--- webclient. (skynet服务).
-- @source https://github.com/dpull/lua-webclient
-- @module webclient
-- @usage local webclient = skynet.newservice("webclient")

local skynet = require "skynet"
local webclientlib = require "webclient"
local webclient = webclientlib.create()
local requests = nil
local assert = assert
local table = table
local string = string

local function resopnd(request)
	if not request.response then
		return
	end

	local content, errmsg = webclient:get_respond(request.req)
	if not errmsg then
		request.response(true, true, content)
	else
		local info = webclient:get_info(request.req)
		if info.response_code == 200 and not info.content_save_failed then
			request.response(true, true, content, errmsg)
		else
			request.response(true, false, errmsg, info)
		end
	end
end

local function query()
	while next(requests) do
		local finish_key = webclient:query()
		if finish_key then
			local request = requests[finish_key]
			assert(request)

			xpcall(
				resopnd,
				function()
					skynet.error(debug.traceback())
				end,
				request
			)

			webclient:remove_request(request.req)
			requests[finish_key] = nil
		else
			skynet.sleep(1)
		end
	end
	requests = nil
end

--- 请求某个url
-- @function request
-- @string url url
-- @tab[opt] get get的参数
-- @param[opt] post post参数，table or string类型
-- @bool[opt] no_reply 使用skynet.call则要设置为nil或false，使用skynet.send则要设置为true
-- @treturn bool 请求是否成功
-- @treturn string 当成功时，返回内容，当失败时，返回出错原因
-- @usage skynet.call(webclient, "lua", "request", "http://www.dpull.com")
-- @usage skynet.send(webclient, "lua", "request", "http://www.dpull.com", nil, nil, true)
local function request(url, get, post, no_reply)
	if get then
		local i = 0
		for k, v in pairs(get) do
			k = webclient:url_encoding(k)
			v = webclient:url_encoding(v)

			url = string.format("%s%s%s=%s", url, i == 0 and "?" or "&", k, v)
			i = i + 1
		end
	end

	if post and type(post) == "table" then
		local data = {}
		for k, v in pairs(post) do
			k = webclient:url_encoding(k)
			v = webclient:url_encoding(v)

			table.insert(data, string.format("%s=%s", k, v))
		end
		post = table.concat(data, "&")
	end

	local req, key = webclient:request(url, post)
	if not req then
		return skynet.ret()
	end
	assert(key)

	local response = nil
	if not no_reply then
		response = skynet.response()
	end

	if requests == nil then
		requests = {}
		skynet.fork(query)
	end

	requests[key] = {
		url = url,
		req = req,
		response = response
	}
end

skynet.start(
	function()
		skynet.dispatch(
			"lua",
			function(session, source, command, ...)
				assert(command == "request")
				request(...)
			end
		)
	end
)