(local core (require :core))
(local socket (require :socket))
(local {: int16-to-bytes : int32-to-bytes : lo} (require :lib.util))

(local config {
  :host "172.24.1.6"
  :port 6502
})

{:cmd {
   :write 0
   :read 1
   :jmp 2
   :pause 3
   :ping 4
 }
 :response {
   :ack 0
   :data 1
 }
 :pending {}
 :msgid 0
 :connect
 (fn [self ?port ?host]
   (when (not self.connection)
     (local [port host] [(or ?port config.port) (or ?host config.host)])
     (set self.connection (assert (socket.udp)))
     (assert (self.connection:setpeername host port))
     (self.connection:settimeout 0)
     (core.add_thread #(while (self:connected?) (self:receive) (coroutine.yield)) self.connection)))
 :connected? (fn [self] (not= self.connection nil))
 :disconnect
 (fn [self]
   (when self.connection
     (self.connection:close)
     (set self.connection nil)
     (set self.pending {})))
 :next-msgid
 (fn [self]
   (set self.msgid (lo (+ self.msgid 1)))
   self.msgid)
 :send
 (fn [self cmd ?data ?callback]
   (let [msgid (self:next-msgid)
         msg (.. (string.char msgid cmd) (or ?data ""))]
     (print "sending" msgid cmd (length msg))
     (when ?callback (tset self.pending msgid ?callback))
     (self.connection:send msg)))
 :receive
 (fn [self]
   (when self.connection
     (let [data (self.connection:receive)]
       (when data
         (let [msgid (string.byte (data:sub 1 1))
               cmd   (string.byte (data:sub 2 2))
               pendingfn (. self.pending msgid)]
           (print "recieved" msgid cmd)
           (when pendingfn
             (tset self.pending msgid nil)
             (pendingfn self cmd (data:sub 3))))))))
 :jump (fn [self addr] (self:send self.cmd.jmp (int32-to-bytes addr)))
 ; todo: break up into multiple calls
 :read
 (fn [self addr len]
   (let [coro (coroutine.running)]
     (self:send self.cmd.read (.. (int32-to-bytes addr)
                                  (int16-to-bytes len))
                              #(coroutine.resume coro $3))
     (coroutine.yield)))
 :write
 (fn [self addr data]
   (if (> (length data) 1400) (do (self:write addr (data:sub 1 1400)) (self:write (+ addr 1400) (data:sub 1401)))
     (let [coro (coroutine.running)]
       (self:send self.cmd.write (.. (int32-to-bytes addr)
                                     (int16-to-bytes (length data))
                                     data)
                                #(coroutine.resume coro $3))
       (coroutine.yield))))
 :launch (fn [self prg] (self:jump (prg:lookup-addr prg.start-symbol)))
}