Tank Monitor

os.loadAPI("ocs/apis/sensor")
os.loadAPI("ocs/apis/graph")
local usedamount = 0
local prox = sensor.wrap("left")
local i = 0
local usage = 0
--print(textutils.serialize(prox.getTargets()))

local targets = prox.getTargets()

for name,basicDetails in pairs(targets) do
  print("Found Tank: "..name)
  tankDetails = prox.getTargetDetails(name)
  if (tankDetails ~= nil) then
    print("That Works")
    tank = name
    break
  end
end

local init = tankDetails.Tanks[1].Amount
local capacity = tankDetails.Tanks[1].Capacity
local type = tankDetails.Tanks[1].Name

if type == "item.fuel" then
 type = "Fuel"
end

function comma_value(amount)
  local formatted = amount
  while true do
    formatted, k = string.gsub(formatted,"^(-?%d+) (%d%d%d)", '%1,%2')
     if (k==0) then
       break
     end
    end
    return formatted
end

function round(val, decimal)
  if (decimal) then
    return math.floor( (val * 10^decimal) + 0.5 / (10^decimal) )
  else
    return math.floor(val+0.5)
  end
end

function format_num(amount, decimal,prefix, neg_prefix)
  local str_amount, formatted, famount, remain

  decimal = decimal or 2
  neg_prefix = neg_prefix or "-"

  famount = math.abs(round(amount,decimal))
  famount = math.floor(famount)

  remain = round(math.abs(amount) - famount, decimal)

  formatted = comma_value(famount)

  if (decimal > 0 ) then
    remain = string.sub(tostring(remain),3)
    formatted = formatted .. "." .. remain ..
    string.rep("0", decimal - string.len(remain))
  end

  if (amount < 0 ) then
    if (neg_prefix=="()") then
      formatted = "("..formatted ..")"
    else
      formatted = neg_prefix .. formatted
    end
  end
  return formatted
end

function update()
  i = i + 1
  local amt = sensor.call("left", "getTargetDetails",tank)
  if amt ~= nil then
  usage = init - amt.Tanks[1].Amount
  fuelcons = ( usage / i * 12 * 60 )
  timeleft = amt.Tanks[1].Amount / fuelcons
  fuelecons = fuelcons * -1

--  fuelcons = format_num(fuelcons,2)
 term.clear()
 term.setCursorPos(1,1)
  print("Consuming " ..fuelcons .." Fuel Per Hour")
  return amt.Tanks[1].Amount
  else
  print("amt was null")
  end
end

function newLine()
  local_,cY= mon.getCursorPos()
  mon.setCursorPos(1,cY+1)
end

mon = peripheral.wrap("top")
graphInstance = graph.new(mon, update, type, nil, 0 , capacity)
mon.setTextScale(5)
while true do

graphInstance:draw()
newLine()
mon.write(" Consuming: ")
mon.setTextColor(colors.lightBlue)
mon.write(fuelcons)
mon.setTextColor(colors.white)
mon.write(" /h")
newLine()
mon.write(" Time Remaining: ")
mon.setTextColor(colors.yellow)
mon.write(timeleft)
mon.setTextColor(colors.white)
mon.write(" Hours")
sleep(5)
end