local cells = {peripheral.wrap("tile_blockcapacitorbank_name_1"),
  peripheral.wrap("tile_blockcapacitorbank_name_3"),
  peripheral.wrap("tile_blockcapacitorbank_name_4"),
  peripheral.wrap("tile_blockcapacitorbank_name_5")
}

local energyTable = {}
local maxEnergyTable = {}

local previousEnergyTotal = 0

local reactor = peripheral.wrap("BigReactors-Reactor_1")
local monitor = peripheral.wrap("monitor_1")

local enableReactorAt = 20

function getLength(text)
  length = string.len(text)
  return length
end

function centerCursor(text)
  textLength = getLength(text)
  x, y = monitor.getSize()
  x2, y2 = monitor.getCursorPos()
  term.setCursorPos(math.round((x / 2) - (textLength / 2)), y2)
end

function monitorClear()
  monitor.setTextColor(colors.white)
  monitor.clear()
  monitor.setCursorPos(1,1)
end

function monitorNewLine()
  x, y = monitor.getCursorPos()
  newY = y + 1
  monitor.setCursorPos(1, newY)
end

function writeTextTable(text)
  monitorClear()
  for i = 1, #text do
    centerCursor(text[i])
    monitor.write(text[i])
    monitorNewLine()
  end
end

function writeText(text, color)
  monitor.setTextColor(color)
  centerCursor(text[i])
  monitor.write(text)
  monitorNewLine()
end

function energyUse(totalEnergyStored)
  reactorEnergyInput = 0
  if reactor.getActive() then
    reactorEnergyInput = reactor.getEnergyProducedLastTick()
  end
  energyTick = ((previousEnergyTotal - totalEnergyStored) / 20) + reactorEnergyInput
  return energyTick
end


function monitorUpdate(totalEnergyStored, totalEnergyCapacity)
  text = {}
  strStart = "Energy Cell "
  for i = 1, #energyTable do
    p = math.round((energyTable[i] / maxEnergyTable[i]) * 100)
    text[i] = strStart .. tostring(i) .. ": " .. tostring(energyTable[i]) .. "/" .. tostring(maxEnergyTable[i]) .. " : " .. p .. "%"
  end
  writeTextTable(text)
  p = math.round((totalEnergyStored / totalEnergyCapacity) * 100)
  textTotal = "Total Energy : " .. tostring(totalEnergyStored) .. "/" .. tostring(totalEnergyCapacity) .. " : " .. p .. "%"
  writeText(textTotal, colors.orange)
  usingEnergy = energyUse(totalEnergyStored)
  textUsing = "Using : " .. tostring(usingEnergy) .. " RF per tick"
  writeText(textUsing, colors.red)
end

function disableReactor()
  reactor.setActive(false)
end

function enableReactor()
  reactor.setActive(true)
end

function checkPower(totalEnergyStored, totalEnergyCapacity)
  isReactorActive = reactor.getActive()
  p = math.ceil((totalEnergyStored / totalEnergyCapacity) * 100)
  if isReactorActive then
    if p == 100 then
      disableReactor()
    else
      return
    end
  elseif p <= enableReactorAt then
    enableReactor()
  end
end

while true do
  totalEnergyStored = 0
  totalEnergyCapacity = 0
  for i = 1, #cells do
    energyStored = cells[i].getEnergyStored()
    maxEnergyStored = cells[i].getMaxEnergyStored()
    energyTable[i] = energyStored
    maxEnergyTable[i] = maxEnergyStored
    totalEnergyStored = totalEnergyStored + tonumber(energyStored)
    totalEnergyCapacity = totalEnergyCapacity + tonumber(maxEnergyStored)
  end
  monitorUpdate(totalEnergyStored, totalEnergyCapacity)
  checkPower(totalEnergyStored, totalEnergyCapacity)
  previousEnergyTotal = totalEnergyStored
  sleep(1)
end