local diskDrive = peripheral.find("drive")
local monitor = require("monitor-driver")
local function getFilePath()
    if diskDrive and diskDrive.isDiskPresent() then
        local path = diskDrive.getMountPath()
        if path then
            return fs.combine(path, "data.tbl")
        end
    end
    return nil
end

local function loadData()
    local path = getFilePath()
    if path and fs.exists(path) then
        local file = fs.open(path, "r")
        local content = file.readAll()
        file.close()
        local parsed
        if content then
            parsed = textutils.unserialize(content)
        end
        return parsed or {}
    end
    return {}
end

local function saveData(data)
    local path = getFilePath()
    if path then
        local file = fs.open(path, "w")
        file.write(textutils.serialize(data))
        file.close()
        return true
    end
    return false
end

local function generateGuid()
    local template ='xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'
    return string.gsub(template, '[xy]', function (c)
        local v = (c == 'x') and math.random(0, 0xf) or math.random(8, 0xb)
        return string.format('%x', v)
    end)
end

local function getValue(key)
    local data = loadData()
    for _, item in ipairs(data) do
        if item.Key == key then
            return item.Value
        end
    end
    return nil
end

local function updateValue(key, value)
    local data = loadData()
    for _, item in ipairs(data) do
        if item.Key == key then
            item.Value = value
            saveData(data)
            return true
        end
    end
    return false
end

local function writeValue(key, value)
    local data = loadData()
    local guid = generateGuid()
    table.insert(data, { GeneratedGuid = guid, Key = key, Value = value })
    saveData(data)
    return guid
end

local function initialize()
    monitor.writeLine("Initializing Data Storage...")
    if diskDrive and diskDrive.isDiskPresent() then
        monitor.writeLine("Disk detected. Initializing data storage.")
        local path = getFilePath()
        if path and not fs.exists(path) then
            saveData({})
        end
        return true
    end
    return false
end

return { getValue = getValue, updateValue = updateValue, writeValue = writeValue, initialize = initialize }