;;; flymake-phpcs.el --- PHP Code Sniffer Flymake backend  -*- lexical-binding: t; -*-

(defcustom flymake-phpcs-standard "PSR12"
  "Setting the Coding Standard for PHP CodeSniffer."
  :type 'string
  :group 'flymake-phpcs)

(defcustom flymake-phpcs-command (executable-find "phpcs")
  "The name of the phpcs executable."
  :type 'string
  :group 'flymake-phpcs)

(defcustom flymake-phpcbf-command (executable-find "phpcbf")
  "The name of the phpcbf executable."
  :type 'string
  :group 'flymake-phpcs)

(defvar-local phpcs--flymake-proc nil)

(defun phpcs-flymake (report-fn &rest _args)
  (unless (executable-find flymake-phpcs-command)
    (error "Cannot find phpcs executable"))

  ;; If a live process launched in an earlier check was found, that
  ;; process is killed.  When that process's sentinel eventually runs,
  ;; it will notice its obsoletion, since it have since reset
  ;; `phpcs-flymake-proc' to a different value
  ;;
  (when (process-live-p phpcs--flymake-proc)
    (kill-process phpcs--flymake-proc))

  ;; Save the current buffer, the narrowing restriction, remove any
  ;; narrowing restriction.
  ;;
  (let ((source (current-buffer)))
    (save-restriction
      (widen)
      ;; Reset the `phpcs--flymake-proc' process to a new process
      ;; calling the phpcs tool.
      ;;
      (setq
       phpcs--flymake-proc
       (make-process
        :name "phpcs-flymake" :noquery t :connection-type 'pipe
        ;; Make output go to a temporary buffer.
        ;;
        :buffer (generate-new-buffer " *phpcs-flymake*")
        :command `(,flymake-phpcs-command "--report=emacs" ,(concat "--standard=" flymake-phpcs-standard))
        :sentinel
        (lambda (proc _event)
          ;; Check that the process has indeed exited, as it might
          ;; be simply suspended.
          ;;
          (when (eq 'exit (process-status proc))
            (unwind-protect
                ;; Only proceed if `proc' is the same as
                ;; `phpcs--flymake-proc', which indicates that
                ;; `proc' is not an obsolete process.
                ;;
                (if (with-current-buffer source (eq proc phpcs--flymake-proc))
                    (with-current-buffer (process-buffer proc)
                      (goto-char (point-min))
                      ;; Parse the output buffer for diagnostic's
                      ;; messages and locations, collect them in a list
                      ;; of objects, and call `report-fn'.
                      ;;
                      (cl-loop
                       while (search-forward-regexp
                              "^STDIN:\\([[:digit:]]+\\):\\([[:digit:]]+\\): \\([[:alpha:]]+\\) - \\(.*\\)$"
                              nil t)
                       for lnum = (string-to-number (match-string 1))
                       ;; for (beg . end) = (flymake-diag-region source lnum (string-to-number (match-string 2)))
                       for (beg . end) = (flymake-diag-region source lnum)
                       for type = (make-symbol (match-string 3))
                       for msg = (match-string 4)
                       collect (flymake-make-diagnostic source
                                                        beg
                                                        end
                                                        type
                                                        msg)
                       into diags
                       finally (funcall report-fn diags)))
                  (flymake-log :warning "Canceling obsolete check %s"
                               proc))
              ;; Cleanup the temporary buffer used to hold the
              ;; check's output.
              ;;
              (kill-buffer (process-buffer proc)))))))
      ;; Send the buffer contents to the process's stdin, followed by
      ;; an EOF.
      ;;
      (process-send-region phpcs--flymake-proc (point-min) (point-max))
      (process-send-eof phpcs--flymake-proc))))

(defun flymake-phpcs-load ()
  "Configure flymake mode to check the current buffer's PHP syntax."
  (interactive)
  (add-hook 'flymake-diagnostic-functions 'phpcs-flymake nil t))

(defun phpcbf ()
  "Run phpcbf on current file (saved-files only)."
  (interactive)
  (shell-command (combine-and-quote-strings (list flymake-phpcbf-command (concat "--standard=" flymake-phpcs-standard) (buffer-file-name))))
  (revert-buffer :ignore-auto :noconfirm))

(provide 'flymake-phpcs)