File server and client for ComputerCraft

FileClient.lua

-- FileClient
-- Ver. 0.1

-- Include external lib
dofile("/lib/amari/string/StringUtil.lua")


local REDNET_SIDE = "left"

local REDNET_PROTOCOL_MASTER = "MasterServer"
local REDNET_PROTOCOL_FILE = "FileServer"


local function ParseCommand(str, pattern)
  local start, tail = string.find(str, pattern)
  local cmd = (start ~= nil) and string.sub(str, 1, start - 1) or str
  local data = (start ~= nil) and string.sub(str, tail + 1, string.len(str)) or nil
  return cmd, data
end



local computerId = os.getComputerID()
print("ComputerId = "..computerId)

rednet.open(REDNET_SIDE)
local isOpen = rednet.isOpen(REDNET_SIDE)
if not isOpen then
  print("Rednet open failed.")
  return
end


local masterServerId = 0
rednet.broadcast("GetServerId", REDNET_PROTOCOL_MASTER)

while true do
  local sender, receive, protocol = rednet.receive(REDNET_PROTOCOL_MASTER)
  if sender == nil then
    -- Time out
    print("MasterServer not found.")
    return
  end

  local starts = "response:"..string.lower("GetServerId")
  print("Receive: "..receive)
  print("Starts: "..starts)
  if string.startsWith(receive, starts) then
    -- Master response
    masterServerId = tonumber(string.split(receive, ":")[4])
    break
  end
end


local fileServerId = 0
rednet.send(masterServerId, "GetServerId", REDNET_PROTOCOL_FILE)

while true do
  local sender, receive, protocol = rednet.receive(REDNET_PROTOCOL_MASTER)
  if sender == nil then
    -- Time out
    print("FileServer not found.")
    return
  end

  if string.startsWith(receive, "response:"..string.lower("GetServerId")) then
    -- Master response
    fileServerId = tonumber(string.split(receive, ":")[4])
    break
  end
end

local dir = ""
while true do
  dir = read()

  if string.lower(dir) == "download" then
    break
  elseif string.lower(dir) == "upload" then
    break
  end

  print("Invalid argument. (Download or Upload)")
end


term.write("Enter file path >> ")
local filePath = read()


if string.lower(dir) == "download" then
  local cmd = "Download:"..filePath
  rednet.send(fileServerId, cmd, REDNET_PROTOCOL_FILE)
  while true do
    local sender, receive = rednet.receive(REDNET_PROTOCOL_FILE, 5)

    if sender == nil then
      print("Failed to connet to server.")
      return
    end

    if receive.startsWith(receive, "response:"..string.lower("Download")) then
      -- "response", "Download:result:data"
      local rcvCmd, receive = ParseCommand(receive, ":")
      -- "Download", "result:data"
      rcvCmd, receive = ParseCommand(receive, ":")

      -- "result", "data"
      if rcvCmd == false then
        print("Server error: "..receive)
        return
      end

      print("** File received **")
      print("FilePath: "..filePath)

      local fileHandle = fs.open(filePath, "w")
      if fileHandle then
        fileHandle.write(receive)
        fileHandle.close()
      else
        print("File cannot open.")
      end

      break
    end
  end
elseif string.lower(dir) == "upload" then
  local fileHandle = fs.open(filePath, "r")

  if fileHandle then
    local cmd = "Upload:"..filePath..":"..fileHandle.readAll()
    rednet.send(fileServerId, cmd, REDNET_PROTOCOL_FILE)
  else
    print("File cannot open.")
  end
  rednet.close(REDNET_SIDE)
else
  print("Invalid command")
  return
end

FileServer.lua

-- FileServer
-- Ver. 0.1

-- Include external lib
dofile("/lib/amari/string/StringUtil.lua")

local REDNET_SIDE = "back"

local REDNET_PROTOCOL_MASTER = "MasterServer"
local REDNET_PROTOCOL = "FileServer"


local function ParseCommand(str, pattern)
  local start, tail = string.find(str, pattern)
  local cmd = (start ~= nil) and string.sub(str, 1, start - 1) or str
  local data = (start ~= nil) and string.sub(str, tail + 1, string.len(str)) or nil
  return cmd, data
end


local stopServer = false

local function readConsoleThread()
  local input = ""
  while (not stopServer) do
    term.write(">> ")
    input = read()
    
    -- TODO Add console command here
    if string.lower(input) == "stop" then
      stopServer = true
      print("Stopping server...")
    else
      print("Unknown command: "..input)
    end
  end
end

local function serverThread()
  local isOpen = true
  local sender, receive, protocol
  while isOpen do
    sender, receive, protocol = rednet.receive(3)
  
    if (sender ~= nil) and (receive ~= nil) then
      -- Message received
      -- local cmdSplit = string.split(receive, ":")
      local cmd, tempReceive = ParseCommand(receive, ":")
      cmd = string.lower(cmd)
      print("Cmd: "..cmd)
      -- print("Data: "..tempReceive)

      -- Execute command
      local result = false
      local data = "Unknown command"

      -- Add command
      if cmd == string.lower("Upload") then
        -- TODO Upload :: Add version
        -- Upload:filePath:fileData
        local filePath, tempReceive = ParseCommand(tempReceive, ":")

        print("** Upload command received **")
        print("FilePath: "..filePath)

        local fileHandle = fs.open(filePath, "w")
        if fileHandle then
          fileHandle.write(tempReceive)
          fileHandle.close()

          result = true
          data = "Success"
        else
          result = false
          data = "Failed to open file"
        end
      elseif cmd == string.lower("Download") then
        -- TODO Download :: Add version
        -- Download:filePath
        local filePath = tempReceive

        print("** Download command received **")
        print("FilePath: "..filePath)

        local fileHandle = fs.open(filePath, "r")
        if fileHandle then
          result = true
          data = fileHandle.readAll()
          fileHandle.close()
        else
          result = false
          data = "Failed to open file"
        end
      end

      -- Message format => response:cmdName:result:data
      local sendMsg = "response:"..cmd..":"..tostring(result)..":"..data
      rednet.send(sender, sendMsg, REDNET_PROTOCOL)
    end
  
    if stopServer == true then
      break
    end
  
    isOpen = rednet.isOpen(REDNET_SIDE)

    if not isOpen then
      break
    end
  end
end


-- Script main
local computerId = os.getComputerID()
print("ComputerId = "..computerId)

rednet.open(REDNET_SIDE)
local isOpen = rednet.isOpen(REDNET_SIDE)
if not isOpen then
  print("Rednet open failed.")
  return
end


print("FileServer started.")
print("Sending server id...")


rednet.broadcast("SetServerId:"..computerId, REDNET_PROTOCOL)

-- TODO delete
while true do
  local sender, receive, protocol = rednet.receive(REDNET_PROTOCOL_MASTER, 5)

  if receive == nil then
    print("Connection time out.")
    break
  end

  print("** Receive **")
  print("Sender: "..sender)
  print("Message: "..receive)
  print("Protocol: "..protocol)

  if string.startsWith(receive, "response") then
    break
  end
end

parallel.waitForAll(readConsoleThread, serverThread)
rednet.close(REDNET_SIZE)

print("FileServer stopped.")