;; tinmop: a multiprotocol client
;; Copyright © cage

;; 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/][http://www.gnu.org/licenses/]].

(in-package :json-rpc-communication)

(defparameter *stop-server*    nil)

(defparameter *server-output-stream* *standard-output*)

(defparameter *server-input-stream*  *standard-input*)

(defparameter *server-error-stream*  *error-output*)

(defparameter *excess-data-from-client* #())

(a:define-constant +command-delimiter+ 0 :test #'=)

(defun read-json (stream)
  (to-s (read-delimited-into-array-unbuffered stream
                                              :delimiter +command-delimiter+)))

(defun elaborate-json-request (data)
  (rpc:encode-to-string (rpc:elaborate-request data)))

(defun read-from-client ()
  (read-json *server-input-stream*))

(defgeneric send-to-client (object))

(defmethod send-to-client ((object string))
  (send-to-client (string->octets object)))

(defmethod send-to-client ((object vector))
  (write-sequence object *server-output-stream*)
  (write-byte +command-delimiter+ *server-output-stream*)
  (finish-output *server-output-stream*))

(defun stop-server ()
  (setf *stop-server* t))

(defun start-server ()
  (init-gemini-window)
  (prepare-rpc
    (loop while (not *stop-server*) do
      (handler-case
          (let ((json (read-from-client)))
            (if (string-empty-p json)
                (setf *stop-server* t)
                (let ((results (elaborate-json-request json)))
                  (send-to-client results))))
        (rpc:json-rpc-error (e)
          (send-to-client (format nil (_ "RPC Error: ~a~%") e))
          (setf *stop-server* t))
        (delimiter-not-found (e)
          (send-to-client (format nil (_ "Read error: ~a~%") e))
          (setf *stop-server* t))
        (error (e)
          (send-to-client (format nil (_ "Error: ~a~%") e))
          (setf *stop-server* t))))
    (send-to-client "Bye!")))