OpenComputers Telegram Bot API

local json = require("JSON")
--local internet = require("internet")
local internet = require("component").internet
local serial = require("serialization")
local fs = require("filesystem")
local Promise = require("Promise")
--local proxyUrl = "http://www.ipv6proxy.net/go.php?u="


local function encode(data)
	return data:gsub("([^%-%_%.%~])", function(char)
		return string.format("%%%02X", string.byte(char))
	end)
end

local function getUrlForProxyificate(url)
	if proxyUrl then
		return proxyUrl .. encode(url)
	else
		return url
	end
end

function request(url,post,headers)
	local success, handler = pcall(internet.request,url,post,headers)
	if success then
		local data = ""
		local resCode,resName,resHeaders
		while not resCode do
			resCode, resName, resHeaders = handler:responce()
		end
		repeat
			local chunk, reason = handler:read()
			if chunk then
				data = data .. chunk
			elseif reason then
				error(reason)
			end
			os.sleep(0)
		until not chunk
		return {
			resCode = resCode,
			resName = resName,
			resHeaders = resHeaders,
			payload = data,
		}
	else
		error(handler)
	end
end

function sendRequest(token,method,POST)
	local data = ""
	local url = "https://api.telegram.org/bot" .. token .. "/" .. method
	data = request(getUrlForProxyificate(url),POST)
	--print(serialization.serialize(data.headers))
	return json.decode(data.payload)
end

local APIMetatable = {}
APIMetatable.__index = function(self,key)
	return function(post)
		return Promise(function(resolve,reject)
			local res = sendRequest(self.token,key,post)
			if res.ok == true then
				resolve(res.result)
			else
				reject(res.error_message)
			end
		end)
	end
end

function Bot(token)
	local bot = {}
	bot.API = {token=token}
	setmetatable(bot.API,APIMetatable)
	function bot.API.rawRequest(method,post)
		return sendRequest(bot.API.token,method,post)
	end
	bot.longpoll = {callbacks={}}
	function bot.longpoll.on(event,callback) --message, edited_message, channel_post, edited_channel_post, inline_query, chosen_inline_result, callback_query, shipping_query, pre_checkout_query
		bot.longpoll.callbacks[event] = bot.longpoll.callbacks[event] or {}
		table.insert(bot.longpoll.callbacks[event],callback)
	end
	function bot.longpoll.start()
		bot.longpoll.active = true
		local errorCounter = 0
		while bot.longpoll.active do
			os.sleep(0)
			local success, updates = pcall(sendRequest,token,"getUpdates",{
				offset = bot.longpoll.offset,
				--timeout = 1,
			})
			if success then
				errorCounter = 0
				if updates.ok then
					local result = updates.result
					for i = 1, #result do
						local update = result[i]
						for key, value in pairs(update) do
							local lngp = bot.longpoll.callbacks[key]
							if lngp then
								for i = 1, #lngp do
									lngp[i](update[key])
								end
							end
						end
					end
					if #result > 0 then
						bot.longpoll.offset = result[#result].update_id+1
					end
				else
					print("error: ",updates.error_message)
				end
			else
				if errorCounter > 3 then
					bot.longpoll.stop()
					print("Exiting: too many errors")
					error(updates)
				end
				errorCounter = errorCounter + 1
				print("internal error: ", updates, errorCounter)
			end
		end
	end
	function bot.longpoll.stop()
		bot.longpoll.active = false
	end
	return bot
end
return Bot