local triggerCHN,sendCHN,readCHN=...

local CHN_demand,CHN_getCount=triggerCHN.demand,triggerCHN.getCount
local CHN_push,CHN_pop=triggerCHN.push,triggerCHN.pop

local SOCK=require'socket'.tcp()
local JSON=require'Zframework.json'

do--Connect
	local host=CHN_demand(sendCHN)
	local port=CHN_demand(sendCHN)
	local path=CHN_demand(sendCHN)
	local body=CHN_demand(sendCHN)
	local timeout=CHN_demand(sendCHN)

	SOCK:settimeout(timeout)
	local res,err=SOCK:connect(host,port)
	assert(res,err)

	--WebSocket handshake
	if not body then body=''end
	SOCK:send(
		'GET '..path..' HTTP/1.1\r\n'..
		'Host: '..host..':'..port..'\r\n'..
		'Connection: Upgrade\r\n'..
		'Upgrade: websocket\r\n'..
		'Content-Type: application/json\r\n'..
		'Content-Length: '..#body..'\r\n'..
		'Sec-WebSocket-Version: 13\r\n'..
		'Sec-WebSocket-Key: osT3F7mvlojIvf3/8uIsJQ==\r\n\r\n'..--secKey
		body
	)

	--First line of HTTP
	res,err=SOCK:receive('*l')
	assert(res,err)
	local code,ctLen
	code=res:find(' ')
	code=res:sub(code+1,code+3)

	--Get body length from headers and remove headers
	repeat
		res,err=SOCK:receive('*l')
		assert(res,err)
		if not ctLen and res:find('length')then
			ctLen=tonumber(res:match('%d+'))
		end
	until res==''

	--Result
	if ctLen then
		if code=='101'then
			CHN_push(readCHN,'success')
		else
			res,err=SOCK:receive(ctLen)
			res=JSON.decode(assert(res,err))
			error((code or"XXX")..":"..(res and res.reason or"Server Error"))
		end
	end
end

local YIELD=coroutine.yield
local byte,char=string.byte,string.char
local band,bor,bxor=bit.band,bit.bor,bit.bxor
local shl,shr=bit.lshift,bit.rshift

local mask_key={1,14,5,14}
local mask_str=char(unpack(mask_key))
local function _send(op,message)
	--Message type
	SOCK:send(char(bor(op,0x80)))

	if message then
		--Length
		local length=#message
		if length>65535 then
			SOCK:send(char(bor(127,0x80),0,0,0,0,band(shr(length,24),0xff),band(shr(length,16),0xff),band(shr(length,8),0xff),band(length,0xff)))
		elseif length>125 then
			SOCK:send(char(bor(126,0x80),band(shr(length,8),0xff),band(length,0xff)))
		else
			SOCK:send(char(bor(length,0x80)))
		end
		local msgbyte={byte(message,1,length)}
		for i=1,length do
			msgbyte[i]=bxor(msgbyte[i],mask_key[(i-1)%4+1])
		end
		return SOCK:send(mask_str..char(unpack(msgbyte)))
	else
		SOCK:send('\128'..mask_str)
		return 0
	end
end
local sendThread=coroutine.wrap(function()
	while true do
		while CHN_getCount(sendCHN)>=2 do
			_send(CHN_pop(sendCHN),CHN_pop(sendCHN))
		end
		YIELD()
	end
end)

local function _receive(sock,len)
	local buffer=""
	while true do
		local r,e,p=sock:receive(len)
		if r then
			buffer=buffer..r
			len=len-#r
		elseif p then
			buffer=buffer..p
			len=len-#p
		elseif e then
			return nil,e
		end
		if len==0 then
			return buffer
		end
		YIELD()
	end
end
local readThread=coroutine.wrap(function()
	local res,err
	local op,fin
	local lBuffer=""--Long multi-pack buffer
	while true do
		--Byte 0-1
		res,err=_receive(SOCK,2)
		assert(res,err)

		op=band(byte(res,1),0x0f)
		fin=band(byte(res,1),0x80)==0x80

		--Calculating data length
		local length=band(byte(res,2),0x7f)
		if length==126 then
			res,err=_receive(SOCK,2)
			assert(res,err)
			length=shl(byte(res,1),8)+byte(res,2)
		elseif length==127 then
			local lenData
			lenData,err=_receive(SOCK,8)
			assert(res,err)
			local _,_,_,_,_5,_6,_7,_8=byte(lenData,1,8)
			length=shl(_5,24)+shl(_6,16)+shl(_7,8)+_8
		end
		res,err=_receive(SOCK,length)
		assert(res,err)

		--React
		if op==8 then--8=close
			CHN_push(readCHN,8)--close
			if type(res)=='string'then
				CHN_push(readCHN,res:sub(3))--Warning: 2 bytes close code at start so :sub(3)
			else
				CHN_push(readCHN,"WS closed")
			end
			return
		elseif op==0 then--0=continue
			lBuffer=lBuffer..res
			if fin then
				CHN_push(readCHN,lBuffer)
				lBuffer=""
			end
		else
			CHN_push(readCHN,op)
			if fin then
				CHN_push(readCHN,res)
				lBuffer=""
			else
				lBuffer=res
			end
		end
		YIELD()
	end
end)

local success,err

while true do--Running
	CHN_demand(triggerCHN)
	success,err=pcall(sendThread)
	if not success or err then break end
	success,err=pcall(readThread)
	if not success or err then break end
end

SOCK:close()
CHN_push(readCHN,8)--close
CHN_push(readCHN,err or"Disconnected")
error()