[ComputerCraft] KreditAPI

--Kredit API by JLW222 (James222)
--Build V 1.0


--Array Database

local name = {}
local money = {}
local password = {}
local inTransactions = {}
local outTransactions = {}


--Enter a number from 0 to 100 (%)
local transactionFee = 10

--The server can hold money because of transaction fees
local serverMoney = 0

--The server's password. It is asked when using admin commands
--CHANGE ME <=========================================================================
local serverAdminPassword = "beta2"
--The encryption's password. It is used to encrypt passwords and data
--CHANGE ME <=========================================================================
local encryptionPassword = "YEAH"

--Defines is KREDITAPI should automatically read the accounts file when api is ran
local autoRead = true

--Function Variables. Don't modify these
local database = ""

local completeDatabase = {}


local foundAccountC = false
local foundAccountCk = false
local foundAccountE = false
local foundAccountCr = false

local databases = {}
local splitDatabases = {}
--Functions

os.loadAPI("enc")

--Writes data from accounts file to tables
function applyDatabase()
  if database == "" then
    print("Database must be loaded first or is empty")
    return false
  else
   databases[1] = textutils.unserialize(database)
   splitDatabases = split(databases[1], "}")
   name = textutils.unserialize(splitDatabases[1])
   money = textutils.unserialize(splitDatabases[2])
   password = textutils.unserialize(splitDatabases[3])
   inTransactions = textutils.unserialize(splitDatabases[4])
   outTransactions = textutils.unserialize(splitDatabases[5])
  end
end

--Save the database's data
function saveDatabase()
  if fs.exists("KACCOUNTS") then
    local h = fs.open("KACCOUNTS", "w")
    completeDatabase[1] = textutils.serialize(name) .. textutils.serialize(money) .. textutils.serialize(password) .. textutils.serialize(inTransactions) .. textutils.serialize(outTransactions)
    h.write(textutils.serialize(completeDatabase[1]))
    h.close()
   else
   loadDatabase()
   saveDatabase()
  end
end

--Loads the bank account file into the tables
function loadDatabase()
  if fs.exists("KACCOUNTS") then
   local h = fs.open("KACCOUNTS", "r")
   database = h.readAll()
   h.close()
   print("Accounts database loaded")
   applyDatabase()
  else
   local h = fs.open("KACCOUNTS", "a")
   h.close()
   print("Accounts database created")
  end
end

--Lists all accounts names
function listAccounts()
  local accounts = ""
  if count() == 0 then
   return "There are no accounts in this database"
  else
  for i = 1, count() do
    accounts = accounts .. " | " .. name[i]
  end
  return accounts
  end
end

--Used to create an account
function createAccount(userName, userPassword)
 for i = 0, count() do
  if userName == name[i] then
    print("Account already exists")
    foundAccountCr = false
    return false
  end
  if i == count() then
    if foundAccountCr == false then
     encryptedPassword = enc.encrypt(userPassword, encryptionPassword)
     table.insert(name, userName)
     table.insert(money, 0)
     table.insert(password, encryptedPassword)
     table.insert(inTransactions, "")
     table.insert(outTransactions, "")
  return true
    end
  end
 end
end

--Used to check account balance
function check(userName, userPassword)
  if checkCredentials(userName, userPassword) == true then
     for i = 0, count() do
      if userName == name[i] then
        foundAccountCk = true
        return money[i]
      end
      if i == count() then
        if foundAccountCk == false then
          print("Account does not exist")
          foundAccountCk = false
        end
      end
     end
  end
end

--Used to give money to certain account
function give(userName, userPassword, amount, receiverName, escapesFee)
 if type(amount) == "number" then
  if checkCredentials(userName, userPassword) == true then
    if (check(userName, userPassword) - amount) >= 0 then
     if checkUserExists(receiverName) == true then
      --Set the receiver's amount of money
      for i = 0, count() do
        if receiverName == name[i] then
          local moneyResult = money[i] + amount
          if escapesFee == true then
            table.insert(money, i, moneyResult)
          else
            table.insert(money, i, transac(moneyResult))
          end
          local osdate = os.time()
          local inTransac = inTransactions[i] .. "| From: " .. userName .. " | +" .. amount .. "$ | " .. osdate .. " |,"
          table.insert(inTransactions, i, inTransac)
        end
      end
      --Set the sender's amount of money
      for i = 0, count() do
        if userName == name[i] then
          local moneyResult = money[i] - amount
          table.insert(money, i, moneyResult)
          local osdate = os.time()
          local outTransac = outTransactions[i] .. "| To: " .. receiverName .. " | -" .. amount .. "$ | " .. osdate .. " |,"
          table.insert(outTransactions, i, outTransac)
        end
      end
      saveDatabase()
      return true
     else
      print("Receiver's account does not exist")
      return false
     end
    else
     return false
    end
  end
  else
  print("Amount provided is not numeric")
  return false
 end
end

--Verify credentials
function checkCredentials(userName, userPassword)
  local encryptedPassword = enc.decrypt(userPassword, encryptionPassword)
   for i = 0, count() do
     if userName == name[i] then
      if encryptedPassword == password[i] then
        foundAccountC = true
        return true
      else
        foundAccountC = true
      end
     end
     if i == count() then
      if foundAccountC == false then
       print("Account does not exist")
       foundAccountC = false
      else
       print("Passwords do not match")
       foundAccountC = false
       return false
      end
     end
   end
end
--Used to check if a user exists. Does not require password
function checkUserExists(userName)
 for i = 0, count() do
   if userName == name[i] then
     foundAccountE = true
     return true
   end
   if i == count then
    if foundAccountE == false then
      print("Account does not exist")
      return false
    end
   end
 end
end

--Used to calculate amount after transactionFee
function transac(amount)
 if transactionFee >= 101 then
  print("No fee applied: Transaction fee is over than 100!")
  return 0
 end
  local fee = (transactionFee / 100) * amount
  local finalAmount = amount - fee
  serverMoney = serverMoney + fee
  return finalAmount
end

--Used to count how many accounts there are
function count()
 local count = 0
 for _ in pairs(name) do count = count + 1 end
 return count
end

--ADMIN FUNCTIONS, BE CAREFUL WITH THESE

--Used to set the money of a user's account
function setMoney(userName, amount, serverPassword)
if serverPassword == serverAdminPassword then
 if checkUserExists(userName) == true then
    for i = 0, count() do
      if userName == name[i] then
        if type(amount) == "number" then
          table.insert(money, i, amount)
          saveDatabase()
          return true
        else
          print("Amount provided is not numeric")
          return false
        end
      end
    end
  else
   print("Account does not exist")
   return false
  end
 else
   print("Server passwords do not match")
   return false
 end
end

--Used to show money of all users
function listMoney(serverPassword)
if serverPassword == serverAdminPassword then
 local moneyList = ""
  if count() == 0 then
   return "There are no accounts in this database"
  else
  for i = 1, count() do
    moneyList = moneyList .. " | " .. name[i] .. ": " .. money[i] .. "$"
  end
  return moneyList
  end
 else
   print("Server passwords do not match")
   return false
 end
end

--Used to show money of a specific user
function showMoney(userName, serverPassword)
if serverPassword == serverAdminPassword then
 if checkUserExists(userName) == true then
    for i = 0, count() do
      if userName == name[i] then
        return name[i] .. " has " .. money[i] .. "$"
      end
    end
  else
    print("Account does not exist")
    return false
  end
 else
   print("Server passwords do not match")
   return false
 end
end


--Used to give money to a user instead having to manually calculate amount and use setMoney()
function addMoney(userName, amount, serverPassword)
if serverPassword == serverAdminPassword then
 if type(amount) == "number" then
  if checkUserExists(userName) == true then
    for i = 0, count() do
      if userName == name[i] then
         local moneyResult = money[i] + amount
         table.insert(money, i, moneyResult)
         saveDatabase()
         return true
      end
    end
  else
    print("Account does not exist")
    return false
  end
 else
  print("Amount provided is not numeric")
  return false
 end
 else
   print("Server passwords do not match")
   return false
 end
end

--Used to remove money from a user instead having to manually calculate amount and use setMoney()
function removeMoney(userName, amount, serverPassword)
if serverPassword == serverAdminPassword then
 if type(amount) == "number" then
  if checkUserExists(userName) == true then
    for i = 0, count() do
      if userName == name[i] then
         local moneyResult = money[i] - amount
         table.insert(money, i, moneyResult)
         saveDatabase()
         return true
      end
    end
  else
    print("Account does not exist")
    return false
  end
 else
  print("Amount provided is not numeric")
  return false
 end
 else
   print("Server passwords do not match")
   return false
 end
end

--Deletes the user's account
function deleteAccount(userName, serverPassword)
 if serverPassword == serverAdminPassword then
  if checkUserExists(userName) == true then
    for i = 0, count() do
      if userName == name[i] then
        table.remove(name, i)
        table.remove(money, i)
        table.remove(password, i)
        table.remove(inTransactions, i)
        table.remove(outTransactions, i)
        saveDatabase()
      end
    end
    return true
  end
 else
   print("Server passwords do not match")
   return false
 end
end

--Lists the user's in transactions
function showInTransaction(userName, serverPassword)
 if serverPassword == serverAdminPassword then
  if checkUserExists(userName) == true then
    for i = 0, count() do
      if userName == name[i] then
        local transactions = ""
        for word in string.gmatch(inTransactions[i], '([^,]+)') do
         transactions = transactions .. "\n" .. word
        end
        return "Last In Transactions of " .. userName .. "\n" .. transactions
      end
    end
  else
   print("Account does not exist")
   return false
  end
  else
   print("Server passwords do not match")
   return false
 end
end

--Lists the user's out transactions
function showOutTransaction(userName, serverPassword)
if serverPassword == serverAdminPassword then
  if checkUserExists(userName) == true then
    for i = 0, count() do
      if userName == name[i] then
        local transactions = ""
        for word in string.gmatch(outTransactions[i], '([^,]+)') do
         transactions = transactions .. "\n" .. word
        end
        return "Last Out Transactions of " .. userName .. "\n" .. transactions
      end
    end
  else
   print("Account does not exist")
   return false
  end
    else
   print("Server passwords do not match")
   return false
 end
end

--Sets the user's password
function setPassword(userName, newPassword, serverPassword)
  if serverPassword == serverAdminPassword then
      encryptedPassword = enc.encrypt(newPassword, encryptionPassword)
      if checkUserExists(userName) == true then
        for i = 0, count() do
          if userName == name[i] then
            table.insert(password, i, encryptedPassword)
            return true
          end
        end
      else
        print("Account does not exist")
        return false
      end
      else
   print("Server passwords do not match")
   return false
  end
end

--Other functions

--Splits the string
function split(str, pat)
   local t = {}  -- NOTE: use {n = 0} in Lua-5.0
   local fpat = "(.-)" .. pat
   local last_end = 1
   local s, e, cap = str:find(fpat, 1)
   while s do
      if s ~= 1 or cap ~= "" then
     table.insert(t,cap .. "}")
      end
      last_end = e+1
      s, e, cap = str:find(fpat, last_end)
   end
   if last_end <= #str then
      cap = str:sub(last_end)
      table.insert(t, cap .. "}")
   end
   return t
end

if autoRead == true then
  loadDatabase()
end