SnowCenter - Channel12

-- Bank server

-- Channels
local BANK_SERVER = 12
local REGISTER_COMPUTER = 14
local IMAGE_SERVER = 17
local EVENT_MANAGER = 18
local TURTLESCREEN_COMS = 19
local CARDREADER = 21
rednet.open("top")

-- Libs

-- Code

local databasepath = "db"
local db
local defaultbalance = 0

if not fs.exists(databasepath) then
    database = {}
    local file = fs.open(databasepath, "w")
    file.write("{}")
    file.close()
else
    local file = fs.open(databasepath, "r")
    database = textutils.unserialise(file.readAll())
    file.close()
end

print("initialized database with success")

while true do
    local id, data = rednet.receive("bank")
    print(textutils.serialise(data))
    if data.type == "getbalance" then
        print("getting balance of user ", data.user)
        rednet.send(id, database[data.user], "bank")
    elseif data.type == "setbalance" then
        print("setting balance of " .. data.user .. " to " .. data.balance)
        database[data.user].balance = data.balance
        local file = fs.open(databasepath, "w")
        file.write(textutils.serialise(database))
        file.close()
        rednet.send(id, nil, "bank")
    elseif data.type == "registeruser" then
        print("Registering user " .. data.user .. ":" .. data.name)
        database[data.user] = {
            name=data.name,
            balance=defaultbalance
        }
        local file = fs.open(databasepath, "w")
        file.write(textutils.serialise(database))
        file.close()
        rednet.send(id, nil, "bank")
    end
end