elev_control.lua

local io = require("io")
local term = require("term")
local event = require("event")
local component = require("component")
local gpu = component.gpu
local modem = component.modem
local note = require("note")
local carriage = component.carriage
local button = require("buttonAPI")

local touch = true

local CALLER_PORT = 3538

modem.open(3539)
modem.setStrength(100)

floors = {}
numFloors = 3

floors[1] = {label="Library", y=145}
floors[2] = {label="Workshop (Ground Level)", y=137}
floors[3] = {label="Industrial Level", y=127}

local function persistYLevel()
  local file = io.open("currY", "w")
  file:write(currentYLevel)
  file:close()
end

local function loadYLevel()
  local file = io.open("currY", "r")
  local prevY = nil
  if file then
    prevY = file:read()
    if prevY ~= nil then
      prevY = tonumber(prevY)
    end
  end
  return prevY
end

local function notifyCallers(status, targetFloor)
  modem.broadcast(CALLER_PORT, status, targetFloor)
end

local function move(targetY, direction)
-- 0 is down, 1 is up
  local errMsg = nil
  local done = (targetY == currentYLevel)
  while(not done) do
  carriage.move(direction, false, false)
    os.sleep(.1)
    local energy, wasSuccess, reason, x, y, z = carriage.status()
    if reason then
      errMsg = reason
      if x then
        errMsg = errMsg.."\nx : "..x
        errMsg = errMsg.."\ny : "..y
        errMsg = errMsg.."\nz : "..z
      end
      break
    end
    if (direction == 0) then
      currentYLevel = currentYLevel - 1
      done = (currentYLevel <= targetY)
    else
      currentYLevel = currentYLevel + 1
      done = (currentYLevel >= targetY)
    end
  end
  persistYLevel()
  return errMsg
end

local function moveUp(target)
  return move(target, 1)
end

local function moveDown(target)
  return move(target, 0)
end

local function goToY(yLevel)
  if yLevel > currentYLevel then
    return moveUp(yLevel)
  else
    if yLevel < currentYLevel then
      return moveDown(yLevel)
    end
  end
end

local function goToFloor(floorNum)
  return goToY(floors[floorNum].y)
end

local function goToFloorByName(name)
  for k,v in pairs(floors) do
    if  (v.label == name) then
      notifyCallers("onroute", name)
      local errMsg =  goToY(v.y)
      if not errMsg then
        notifyCallers("arrived", name)
      else
        notifyCallers("arrived", "???")
      end
      return errMsg
    end
  end
  return nil
end

local function buttonHighlight(name)
  for k,v in pairs(floors) do
    if v.label == name then
      button.setActive(v.label, true)
    else
     button.setActive(v.label, false)
    end
  end
end

local function init()

  currentYLevel = loadYLevel()

  term.clear()

  if (currentYLevel == nil) then
    print("Unable to determine current Y level.")
    while(true) do
      io.write("Please provide correct value: ")
      local userYVal = io.read()
      userYVal = tonumber(userYVal)
      if userYVal == nil then
        print("\nNot a valid height value.")
      else
        currentYLevel = userYVal
        break
      end
    end
  end

  local currFloor = nil
  for k,v in pairs(floors) do
    if v.y == currentYLevel then
      currFloor = k
    end
  end

  if currFloor == nil then
    os.sleep(1)
    notifyCallers("arrived", "???")
    if not touch then
      print("Elevator starting between floors, at height " .. currentYLevel)
    end
  else
    if not touch then
      print("Elevator starting on floor: "..floors[currFloor].label)
    else
      buttonHighlight(floors[currFloor].label)
    end
    os.sleep(1)
    notifyCallers("arrived", floors[currFloor].label)
  end
end

local function listAvailableFloors()

  for k,v in pairs(floors) do
    io.write("\n"..k..") ".. v.label)
    if v.y == currentYLevel then
      io.write(" {*}")
    end
  end

end

local function mainCLI()

  init()

  while(true) do
    print("\n Available Floors: ")
    listAvailableFloors()

    local selection = nil
    while(true) do
      io.write("\n\nEnter desired floor number: ")
      selection = io.read()
      selection = tonumber(selection)
      if not selection or (selection < 1) or (selection > numFloors) then
        print("\n Invalid floor.")
      else
        break
      end
    end

    term.clear()
    local err = goToFloor(selection)
    if err then
      print(err)
    end

  end

end

local function eventFilter(id)
  return (id == "touch" or id == "modem_message")
end


local function buttonHandler(name)
  buttonHighlight(name)
  os.sleep(1)
  local err = goToFloorByName(name)
  if(err) then
    button.label(1,34,err)
  else
    note.play(72, 0.3)
    note.play(67, 0.3)
  end
end

local function getClickOrUpdate()
  local e, _, x, y, _, floorName = event.pullFiltered(1,eventFilter)
  if (e == "touch") then
    if x == nil or y == nil then
      local h, w = gpu.getResolution()
      gpu.set(h,w,".")
      gpu.set(h,w," ")
    else
      button.checkxy(x,y)
    end
  elseif (e == "modem_message") then
    buttonHandler(floorName)
  end
end

local function displayAvailableFloors()
  term.setCursorBlink(false)
  button.clear()

  local minX = 8
  local minY  = 3
  local buttonHeight = 2
  local buttonWidth = 24
  local buttonSpacing = 2

  for k,v in pairs(floors) do
    button.setTable(v.label, buttonHandler, minX, minX + buttonWidth, minY, minY + buttonHeight)
    minY = minY + buttonHeight+ buttonSpacing
  end

  button.screen()

end

function mainTouch()
  gpu.setResolution(40, 40)

  displayAvailableFloors()

  init()

  button.heading("Please Choose A Floor:")

  while(true)  do
    getClickOrUpdate()
  end

end

if touch then
  mainTouch()
else
  mainCLI()
end