anaconda-mode.el

;;; anaconda-mode.el --- Code navigation, documentation lookup and completion for Python  -*- lexical-binding: t; -*-

;; Copyright (C) 2013-2018 by Artem Malyshev

;; Author: Artem Malyshev <proofit404@gmail.com>
;; URL: https://github.com/proofit404/anaconda-mode
;; Version: 0.1.13
;; Package-Requires: ((emacs "25.1") (pythonic "0.1.0") (dash "2.6.0") (s "1.9") (f "0.16.2"))

;; 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:

;; See the README for more details.

;;; Code:

(require 'ansi-color)
(require 'pythonic)
(require 'tramp)
(require 'xref)
(require 'json)
(require 'dash)
(require 'url)
(require 's)
(require 'f)

(defgroup anaconda nil
  "Code navigation, documentation lookup and completion for Python."
  :group 'programming)

(defcustom anaconda-mode-installation-directory
  (locate-user-emacs-file "anaconda-mode")
  "Installation directory for `anaconda-mode' server."
  :type 'directory)

(defcustom anaconda-mode-eldoc-as-single-line nil
  "If not nil, trim eldoc string to frame width."
  :type 'boolean)

(defcustom anaconda-mode-lighter " Anaconda"
  "Text displayed in the mode line when `anaconda-mode’ is active."
  :type 'sexp)

(defcustom anaconda-mode-localhost-address "127.0.0.1"
  "Address used by `anaconda-mode' to resolve localhost."
  :type 'string)

(defcustom anaconda-mode-doc-frame-background (face-attribute 'default :background)
  "Doc frame background color, default color is current theme's background."
  :type 'string)

(defcustom anaconda-mode-doc-frame-foreground (face-attribute 'default :foreground)
  "Doc frame foreground color, default color is current theme's foreground."
  :type 'string)

(defcustom anaconda-mode-use-posframe-show-doc nil
  "If the value is not nil, use posframe to show eldoc."
  :type 'boolean)

(defcustom anaconda-mode-tunnel-setup-sleep 2
  "Time in seconds `anaconda-mode' waits after tunnel creation before first RPC call."
  :group 'anaconda-mode
  :type 'integer)

;;; Compatibility

;; Functions from posframe which is an optional dependency
(declare-function posframe-workable-p "posframe")
(declare-function posframe-hide "posframe")
(declare-function posframe-show "posframe")

;;; Server.
(defvar anaconda-mode-server-version "0.1.13"
  "Server version needed to run `anaconda-mode'.")

(defvar anaconda-mode-server-command "
from __future__ import print_function

# CLI arguments.

import sys

assert len(sys.argv) > 3, 'CLI arguments: %s' % sys.argv

server_directory = sys.argv[-3]
server_address = sys.argv[-2]
virtual_environment = sys.argv[-1]

# Ensure directory.

import os

server_directory = os.path.expanduser(server_directory)
virtual_environment = os.path.expanduser(virtual_environment)

if not os.path.exists(server_directory):
    os.makedirs(server_directory)

# Installation check.

jedi_dep = ('jedi', '0.13.0')
service_factory_dep = ('service_factory', '0.1.5')

missing_dependencies = []

def instrument_installation():
    for package in (jedi_dep, service_factory_dep):
        package_is_installed = False
        for path in os.listdir(server_directory):
            path = os.path.join(server_directory, path)
            if path.endswith('.egg') and os.path.isdir(path):
                if path not in sys.path:
                    sys.path.insert(0, path)
                if package[0] in path:
                    package_is_installed = True
        if not package_is_installed:
            missing_dependencies.append('>='.join(package))

instrument_installation()

# Installation.

def install_deps():
    import site
    import setuptools.command.easy_install
    site.addsitedir(server_directory)
    cmd = ['--install-dir', server_directory,
           '--site-dirs', server_directory,
           '--always-copy','--always-unzip']
    cmd.extend(missing_dependencies)
    setuptools.command.easy_install.main(cmd)
    instrument_installation()

if missing_dependencies:
    install_deps()

del missing_dependencies[:]

try:
    import jedi
except ImportError:
    missing_dependencies.append('>='.join(jedi_dep))

try:
    import service_factory
except ImportError:
    missing_dependencies.append('>='.join(service_factory_dep))

# Try one more time in case if anaconda installation gets broken somehow
if missing_dependencies:
    install_deps()
    import jedi
    import service_factory

# Setup server.

assert jedi.__version__ >= jedi_dep[1], 'Jedi version should be >= %s, current version: %s' % (jedi_dep[1], jedi.__version__,)

if virtual_environment:
    virtual_environment = jedi.create_environment(virtual_environment, safe=False)
else:
    virtual_environment = None

# Define JSON-RPC application.

import functools
import threading

def script_method(f):
    @functools.wraps(f)
    def wrapper(source, line, column, path):
        timer = threading.Timer(30.0, sys.exit)
        timer.start()
        result = f(jedi.Script(source, line, column, path, environment=virtual_environment))
        timer.cancel()
        return result
    return wrapper

def process_definitions(f):
    @functools.wraps(f)
    def wrapper(script):
        definitions = f(script)
        if len(definitions) == 1 and not definitions[0].module_path:
            return '%s is defined in %s compiled module' % (
                definitions[0].name, definitions[0].module_name)
        return [[definition.module_path,
                 definition.line,
                 definition.column,
                 definition.get_line_code().strip()]
                for definition in definitions
                if definition.module_path] or None
    return wrapper

@script_method
def complete(script):
    return [[definition.name, definition.type]
            for definition in script.completions()]

@script_method
def company_complete(script):
    return [[definition.name,
             definition.type,
             definition.docstring(),
             definition.module_path,
             definition.line]
            for definition in script.completions()]

@script_method
def show_doc(script):
    return [[definition.module_name, definition.docstring()]
            for definition in script.goto_definitions()]

@script_method
@process_definitions
def goto_definitions(script):
    return script.goto_definitions()

@script_method
@process_definitions
def goto_assignments(script):
    return script.goto_assignments()

@script_method
@process_definitions
def usages(script):
    return script.usages()

@script_method
def eldoc(script):
    signatures = script.call_signatures()
    if len(signatures) == 1:
        signature = signatures[0]
        return [signature.name,
                signature.index,
                [param.description[6:] for param in signature.params]]

# Run.

app = [complete, company_complete, show_doc, goto_definitions, goto_assignments, usages, eldoc]

service_factory.service_factory(app, server_address, 0, 'anaconda_mode port {port}')
" "Run `anaconda-mode' server.")

(defvar anaconda-mode-process-name "anaconda-mode"
  "Process name for `anaconda-mode' processes.")

(defvar anaconda-mode-process-buffer "*anaconda-mode*"
  "Buffer name for `anaconda-mode' process.")

(defvar anaconda-mode-process nil
  "Currently running `anaconda-mode' process.")

(defvar anaconda-mode-response-buffer "*anaconda-response*"
  "Buffer name for error report when `anaconda-mode' fail to read server response.")

(defvar anaconda-mode-socat-process-name "anaconda-socat"
  "Process name for `anaconda-mode' socat companion process.")

(defvar anaconda-mode-socat-process-buffer "*anaconda-socat*"
  "Buffer name for `anaconda-mode' socat companion process.")

(defvar anaconda-mode-socat-process nil
  "Currently running `anaconda-mode' socat companion process.")

(defvar anaconda-mode-ssh-process-name "anaconda-ssh"
  "Process name for `anaconda-mode' ssh port forward companion process.")

(defvar anaconda-mode-ssh-process-buffer "*anaconda-ssh*"
  "Buffer name for `anaconda-mode' ssh port forward companion process.")

(defvar anaconda-mode-ssh-process nil
  "Currently running `anaconda-mode' ssh port forward companion process.")

(defvar anaconda-mode-doc-frame-name "*Anaconda Posframe*"
  "The posframe to show anaconda documentation.")

(defvar anaconda-mode-frame-last-point 0
  "The last point of anaconda doc view frame, use for hide frame after move point.")

(defvar anaconda-mode-frame-last-scroll-offset 0
  "The last scroll offset when show doc view frame, use for hide frame after window scroll.")

(defun anaconda-mode-server-directory ()
  "Anaconda mode installation directory."
  (f-short (f-join anaconda-mode-installation-directory
                   anaconda-mode-server-version)))

(defun anaconda-mode-host ()
  "Target host with `anaconda-mode' server."
  (cond
   ((pythonic-remote-docker-p)
    anaconda-mode-localhost-address)
   ((pythonic-remote-p)
    (pythonic-remote-host))
   (t
    anaconda-mode-localhost-address)))

(defun anaconda-mode-port ()
  "Port for `anaconda-mode' connection."
  (process-get anaconda-mode-process 'port))

(defun anaconda-mode-start (&optional callback)
  "Start `anaconda-mode' server.
CALLBACK function will be called when `anaconda-mode-port' will
be bound."
  (when (anaconda-mode-need-restart)
    (anaconda-mode-stop))
  (if (anaconda-mode-running-p)
      (and callback
           (anaconda-mode-bound-p)
           (funcall callback))
    (anaconda-mode-bootstrap callback)))

(defun anaconda-mode-stop ()
  "Stop `anaconda-mode' server."
  (when (anaconda-mode-running-p)
    (set-process-filter anaconda-mode-process nil)
    (set-process-sentinel anaconda-mode-process nil)
    (kill-process anaconda-mode-process)
    (setq anaconda-mode-process nil))
  (when (anaconda-mode-socat-running-p)
    (kill-process anaconda-mode-socat-process)
    (setq anaconda-mode-socat-process nil))
  (when (anaconda-mode-ssh-running-p)
    (kill-process anaconda-mode-ssh-process)
    (setq anaconda-mode-ssh-process nil)))

(defun anaconda-mode-running-p ()
  "Is `anaconda-mode' server running."
  (and anaconda-mode-process
       (process-live-p anaconda-mode-process)))

(defun anaconda-mode-socat-running-p ()
  "Is `anaconda-mode' socat companion process running."
  (and anaconda-mode-socat-process
       (process-live-p anaconda-mode-socat-process)))

(defun anaconda-mode-ssh-running-p ()
  "Is `anaconda-mode' ssh port forward companion process running."
  (and anaconda-mode-ssh-process
       (process-live-p anaconda-mode-ssh-process)))

(defun anaconda-mode-bound-p ()
  "Is `anaconda-mode' port bound."
  (numberp (anaconda-mode-port)))

(defun anaconda-mode-need-restart ()
  "Check if we need to restart `anaconda-mode-server'."
  (when (and (anaconda-mode-running-p)
             (anaconda-mode-bound-p))
    (not (and (equal (process-get anaconda-mode-process 'interpreter)
                     python-shell-interpreter)
              (equal (process-get anaconda-mode-process 'virtualenv)
                     python-shell-virtualenv-root)
              (equal (process-get anaconda-mode-process 'remote-p)
                     (pythonic-remote-p))
              (if (pythonic-local-p)
                  t
                (equal (process-get anaconda-mode-process 'remote-method)
                       (pythonic-remote-method))
                (equal (process-get anaconda-mode-process 'remote-user)
                       (pythonic-remote-user))
                (equal (process-get anaconda-mode-process 'remote-host)
                       (pythonic-remote-host))
                (equal (process-get anaconda-mode-process 'remote-port)
                       (pythonic-remote-port)))))))

(defun anaconda-mode-bootstrap (&optional callback)
  "Run `anaconda-mode' server.
CALLBACK function will be called when `anaconda-mode-port' will
be bound."
  (setq anaconda-mode-process
        (pythonic-start-process :process anaconda-mode-process-name
                                :buffer (get-buffer-create anaconda-mode-process-buffer)
                                :query-on-exit nil
                                :filter (lambda (process output)
                                          (anaconda-mode-bootstrap-filter process output callback))
                                :sentinel (lambda (_process _event))
                                :args `("-c"
                                        ,anaconda-mode-server-command
                                        ,(anaconda-mode-server-directory)
                                        ,(if (pythonic-remote-p)
                                             "0.0.0.0"
                                           anaconda-mode-localhost-address)
                                        ,(or python-shell-virtualenv-root ""))))
  (process-put anaconda-mode-process 'interpreter python-shell-interpreter)
  (process-put anaconda-mode-process 'virtualenv python-shell-virtualenv-root)
  (process-put anaconda-mode-process 'port nil)
  (when (pythonic-remote-p)
    (process-put anaconda-mode-process 'remote-p t)
    (process-put anaconda-mode-process 'remote-method (pythonic-remote-method))
    (process-put anaconda-mode-process 'remote-user (pythonic-remote-user))
    (process-put anaconda-mode-process 'remote-host (pythonic-remote-host))
    (process-put anaconda-mode-process 'remote-port (pythonic-remote-port))))

(defun anaconda-jump-proxy-string ()
  "Create -J option string for SSH tunnel."
  (let ((dfn
         (tramp-dissect-file-name (pythonic-aliased-path default-directory))))
    (when (tramp-file-name-hop dfn)
      (let ((hop-list (split-string (tramp-file-name-hop dfn) "|"))
            (result "-J "))
        (delete "" hop-list) ;; remove empty string after final pipe
        (dolist (elt hop-list result)
          ;; tramp-dissect-file-name expects a filename so give it dummy.file
          (let ((ts (tramp-dissect-file-name (concat "/" elt ":/dummy.file"))))
            (setq result (concat result
                                 (format "%s@%s:%s,"
                                         (tramp-file-name-user ts)
                                         (tramp-file-name-host ts)
                                         (or (tramp-file-name-port-or-default ts) 22))))))
        ;; Remove final comma
        (substring result 0 -1)))))

(defun anaconda-mode-bootstrap-filter (process output &optional callback)
  "Set `anaconda-mode-port' from PROCESS OUTPUT.
Connect to the `anaconda-mode' server.  CALLBACK function will be
called when `anaconda-mode-port' will be bound."
  ;; Mimic default filter.
  (when (buffer-live-p (process-buffer process))
    (with-current-buffer (process-buffer process)
      (save-excursion
        (goto-char (process-mark process))
        (insert (ansi-color-apply output))
        (set-marker (process-mark process) (point)))))
  (unless (anaconda-mode-bound-p)
    (--when-let (s-match "anaconda_mode port \\([0-9]+\\)" output)
      (process-put anaconda-mode-process 'port (string-to-number (cadr it)))
      (cond ((pythonic-remote-docker-p)
             (let* ((container-raw-description (with-output-to-string
                                                 (with-current-buffer
                                                     standard-output
                                                   (call-process "docker" nil t nil "inspect" (pythonic-remote-host)))))
                    (container-description (let ((json-array-type 'list))
                                             (json-read-from-string container-raw-description)))
                    (container-ip (cdr (assoc 'IPAddress
                                              (cdadr (assoc 'Networks
                                                            (cdr (assoc 'NetworkSettings
                                                                        (car container-description)))))))))
               (setq anaconda-mode-socat-process
                     (start-process anaconda-mode-socat-process-name
                                    anaconda-mode-socat-process-buffer
                                    "socat"
                                    (format "TCP4-LISTEN:%d" (anaconda-mode-port))
                                    (format "TCP4:%s:%d" container-ip (anaconda-mode-port))))
               (set-process-query-on-exit-flag anaconda-mode-socat-process nil)))
            ((pythonic-remote-ssh-p)
             (let ((jump (anaconda-jump-proxy-string)))
               (message (format "Anaconda Jump Proxy: %s" jump))
               (setq anaconda-mode-ssh-process
                     (if jump
                         (start-process anaconda-mode-ssh-process-name
                                        anaconda-mode-ssh-process-buffer
                                        "ssh" jump "-nNT"
                                        "-L" (format "%s:localhost:%s" (anaconda-mode-port) (anaconda-mode-port))
                                        (format "%s@%s" (pythonic-remote-user) (pythonic-remote-host))
                                        "-p" (number-to-string (or (pythonic-remote-port) 22)))
                       (start-process anaconda-mode-ssh-process-name
                                      anaconda-mode-ssh-process-buffer
                                      "ssh" "-nNT"
                                      "-L" (format "%s:localhost:%s" (anaconda-mode-port) (anaconda-mode-port))
                                      (format "%s@%s" (pythonic-remote-user) (pythonic-remote-host))
                                      "-p" (number-to-string (or (pythonic-remote-port) 22)))))
               ;; prevent race condition between tunnel setup and first use
               (sleep-for anaconda-mode-tunnel-setup-sleep)
               (set-process-query-on-exit-flag anaconda-mode-ssh-process nil))))
      (when callback
        (funcall callback)))))


;;; Interaction.

(defun anaconda-mode-call (command callback)
  "Make remote procedure call for COMMAND.
Apply CALLBACK to it result."
  (anaconda-mode-start
   (lambda () (anaconda-mode-jsonrpc command callback))))

(defun anaconda-mode-jsonrpc (command callback)
  "Perform JSONRPC call for COMMAND.
Apply CALLBACK to the call result when retrieve it.  Remote
COMMAND must expect four arguments: python buffer content, line
number position, column number position and file path."
  (let ((url-request-method "POST")
        (url-request-data (anaconda-mode-jsonrpc-request command)))
    (url-retrieve
     (format "http://%s:%s" anaconda-mode-localhost-address (anaconda-mode-port))
     (anaconda-mode-create-response-handler callback)
     nil
     t)))

(defun anaconda-mode-jsonrpc-request (command)
  "Prepare JSON encoded buffer data for COMMAND call."
  (encode-coding-string (json-encode (anaconda-mode-jsonrpc-request-data command)) 'utf-8))

(defun anaconda-mode-jsonrpc-request-data (command)
  "Prepare buffer data for COMMAND call."
  `((jsonrpc . "2.0")
    (id . 1)
    (method . ,command)
    (params . ((source . ,(buffer-substring-no-properties (point-min) (point-max)))
               (line . ,(line-number-at-pos (point)))
               (column . ,(- (point) (line-beginning-position)))
               (path . ,(when (buffer-file-name)
                          (pythonic-python-readable-file-name (buffer-file-name))))))))

(defun anaconda-mode-create-response-handler (callback)
  "Create server response handler based on CALLBACK function."
  (let ((anaconda-mode-request-point (point))
        (anaconda-mode-request-buffer (current-buffer))
        (anaconda-mode-request-window (selected-window))
        (anaconda-mode-request-tick (buffer-chars-modified-tick)))
    (lambda (status)
      (let ((http-buffer (current-buffer)))
        (unwind-protect
            (if (or (not (equal anaconda-mode-request-window (selected-window)))
                    (with-current-buffer (window-buffer anaconda-mode-request-window)
                      (or (not (equal anaconda-mode-request-buffer (current-buffer)))
                          (not (equal anaconda-mode-request-point (point)))
                          (not (equal anaconda-mode-request-tick (buffer-chars-modified-tick))))))
                nil
              (search-forward-regexp "\r?\n\r?\n" nil t)
              (let ((response (condition-case nil
                                  (json-read)
                                ((json-readtable-error json-end-of-file end-of-file)
                                 (let ((response (concat (format "# status: %s\n# point: %s\n" status (point))
                                                         (buffer-string))))
                                   (with-current-buffer (get-buffer-create anaconda-mode-response-buffer)
                                     (erase-buffer)
                                     (insert response)
                                     (goto-char (point-min)))
                                   nil)))))
                (if (null response)
                    (message "Cannot read anaconda-mode server response")
                  (if (assoc 'error response)
                      (let* ((error-structure (cdr (assoc 'error response)))
                             (error-message (cdr (assoc 'message error-structure)))
                             (error-data (cdr (assoc 'data error-structure)))
                             (error-template (if error-data "%s: %s" "%s")))
                        (apply 'message error-template (delq nil (list error-message error-data))))
                    (with-current-buffer anaconda-mode-request-buffer
                      (let ((result (cdr (assoc 'result response))))
                        ;; Terminate `apply' call with empty list so response
                        ;; will be treated as single argument.
                        (apply callback result nil)))))))
          (kill-buffer http-buffer))))))


;;; Code completion.

(defun anaconda-mode-complete ()
  "Request completion candidates."
  (interactive)
  (unless (python-syntax-comment-or-string-p)
    (anaconda-mode-call "complete" 'anaconda-mode-complete-callback)))

(defun anaconda-mode-complete-callback (result)
  "Start interactive completion on RESULT receiving."
  (let* ((bounds (bounds-of-thing-at-point 'symbol))
         (start (or (car bounds) (point)))
         (stop (or (cdr bounds) (point)))
         (collection (anaconda-mode-complete-extract-names result))
         (completion-extra-properties '(:annotation-function anaconda-mode-complete-annotation)))
    (completion-in-region start stop collection)))

(defun anaconda-mode-complete-extract-names (result)
  "Extract completion names from `anaconda-mode' RESULT."
  (--map (let ((name (aref it 0))
               (type (aref it 1)))
           (put-text-property 0 1 'type type name)
           name)
         result))

(defun anaconda-mode-complete-annotation (candidate)
  "Get annotation for CANDIDATE."
  (--when-let (get-text-property 0 'type candidate)
    (concat " <" it ">")))


;;; View documentation.

(defun anaconda-mode-show-doc ()
  "Show documentation for context at point."
  (interactive)
  (anaconda-mode-call "show_doc" 'anaconda-mode-show-doc-callback))

(defun anaconda-mode-show-doc-callback (result)
  "Process view doc RESULT."
  (if (> (length result) 0)
      (if (and anaconda-mode-use-posframe-show-doc
               (require 'posframe nil 'noerror)
               (posframe-workable-p))
          (anaconda-mode-documentation-posframe-view result)
        (pop-to-buffer (anaconda-mode-documentation-view result) t))
    (message "No documentation available")))

(defun anaconda-mode-documentation-view (result)
  "Show documentation view for rpc RESULT, and return buffer."
  (let ((buf (get-buffer-create "*Anaconda*")))
    (with-current-buffer buf
      (view-mode -1)
      (erase-buffer)
      (mapc
       (lambda (it)
         (insert (propertize (aref it 0) 'face 'bold))
         (insert "\n")
         (insert (s-trim-right (aref it 1)))
         (insert "\n\n"))
       result)
      (view-mode 1)
      (goto-char (point-min))
      buf)))

(defun anaconda-mode-documentation-posframe-view (result)
  "Show documentation view in posframe for rpc RESULT."
  (with-current-buffer (get-buffer-create anaconda-mode-doc-frame-name)
    (erase-buffer)
    (mapc
     (lambda (it)
       (insert (propertize (aref it 0) 'face 'bold))
       (insert "\n")
       (insert (s-trim-left (aref it 1)))
       (insert "\n\n"))
     result))
  (posframe-show anaconda-mode-doc-frame-name
                 :position (point)
                 :internal-border-width 10
                 :background-color anaconda-mode-doc-frame-background
                 :foreground-color anaconda-mode-doc-frame-foreground)
  (add-hook 'post-command-hook 'anaconda-mode-hide-frame)
  (setq anaconda-mode-frame-last-point (point))
  (setq anaconda-mode-frame-last-scroll-offset (window-start)))

(defun anaconda-mode-hide-frame ()
  "Hide posframe when window scroll or move point."
  (ignore-errors
    (when (get-buffer anaconda-mode-doc-frame-name)
      (unless (and (equal (point) anaconda-mode-frame-last-point)
                   (equal (window-start) anaconda-mode-frame-last-scroll-offset))
        (posframe-hide anaconda-mode-doc-frame-name)
        (remove-hook 'post-command-hook 'anaconda-mode-hide-frame)))))


;;; Find definitions.

(defun anaconda-mode-find-definitions ()
  "Find definitions for thing at point."
  (interactive)
  (anaconda-mode-call
   "goto_definitions"
   (lambda (result)
     (anaconda-mode-show-xrefs result nil "No definitions found"))))

(defun anaconda-mode-find-definitions-other-window ()
  "Find definitions for thing at point."
  (interactive)
  (anaconda-mode-call
   "goto_definitions"
   (lambda (result)
     (anaconda-mode-show-xrefs result 'window "No definitions found"))))

(defun anaconda-mode-find-definitions-other-frame ()
  "Find definitions for thing at point."
  (interactive)
  (anaconda-mode-call
   "goto_definitions"
   (lambda (result)
     (anaconda-mode-show-xrefs result 'frame "No definitions found"))))


;;; Find assignments.

(defun anaconda-mode-find-assignments ()
  "Find assignments for thing at point."
  (interactive)
  (anaconda-mode-call
   "goto_assignments"
   (lambda (result)
     (anaconda-mode-show-xrefs result nil "No assignments found"))))

(defun anaconda-mode-find-assignments-other-window ()
  "Find assignments for thing at point."
  (interactive)
  (anaconda-mode-call
   "goto_assignments"
   (lambda (result)
     (anaconda-mode-show-xrefs result 'window "No assignments found"))))

(defun anaconda-mode-find-assignments-other-frame ()
  "Find assignments for thing at point."
  (interactive)
  (anaconda-mode-call
   "goto_assignments"
   (lambda (result)
     (anaconda-mode-show-xrefs result 'frame "No assignments found"))))


;;; Find references.

(defun anaconda-mode-find-references ()
  "Find references for thing at point."
  (interactive)
  (anaconda-mode-call
   "usages"
   (lambda (result)
     (anaconda-mode-show-xrefs result nil "No references found"))))

(defun anaconda-mode-find-references-other-window ()
  "Find references for thing at point."
  (interactive)
  (anaconda-mode-call
   "usages"
   (lambda (result)
     (anaconda-mode-show-xrefs result 'window "No references found"))))

(defun anaconda-mode-find-references-other-frame ()
  "Find references for thing at point."
  (interactive)
  (anaconda-mode-call
   "usages"
   (lambda (result)
     (anaconda-mode-show-xrefs result 'frame "No references found"))))


;;; Xref.

(defun anaconda-mode-show-xrefs (result display-action error-message)
  "Show xref from RESULT using DISPLAY-ACTION.
Show ERROR-MESSAGE if result is empty."
  (if result
      (if (stringp result)
          (message result)
        (let ((xrefs (anaconda-mode-make-xrefs result)))
          (if (not (cdr xrefs))
              (progn
                (xref-push-marker-stack)
                (funcall (if (fboundp 'xref-pop-to-location)
                             'xref-pop-to-location
                           'xref--pop-to-location)
                         (cl-first xrefs)
                         display-action))
            (xref--show-xrefs (if (functionp 'xref--create-fetcher)
                                  (lambda (&rest _) xrefs)
                                xrefs)
                              display-action))))
    (message error-message)))

(defun anaconda-mode-make-xrefs (result)
  "Return a list of x-reference candidates created from RESULT."
  (--map
   (xref-make
    (aref it 3)
    (xref-make-file-location (pythonic-emacs-readable-file-name (aref it 0)) (aref it 1) (aref it 2)))
   result))


;;; Eldoc.

(defun anaconda-mode-eldoc-function ()
  "Show eldoc for context at point."
  (anaconda-mode-call "eldoc" 'anaconda-mode-eldoc-callback)
  ;; Don't show response buffer name as ElDoc message.
  nil)

(defun anaconda-mode-eldoc-callback (result)
  "Display eldoc from server RESULT."
  (eldoc-message (anaconda-mode-eldoc-format result)))

(defun anaconda-mode-eldoc-format (result)
  "Format eldoc string from RESULT."
  (when result
    (let ((doc (anaconda-mode-eldoc-format-definition
                (aref result 0)
                (aref result 1)
                (aref result 2))))
      (if anaconda-mode-eldoc-as-single-line
          (substring doc 0 (min (frame-width) (length doc)))
        doc))))

(defun anaconda-mode-eldoc-format-definition (name index params)
  "Format function definition from NAME, INDEX and PARAMS."
  (when index
    (aset params index (propertize (aref params index) 'face 'eldoc-highlight-function-argument)))
  (concat (propertize name 'face 'font-lock-function-name-face) "(" (mapconcat 'identity params ", ") ")"))


;;; Anaconda minor mode.

(defvar anaconda-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map (kbd "C-M-i") 'anaconda-mode-complete)
    (define-key map (kbd "M-.") 'anaconda-mode-find-definitions)
    (define-key map (kbd "C-x 4 .") 'anaconda-mode-find-definitions-other-window)
    (define-key map (kbd "C-x 5 .") 'anaconda-mode-find-definitions-other-frame)
    (define-key map (kbd "M-=") 'anaconda-mode-find-assignments)
    (define-key map (kbd "C-x 4 =") 'anaconda-mode-find-assignments-other-window)
    (define-key map (kbd "C-x 5 =") 'anaconda-mode-find-assignments-other-frame)
    (define-key map (kbd "M-r") 'anaconda-mode-find-references)
    (define-key map (kbd "C-x 4 r") 'anaconda-mode-find-references-other-window)
    (define-key map (kbd "C-x 5 r") 'anaconda-mode-find-references-other-frame)
    (define-key map (kbd "M-,") 'xref-pop-marker-stack)
    (define-key map (kbd "M-?") 'anaconda-mode-show-doc)
    map)
  "Keymap for `anaconda-mode'.")

;;;###autoload
(define-minor-mode anaconda-mode
  "Code navigation, documentation lookup and completion for Python.

\\{anaconda-mode-map}"
  :lighter anaconda-mode-lighter
  :keymap anaconda-mode-map
  (setq-local url-http-attempt-keepalives nil))

;;;###autoload
(define-minor-mode anaconda-eldoc-mode
  "Toggle echo area display of Python objects at point."
  :lighter ""
  (if anaconda-eldoc-mode
      (turn-on-anaconda-eldoc-mode)
    (turn-off-anaconda-eldoc-mode)))

(defun turn-on-anaconda-eldoc-mode ()
  "Turn on `anaconda-eldoc-mode'."
  (make-local-variable 'eldoc-documentation-function)
  (setq-local eldoc-documentation-function 'anaconda-mode-eldoc-function)
  (eldoc-mode +1))

(defun turn-off-anaconda-eldoc-mode ()
  "Turn off `anaconda-eldoc-mode'."
  (kill-local-variable 'eldoc-documentation-function)
  (eldoc-mode -1))

(provide 'anaconda-mode)

;;; anaconda-mode.el ends here