function createBot(token, onMessage, onDocument)
    local cjson = require("cjson")
    local api_url = "https://api.telegram.org/bot" .. token
    local last_update_id = nil
    local onMessage = onMessage or function() end
    local onDocument = onDocument or function() end

    local function apiRequest(method, parameters)
        local url = api_url .. "/" .. method
        local res, header, body
        if not parameters or next(parameters) == nil then
            res, header, body = net.curl.get(url)
        else
            res, header, body = net.curl.post(url, parameters)
        end
        if res then
            return cjson.decode(body)
        else
            print(header, body)
        end
    end

    local function sendMessage(chat_id, text)
        apiRequest("sendMessage", { chat_id = chat_id, text = text })
    end

    local function getMe()
        apiRequest("getMe")
    end

    local function sendDocument(chat_id, filename, documentPath, caption)
        local parameters = {
            chat_id = chat_id,
            caption = caption,
            --document = net.curl.form.file(documentPath),
        }
        --parameters['_FILE_'..filename]  = documentPath
        --apiRequest("sendDocument", parameters)
        print("Not implemented yet!")
    end

    local function saveDocument(file_id, file_name)
        local fileInfo = apiRequest("getFile", {file_id = file_id})
        if fileInfo and fileInfo.result and fileInfo.result.file_path then
            local file_path = fileInfo.result.file_path
            local download_url = "https://api.telegram.org/file/bot" .. token .. "/" .. file_path
            local res, header, body = net.curl.get(download_url, file_name)
            return res or header
        end
    end

    local function getUpdates()
        local updates = apiRequest("getUpdates", { timeout = 100, offset = last_update_id and last_update_id + 1 or nil })
        if updates and updates.result then
            for i, update in ipairs(updates.result) do
                if update.message then
                    if update.message.document then
                        onDocument(update.message.chat.id, update.message.document, sendMessage, saveDocument)
                    else
                        local chat_id = update.message.chat.id
                        local text = update.message.text
                        onMessage(chat_id, text, sendMessage, sendDocument)
                    end
                    last_update_id = update.update_id
                end
            end
        end
    end

    return {
        getMe = getMe,
        getUpdates = getUpdates,
        sendMessage = sendMessage,
        sendDocument = sendDocument
    }
end

return createBot
--[[
local bot = createBot(token,
    function(chat_id, text, sendMessage, sendDocument)
        -- input text
        sendMessage(chat_id, "Вы сказали: " .. text)
        --sendDocument(chat_id, 'autorun', '/romfs/autorun.lua', 'Report')
    end,
    function(chat_id, document, sendMessage, saveDocument)
        -- input file
        local res, msg = saveDocument(document.file_id, "/downloads/"..document.file_name)
        sendMessage(chat_id, "Загрузка документа: " .. (res and "успешно" or msg))
    end
)

while true do
    bot.getUpdates()
    thread.sleepms(200)
end
]]--