--Var init
local RP_BOOL = true
os.loadAPI("StringUtils")
local modem = peripheral.find("modem")
local MODEM_CHANNEL = 644

--Log
local function log(ID, oMSG, reason)
  local FILE = fs.open("/log", "a")

  if type(oMSG) == "string" then
    toMSG = "bad type(string)"
  elseif type(oMSG) == "table" then
    if oMSG["type"] ~= nil then
      toMSG = "bad table"
    else
      toMSG = oMSG["type"]
    end
  else
    toMSG = "unknown"
  end

  local TEMP = "[LOG] ID:"..ID.." toMSG: "..toMSG.." Reason: "..reason
  print(TEMP)
  FILE.writeLine(TEMP)
  FILE.close()

  return true
end


--Users management
local USER_FILE = "/users"
local DB_SCHEM = {Users = {}, Password = {}, Biolock = {}, AccessLevel = {}, Token= {}, Where= {}}

local function USERS_CREATEDB()
  local USER_TEMP = fs.open(USER_FILE, "w")
  USER_TEMP.write(textutils.serialise(DB_SCHEM))
  USER_TEMP.close()
end

local function USERS_GET()
  local OBJECT_UF = fs.open(USER_FILE, "r")
  local USERS = textutils.unserialise(OBJECT_UF.readAll())
  if USERS == nil then
    USERS_CREATEDB()
    USERS = textutils.unserialise(OBJECT_UF.readAll())
  end
  OBJECT_UF.close()
  return USERS
end

local function USERS_ID(users, tofind)
  local ID = nil
  for i = 1,#users["Users"] do
    if tofind == nil then
      ID = i
    else
      if users["Users"][i] == tofind then
        ID = i
      end
    end
  end
  return ID
end

local function USERS_BIOLOCK(users, tofind)
  local ID = nil
  for i = 1,#users["Biolock"] do
    if tofind == nil then return false
    else
      if users["Biolock"][i] == tofind then
        ID = i
      end
    end
  end
  return ID
end

local function USERS_TOKEN(users, tofind)
  local ID = nil
  for i = 1,#users["Token"] do
    if tofind == nil then return false
	else
      if users["Token"][i] == tofind then
        ID = i
      end
    end
  end
  return ID
end

local function USERS_WHERE(users, tofind)
  local ID = nil
  for i = 1,#users["Where"] do
    if tofind == nil then return false
	else
      if users["Where"][i] == tofind then
        ID = i
      end
    end
  end
  return ID
end

--Encryption and modems
local function SEND(sID, content)
	if type(sID) ~= "number" or content == nil then return false end
	local Users = USERS_GET()
	local Token = Users[Tokens][uID]
	--local serialised = textutils.serialise(content)
	--local FinalTable = StringUtils.encrypt(serialised) DO NOT WORK
	modem.transmit(MODEM_CHANNEL, MODEM_CHANNEL, content)
end

local function USERS_CREATE(name, pass, biolock, accesslevel)


  local oUSERS = USERS_GET()
  local fUSERS = oUSERS
  local lastID = USERS_ID(oUSERS)

  --Check if user already exist because or AL will not fuck my script ;(
  if USERS_ID(oUSERS, name) ~= nil then return false end
  if accesslevel > 5 or accesslevel < 1 then return false end
  if lastID == nil then lastID = 1 else lastID = lastID + 1 end
  if name == nil or pass == nil or accesslevel == nil then
    return false
  end
  if biolock == nil then biolock = "unknown" end
  --end of check

  fUSERS["Users"][lastID] = name
  fUSERS["Password"][lastID] = StringUtils.SHA1(pass)
  fUSERS["Biolock"][lastID] = biolock
  fUSERS["Token"][lastID] = "unknown"
  fUSERS["AccessLevel"][lastID] = accesslevel
  fUSERS["Where"][lastID] = "unknown"
  local TO_SAVE = fs.open(USER_FILE,"w")
  TO_SAVE.write(textutils.serialise(fUSERS))
  TO_SAVE.close()
  return true
end

local function USERS_UPDATE(toUpdate, userID, newUpdate)
	if type(toUpdate) ~= "string" or type(userID) ~= "number" or newUpdate == nil then return false end
	local oUSERS = USERS_GET()
	--Check if id exist
	local lastID = USERS_ID(oUSERS)
	if userID > lastID then return false end

	if toUpdate == "token" then
		oUSERS["Token"][userID] = newUpdate
		local TO_SAVE = fs.open(USER_FILE,"w")
  		TO_SAVE.write(textutils.serialise(oUSERS))
  		TO_SAVE.close()
		return true
	elseif toUpdate == "accesslevel" then
		if type(newUpdate) ~= "number" then return false end
		oUSERS["AccessLevel"][userID] = newUpdate
		local TO_SAVE = fs.open(USER_FILE,"w")
  		TO_SAVE.write(textutils.serialise(oUSERS))
  		TO_SAVE.close()
		return true
	end

end




--Token functions

local function TOKEN_GEN()
	local TOKEN_LENGHT = 25
	local TOKEN = ""
	local TOKEN_TABLE = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9","#", "$", "*"}
 local x	= 0
 while TOKEN_LENGHT > 0 do
  x=x+1
		local mRandom = math.random(1,#TOKEN_TABLE)
		TOKEN = TOKEN..TOKEN_TABLE[mRandom]
		TOKEN_LENGHT = TOKEN_LENGHT - 1
  print("Generating Token: "..tostring(x).."/25")
	end
	return TOKEN
end

local function TOKEN_CREATE(id)
	local USERS = USERS_GET()
	if type(id) ~= "number" then return false end
	local newToken = TOKEN_GEN()
	--Check if token already exist
	local YES = false
	while YES do
		if USERS_TOKEN(USERS, newToken) == nil then YES = false else
		newToken = TOKEN_GEN() end
	end
	--Write the new token
	if USERS_UPDATE("token", id, newToken) then
		return newToken
	else
		return false
	end
end

--We need the famous Gitano Parser !
local function gitanoParser(sTable,sID)
	if sTable["tokenUsername"] == nil or sTable["tokenCheck"] == nil then return SEND(sID, "Nil entry") end
	--Check account
	local uTable = USERS_GET()
	local uID = USERS_ID(uTable, sTable["tokenUsername"])
	if uID == nil return then SEND(sID, "Bad Username") end
	local uTOKEN = uTable["Token"][uID]
	if StringUtils.decrypt(sTable["tokenCheck"], uTOKEN) ~= "true" end return SEND(sID, "Bad token") end
	local uLevel = uTable["AccessLevel"][uID]

  if sTable.type == "mdr" then
    log(sID, sTable, "bad type")
    return false

  elseif sTable.type == "token" then
  	if sTable.todo == "createToken" then
      if type(sTable.enc) ~= "string" or type(sTable.Username) ~= "string" or type(sTable.math) ~= "string" then SEND(sID, "nil entry") else
      local oTable = USERS_GET()
      local uID = USERS_ID(oTable,sTable.Username)
      if uID == nil then send(sID, "Unknown user") return false end
      local SHA1Pass = oTable["Password"][uID]
      local crypted = StringUtils.decrypt(sTable.enc, SHA1Pass)
      if crypted == sTable.math then
        --He got it we need to give a token to him
        local Token = TOKEN_CREATE(uID)
        SEND(sID, Token)
        print("Token created for: "..sTable["Username"])
        print("New Token hash: "..StringUtils.SHA1(Token))
      else
        SEND(sID, "Bad password")
      end
	  end

	elseif sTable.todo == "getToken" then
      if type(sTable.enc) ~= "string" or type(sTable.Username) ~= "string" or type(sTable.math) ~= "string" then SEND(sID, "nil entry") else
      local oTable = USERS_GET()
      local uID = USERS_ID(oTable,sTable.Username)
      if uID == nil then SEND(sID, "Unknown user") return false end
      local SHA1Pass = oTable["Password"][uID]
      local crypted = StringUtils.decrypt(sTable.enc, SHA1Pass)
      if crypted == sTable.math then
        --He got it we need to give a token to him
        SEND(sID, oTable["Token"][uID])
      else
        SEND(sID, "Bad password")
      end
	  end
    end

  elseif sTable.type == "ping" then
    SEND(sID, "true")
    log(sID, sTable, "ping")

  elseif sTable.type == "database" then

    if sTable.todo == "createUser" then
		if uLevel < 4 then return SEND(sID, "Bad accessLevel") end
      if sTable.Username == nil or sTable.Password == nil or sTable.Biolock == nil or type(sTable.accesslevel) == number then
        print("User creation failed")
        SEND(sID, "nil in table")
      else
        if USERS_CREATE(sTable.Username,sTable.Password,sTable.Biolock,sTable.accesslevel) then
          print("User Created")
          SEND(sID, "true")
        else
          print("Failed to create")
          SEND(sID, "error")
        end
      end

    elseif sTable.todo == "reset" then
		if uLevel < 4 then return SEND(sID, "Bad accessLevel") end
      USERS_CREATEDB()
      print("Database reseted") --Pls add a Terminal confirm
      SEND(sID, "true")

	elseif sTable.todo == "Userinfo" then
		if uLevel ~= 0 then return SEND(sID, "Bad accessLevel") end
      if sTable.Username == nil then
      SEND(sID, "Nil entry")

      else
        local TUserTable = USERS_GET()
        local Tid = USERS_ID(TUserTable, sTable.Username)
        if Tid == nil then print("Nil TID") SEND(sID, "nil id") else
        	local Tbiolock = TUserTable["Biolock"][Tid]
        	local TAccessL = TUserTable["AccessLevel"][Tid]
        	local TEMP_TABLE = {id = Tid, biolockid = Tbiolock, accesslevel = TAccessL}
        	SEND(sID, TEMP_TABLE)
        	print("Succefuly sended")
        end
      end
	end

  else
    SEND(sID, "bad TableType")
  end
end

--Starting
term.write("Modem state: ")
if modem.isOpen(MODEM_CHANNEL) then print("True") else print("False") end
if modem.isOpen(MODEM_CHANNEL) ~= true then modem.open(MODEM_CHANNEL) end
print("Modem opened\nID: ".. os.computerID())

local function receiveparse()
  while RP_BOOL do
    local event, modemSide, sID, rID, msg, distance = os.pullEvent("modem_message")
    if type(msg) ~= "table" then SEND(sID, "Please use API") log(sID, msg, "Dont use a table") else
      gitanoParser(msg,sID)       -- redirect to gitanoParser
    end
  end
end

parallel.waitForAll(receiveparse)