) is provided.
\"def\" is the only builtin Clojure symbol that behaves like this.")

(defconst clojure-ts--variable-definition-symbol-regexp
  (eval-and-compile
    (rx line-start (or "def" "defonce") line-end))
  "A regular expression matching a symbol used to define a variable.")

(defconst clojure-ts--typedef-symbol-regexp
  (eval-and-compile
    (rx line-start
        (or "defprotocol" "defmulti" "deftype" "defrecord"
            "definterface" "defmethod" "defstruct")
        line-end))
  "A regular expression matching a symbol used to define a type.")

(defconst clojure-ts--type-symbol-regexp
  (eval-and-compile
    (rx line-start
        (or "deftype" "defrecord"
            ;; While not reifying, helps with doc strings
            "defprotocol" "definterface"
            "reify" "proxy" "extend-type" "extend-protocol")
        line-end))
  "A regular expression matching a symbol used to define or instantiate a type.")

(defconst clojure-ts--interface-def-symbol-regexp
  (eval-and-compile
    (rx line-start (or "defprotocol" "definterface") line-end))
  "A regular expression matching a symbol used to define an interface.")

(defun clojure-ts--docstring-query (capture-symbol)
  "Return a query that captures docstrings with CAPTURE-SYMBOL."
  `(;; Captures docstrings in def
    ((list_lit :anchor (meta_lit) :?
               :anchor (sym_lit) @_def_symbol
               :anchor (comment) :?
               :anchor (sym_lit) ; variable name
               :anchor (comment) :?
               :anchor (str_lit) ,capture-symbol
               :anchor (_)) ; the variable's value
     (:match ,(clojure-ts-symbol-regexp clojure-ts-definition-docstring-symbols)
             @_def_symbol))
    ;; Captures docstrings in metadata of definitions
    ((list_lit :anchor (sym_lit) @_def_symbol
               :anchor (comment) :?
               :anchor (sym_lit
                        (meta_lit
                         value: (map_lit
                                 (kwd_lit) @_doc-keyword
                                 :anchor
                                 (str_lit) ,capture-symbol))))
     ;; We're only supporting this on a fixed set of defining symbols
     ;; Existing regexes don't encompass def and defn
     ;; Naming another regex is very cumbersome.
     (:match ,(clojure-ts-symbol-regexp
               '("def" "defonce" "defn" "defn-" "defmacro" "ns"
                 "defmulti" "definterface" "defprotocol"
                 "deftest" "deftest-"
                 "deftype" "defrecord" "defstruct"))
             @_def_symbol)
     (:equal @_doc-keyword ":doc"))
    ;; Captures docstrings defn, defmacro, ns, and things like that
    ((list_lit :anchor (meta_lit) :?
               :anchor (sym_lit) @_def_symbol
               :anchor (comment) :?
               :anchor (sym_lit) ; function_name
               :anchor (comment) :?
               :anchor (str_lit) ,capture-symbol)
     (:match ,(clojure-ts-symbol-regexp clojure-ts-function-docstring-symbols)
             @_def_symbol))
    ;; Captures docstrings in defprotcol, definterface
    ((list_lit :anchor (sym_lit) @_def_symbol
               (list_lit
                :anchor (sym_lit) (vec_lit) :*
                (str_lit) ,capture-symbol :anchor)
               :*)
     (:match ,clojure-ts--interface-def-symbol-regexp @_def_symbol))))

(defvar clojure-ts--treesit-range-settings
  (treesit-range-rules
   :embed 'markdown_inline
   :host 'clojure
   (clojure-ts--docstring-query '@capture)))

(defun clojure-ts--font-lock-settings (markdown-available)
  "Return font lock settings suitable for use in `treesit-font-lock-settings'.
When MARKDOWN-AVAILABLE is non-nil, includes rules for highlighting docstrings
with the markdown_inline grammar."
  (append
   (treesit-font-lock-rules
    :feature 'string
    :language 'clojure
    '((str_lit) @font-lock-string-face
      (regex_lit) @font-lock-regexp-face)

    :feature 'regex
    :language 'clojure
    :override t
    '((regex_lit marker: _ @font-lock-property-face))

    :feature 'number
    :language 'clojure
    '((num_lit) @font-lock-number-face)

    :feature 'constant
    :language 'clojure
    '([(bool_lit) (nil_lit)] @font-lock-constant-face)

    :feature 'char
    :language 'clojure
    '((char_lit) @clojure-ts-character-face)

    :feature 'keyword
    :language 'clojure
    '((kwd_ns) @font-lock-type-face
      (kwd_name) @clojure-ts-keyword-face
      (kwd_lit
       marker: _ @clojure-ts-keyword-face
       delimiter: _ :? @default))

    :feature 'builtin
    :language 'clojure
    `(((list_lit meta: _ :? :anchor (sym_lit (sym_name) @font-lock-keyword-face))
       (:match ,clojure-ts--builtin-symbol-regexp @font-lock-keyword-face))
      ((sym_name) @font-lock-builtin-face
       (:match ,clojure-ts--builtin-dynamic-var-regexp @font-lock-builtin-face)))

    ;; Any function calls, not built-ins.
    ;; This can give false positives (macros, quoted lists, namespace imports)
    ;; but is a level 4 feature and never enabled by default.
    :feature 'function
    :language 'clojure
    '((list_lit :anchor (sym_lit (sym_name) @font-lock-function-call-face)))

    :feature 'symbol
    :language 'clojure
    '((sym_ns) @font-lock-type-face)

    ;; How does this work for defns nested in other forms, not at the top level?
    ;; Should I match against the source node to only hit the top level? Can that be expressed?
    ;; What about valid usages like `(let [closed 1] (defn +closed [n] (+ n closed)))'??
    ;; No wonder the tree-sitter-clojure grammar only touches syntax, and not semantics
    :feature 'definition ;; defn and defn like macros
    :language 'clojure
    `(((list_lit :anchor meta: _ :?
                 :anchor (sym_lit (sym_name) @def)
                 :anchor (sym_lit (sym_name) @font-lock-function-name-face))
       (:match ,(rx-to-string
                 `(seq bol
                       (or
                        "defn"
                        "defn-"
                        "defmulti"
                        "defmethod"
                        "deftest"
                        "deftest-"
                        "defmacro"
                        "definline")
                       eol))
               @def))
      ((anon_fn_lit
        marker: "#" @font-lock-property-face))
      ;; Methods implementation
      ((list_lit
        ((sym_lit name: (sym_name) @def)
         ((:match ,(rx-to-string
                    `(seq bol
                          (or
                           "defrecord"
                           "definterface"
                           "deftype"
                           "defprotocol")
                          eol))
                  @def)))
        :anchor
        (sym_lit (sym_name) @font-lock-type-face)
        (list_lit
         (sym_lit name: (sym_name) @font-lock-function-name-face))))
      ((list_lit
        ((sym_lit name: (sym_name) @def)
         ((:equal "reify" @def)))
        (list_lit
         (sym_lit name: (sym_name) @font-lock-function-name-face)))))

    :feature 'variable ;; def, defonce
    :language 'clojure
    `(((list_lit :anchor meta: _ :?
                 :anchor (sym_lit (sym_name) @def)
                 :anchor (sym_lit (sym_name) @font-lock-variable-name-face))
       (:match ,clojure-ts--variable-definition-symbol-regexp @def)))

    ;; Can we support declarations in the namespace form?
    :feature 'type
    :language 'clojure
    `(;; Type Declarations
      ((list_lit :anchor (sym_lit (sym_name) @def)
                 :anchor (sym_lit (sym_name) @font-lock-type-face))
       (:match ,clojure-ts--typedef-symbol-regexp @def))
      ;; Type Hints
      (meta_lit
       marker: "^" @font-lock-operator-face
       value: (sym_lit (sym_name) @font-lock-type-face))
      (old_meta_lit
       marker: "#^" @font-lock-operator-face
       value: (sym_lit (sym_name) @font-lock-type-face))
      ;; Highlight namespace
      ((list_lit :anchor (sym_lit (sym_name) @def)
                 :anchor (sym_lit (sym_name) @font-lock-type-face))
       (:equal "ns" @def)))

    :feature 'metadata
    :language 'clojure
    :override t
    `((meta_lit
       marker: "^" @font-lock-operator-face
       value: (kwd_lit (kwd_name) @font-lock-property-name-face))
      (old_meta_lit
       marker: "#^" @font-lock-operator-face
       value: (kwd_lit (kwd_name) @font-lock-property-name-face)))

    :feature 'tagged-literals
    :language 'clojure
    :override t
    '((tagged_or_ctor_lit marker: "#" @font-lock-preprocessor-face
                          tag: (sym_lit) @font-lock-preprocessor-face))

    :feature 'doc
    :language 'clojure
    :override t
    (clojure-ts--docstring-query '@font-lock-doc-face))

   (when markdown-available
     (treesit-font-lock-rules
      :feature 'doc
      :language 'markdown_inline
      :override t
      `((inline
          (code_span (code_span_delimiter) :* @font-lock-delimiter-face)
          @font-lock-constant-face))))

   (treesit-font-lock-rules
    :feature 'quote
    :language 'clojure
    '((quoting_lit
       marker: _ @font-lock-delimiter-face)
      (var_quoting_lit
       marker: _ @font-lock-delimiter-face)
      (syn_quoting_lit
       marker: _ @font-lock-delimiter-face)
      (unquoting_lit
       marker: _ @font-lock-delimiter-face)
      (unquote_splicing_lit
       marker: _ @font-lock-delimiter-face)
      (var_quoting_lit
       marker: _ @font-lock-delimiter-face))

    :feature 'bracket
    :language 'clojure
    '((["(" ")" "[" "]" "{" "}"]) @font-lock-bracket-face
      (set_lit :anchor "#" @font-lock-bracket-face))

    :feature 'comment
    :language 'clojure
    :override t
    `((comment) @font-lock-comment-face
      (dis_expr
       marker: "#_" @font-lock-comment-delimiter-face
       value: _ @font-lock-comment-face)
      (,(append
         '(list_lit :anchor (sym_lit) @font-lock-comment-delimiter-face)
         (when clojure-ts-comment-macro-font-lock-body
           '(_ :* @font-lock-comment-face)))
       (:match "^\\(\\(clojure.core/\\)?comment\\)$" @font-lock-comment-delimiter-face)))

    :feature 'deref ;; not part of clojure-mode, but a cool idea?
    :language 'clojure
    '((derefing_lit
       marker: "@" @font-lock-warning-face)))))

;; Node predicates

(defun clojure-ts--list-node-p (node)
  "Return non-nil if NODE is a Clojure list."
  (string-equal "list_lit" (treesit-node-type node)))

(defun clojure-ts--symbol-node-p (node)
  "Return non-nil if NODE is a Clojure symbol."
  (string-equal "sym_lit" (treesit-node-type node)))

(defun clojure-ts--string-node-p (node)
  "Return non-nil if NODE is a Clojure string literal."
  (string-equal "str_lit" (treesit-node-type node)))

(defun clojure-ts--keyword-node-p (node)
  "Return non-nil if NODE is a Clojure keyword."
  (string-equal "kwd_lit" (treesit-node-type node)))

(defun clojure-ts--metadata-node-p (node)
  "Return non-nil if NODE is a Clojure metadata node."
  (string-equal "meta_lit" (treesit-node-type node)))

(defun clojure-ts--var-node-p (node)
  "Return non-nil if NODE is a var (eg.  #\\'foo)."
  (string-equal "var_quoting_lit" (treesit-node-type node)))

(defun clojure-ts--named-node-text (node)
  "Gets the name of a symbol or keyword NODE.
This does not include the NODE's namespace."
  (treesit-node-text (treesit-node-child-by-field-name node "name")))

(defun clojure-ts--symbol-named-p (expected-symbol-name node)
  "Return non-nil if NODE is a symbol with text matching EXPECTED-SYMBOL-NAME."
  (and (clojure-ts--symbol-node-p node)
       (string-equal expected-symbol-name (clojure-ts--named-node-text node))))

(defun clojure-ts--node-child-skip-metadata (node n)
  "Return the Nth child of NODE like `treesit-node-child`, skipping the optional metadata node at pos 0 if present."
  (let ((first-child (treesit-node-child node 0 t)))
    (treesit-node-child node (if (clojure-ts--metadata-node-p first-child) (1+ n) n) t)))

(defun clojure-ts--symbol-matches-p (symbol-regexp node)
  "Return non-nil if NODE is a symbol that matches SYMBOL-REGEXP."
  (and (clojure-ts--symbol-node-p node)
       (string-match-p symbol-regexp (clojure-ts--named-node-text node))))

(defun clojure-ts--definition-node-p (definition-type-name node)
  "Return non-nil if NODE is a definition, defined by DEFINITION-TYPE-NAME.
DEFINITION-TYPE-NAME might be a string like defn, def, defmulti, etc.
See `clojure-ts--definition-node-match-p'  when an exact match is not desired."
  (and
   (clojure-ts--list-node-p node)
   (clojure-ts--symbol-named-p definition-type-name (treesit-node-child node 0 t))))

(defun clojure-ts--definition-node-match-p (definition-type-regexp node)
  "Return non-nil if NODE is a definition matching DEFINITION-TYPE-REGEXP.
DEFINITION-TYPE-REGEXP matched the symbol used to construct the definition,
like \"defn\".
See `clojure-ts--definition-node-p' when an exact match is possible."
  (and
   (clojure-ts--list-node-p node)
   (let* ((child (clojure-ts--node-child-skip-metadata node 0))
          (child-txt (clojure-ts--named-node-text child)))
     (and (clojure-ts--symbol-node-p child)
          (string-match-p definition-type-regexp child-txt)))))

(defun clojure-ts--standard-definition-node-name (node)
  "Return the definition name for the given NODE.
Returns nil if NODE is not a list with symbols as the first two children.
For example the node representing the expression (def foo 1) would return foo.
The node representing (ns user) would return user.
Does not does any matching on the first symbol (def, defn, etc), so identifying
that a node is a definition is intended to be done elsewhere.

Can be called directly, but intended for use as `treesit-defun-name-function'."
  (when (and (clojure-ts--list-node-p node)
             (clojure-ts--symbol-node-p (clojure-ts--node-child-skip-metadata node 0)))
    (let ((sym (clojure-ts--node-child-skip-metadata node 1)))
      (when (clojure-ts--symbol-node-p sym)
        ;; Extracts ns and name, and recreates the full var name.
        ;; We can't just get the node-text of the full symbol because
        ;; that could include metadata that isn't part of the name.
        (let ((ns (treesit-node-child-by-field-name sym "ns"))
              (name (treesit-node-child-by-field-name sym "name")))
          (if ns
              (concat (treesit-node-text ns) "/" (treesit-node-text name))
            (treesit-node-text name)))))))

(defvar clojure-ts--function-type-regexp
  (rx string-start (or (seq "defn" (opt "-")) "defmethod" "deftest") string-end)
  "Regular expression for matching definition nodes that resemble functions.")

(defun clojure-ts--function-node-p (node)
  "Return non-nil if NODE is a defn form."
  (clojure-ts--definition-node-match-p clojure-ts--function-type-regexp node))

(defun clojure-ts--function-node-name (node)
  "Return the name of a function NODE.
Includes a dispatch value when applicable (defmethods)."
  (if (clojure-ts--definition-node-p "defmethod" node)
      (let ((dispatch-value (treesit-node-text (treesit-node-child node 2 t))))
        (concat (clojure-ts--standard-definition-node-name node)
                " "
                dispatch-value))
    (clojure-ts--standard-definition-node-name node)))

(defun clojure-ts--defmacro-node-p (node)
  "Return non-nil if NODE is a defmacro form."
  (clojure-ts--definition-node-p "defmacro" node))

(defun clojure-ts--ns-node-p (node)
  "Return non-nil if NODE is a ns form."
  (clojure-ts--definition-node-p "ns" node))

(defvar clojure-ts--variable-definition-type-regexp
  (rx string-start (or "def" "defonce") string-end)
  "Regular expression for matching definition nodes that resemble variables.")

(defun clojure-ts--variable-definition-node-p (node)
  "Return non-nil if NODE is a def or defonce form."
  (clojure-ts--definition-node-match-p clojure-ts--variable-definition-type-regexp node))

(defvar clojure-ts--class-type-regexp
  (rx string-start (or "deftype" "defrecord" "defstruct") string-end)
  "Regular expression for matching definition nodes that resemble classes.")

(defun clojure-ts--class-node-p (node)
  "Return non-nil if NODE represents a type, record, or struct definition."
  (clojure-ts--definition-node-match-p clojure-ts--class-type-regexp node))

(defvar clojure-ts--interface-type-regexp
  (rx string-start (or "defprotocol" "definterface" "defmulti") string-end)
  "Regular expression for matching definition nodes that resemble interfaces.")

(defun clojure-ts--interface-node-p (node)
  "Return non-nil if NODE represents a protocol or interface definition."
  (clojure-ts--definition-node-match-p clojure-ts--interface-type-regexp node))


(defvar clojure-ts--imenu-settings
  `(("Namespace" "list_lit" clojure-ts--ns-node-p)
    ("Function" "list_lit" clojure-ts--function-node-p
     ;; Used instead of treesit-defun-name-function.
     clojure-ts--function-node-name)
    ("Macro" "list_lit" clojure-ts--defmacro-node-p)
    ("Variable" "list_lit" clojure-ts--variable-definition-node-p)
    ("Interface" "list_lit" clojure-ts--interface-node-p)
    ("Class" "list_lit" clojure-ts--class-node-p))
  "The value for `treesit-simple-imenu-settings'.
By default `treesit-defun-name-function' is used to extract definition names.
See `clojure-ts--standard-definition-node-name' for the implementation used.")

(defcustom clojure-ts-indent-style 'semantic
  "Automatic indentation style to use when mode `clojure-ts-mode' is run.

The possible values for this variable are
    `semantic' - Semantic indentation.
        Tries to follow the same rules as cljfmt with default settings.
        See:
          - https://github.com/weavejester/cljfmt
          - https://guide.clojure.style/
    `fixed' - A simpler set of indentation rules that can be summarized as
        1. Multi-line lists that start with a symbol are always indented with
           two spaces.
        2. Other multi-line lists, vectors, maps and sets are aligned with the
           first element (1 or 2 spaces).
        See: https://tonsky.me/blog/clojurefmt/"
  :safe #'symbolp
  :type
  '(choice (const :tag "Semantic indentation rules." semantic)
           (const :tag "Simple fixed indentation rules." fixed))
  :package-version '(clojure-ts-mode . "0.2.0"))

(defvar clojure-ts--fixed-indent-rules
  ;; This is in contrast to semantic
  ;; fixed-indent-rules come from https://tonsky.me/blog/clojurefmt/
  `((clojure
     ((parent-is "source") parent-bol 0)
     ;; ((query "(list_lit . [(sym_lit) (kwd_lit)] _* @node)") parent 2)
     ;; Using the above `query' rule here doesn't always work because sometimes `node' is nil.
     ;; `query' requires `node' to be matched.
     ;; We really only care about the parent node being a function-call like list.
     ;; with it's first named child being a symbol
     ((lambda (node parent _)
        (and (clojure-ts--list-node-p parent)
             ;; Should we also check for keyword first child, as in (:k map) calls?
             (let ((first-child (treesit-node-child parent 0 t)))
               (or (clojure-ts--symbol-node-p first-child)
                   (clojure-ts--keyword-node-p first-child)))))
      parent 2)
     ((parent-is "vec_lit") parent 1)
     ((parent-is "map_lit") parent 1)
     ((parent-is "list_lit") parent 1)
     ((parent-is "set_lit") parent 2))))

(defvar clojure-ts--symbols-with-body-expressions-regexp
  (eval-and-compile
    (rx (or
         ;; Match def* symbols,
         ;; we also explicitly do not match symbols beginning with
         ;; "default" "deflate" and "defer", like cljfmt
         (and line-start "def")
         ;; Match with-* symbols
         (and line-start "with-")
         ;; Exact matches
         (and line-start
              (or "alt!" "alt!!" "are" "as->"
                  "binding" "bound-fn"
                  "case" "catch" "comment" "cond" "condp" "cond->" "cond->>"
                  "delay" "do" "doseq" "dotimes" "doto"
                  "extend" "extend-protocol" "extend-type"
                  "fdef" "finally" "fn" "for" "future"
                  "go" "go-loop"
                  "if" "if-let" "if-not" "if-some"
                  "let" "letfn" "locking" "loop"
                  "match" "ns" "proxy" "reify" "struct-map"
                  "testing" "thread" "try"
                  "use-fixtures"
                  "when" "when-first" "when-let" "when-not" "when-some" "while")
              line-end))))
  "A regex to match symbols that are functions/macros with a body argument.
Taken from cljfmt:
https://github.com/weavejester/cljfmt/blob/fb26b22f569724b05c93eb2502592dfc2de898c3/cljfmt/resources/cljfmt/indents/clojure.clj")

(defun clojure-ts--match-function-call-arg (node parent _bol)
  "Match NODE if PARENT is a list expressing a function or macro call."
  (and (clojure-ts--list-node-p parent)
       ;; Can the following two clauses be replaced by checking indexes?
       ;; Does the second child exist, and is it not equal to the current node?
       (treesit-node-child parent 1 t)
       (not (treesit-node-eq (treesit-node-child parent 1 t) node))
       (let ((first-child (treesit-node-child parent 0 t)))
         (or (clojure-ts--symbol-node-p first-child)
             (clojure-ts--keyword-node-p first-child)
             (clojure-ts--var-node-p first-child)))))

(defun clojure-ts--match-expression-in-body (node parent _bol)
  "Match NODE if it is an expression used in a body argument.
PARENT is expected to be a list literal.
See `treesit-simple-indent-rules'."
  (and
   (clojure-ts--list-node-p parent)
   (let ((first-child (clojure-ts--node-child-skip-metadata parent 0)))
     (and
      (not
       (clojure-ts--symbol-matches-p
        ;; Symbols starting with this are false positives
        (rx line-start (or "default" "deflate" "defer"))
        first-child))
      (not (clojure-ts--match-with-metadata node))
      (clojure-ts--symbol-matches-p
       clojure-ts--symbols-with-body-expressions-regexp
       first-child)))))

(defun clojure-ts--match-method-body (_node parent _bol)
  "Matches a `NODE' in the body of a `PARENT' method implementation.
A method implementation referes to concrete implementations being defined in
forms like deftype, defrecord, reify, proxy, etc."
  (and
   (clojure-ts--list-node-p parent)
   (let* ((grandparent (treesit-node-parent parent))
          ;; auncle: gender neutral sibling of parent, aka child of grandparent
          (first-auncle (treesit-node-child grandparent 0 t)))
     (and (clojure-ts--list-node-p grandparent)
          (clojure-ts--symbol-matches-p clojure-ts--type-symbol-regexp
                                        first-auncle)))))

(defvar clojure-ts--threading-macro
  (eval-and-compile
    (rx (and "->" (? ">") line-end)))
  "A regular expression matching a threading macro.")

(defun clojure-ts--match-threading-macro-arg (_node parent _)
  "Match NODE if it is an argument to a PARENT threading macro."
  ;; We want threading macros to indent 2 only if the ->> is on it's own line.
  ;; If not, then align function arg.
  (and (clojure-ts--list-node-p parent)
       (let ((first-child (treesit-node-child parent 0 t)))
         (clojure-ts--symbol-matches-p
          clojure-ts--threading-macro
          first-child))))

(defun clojure-ts--match-fn-docstring (node)
  "Match NODE when it is a docstring for PARENT function definition node."
  ;; A string that is the third node in a function defn block
  (let ((parent (treesit-node-parent node)))
    (and (treesit-node-eq node (treesit-node-child parent 2 t))
         (let ((first-auncle (treesit-node-child parent 0 t)))
           (clojure-ts--symbol-matches-p
            (regexp-opt clojure-ts-function-docstring-symbols)
            first-auncle)))))

(defun clojure-ts--match-def-docstring (node)
  "Match NODE when it is a docstring for PARENT variable definition node."
  ;; A string that is the fourth node in a variable definition block.
  (let ((parent (treesit-node-parent node)))
    (and (treesit-node-eq node (treesit-node-child parent 2 t))
         ;; There needs to be a value after the string.
         ;; If there is no 4th child, then this string is the value.
         (treesit-node-child parent 3 t)
         (let ((first-auncle (treesit-node-child parent 0 t)))
           (clojure-ts--symbol-matches-p
            (regexp-opt clojure-ts-definition-docstring-symbols)
            first-auncle)))))

(defun clojure-ts--match-method-docstring (node)
  "Match NODE when it is a docstring in a method definition."
  (let* ((grandparent (treesit-node-parent ;; the protocol/interface
                       (treesit-node-parent node))) ;; the method definition
         (first-grandauncle (treesit-node-child grandparent 0 t)))
    (clojure-ts--symbol-matches-p
     clojure-ts--interface-def-symbol-regexp
     first-grandauncle)))

(defun clojure-ts--match-docstring (_node parent _bol)
  "Match PARENT when it is a docstring node."
  (and (clojure-ts--string-node-p parent) ;; We are IN a string
       (or (clojure-ts--match-def-docstring parent)
           (clojure-ts--match-fn-docstring parent)
           (clojure-ts--match-method-docstring parent))))

(defun clojure-ts--match-with-metadata (node &optional _parent _bol)
  "Match NODE when it has metadata."
  (let ((prev-sibling (treesit-node-prev-sibling node)))
    (and prev-sibling
         (clojure-ts--metadata-node-p prev-sibling))))

(defun clojure-ts--semantic-indent-rules ()
  "Return a list of indentation rules for `treesit-simple-indent-rules'."
  `((clojure
     ((parent-is "source") parent-bol 0)
     (clojure-ts--match-docstring parent 0)
     ;; https://guide.clojure.style/#body-indentation
     (clojure-ts--match-method-body parent 2)
     (clojure-ts--match-expression-in-body parent 2)
     ;; https://guide.clojure.style/#threading-macros-alignment
     (clojure-ts--match-threading-macro-arg prev-sibling 0)
     ;; https://guide.clojure.style/#vertically-align-fn-args
     (clojure-ts--match-function-call-arg (nth-sibling 2 nil) 0)
     (clojure-ts--match-with-metadata parent 0)
     ;; Literal Sequences
     ((parent-is "list_lit") parent 1) ;; https://guide.clojure.style/#one-space-indent
     ((parent-is "vec_lit") parent 1) ;; https://guide.clojure.style/#bindings-alignment
     ((parent-is "map_lit") parent 1) ;; https://guide.clojure.style/#map-keys-alignment
     ((parent-is "set_lit") parent 2))))

(defun clojure-ts--configured-indent-rules ()
  "Gets the configured choice of indent rules."
  (cond
   ((eq clojure-ts-indent-style 'semantic) (clojure-ts--semantic-indent-rules))
   ((eq clojure-ts-indent-style 'fixed) clojure-ts--fixed-indent-rules)
   (t (error
       (format
        "Invalid value for clojure-ts-indent-style. Expected one of '%S, but found '%S instead."
        '(semantic fixed)
        clojure-ts-indent-style)))))

(defun clojure-ts--docstring-fill-prefix ()
  "The prefix string used by `clojure-ts--fill-paragraph'.
It is simply `clojure-ts-docstring-fill-prefix-width' number of spaces."
  (make-string clojure-ts-docstring-fill-prefix-width ? ))

(defun clojure-ts--fill-paragraph (&optional justify)
  "Like `fill-paragraph', but can handler Clojure docstrings.
If JUSTIFY is non-nil, justify as well as fill the paragraph."
  (let ((current-node (treesit-node-at (point))))
    (if (clojure-ts--match-docstring nil current-node nil)
        (let ((fill-column (or clojure-ts-docstring-fill-column fill-column))
              (fill-prefix (clojure-ts--docstring-fill-prefix))
              (beg-doc (treesit-node-start current-node))
              (end-doc (treesit-node-end current-node)))
          (save-restriction
            (narrow-to-region beg-doc end-doc)
            (fill-paragraph justify)))
      (or (fill-comment-paragraph justify)
          (fill-paragraph justify)))
    t))

(defconst clojure-ts--sexp-nodes
  '("#_" ;; transpose-sexp near a discard macro moves it around.
    "num_lit" "sym_lit" "kwd_lit" "nil_lit" "bool_lit"
    "regex_lit" "str_lit" "char_lit"
    "list_lit" "map_lit" "vec_lit" "set_lit" "ns_map_lit"
    "anon_fn_lit" "read_cond_lit"
    "var_quoting_lit" "sym_val_lit" "evaling_lit"
    "tagged_or_ctor_lit" "splicing_read_cond_lit"
    "derefing_lit" "quoting_lit" "syn_quoting_lit"
    "unquote_splicing_lit" "unquoting_lit")
  "A regular expression that matches nodes that can be treated as s-expressions.")

(defconst clojure-ts--thing-settings
  `((clojure
     (sexp ,(regexp-opt clojure-ts--sexp-nodes)
           text ,(regexp-opt '("comment"))))))

(defvar clojure-ts-mode-map
  (let ((map (make-sparse-keymap)))
    ;;(set-keymap-parent map clojure-mode-map)
    map))

(defvar clojure-ts-clojurescript-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map clojure-ts-mode-map)
    map))

(defvar clojure-ts-clojurec-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map clojure-ts-mode-map)
    map))

(defvar clojure-ts-clojuredart-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map clojure-ts-mode-map)
    map))

(defvar clojure-ts-jank-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map clojure-ts-mode-map)
    map))

(defun clojure-ts-mode-display-version ()
  "Display the current `clojure-mode-version' in the minibuffer."
  (interactive)
  (let ((pkg-version (package-get-version)))
    (if pkg-version
        (message "clojure-ts-mode %s (package: %s)" clojure-ts-mode-version pkg-version)
      (message "clojure-ts-mode %s" clojure-ts-mode-version))))

(defconst clojure-ts-grammar-recipes
  '((clojure "https://github.com/sogaiu/tree-sitter-clojure.git"
             "v0.0.12")
    (markdown_inline "https://github.com/MDeiml/tree-sitter-markdown"
                     "v0.1.6"
                     "tree-sitter-markdown-inline/src"))
  "Intended to be used as the value for `treesit-language-source-alist'.")

(defun clojure-ts--ensure-grammars ()
  "Install required language grammars if not already available."
  (when clojure-ts-ensure-grammars
    (dolist (recipe clojure-ts-grammar-recipes)
      (let ((grammar (car recipe)))
        (unless (treesit-language-available-p grammar nil)
          (message "Installing %s tree-sitter grammar" grammar)
          ;; `treesit-language-source-alist' is dynamically scoped.
          ;; Binding it in this let expression allows
          ;; `treesit-install-language-gramamr' to pick up the grammar recipes
          ;; without modifying what the user has configured themselves.
          (let ((treesit-language-source-alist clojure-ts-grammar-recipes))
            (treesit-install-language-grammar grammar)))))))

(defun clojure-ts-mode-variables (&optional markdown-available)
  "Initialize buffer-local variables for `clojure-ts-mode'.
See `clojure-ts--font-lock-settings' for usage of MARKDOWN-AVAILABLE."
  (setq-local comment-add 1)
  (setq-local comment-start ";")

  (setq-local treesit-font-lock-settings
              (clojure-ts--font-lock-settings markdown-available))
  (setq-local treesit-font-lock-feature-list
              '((comment definition variable)
                (keyword string char symbol builtin type)
                (constant number quote metadata doc)
                (bracket deref function regex tagged-literals)))

  (setq-local treesit-defun-prefer-top-level t)
  (setq-local treesit-defun-tactic 'top-level)
  (setq-local treesit-defun-type-regexp
              (cons
               ;; consider all clojure sexps as valid top level forms...
               (regexp-opt clojure-ts--sexp-nodes)
               ;; ...except `comment' forms if `clojure-ts-toplevel-inside-comment-form' is set
               (lambda (node)
                 (or (not clojure-ts-toplevel-inside-comment-form)
                     (not (clojure-ts--definition-node-p "comment" node))))))
  (setq-local treesit-defun-name-function
              #'clojure-ts--standard-definition-node-name)

  (setq-local treesit-simple-indent-rules
              (clojure-ts--configured-indent-rules))
  (setq-local fill-paragraph-function #'clojure-ts--fill-paragraph)

  (setq-local treesit-simple-imenu-settings
              clojure-ts--imenu-settings)

  (when (boundp 'treesit-thing-settings) ;; Emacs 30+
    (setq-local treesit-thing-settings clojure-ts--thing-settings)))

;;;###autoload
(define-derived-mode clojure-ts-mode prog-mode "Clojure[TS]"
  "Major mode for editing Clojure code.

\\{clojure-ts-mode-map}"
  :syntax-table clojure-ts-mode-syntax-table
  (clojure-ts--ensure-grammars)
  (let ((use-markdown-inline (and clojure-ts-use-markdown-inline
                                  (treesit-ready-p 'markdown_inline t))))
    (when use-markdown-inline
      (treesit-parser-create 'markdown_inline)
      (setq-local treesit-range-settings clojure-ts--treesit-range-settings))

    (when (treesit-ready-p 'clojure)
      (treesit-parser-create 'clojure)
      (clojure-ts-mode-variables use-markdown-inline)

      (when clojure-ts--debug
        (setq-local treesit--indent-verbose t)
        (when (eq clojure-ts--debug 'font-lock)
          (setq-local treesit--font-lock-verbose t))
        (treesit-inspect-mode))

      (treesit-major-mode-setup)

      ;; Workaround for treesit-transpose-sexps not correctly working with
      ;; treesit-thing-settings on Emacs 30.
      ;; Once treesit-transpose-sexps it working again this can be removed
      (when (fboundp 'transpose-sexps-default-function)
        (setq-local transpose-sexps-function #'transpose-sexps-default-function)))))

;; For Emacs 30+, so that `clojure-ts-mode' is treated as deriving from
;; `clojure-mode'
(when (fboundp 'derived-mode-add-parents)
  (derived-mode-add-parents 'clojure-ts-mode '(clojure-mode)))

;;;###autoload
(define-derived-mode clojure-ts-clojurescript-mode clojure-ts-mode "ClojureScript[TS]"
  "Major mode for editing ClojureScript code.

\\{clojure-ts-clojurescript-mode-map}")

;;;###autoload
(define-derived-mode clojure-ts-clojurec-mode clojure-ts-mode "ClojureC[TS]"
  "Major mode for editing ClojureC code.

\\{clojure-ts-clojurec-mode-map}")

;;;###autoload
(define-derived-mode clojure-ts-clojuredart-mode clojure-ts-mode "ClojureDart[TS]"
  "Major mode for editing Clojure Dart code.

\\{clojure-ts-clojuredart-mode-map}")

;;;###autoload
(define-derived-mode clojure-ts-jank-mode clojure-ts-mode "Jank[TS]"
  "Major mode for editing Jank code.

\\{clojure-ts-jank-mode-map}")

(defun clojure-ts--register-novel-modes ()
  "Set up Clojure modes not present in progenitor clojure-mode.el."
  (add-to-list 'auto-mode-alist '("\\.cljd\\'" . clojure-ts-clojuredart-mode))
  (add-to-list 'auto-mode-alist '("\\.jank\\'" . clojure-ts-jank-mode)))

(if (treesit-available-p)
    ;; Redirect clojure-mode to clojure-ts-mode if clojure-mode is present
    (if (require 'clojure-mode nil 'noerror)
        (progn
          (add-to-list 'major-mode-remap-alist '(clojure-mode . clojure-ts-mode))
          (add-to-list 'major-mode-remap-alist '(clojurescript-mode . clojure-ts-clojurescript-mode))
          (add-to-list 'major-mode-remap-alist '(clojurec-mode . clojure-ts-clojurec-mode))
          (clojure-ts--register-novel-modes))
      ;; When Clojure-mode is not present, setup auto-modes ourselves
      (progn
        ;; Regular clojure/edn files
        ;; I believe dtm is for datomic queries and datoms, which are just edn.
        (add-to-list 'auto-mode-alist
                     '("\\.\\(clj\\|dtm\\|edn\\)\\'" . clojure-ts-mode))
        (add-to-list 'auto-mode-alist '("\\.cljs\\'" . clojure-ts-clojurescript-mode))
        (add-to-list 'auto-mode-alist '("\\.cljc\\'" . clojure-ts-clojurec-mode))
        ;; boot build scripts are Clojure source files
        (add-to-list 'auto-mode-alist '("\\(?:build\\|profile\\)\\.boot\\'" . clojure-ts-mode))
        ;; babashka scripts are Clojure source files
        (add-to-list 'interpreter-mode-alist '("bb" . clojure-ts-mode))
        ;; nbb scripts are ClojureScript source files
        (add-to-list 'interpreter-mode-alist '("nbb" . clojure-ts-clojurescript-mode))
        (clojure-ts--register-novel-modes)))
  (message "Clojure TS Mode will not be activated as tree-sitter support is missing."))

(defvar clojure-ts--find-ns-query
  (treesit-query-compile
   'clojure
   '(((source (list_lit
               :anchor (sym_lit name: (sym_name) @ns)
               :anchor (sym_lit name: (sym_name) @ns-name)))
      (:equal @ns "ns"))
     ((source (list_lit
               :anchor (sym_lit name: (sym_name) @in-ns)
               :anchor (quoting_lit
                        :anchor (sym_lit name: (sym_name) @ns-name))))
      (:equal @in-ns "in-ns")))))

(defun clojure-ts-find-ns ()
  "Return the name of the current namespace."
  (let ((nodes (treesit-query-capture 'clojure clojure-ts--find-ns-query)))
    (treesit-node-text (cdr (assoc 'ns-name nodes)) t)))

(provide 'clojure-ts-mode)

;;; clojure-ts-mode.el ends here