mess_serv

--[[
   *Apokalypsys, Dimus
   *http://minecrafting.ru/
   *http://minecrafting.ru/forum/viewtopic.php?f=32&t=5331
]]

local hex_char = "0123456789abcdef"

local function getHex(seed)
   local str = ""
   for i = 0, 3 do
      local ind1, ind2 = bit.band(bit.brshift(seed, i * 8 + 4), 15) + 1, bit.band(bit.brshift(seed, i * 8), 15) + 1
      str = str..
      hex_char:sub(ind1, ind1)..
      hex_char:sub(ind2, ind2)
   end
   return str
end

local function string_to_blks(str)
   local nblk = bit.brshift((str:len() + 8), 6) + 1
   local blks = {}
   local len = str:len()
   for i = 0, nblk * 16 - 1 do
      blks[i] = 0
   end
   for i = 0, str:len() - 1 do
      blks[bit.brshift(i, 2)] =
      bit.bor(
         blks[bit.brshift(i, 2)],
         bit.blshift(
            str:byte(i+1),
             (((i) % 4) * 8)
          )
      )
   end
      blks[bit.brshift(len, 2)] =
      bit.bor(
         blks[bit.brshift(len, 2)],
         bit.blshift(
            128,
            (((len) % 4) * 8)
         )
      )
      blks[nblk * 16 - 2] = len * 8
   return blks
end

local function add(x, y)
   return x + y > 4294967296 and x + y or x + y - 4294967296
end

local function rol(number, count)
   return bit.bor(bit.blshift(number, count), bit.blogic_rshift(number, (32 - count)))
end

local function X(a, b, c, x, s, t)
   return add(rol(add(add(b, a), add(x, t)), s), c)
end

local function F(a, b, c, d, x, s, t)
   return X(bit.bor(bit.band(b, c), bit.band(bit.bnot(b), d)), a, b, x, s, t)
end

local function G(a, b, c, d, x, s, t)
   return X(bit.bor(bit.band(b, d), bit.band(c, bit.bnot(d))), a, b, x, s, t)
end

local function H(a, b, c, d, x, s, t)
   return X(bit.bxor(bit.bxor(b, c), d), a, b, x, s, t)
end

local function I(a, b, c, d, x, s, t)
   return X(bit.bxor(c, bit.bor(b, bit.bnot(d))), a, b, x, s, t)
end

function md5(encoding_string)
   local blks = string_to_blks(encoding_string)

   local a = 1732584193
   local b = -271733879
   local c = -1732584194
   local d = 271733878

   for i = 0, #blks-1, 16 do
      local olda, oldb, oldc, oldd = a, b, c, d

      a = F(a, b, c, d, blks[i+ 0], 7, -680876936)
      d = F(d, a, b, c, blks[i+ 1], 12, -389564586)
      c = F(c, d, a, b, blks[i+ 2], 17, 606105819)
      b = F(b, c, d, a, blks[i+ 3], 22, -1044525330)
      a = F(a, b, c, d, blks[i+ 4], 7, -176418897)
      d = F(d, a, b, c, blks[i+ 5], 12, 1200080426)
      c = F(c, d, a, b, blks[i+ 6], 17, -1473231341)
      b = F(b, c, d, a, blks[i+ 7], 22, -45705983)
      a = F(a, b, c, d, blks[i+ 8], 7, 1770035416)
      d = F(d, a, b, c, blks[i+ 9], 12, -1958414417)
      c = F(c, d, a, b, blks[i+10], 17, -42063)
      b = F(b, c, d, a, blks[i+11], 22, -1990404162)
      a = F(a, b, c, d, blks[i+12], 7, 1804603682)
      d = F(d, a, b, c, blks[i+13], 12, -40341101)
      c = F(c, d, a, b, blks[i+14], 17, -1502002290)
      b = F(b, c, d, a, blks[i+15], 22, 1236535329)

      a = G(a, b, c, d, blks[i+ 1], 5, -165796510)
      d = G(d, a, b, c, blks[i+ 6], 9, -1069501632)
      c = G(c, d, a, b, blks[i+11], 14, 643717713)
      b = G(b, c, d, a, blks[i+ 0], 20, -373897302)
      a = G(a, b, c, d, blks[i+ 5], 5, -701558691)
      d = G(d, a, b, c, blks[i+10], 9, 38016083)
      c = G(c, d, a, b, blks[i+15], 14, -660478335)
      b = G(b, c, d, a, blks[i+ 4], 20, -405537848)
      a = G(a, b, c, d, blks[i+ 9], 5, 568446438)
      d = G(d, a, b, c, blks[i+14], 9, -1019803690)
      c = G(c, d, a, b, blks[i+ 3], 14, -187363961)
      b = G(b, c, d, a, blks[i+ 8], 20, 1163531501)
      a = G(a, b, c, d, blks[i+13], 5, -1444681467)
      d = G(d, a, b, c, blks[i+ 2], 9, -51403784)
      c = G(c, d, a, b, blks[i+ 7], 14, 1735328473)
      b = G(b, c, d, a, blks[i+12], 20, -1926607734)

      a = H(a, b, c, d, blks[i+ 5], 4, -378558)
      d = H(d, a, b, c, blks[i+ 8], 11, -2022574463)
      c = H(c, d, a, b, blks[i+11], 16, 1839030562)
      b = H(b, c, d, a, blks[i+14], 23, -35309556)
      a = H(a, b, c, d, blks[i+ 1], 4, -1530992060)
      d = H(d, a, b, c, blks[i+ 4], 11, 1272893353)
      c = H(c, d, a, b, blks[i+ 7], 16, -155497632)
      b = H(b, c, d, a, blks[i+10], 23, -1094730640)
      a = H(a, b, c, d, blks[i+13], 4, 681279174)
      d = H(d, a, b, c, blks[i+ 0], 11, -358537222)
      c = H(c, d, a, b, blks[i+ 3], 16, -722521979)
      b = H(b, c, d, a, blks[i+ 6], 23, 76029189)
      a = H(a, b, c, d, blks[i+ 9], 4, -640364487)
      d = H(d, a, b, c, blks[i+12], 11, -421815835)
      c = H(c, d, a, b, blks[i+15], 16, 530742520)
      b = H(b, c, d, a, blks[i+ 2], 23, -995338651)

      a = I(a, b, c, d, blks[i+ 0], 6, -198630844)
      d = I(d, a, b, c, blks[i+ 7], 10, 1126891415)
      c = I(c, d, a, b, blks[i+14], 15, -1416354905)
      b = I(b, c, d, a, blks[i+ 5], 21, -57434055)
      a = I(a, b, c, d, blks[i+12], 6, 1700485571)
      d = I(d, a, b, c, blks[i+ 3], 10, -1894986606)
      c = I(c, d, a, b, blks[i+10], 15, -1051523)
      b = I(b, c, d, a, blks[i+ 1], 21, -2054922799)
      a = I(a, b, c, d, blks[i+ 8], 6, 1873313359)
      d = I(d, a, b, c, blks[i+15], 10, -30611744)
      c = I(c, d, a, b, blks[i+ 6], 15, -1560198380)
      b = I(b, c, d, a, blks[i+13], 21, 1309151649)
      a = I(a, b, c, d, blks[i+ 4], 6, -145523070)
      d = I(d, a, b, c, blks[i+11], 10, -1120210379)
      c = I(c, d, a, b, blks[i+ 2], 15, 718787259)
      b = I(b, c, d, a, blks[i+ 9], 21, -343485551)

      a = add(a, olda)
      b = add(b, oldb)
      c = add(c, oldc)
      d = add(d, oldd)
   end
   return getHex(a)..getHex(b)..getHex(c)..getHex(d)
end
--[[
   *End of MD5 encoding
]]
function open()
  local bOpen, sFreeSide = false, nil
  for n,sSide in pairs(rs.getSides()) do
    if peripheral.getType( sSide ) == "modem" then
      sFreeSide = sSide
      if rednet.isOpen( sSide ) then
        bOpen = true
        break
      end
    end
  end
  if not bOpen then
    if sFreeSide then
      print( "No modem active. Opening "..sFreeSide.." modem" )
      rednet.open( sFreeSide )
      return true
    else
      print( "No modem attached" )
      return false
    end
  end
  return true
end

ActiveUser={}
AllUsers={}
eventKey={}
eventRednet={}
pwdfilename=shell.resolve('passwd')
messdir=shell.dir()..'/messages/'
readdir=shell.dir()..'/readed/'
newsdir=shell.dir()..'/news/'

eventRednet.ask=function (dat,id)
  if ActiveUser[id] then
    return 'You are logined as '..ActiveUser[id].name
  else
    return 'You are not logined'
  end
end

eventRednet.adduser=function (dat,id)
  local user,pwd=dat:match('user=([%w_]+)%s+pwd=(%S+)')
  if not user then return 'Incorrect login or password' end
  if AllUsers[user] then return 'User '..user..' already exists' end
  file=fs.open(pwdfilename,'a')
  file.write(user..' '..md5(pwd)..'\r\n')
  file:close()
  AllUsers[user]=md5(pwd)
  ActiveUser[id]={}
  ActiveUser[id].name=user
  ActiveUser[id].mess={}
  print ('Create user '..user..' id '..id)
  return 'User '..user..' created'
end

eventRednet.login=function (dat,id)
  local user,pwd=dat:match('user=([%w_]+)%s+pwd=(%S+)')
  if not user then
    return 'Incorrect login or password'
  end
  if AllUsers[user]==md5(pwd) then
    ActiveUser[id]={}
    ActiveUser[id].name=user
    ActiveUser[id].mess={}
    print ('Login user '..user..' id '..id)
    local file=fs.open(readdir..user,'r')
    if file then
      local line=file.readLine()
      while line do
        table.insert( ActiveUser[id].mess, line )
        line=file.readLine()
      end
      file:close()
    end
    return 'User '..user..' connected'
  else
    print ('Unsuccessful login user '..user..' id '..id)
    return 'Incorrect login or password'
  end
end

eventRednet.logout=function (dat,id)
  if ActiveUser[id] then
    local name=ActiveUser[id].name
    ActiveUser[id]=nil
    print ('User '..name..' disconnected id '..id)
    return 'User '..name..' disconnected'
  end
end

eventRednet.checkmess=function (dat,id)
  if ActiveUser[id] then
    local file=fs.open(messdir..ActiveUser[id].name,'r')
    if file then
      local n=0
      local line=file.readLine()
      while line do
        n=n+1
        table.insert( ActiveUser[id].mess, line )
        line=file.readLine()
      end
      file:close()
      if n>0 then
        file=fs.open(readdir..ActiveUser[id].name,'w')
        if file then
          for i,mess in ipairs(ActiveUser[id].mess) do
            file.write(ActiveUser[id].mess[i]..'\r\n')
          end
          file:close()
          fs.delete(messdir..ActiveUser[id].name)
        end
        return 'You have '..n..' new message(s)'
      end
    end
    return 'You have not new messages'
  end
  return 'You need login'
end

eventRednet.readmess=function (dat,id)
  if ActiveUser[id] then
    if ActiveUser[id].mess and #ActiveUser[id].mess>ActiveUser[id].nummes then
      ActiveUser[id].nummes=ActiveUser[id].nummes+1
      return ActiveUser[id].mess[ActiveUser[id].nummes]
    else
      return 'You have not more messages.'
    end
  end
  return 'You need login'
end

eventRednet.readfirst=function (dat,id)
  if ActiveUser[id] then
    ActiveUser[id].nummes=0
    return eventRednet.readmess(dat,id)
  end
  return 'You need login'
end

eventRednet.delmess=function (dat,id)
  if ActiveUser[id] then
    if ActiveUser[id].mess and #ActiveUser[id].mess>ActiveUser[id].nummes then
    table.remove (ActiveUser[id].mess , ActiveUser[id].nummes)
    ActiveUser[id].nummes=ActiveUser[id].nummes-1
    file=fs.open(readdir..ActiveUser[id].name,'w')
    if file then
      for i,mess in ipairs(ActiveUser[id].mess) do
        file.write(ActiveUser[id].mess[i]..'\r\n')
      end
      file:close()
    end
    end
    return eventRednet.readmess(dat,id)
  end
  return 'You need login'
end

eventRednet.sendmess=function (dat,id)
  if ActiveUser[id] then
    local user,mess=dat:match('user=(%S+)(.*)')
    if not AllUsers[user] then return 'Incorrect user name' end
    file=fs.open(messdir..user,'a')
    if not file then
      return 'Cannt open message file'
    end
    file.write('<'..ActiveUser[id].name..'> '..mess..'\r\n')
    file:close()
    local k=next(ActiveUser)
    while k do
      if user==ActiveUser[k].name then
        rednet.send(k,'You have new message')
      end
      k=next(ActiveUser,k)
    end
    return 'Message is sent successful'
  end
  return 'You need login'
end

eventRednet.users=function(dat,id)
  local users=''
  for name in pairs(AllUsers) do
    users=users..name..' '
  end
  return users
end

eventRednet.news=function(dat,id)
  if ActiveUser[id] then
    if not ActiveUser[id].news or #ActiveUser[id].news==0 then
      ActiveUser[id].news={}
      for n,file in pairs(fs.list(newsdir)) do
        if not fs.isDir(newsdir..file) then
            table.insert( ActiveUser[id].news, file )
        end
      end
    end
--    print('News ',#ActiveUser[id].news)
    if #ActiveUser[id].news==0 then
      return 'No more news'
    else
      local filename = table.remove (ActiveUser[id].news , 1)
      local text=''
      local file=fs.open(newsdir..filename,'r')
      if file then
        local line=file.readLine()
        while line do
          text=text..line..'\n'
          line=file.readLine()
        end
        file:close()
      end
      return text
    end
  end
  return 'You need login'
end

work=true

eventKey[keys.a]=function ()
  local k=next(ActiveUser)
  if not k then
    print('No active users')
    return
  end
  print('Active users:')
  while k do
    print(k,' ',ActiveUser[k].name)
    k=next(ActiveUser,k)
  end
end

eventKey[keys.q]= function ()
  work=false
end

eventKey[keys.u]= function ()
  print('All users:')
  print(eventRednet.users())
end

if not fs.exists(pwdfilename) then
  local file=fs.open(pwdfilename,'w')
  file:close()
end
if not fs.exists(messdir) then fs.makeDir(messdir) end
if not fs.exists(readdir) then fs.makeDir(readdir) end
if not fs.exists(newsdir) then fs.makeDir(newsdir) end

local file=fs.open(pwdfilename,'r')
local line=file.readLine()
while line do
  local name,md5pwd=line:match('(%S+)%s+(%S+)')
  if name then
    AllUsers[name]=md5pwd
  end
  line=file.readLine()
end
file.close()

if open() then
  while work do
    local event,p1,p2=os.pullEvent()
    if event=='rednet_message' then
      local func,dat=p2:match('(%S+)(.*)')
      if eventRednet[func]~=nil then
--        print(func,' ',dat)
        p2=eventRednet[func](dat,p1)
      else
        p2='Incorrect function "'..func..'"'
      end
      rednet.send(p1,p2)
    elseif event=='key' then
      if eventKey[p1]~=nil then
        eventKey[p1]()
      end
    end
  end
end