FTP

args = {...}
if not rednet.isOpen() then
  print("ftp requires rednet to function. Please open rednet before using")
  return false
end

send = function( id, file, sendAs )
  if type(id)=="number" and type(file)=="string" then
    if not fs.exists(file) then
      print("file "..file.." does not exist")
      return false
    end
    if fs.isDir(file) then
      ft = addDirToFileTable({},file,sendAs)
      rednet.send(id,{type="send", files = ft},"ftp")
      return true
    end
    f = fs.open(file,"r")
    m = f.readAll()
    ft = {}
    if sendAs and type(sendAs) == "string" then
      ft[sendAs] = m
    else
      ft[file] = m
    end
    t = {type = "send", files = ft}
    rednet.send(id,t,"ftp")
  elseif type(id) == "string" then
    id = rednet.lookup("ftp",id)
    if id then
      send(id,file,sendAs)
    end
  end
end

receive = function( id, file, receiveAs )
  print("called receive")
  if type(id)=="number" and type(file) == "string" then
    rednet.send(id,{type="get",files={file}},"ftp")
    done = false
    while not done do
      print("waiting for response")
      s,m,p = rednet.receive("ftp")
      if s == id then
        if type(m) == "table" and m.type == "send" and type(m.files) == "table" then
          f = {}
          if receiveAs then
            f = fs.open(receiveAs,"w")
          else
            f = fs.open(file,"w")
          end
          f.write(m.files[file])
          f.flush()
          f.close()
          done = true
        end
      end
    end
  elseif type(id) == "string" then
    id = rednet.lookup("ftp",id)
    if id then
      receive(id,file,receiveAs)
    end
  end
end

getDirectoryListing = function( id, dir)
  if type(id) == "string" then
    id = rednet.lookup("ftp",id)
  end
  if type(id) == "number" and type(dir) == "string" then
    rednet.send(id,{type="listRequest",dir=dir},"ftp")
    done = false
    while not done do
      s,m,p = rednet.receive("ftp")
      if s == id and type(m) == "table" and m.type == "listAnswer" and m.dir == dir then
        return m.files
      end
    end
  end
end

addDirToFileTable = function( ft, dir, aliasDir)
  for i,path in pairs(fs.list(dir)) do
    if fs.isDir(fs.combine(dir,path)) then
      addDirToFileTable(ft, fs.combine(dir,path), fs.combine(aliasDir,path))
    else
      f = fs.open(fs.combine(dir,path),"r")
      if aliasDir then
        ft[fs.combine(aliasDir,path)] = f.readAll()
      else
        ft[fs.combine(dir,path)] = f.readAll()
      end
      f.close()
    end
  end
end

sendMultiple = function( id, t , dir )
  if type(id) == "string" then
    id = rednet.lookup("ftp",id)
  end
  ft = {}
  for i,path in pairs(t) do
    if fs.exists(fs.combine(dir,path)) then
      if not fs.isDir(fs.combine(dir,path)) then
        f = fs.open(fs.combine(dir,path),"r")
        ft[path] = f.readAll()
        f.close()
      else
        addDirToFileTable(ft,fs.combine(dir,path),path)
      end
    else
      ft[path] = ""
    end
  end
  t = { type = "send", files = ft}
  rednet.send(id,t,"ftp")
end

receiveMultiple = function(id, t, dir)
  if type(id) == "string" then
    id = rednet.lookup("ftp",id)
  end
  rednet.send(id,t,"ftp")
  done = false
  while not done do
    s,m,p = rednet.receive("ftp")
    if s == id and type(m) == "table" and m.type == "send" and type(m.files) == "table" then
      saveMultiple(m.files, dir)
    end
  end
end

saveMultiple = function( ft, dir )
  for path,file in pairs(ft) do
    f = fs.open(fs.combine(dir,path),"w")
    f.write(file)
    f.flush()
    f.close()
  end
end

sendListOfFiles = function( id, path, dir)
  ft = {}
  for i,j in pairs(fs.list(fs.combine(dir,path))) do
    ft[j] = fs.isDir(j)
  end
  rednet.send(id,{type="listAnswer",dir=path,files=ft},"ftp")
end

server = function( args )
  dir = "/"
  if args[2] and type(args[2]) == "string" then
    if not fs.isDir(args[2]) then
      fs.makeDir(args[2])
    end
    print("setting dir to "..args[2])
    dir = args[2]
  end
  if args[3] and type(args[3]) == "string" then
    rednet.host("ftp",args[3])
    print("Hostname is "..args[3])
  end
  while true do
    print("waiting for calls")
    s,m,p = rednet.receive("ftp")
    if type(m) == "table" then
      if m.type == "send" and type(m.files) == "table" then
        saveMultiple(m.files, dir)
      end
      if m.type == "get" and type(m.files) == "table" then
        sendMultiple(s, m.files, dir)
      end
      if m.type == "listRequest" and type(m.dir) == "string" then
        sendListOfFiles(s,m.dir,dir)
      end
    end
  end
end

if args[1] then
  if args[1] == "server" then
    server(args)
  end
  if args[1] == "send" then
    send(tonumber(args[2]),args[3],args[4])
  end
  if args[1] == "receive" then
    receive(tonumber(args[2]),args[3],args[4])
  end
end