Mikubot-2/otouto/bindings.lua

--[[
    bindings.lua (rev. 2016/05/28)
    otouto's bindings for the Telegram bot API.
    https://core.telegram.org/bots/api
    Copyright 2016 topkecleon. Published under the AGPLv3.

    See the "Bindings" section of README.md for usage information.
]]--

local bindings = {}

local HTTPS = require('ssl.https')
local JSON = require('dkjson')
local ltn12 = require('ltn12')
local MP_ENCODE = require('multipart-post').encode

 -- Build and send a request to the API.
 -- Expecting self, method, and parameters, where method is a string indicating
 -- the API method and parameters is a key/value table of parameters with their
 -- values.
 -- Returns the table response with success. Returns false and the table
 -- response with failure. Returns false and false with a connection error.
 -- To mimic old/normal behavior, it errs if used with an invalid method.
function bindings:request(method, parameters, file)
    parameters = parameters or {}
    for k,v in pairs(parameters) do
        parameters[k] = tostring(v)
    end
    if file and next(file) ~= nil then
        local file_type, file_name = next(file)
        local file_file = io.open(file_name, 'r')
        local file_data = {
            filename = file_name,
            data = file_file:read('*a')
        }
        file_file:close()
        parameters[file_type] = file_data
    end
    if next(parameters) == nil then
        parameters = {''}
    end
    local response = {}
    local body, boundary = MP_ENCODE(parameters)
    local success, code = HTTPS.request{
        url = self.BASE_URL .. method,
        method = 'POST',
        headers = {
            ["Content-Type"] =    "multipart/form-data; boundary=" .. boundary,
            ["Content-Length"] = #body,
        },
        source = ltn12.source.string(body),
        sink = ltn12.sink.table(response)
    }
    local data = table.concat(response)
    if not success or success == 1 then
        print(method .. ': Connection error. [' .. code  .. ']')
        return false, false
    else
        local result = JSON.decode(data)
        if not result then
            return false, false
        elseif result.ok then
            return result
        else
            assert(result.description ~= 'Method not found', method .. ': Method not found.')
            return false, result
        end
    end
end

function bindings.gen(_, key)
    return function(self, params, file)
        return bindings.request(self, key, params, file)
    end
end
setmetatable(bindings, { __index = bindings.gen })

return bindings