mwapi.lua

--[[
Author: Trougnouf (Benoit Brummer) <trougnouf@gmail.com>
Contributor: Simon Legner (simon04), Alexander Misel

mediawikiapi.lua uses some code adapted from LrMediaWiki
LrMediaWiki authors:
Robin Krahl <robin.krahl@wikipedia.de>
Eckhard Henkel <eckhard.henkel@wikipedia.de>

Dependencies:
* lua-sec: Lua bindings for OpenSSL library to provide TLS/SSL communication
* lua-luajson: JSON parser/encoder for Lua
* lua-multipart-post: HTTP Multipart Post helper
]]
local Utils = require('mwtest/utils')
local https = require('ssl.https')
local json = require('rapidjson')
local ltn12 = require('ltn12')
local mpost = require('multipart-post')

local MediaWikiApi = {
  userAgent = string.format('mediawikilua %d.%d', 0, 2),
  apiPath = 'https://zh.wikipedia.org/w/api.php',
  cookie = {},
  done_pages = {},
  edit_token = nil,
  base_time = nil
}

local function httpsget(url, reqheaders)
  local res = {}
  local _, code, resheaders, _ = https.request {
    url = url,
    protocol = 'tlsv1_2',
    headers = reqheaders,
    sink = ltn12.sink.table(res)
  }
  resheaders = resheaders or {}
  resheaders.status = code

  return table.concat(res), resheaders
end

local function httpspost(url, postBody, reqheaders)
  local res = {}
  local _, code, resheaders, _ = https.request {
    url = url,
    method = 'POST',
    protocol = 'tlsv1_2',
    headers = reqheaders,
    source = ltn12.source.string(postBody),
    sink = ltn12.sink.table(res)
  }
  resheaders = resheaders or {}
  resheaders.status = code

  return table.concat(res), resheaders
end

local function throwUserError(text)
  print(json.encode(MediaWikiApi.done_pages))
  
  error(text)
end

-- parse a received cookie and update MediaWikiApi.cookie
function MediaWikiApi.parseCookie(unparsedcookie)
  while unparsedcookie and string.len(unparsedcookie) > 0 do
    local i = string.find(unparsedcookie, ';')
    local crumb = string.sub(unparsedcookie, 1, i - 1)
    local isep = string.find(crumb, '=')
    if isep then
      local cvar = string.sub(crumb, 1, isep - 1)
      local icvarcomma = string.find(cvar, ',')
      while icvarcomma do
        cvar = string.sub(cvar, icvarcomma + 2)
        icvarcomma = string.find(cvar, ',')
      end
      MediaWikiApi.cookie[cvar] = string.sub(crumb, isep + 1)
    end
    local nexti = string.find(unparsedcookie, ',')
    if not nexti then
      return
    end
    unparsedcookie = string.sub(unparsedcookie, nexti + 2)
  end
end

-- generate a cookie string from MediaWikiApi.cookie to send to server
function MediaWikiApi.cookie2string()
  local prestr = {}
  for cvar, cval in pairs(MediaWikiApi.cookie) do
    table.insert(prestr, cvar .. '=' .. cval .. ';')
  end
  return table.concat(prestr)
end

function MediaWikiApi.getCurrent(title)
  local arguments = {
    action = 'query',
    prop = 'revisions',
    titles = title,
    rvprop = 'ids|content|timestamp',
    format = 'json',
    formatversion = 2
  }
  local jsonres = MediaWikiApi.performRequest(arguments)
  if not jsonres.query.pages[1].missing then
    return jsonres.query.pages[1].revisions[1]
  end
end

-- Demand an edit token. probably can change this to request only one per session
function MediaWikiApi.getEditToken()
  if MediaWikiApi.edit_token == nil then
    local arguments = {
      action = 'query',
      meta = 'tokens',
      type = 'csrf',
      format = 'json'
    }
    local jsonres = MediaWikiApi.performRequest(arguments)
    MediaWikiApi.edit_token = jsonres.query.tokens.csrftoken
  end
  return MediaWikiApi.edit_token
end

function MediaWikiApi.edit(title, text, summary)
  --print('\nEditing', title, text)
  local arguments = {
    action = 'edit',
    title = title,
    text = text,
    summary = summary,
    token = MediaWikiApi.getEditToken(),
    basetimestamp = MediaWikiApi.base_time,
    starttimestamp = os.time(),
    format = 'json'
  }
  local res_error = MediaWikiApi.performRequest(arguments).error
  if res_error then
    throwUserError('Edit failed. Reason: ' .. res_error.info)
  end
end

function MediaWikiApi.editPend(title, text, summary, isPrepend)
  --print('\nEditing', title, text)
  local arguments = {
    action = 'edit',
    title = title,
    summary = summary,
    token = MediaWikiApi.getEditToken(),
    format = 'json'
  }
  if isPrepend then
    arguments.prependtext = text
  else
    arguments.appendtext = text
  end
  
  local res_error = MediaWikiApi.performRequest(arguments).error
  if res_error then
    if res_error.code == 'editconflict' then
      MediaWikiApi.trace(res_error.info)
    else
      throwUserError('Edit failed. Reason: ' .. res_error.info)
    end
  end
end

function MediaWikiApi.uploadfile(filepath, pagetext, filename, overwrite, comment)
  local file_handler = io.open(filepath)
  local content = {
    action = 'upload',
    filename = filename,
    text = pagetext,
    comment = comment,
    token = MediaWikiApi.getEditToken(),
    file = {
      filename = 'whatevs',
      data = file_handler:read('*all')
    }
  }
  if overwrite then
    content['ignorewarnings'] = 'true'
  end
  local res = {}
  local req = mpost.gen_request(content)
  req.headers['cookie'] = MediaWikiApi.cookie2string()
  req.url = MediaWikiApi.apiPath
  req.sink = ltn12.sink.table(res)
  local _, code, resheaders = https.request(req)
  --MediaWikiApi.trace('  Result headers:', resheaders)
  MediaWikiApi.parseCookie(resheaders['set-cookie'])
  return code, resheaders, res
end

-- Code adapted from LrMediaWiki:
MediaWikiApi.trace = function(...)
  print(...)
end

--- Convert HTTP arguments to a URL-encoded request body.
-- @param arguments (table) the arguments to convert
-- @return (string) a request body created from the URL-encoded arguments
function MediaWikiApi.createRequestBody(arguments)
  local body = nil
  for key, value in pairs(arguments) do
    if body then
      body = body .. '&'
    else
      body = ''
    end
    body = body .. Utils.urlEncode(key) .. '=' .. Utils.urlEncode(value)
  end
  return body or ''
end

function MediaWikiApi.performHttpRequest(path, arguments, post) -- changed signature!
  local requestBody = MediaWikiApi.createRequestBody(arguments)
  local requestHeaders = {
    ['Content-Type'] = 'application/x-www-form-urlencoded',
    ['User-Agent'] = MediaWikiApi.userAgent
  }
  if post then
    requestHeaders['Content-Length'] = #requestBody
  end
  requestHeaders['Cookie'] = MediaWikiApi.cookie2string()
  MediaWikiApi.trace('Performing HTTP request')
  -- MediaWikiApi.trace('  Path:', path)
  -- MediaWikiApi.trace('  Request body:', requestBody)

  local resultBody, resultHeaders
  local dorequest = function(try_num)
    if post then
      resultBody, resultHeaders = httpspost(path, requestBody, requestHeaders)
    else
      resultBody, resultHeaders = httpsget(path .. '?' .. requestBody, requestHeaders)
    end
  end
  
  for i = 1, 3 do
    print('  Attempt ' .. i)
    dorequest(i)
    if resultHeaders.status ~= 'timeout' and resultHeaders.status ~= 'wantread' then
      break
    end
  end
  if not resultHeaders.status or resultHeaders.status == 'closed' then
    throwUserError('No network connection')
  elseif resultHeaders.status ~= 200 then
    throwUserError('HttpError! Received HTTP status = ' .. resultHeaders.status)
  end

  MediaWikiApi.trace('  Result status:', resultHeaders.status)

  MediaWikiApi.parseCookie(resultHeaders['set-cookie'])
  -- MediaWikiApi.trace('new cookie: '..resultHeaders['set-cookie'])
  -- MediaWikiApi.trace('  Result body:', resultBody)
  return resultBody
end

function MediaWikiApi.performRequest(arguments)
  local post = true
  if arguments.action == 'query' then
    post = false
  end
  local resultBody = MediaWikiApi.performHttpRequest(MediaWikiApi.apiPath, arguments, post)
  local jsonres = json.decode(resultBody)
  return jsonres
end

function MediaWikiApi.logout()
  -- See https://www.mediawiki.org/wiki/API:Logout
  local arguments = {
    action = 'logout'
  }
  MediaWikiApi.performRequest(arguments)
end

function MediaWikiApi.login(username, password)
  -- See https://www.mediawiki.org/wiki/API:Login
  -- Check if the credentials are a main-account or a bot-account.
  -- The different credentials need different login arguments.
  -- The existance of the character '@' inside of an username is an
  -- identicator if the credentials are a bot-account or a main-account.
  local credentials
  if string.find(username, '@') then
    credentials = 'bot-account'
  else
    credentials = 'main-account'
  end
  MediaWikiApi.trace('Credentials: ' .. credentials)

  -- Check if a user is logged in:
  local arguments = {
    action = 'query',
    meta = 'userinfo',
    format = 'json'
  }
  local jsonres = MediaWikiApi.performRequest(arguments)
  local id = jsonres.query.userinfo.id
  local name = jsonres.query.userinfo.name
  if id == '0' or id == 0 then -- not logged in, name is the IP address
    MediaWikiApi.trace('Not logged in, need to login')
  else -- id ~= '0' – logged in
    MediaWikiApi.trace('Logged in as user "' .. name .. '" (ID: ' .. id .. ')')
    if name == username then -- user is already logged in
      MediaWikiApi.trace('No new login needed (1)')
      return true
    else -- name ~= username
      -- Check if name is main-account name of bot-username
      if credentials == 'bot-account' then
        local pattern = '(.*)@' -- all characters up to '@'
        if name == string.match(username, pattern) then
          MediaWikiApi.trace('No new login needed (2)')
          return true
        end
      end
      MediaWikiApi.trace('Logout and new login needed with username "' .. username .. '".')
      MediaWikiApi.logout() -- without this logout a new login MIGHT fail
    end
  end

  -- A login token needs to be retrieved prior of a login action:
  arguments = {
    action = 'query',
    meta = 'tokens',
    type = 'login',
    format = 'json'
  }
  jsonres = MediaWikiApi.performRequest(arguments)
  local logintoken = jsonres.query.tokens.logintoken

  -- Perform login:
  if credentials == 'main-account' then
    arguments = {
      format = 'json',
      action = 'clientlogin',
      loginreturnurl = 'https://www.mediawiki.org', -- dummy; required parameter
      username = username,
      password = password,
      logintoken = logintoken
    }
    jsonres = MediaWikiApi.performRequest(arguments)
    local loginResult = jsonres.clientlogin.status
    if loginResult == 'PASS' then
      return true
    else
      return jsonres.clientlogin.message
    end
  else -- credentials == bot-account
    assert(credentials == 'bot-account')
    arguments = {
      format = 'json',
      action = 'login',
      lgname = username,
      lgpassword = password,
      lgtoken = logintoken
    }
    jsonres = MediaWikiApi.performRequest(arguments)
    local loginResult = jsonres.login.result
    if loginResult == 'Success' then
      return true
    else
      return jsonres.login.reason
    end
  end
end
-- end of LrMediaWiki code

return MediaWikiApi