;;; ac-nrepl.el --- auto-complete sources for Clojure using nrepl completions

;; Copyright (C) 2012-2014  Steve Purcell <steve@sanityinc.com>

;; Author: Steve Purcell <steve@sanityinc.com>
;;         Sam Aaron <samaaron@gmail.com>
;; URL: https://github.com/purcell/ac-nrepl
;; Keywords: languages, clojure, nrepl
;; Version: DEV
;; Package-Requires: ((cider "0.1") (auto-complete "1.4"))

;; 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 this program. If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Provides a number of auto-complete sources for Clojure projects
;; using nrepl.

;;; Installation:

;; Available as a package in both Melpa (recommended) at
;; http://melpa.org/ and Marmalade at http://marmalade-repo.org/
;; M-x package-install ac-nrepl

;;; Usage:

;;     (require 'ac-nrepl)
;;     (add-hook 'cider-repl-mode-hook 'ac-nrepl-setup)
;;     (add-hook 'cider-mode-hook 'ac-nrepl-setup)
;;     (eval-after-load "auto-complete"
;;       '(add-to-list 'ac-modes 'cider-repl-mode))

;; If you want to trigger auto-complete using TAB in nrepl buffers, you may
;; want to use auto-complete in your `completion-at-point-functions':

;;     (defun set-auto-complete-as-completion-at-point-function ()
;;       (setq completion-at-point-functions '(auto-complete)))
;;     (add-hook 'auto-complete-mode-hook 'set-auto-complete-as-completion-at-point-function)
;;
;;     (add-hook 'cider-repl-mode-hook 'set-auto-complete-as-completion-at-point-function)
;;     (add-hook 'cider-mode-hook 'set-auto-complete-as-completion-at-point-function)
;;
;; You might consider using ac-nrepl's popup documentation in place of `nrepl-doc':
;;
;;     (eval-after-load 'cider
;;       '(define-key cider-mode-map (kbd "C-c C-d") 'ac-nrepl-popup-doc))

;;; Code:

(message "Notice: You probably want to use ac-cider instead of ac-nrepl.")

(require 'nrepl-client)
(require 'cider-interaction)
(require 'auto-complete)

(defun ac-nrepl-available-p ()
  "Return t if nrepl is available for completion, otherwise nil."
  (condition-case nil
      (not (null (nrepl-current-tooling-session)))
    (error nil)))

(defun ac-nrepl-sync-eval (clj)
  "Synchronously evaluate CLJ.
Result is a plist, as returned from `nrepl-sync-request:eval'."
  (nrepl-sync-request:eval clj (cider-current-ns) (nrepl-current-tooling-session)))

(defun ac-nrepl-candidates* (clj)
  "Return completion candidates produced by evaluating CLJ."
  (let ((response (plist-get (ac-nrepl-sync-eval (concat "(require 'complete.core) " clj))
                             :value)))
    (when response
      (car (read-from-string response)))))

(defun ac-nrepl-unfiltered-clj (clj)
  "Return a version of CLJ with the completion prefix inserted."
  (format clj ac-prefix))

(defun ac-nrepl-filtered-clj (clj)
  "Build an expression which extracts the prefixed values from CLJ."
  (concat "(filter #(.startsWith % \"" ac-prefix "\")"
          (ac-nrepl-unfiltered-clj clj) ")"))

(defun ac-nrepl-candidates-ns ()
  "Return namespace candidates."
  (ac-nrepl-candidates*
   (ac-nrepl-filtered-clj "(complete.core/namespaces *ns*)")))

(defun ac-nrepl-candidates-vars ()
  "Return var candidates."
  (ac-nrepl-candidates*
   (ac-nrepl-filtered-clj "(let [prefix \"%s\"]
    (if-not (.contains prefix \"/\")
      (complete.core/ns-vars *ns*)
      (let [ns-alias (symbol (first (.split prefix \"/\")))
            core     (find-ns 'clojure.core)]
        (if-let [ns (or (get (ns-aliases *ns*) ns-alias)
                        (find-ns ns-alias))]
          (let [vars (complete.core/ns-vars ns)
                vars (if (= core ns)
                       vars
                       (remove (into #{} (complete.core/ns-vars core)) vars))]
            (map (fn [x] (str ns-alias \"/\" x)) vars))
           '()))))")))

(defun ac-nrepl-candidates-ns-classes ()
  "Return namespaced class candidates."
  (ac-nrepl-candidates*
   (ac-nrepl-filtered-clj "(complete.core/ns-classes *ns*)")))

(defvar ac-nrepl-all-classes-cache nil
  "Cached list of all classes loaded in the JVM backend.")

(defun ac-nrepl-refresh-class-cache ()
  "Clear `ac-nrepl-all-classes-cache' and then refill it asynchronously."
  (setq ac-nrepl-all-classes-cache nil)
  (nrepl-request:eval
   (concat "(require 'complete.core)"
           (ac-nrepl-unfiltered-clj "(concat @complete.core/nested-classes
                                       @complete.core/top-level-classes)"))
   (nrepl-make-response-handler
    (nrepl-current-connection-buffer)
    (lambda (buffer value)
      (setq ac-nrepl-all-classes-cache (car (read-from-string value))))
    nil nil nil)
   (cider-current-ns)
   (nrepl-current-tooling-session)))


(add-hook 'nrepl-connected-hook 'ac-nrepl-refresh-class-cache t)

(defun ac-nrepl-candidates-all-classes ()
  "Return java method candidates."
  (when (string-match-p "^[a-zA-Z]+[a-zA-Z0-9$_]*\\.[a-zA-Z0-9$_.]*$" ac-prefix)
    ac-nrepl-all-classes-cache))

(defun ac-nrepl-candidates-java-methods ()
  "Return java method candidates."
  (mapcar (lambda (hit)
            (let* ((parts (split-string hit "#"))
                   (meth (nth 0 parts))
                   (classname (nth 1 parts)))
              (propertize meth 'summary classname)))
          (ac-nrepl-candidates*
           (ac-nrepl-filtered-clj
            "(for [class (vals (ns-imports *ns*))
                   method (.getMethods class)
                   :when (not (java.lang.reflect.Modifier/isStatic (.getModifiers method)))]
               (str \".\" (.getName method) \"#\" (.getName class)))"))))

(defun ac-nrepl-candidates-static-methods ()
  "Return static method candidates."
  (ac-nrepl-candidates*
   (ac-nrepl-filtered-clj
    "(let [prefix \"%s\"]
       (if (or (not (.contains prefix \"/\"))
               (.startsWith prefix \"/\"))
         '()
          (let [scope (symbol (first (.split prefix \"/\")))]
            (map (fn [memb] (str scope \"/\" memb))
                 (when-let [class (try (complete.core/resolve-class scope)
                                   (catch java.lang.ClassNotFoundException e nil))]
                   (complete.core/static-members class))))))  ")))

(defun ac-nrepl-documentation (symbol)
  "Return documentation for the given SYMBOL, if available."
  (let ((raw-doc (plist-get (ac-nrepl-sync-eval
                             (format "(try (eval '(clojure.repl/doc %s))
                                        (catch Exception e nil))"
                                     symbol))
                            :stdout)))
    (when raw-doc
      (let ((doc
             (substring-no-properties
              (replace-regexp-in-string
               "\r" ""
               (replace-regexp-in-string
                "^\\(  \\|-------------------------\r?\n\\)" ""
                raw-doc)))))
        (unless (string-match "\\`[ \t\n]*\\'" doc)
          doc)))))

(defun ac-nrepl-symbol-start-pos ()
  "Find the starting position of the symbol at point, unless inside a string."
  (let ((sap (symbol-at-point)))
    (when (and sap (not (in-string-p)))
      (car (bounds-of-thing-at-point 'symbol)))))

;;;###autoload
(defface ac-nrepl-candidate-face
  '((t (:inherit ac-candidate-face)))
  "Face for nrepl candidates."
  :group 'auto-complete)

;;;###autoload
(defface ac-nrepl-selection-face
  '((t (:inherit ac-selection-face)))
  "Face for the nrepl selected candidate."
  :group 'auto-complete)

;;;###autoload
(defconst ac-nrepl-source-defaults
  '((available . ac-nrepl-available-p)
    (candidate-face . ac-nrepl-candidate-face)
    (selection-face . ac-nrepl-selection-face)
    (prefix . ac-nrepl-symbol-start-pos)
    (document . ac-nrepl-documentation))
  "Defaults common to the various completion sources.")

;;;###autoload
(defvar ac-source-nrepl-ns
  (append
   '((candidates . ac-nrepl-candidates-ns)
     (symbol . "n"))
   ac-nrepl-source-defaults)
  "Auto-complete source for nrepl ns completion.")

;;;###autoload
(defvar ac-source-nrepl-vars
  (append
   '((candidates . ac-nrepl-candidates-vars)
     (symbol . "v"))
   ac-nrepl-source-defaults)
  "Auto-complete source for nrepl var completion.")

;;;###autoload
(defvar ac-source-nrepl-ns-classes
  (append
   '((candidates . ac-nrepl-candidates-ns-classes)
     (symbol . "c"))
   ac-nrepl-source-defaults)
  "Auto-complete source for nrepl ns-specific class completion.")

;;;###autoload
(defvar ac-source-nrepl-all-classes
  (append
   '((candidates . ac-nrepl-candidates-all-classes)
     (symbol . "c"))
   ac-nrepl-source-defaults)
  "Auto-complete source for nrepl all class completion.")

;;;###autoload
(defvar ac-source-nrepl-java-methods
  (append
   '((candidates . ac-nrepl-candidates-java-methods)
     (symbol . "m"))
   ac-nrepl-source-defaults)
  "Auto-complete source for nrepl java method completion.")

;;;###autoload
(defvar ac-source-nrepl-static-methods
  (append
   '((candidates . ac-nrepl-candidates-static-methods)
     (symbol . "s"))
   ac-nrepl-source-defaults)
  "Auto-complete source for nrepl java static method completion.")

;;;###autoload
(defun ac-nrepl-setup ()
  "Add the nrepl completion source to the front of `ac-sources'.
This affects only the current buffer."
  (interactive)
  (add-to-list 'ac-sources 'ac-source-nrepl-ns)
  (add-to-list 'ac-sources 'ac-source-nrepl-vars)
  (add-to-list 'ac-sources 'ac-source-nrepl-ns-classes)
  (add-to-list 'ac-sources 'ac-source-nrepl-all-classes)
  (add-to-list 'ac-sources 'ac-source-nrepl-java-methods)
  (add-to-list 'ac-sources 'ac-source-nrepl-static-methods))

;;;###autoload
(defun ac-nrepl-popup-doc ()
  "A popup alternative to `nrepl-doc'."
  (interactive)
  (let ((doc (ac-nrepl-documentation (symbol-at-point))))
    (when doc
     (popup-tip doc
                :point (ac-nrepl-symbol-start-pos)
                :around t
                :scroll-bar t
                :margin t))))

(provide 'ac-nrepl)

;; Local Variables:
;; coding: utf-8
;; eval: (checkdoc-minor-mode 1)
;; End:

;;; ac-nrepl.el ends here