elevator server

local modem = peripheral.find("modem")

local state = "idle"
local currentFloor = 1
local lastUpDownTime = nil
local computerID = os.getComputerID()

-- Configuration
local configFileName = "elevator_server_config.txt"
local config = {channel = "69", computerID = "0"}

-- Save Config to file
local function saveConfig(config)
    local configData = textutils.serializeJSON(config)
    local file = fs.open(configFileName, "w")
    file.write(configData)
    file.close()
end

-- Load Config from file
local function loadConfig()
    if fs.exists(configFileName) then
        local file = fs.open(configFileName, "r")
        local configData = file.readAll()
        file.close()
        local loadedConfig = textutils.unserializeJSON(configData)
        config = loadedConfig
    end
end


local function controlElevator(direction)
    if direction == "up" or direction == "down" then
        lastUpDownTime = os.epoch('utc')
    end

    if direction == "up" then
        redstone.setOutput("left", true)
        redstone.setOutput("right", false)
    elseif direction == "down" then
        redstone.setOutput("left", false)
        redstone.setOutput("right", false)
    elseif direction == "stop" then
        redstone.setOutput("left", false)
        redstone.setOutput("right", true)
    else
        print("Debug: Invalid direction")
    end
end

local function stateMachine()
    print("Current state: " .. state)
    if state == "idle" then
        controlElevator("stop")
    elseif state == "up" then
        controlElevator("up")
    elseif state == "down" then
        controlElevator("down")
    else
        print("Debug: Invalid state")
    end
end

local function handleModemMessages(config)
    local event, modemSide, senderChannel, replyChannel, message, senderDistance = os.pullEvent()
    if event == "modem_message" then
        if senderChannel == tonumber(config.channel) then
            if string.sub(message, 1, 5) == "idle:" then
                if lastUpDownTime == nil or (os.epoch('utc') - lastUpDownTime) >= 1000 then
                    state = "idle"
                    local newFloor = tonumber(string.sub(message, 6))
                    print("Elevator floor: " .. newFloor)
                    currentFloor = newFloor
                end
            else
                state = message
            end
        end
    end
end

-- Main Loop
local function mainLoop(config)
    modem.open(tonumber(config.channel))
    while true do
        handleModemMessages(config)
        stateMachine()
    end
end

-- Initialization
local function initializeClient()
    loadConfig()
    if not config.channel or config.channel == "" then
        print("Please enter the channel to use:")
        config.channel = tonumber(read())
    end
    if not config.computerID then
        config.computerID = computerID
    end
    saveConfig(config)
    mainLoop(config)
end

-- Entry Point
initializeClient()