(require 'cl)
(require 'erlang-start)

;; Run a emacs repl with yaws loaded and configured
(defvar yaws-path "~/Applications/YAWS")
(defvar yaws-listening-regex "Yaws: Listening")
(defvar yaws-extra-paths ())
(defvar yaws-extra-flags ())

(defadvice inferior-erlang-wait-prompt (before send-ret-before-waiting last () activate)
  (or (with-current-buffer inferior-erlang-buffer (save-excursion
        (goto-char (process-mark inferior-erlang-process))
        (forward-line 0)
        (looking-at comint-prompt-regexp)))
      (comint-send-string inferior-erlang-process "\n")))

(defun* erlang-yaws-wait-for-listen (&key (timeout 2) (buffer (current-buffer)))
  (ignore-errors
    (while (not (string-match-p yaws-listening-regex (buffer-string)))
      (or (accept-process-output (get-buffer-process buffer) timeout)
          (error "Yaws didn't seems to listen before timeout (%s) in %s" timeout buffer)))
    (comint-send-string (get-buffer-process buffer) "\n") t))


(defun erlang-yaws-do-wait-for-listen ()
  (message "Waiting for yaws to listen...")
  (if (erlang-yaws-wait-for-listen)
      (progn (message "Erlang+YAWS Ready")
             t)
    (message "Erlang+YAWS load FAILED")
    nil))

(defun erlang-yaws-get-extra-paths ()
  ())

(defun erlang-yaws-get-extra-flags ()
  ())

(defun run-erlang-yaws ()
  (interactive)
  (let ((inferior-erlang-machine-options `("-pa" ,(expand-file-name (concat yaws-path "/lib/yaws/ebin"))
                                           ,@(or (erlang-yaws-get-extra-paths) '(""))
                                           ,@(or (erlang-yaws-get-extra-flags) '(""))
                                           "-yaws" "debug"
                                           "-run" "yaws"
                                           "-yaws" "id" "default"))
        (erlang-shell-mode-hook ()))
    (add-hook 'erlang-shell-mode-hook 'erlang-yaws-do-wait-for-listen)
    (run-erlang)))

(message "Eval'd")
(provide 'erlang-yaws)