(in-package :slacker)
 
 (defvar *api-token*) 
 
 (defun make-client (event-pump)
   (flet ((get-ws-url (slack-response)

            (gethash "url" slack-response)))

     (fw.lu:let-each (:be slack-data)

       (format nil "https://slack.com/api/rtm.connect?token=~a" *api-token*)

       (drakma:http-request slack-data :want-stream t)
       (yason:parse slack-data)
 
       (let* ((url (get-ws-url slack-data))

              (client (wsd:make-client url)))
         (setf (ws-client event-pump)
               client)
         (wsd:on :message client
                 (lambda (message)
                   (chanl:send (result-queue event-pump)
                               message)))

         (wsd:on :close client
                 (lambda (&key code reason)

                   (if (running event-pump)
                       (progn
                         (format t "~&Closed with code: ~a for reason ~a. Restarting in 2 seconds~%"
                                 code reason)
                         (sleep 2)
                         (format t "~& ... restarting~%")
                         (make-client event-pump))
                       (format t "~&exiting~%"))))

         (wsd:start-connection client)))))

 
 (defgeneric send-message (client type &key)
   (:documentation "Send a slack message")
   (:method :around ((client event-pump) _type &key)
     (declare (ignorable client _type))
     (let ((result (call-next-method)))

       (values result
               (wsd:send (ws-client client)
                         (with-output-to-string (s)
                           (yason:encode result s)))))))

 (defmethod send-message ((client event-pump) (type (eql :ping)) &key data)
   (let* ((id (incf (latest-id client)))
          (message `(("id" . ,id)
                     ("type" . "ping"))))
 
     (when data
       (aconsf message "data" data))
 
     (format t "~&pinging with id: ~a at time: ~a~%" id (local-time:now))
     (incf (waiting-pings client))
     (alist-hash-table message
                       :test 'equal)))
 
 (defmethod send-message ((client event-pump) (type (eql :message)) &key channel data thread)
   (let* ((id (incf (latest-id client)))

          (message `(("id" . ,id)
                     ("type" . "message")
                     ("channel" . ,channel)
                     ("text" . ,data)
                     ,@(unsplice
                        (when thread
                          `("thread_ts" . ,thread))))))

     (alist-hash-table message

                       :test 'equal)))

 (define-condition connection-lost (error)

   ())
 

 (defclass slack-client ()
   ((%commands :accessor commands :initform (make-hash-table))
    (%modules :accessor modules :initform '())))
 
 (defgeneric start (event-pump client &key queue-pair))
 
 (defgeneric bind (what where))
 (defmethod bind ((queue-pair queue-pair) (event-pump event-pump))
   (setf (queue-pair event-pump) queue-pair))
 
 (defun handle-work-queue (event-pump)
   (multiple-value-bind (message message-p)
       (chanl:recv (work-queue event-pump)

                   :blockp nil)

     (when message-p
       (funcall message

                event-pump))))

 
 (defun send-pings (event-pump client)

   "Ping slack for connectivity, error if we have too many waiting pings."

   ;; Eventually drop client
   (declare (ignorable client))
   (if (> 100 (waiting-pings event-pump))
       (send-message event-pump :ping)
       (error 'connection-lost)))
 

 (defun network-loop (event-pump modules)

   (declare (optimize (debug 3)))
   (loop for (module . args) in modules

         while (running event-pump) do
           (start-module event-pump
                         (apply #'attach-module
                                event-pump module args)))
 

   (fwoar.event-loop:run-loop event-pump))

 (defun start-client (implementation &key (queue-pair (make-instance 'queue-pair)) modules impl-args)
   (let* ((event-pump (apply #'make-instance implementation
 			    :queue-pair queue-pair
 			    :client-factory (op (make-client _))
 			    impl-args)))

     (setf (running event-pump) t)

     (values event-pump

             (bt:make-thread (lambda ()

                               (network-loop event-pump
                                             modules))

                             :name "Event Server"
                             :initial-bindings `((*api-token* . ,*api-token*))))))

 
 (defmethod get-event-nonblocking ((event-pump event-pump) &key (object-as :hash-table))
   (multiple-value-bind (message message-p) (chanl:recv (result-queue event-pump) :blockp nil)
     (values (when message-p

               (yason:parse message :object-as object-as))
             message-p)))

 (defmethod get-event ((queue-pair queue-pair) &key (object-as :hash-table))
   (multiple-value-bind (message message-p) (chanl:recv (result-queue queue-pair))

     (values (when message-p

               (yason:parse message :object-as object-as))
             message-p)))

 (defparameter *ignored-messages* '(:pong :user_typing :desktop_notification))

 (defgeneric handle-message (type event-pump ts channel message)

   (:method :around (type event-pump ts channel message)
     (flet ((report-continue (stream)
              (format stream "Skip message of type ~s" type))
            (report-retry (stream)
              (format stream "Retry message of type ~s" type)))
       (tagbody start
          (restart-case (call-next-method)
            (continue () :report report-continue)
            (skip-message () :report report-continue)
            (retry () :report report-retry
              (go start))))))

   (:method :before (type event-pump ts channel message)
     (declare (ignore event-pump ts channel))
     (unless (member type *ignored-messages*)
       (fresh-line)
       (yason:encode message)
       (terpri)))
   (:method (type (event-pump event-pump) ts channel message)
     (declare (ignore type event-pump ts channel message))
     nil)
   (:method ((type (eql :pong)) (event-pump event-pump) ts channel message)
     (declare (ignore ts type channel))

     (format t "~&Was waiting on ~a pings," (waiting-pings event-pump))

     (decf (waiting-pings event-pump))

     (format t "after pong received for ~a, now waiting on ~a~%"

             (gethash "reply_to" message)
             (waiting-pings event-pump))))

 
 (defmethod handle-message ((type (eql :message)) (event-pump event-pump) ts channel message)
   (when-let* ((msg (gethash "text" message))

               (parsed-message (tokens msg))) 

     (when (eql #\; (elt msg 0))
       (handle-command event-pump message channel

                       (plump:decode-entities
                        (car parsed-message))

                       (cdr parsed-message))))) 

 (defun event-loop (event-pump)

   (loop
     with message with message-p
     while (running event-pump) do
       (multiple-value-setq (message message-p)
         (get-event (queue-pair event-pump)))
     when message-p do
       (let ((type (gethash "type" message))
             (reply (gethash "reply_to" message))
             (ts (gethash "ts" message))
             (channel (gethash "channel" message)))
         (cond (type
                (handle-message (make-keyword (string-upcase type))
                                event-pump ts channel message))
               (reply )))
     do (sleep 0.01)))

 (defun coordinate-threads (&optional queue-pair (implementation 'event-pump) args)

   (let* ((event-pump (start-client implementation
                                    :queue-pair queue-pair

                                    :modules '((hhgbot-augmented-assistant::js-executor))

                                    :impl-args args)))

     (bt:make-thread (lambda ()
                       (loop until (running event-pump)
                             finally
                                (unwind-protect (event-loop event-pump)
                                  (stop-slacker event-pump))))

                     :name "Event Loop") 

     event-pump))
 

 (defvar *command-table* (make-hash-table :test 'equal))

 
 (defun quote-output (str)
   (with-output-to-string (s)
     (format s "```~%~a```~%" str)))
 
 (defmacro in-wq ((client-sym) &body body)
   `(let ((promise (blackbird-base:make-promise)))
      (values promise

              (chanl:send (work-queue ,client-sym)
                          (lambda (,client-sym)
                            (declare (ignorable ,client-sym))
                            (let ((result (progn ,@body)))
                              (blackbird-base:finish promise result)
                              result))))))

 (defun queue-message (event-pump channel message &key quote thread)

   (let ((message (if quote (quote-output message)

                      message)))

     (in-wq (event-pump)
       (send-message event-pump :message

                     :channel channel
                     :data message
                     :thread thread))))

 
 (define-condition command-error () ())
 (define-condition unsupported-args (command-error) ())
 

 (defgeneric add-command ())

 (defmacro define-command (name (event-pump ts channel &rest args) &body body)
   (let* ((command-sym (intern (string-upcase name)))

          (has-rest (position '&rest args))
          (rest-sym (gensym "rest"))
          (args (if has-rest
                    args
                    (append args `(&rest ,rest-sym)))))

     `(progn
        (defun ,command-sym (,event-pump ,ts ,channel ,@args)

          (declare (ignorable ,event-pump ,ts ,@(when (not has-rest) `(,rest-sym))))
          ,@body)

        (setf (gethash ,name *command-table*) ',command-sym))))

 (defun safe-apply (func event-pump message channel args)

   (with-simple-restart (continue "Skip command")

     (apply func event-pump message channel args)))

 (defun handle-command (event-pump message channel command args)

   (declare (ignorable args))

   (let* ((command (subseq command 1))

          (handler (gethash command *command-table*)))

     (print (hash-table-alist *command-table*))
     (terpri)
     (print command)
     (if handler

         (safe-apply handler event-pump message channel args)

         (queue-message event-pump channel
                        (concat "I don't understand the command `" command "`.")
                        :thread (ensure-thread message)))))

 (defun edit-message (ts channel text)
   (babel:octets-to-string
    (drakma:http-request "https://slack.com/api/chat.update"

                         :method :post
                         :content (concat "token=" *api-token*
                                          "&channel=" channel
                                          "&ts=" ts
                                          "&text=" text))))

 (defmacro with-output-to-message ((stream event-pump channel &key quote thread) &body body)

   (once-only (event-pump channel quote)
     `(queue-message ,event-pump ,channel

                     (with-output-to-string (,stream)
                       ,@body)
                     :quote ,quote
                     :thread ,thread)))

 
 (defmacro with-thread-info ((ts thread-ts in-thread is-reply) message &body body)
   (once-only (message)
     `(let* ((,ts (gethash "ts" ,message))

             (,thread-ts (gethash "thread_ts" ,message))
             (,in-thread (not (null ,thread-ts)))
             (,is-reply (and ,in-thread (string/= ,ts ,thread-ts))))

        ,@body)))
 
 (defun ensure-thread (message)
   "Continue thread or else start a new one"
   (with-thread-info (ts thread-ts in-thread is-reply) message
     (declare (ignore is-reply))
     (if in-thread thread-ts ts)))
 
 (defun keep-in-thread (message)
   "Continue thread or continue in main thread"
   (with-thread-info (ts thread-ts in-thread is-reply) message
     (declare (ignore is-reply))
     (if in-thread thread-ts nil)))
 
 (define-command "help" (event-pump message channel)

   (let ((*print-right-margin* (max (or *print-right-margin* 0)

                                    80)))

     (with-thread-info (ts thread-ts in-thread is-reply) message
       (format t "~&THREAD INFO: (ts ~s) (thread-ts ~s) (in-thread ~s) (is-reply ~s)~%" ts thread-ts in-thread is-reply)
       (with-output-to-message (s event-pump channel :thread (ensure-thread message))

         (format s "I understand these commands:~%~{`~a`~^ ~}"
                 (hash-table-keys *command-table*))
         :quote t))))

 (defvar *id* 0)

 (defun make-message (data channel)
   (incf *id*)
   (with-output-to-string (s)
     (yason:encode
      (alist-hash-table
       `(("id" . ,*id*)

         ("type" . "message")
         ("channel" . ,channel)
         ("text" . ,data)))

      s)))