CC Control passive cooled Big Reactor

--
-- Control passive cooled Big Reactor (http://big-reactors.com/).
--
-- Author: kla_sch
-- post: http://www.computercraft.info/forums2/index.php?/topic/18515-control-passive-cooled-big-reactors/
--
-- History:
--     v0.1, 2014-05-05:
--         first version
--
-- Remarks:
--     Reactor API: http://big-reactors.com/cc_api.html
--

--
-- Constant values (configuration)
--

-- Critical energy mark: give us the maximum power.
critEnergy=3000000

-- Low energy mark: turn reactor on to get more energy
lowEnergy=7000000

-- Heigh energy mark: we have enough, so turn the reactor off.
highEnergy=9000000


--
-- Calculate the control rod level (in %) by stored energy of internal
-- recator cell.
--
-- * If cellEnergy <= critEnergy, the calculation results in maximum
--   energy generation (control rod level = 0%).
-- * If cellEnergy >= highEnergy, the calculation results in 10% energy
--   generation (control rod level = 90%).
--
-- Parameters:
--     cellEnergy - stored energy of internal cell in RF
--
-- Return:
--     New control rod level in %.
--
function calcRodLevel(cellEnergy)
   -- Delta between critical and heigh energy mark
   local deltaEnergy = highEnergy - critEnergy

   -- Calculated maximum delta energy (not the real maximum), so that
   -- the high energy mark results into a control rod level of 90%
   local deltaEnergy100 = deltaEnergy * 100 / 90

   -- Energy for calculation: value between 0 and 'deltaEnergy'
   local calcEnergy = cellEnergy - critEnergy

   if calcEnergy < 0 then
      calcEnergy = 0
   elseif calcEnergy > deltaEnergy then
      calcEnergy = deltaEnergy
   end

   -- Calculate control rod level and round the result (math.floor + 0.5)
   return math.floor(calcEnergy * 100 / deltaEnergy100 + 0.5)
end


--
-- Write text with colors, if possible (advance monitor)
--
-- Parameters:
--     mon   - handle of monitor
--     color - text color
--     text  - text to write
--
function writeColor(mon, color, text)
   if (mon.isColor()) then
      mon.setTextColor(color)
   end
   mon.write(text)
   if (mon.isColor()) then
      mon.setTextColor(colors.white)
   end
end


--
-- Display reactor status to a monitor.
--
-- Parameters:
--     mon        - handle of monitor.
--     state      - state of reactor (on/off)
--     rodLvl     - Level of control rods in %
--     cellEnergy - stored energy of internal cell (in RF)
--
function displayStatusToMonitor(mon, state, rodLvl, cellEnergy)
   mon.clear()

   -- First get the monitor size and try to scale, if the feature ist
   -- available.
   if mon.setTextScale ~= nil then
      -- reset text scale
      mon.setTextScale(1)
   end

   local width, height = mon.getSize()
   if width < 15 or height < 5 then
      -- too small: try to scale down.
      if mon.setTextScale ~= nil then
         mon.setTextScale(0.5)
      else
         return -- too small und no text scale available
      end

      width, height = mon.getSize()
      if width < 15 or height < 5 then
         return -- still too small
      end
   else
      -- Huge monitors? Try to scale up, if possible (max scale=5).
      local scale = math.min(width / 16, height / 5, 5)
      scale = math.floor(scale * 2) / 2 -- multiple of 0.5

      if scale > 1 and mon.setTextScale ~= nil then
         mon.setTextScale(scale)
         width, height = mon.getSize()
      end
   end


   --
   -- Output the data
   --

   mon.setCursorPos(1,1)
   mon.write("Reactor")

   mon.setCursorPos(1,3)
   mon.write("Status ")

   if state then
      writeColor(mon, colors.green, "ON")
   else
      writeColor(mon, colors.red, "OFF")
   end

   mon.setCursorPos(1,4)
   mon.write("Rod Level: " .. rodLvl .. "%")

   mon.setCursorPos(1,5)
   if width < 16 then
      mon.write("Cell: ") -- One block monitor (15x5 with scale 0.5)
   else
      mon.write("Energy: ")
   end

   local c
   if cellEnergy < critEnergy then
      c = colors.red -- Red: We use too much energy
   elseif cellEnergy > lowEnergy then
      c = colors.green -- Green: More energy then low water mark
   else
      c = colors.orange -- Orange: Less energy the low water mark, but OK
   end
   writeColor(mon, c, string.format("%d", math.floor(cellEnergy/1000 + 0.5)))
   mon.write(" kRF")
end


--
-- Display reactor status to any connected monitor and also to console.
--
-- Parameters:
--     state      - state of reactor (on/off)
--     rodLvl     - Level of control rods in %
--     cellEnergy - stored energy of internal energy cell in RF
--
function displayStatus(state, rodLvl, cellEnergy)
   displayStatusToMonitor(term, state, rodLvl, cellEnergy) -- console
   term.setCursorPos(1,7)
   term.write("* Hold Crtl-T to terminate program")
   term.setCursorPos(1,8)

   local pList = peripheral.getNames()
   local i, name
   for i, name in pairs(pList) do
      if peripheral.getType(name) == "monitor" then
         -- found monitor as peripheral
         displayStatusToMonitor(peripheral.wrap(name),
                                state, rodLvl, cellEnergy)
      end
   end
end


--
-- Find the first connected big reactor and return the wraped handle.
--
-- If no reactor was found this function terminate the program.
--
-- Return:
--     Handle of first connected reactor found.
--
function getReactorHandle()
   local pList = peripheral.getNames()
   local i, name
   for i, name in pairs(pList) do
      if peripheral.getType(name) == "BigReactors-Reactor" then
         return peripheral.wrap(name)
      end
   end

   error("No big reactor connected: Exit program")
   exit()
end


reactor = getReactorHandle()

--
-- Endless loop: Recalculate rod level, set rod level, display result
-- and wait for 5 secounds.
--
while true do
   cellEnergy = reactor.getEnergyStored()
   if cellEnergy < lowEnergy then
      -- Low energy: switch reactor ON and calculate control rods by
      -- energy cell level.
      reactor.setActive(true)
      rodLvl=calcRodLevel(cellEnergy)
   elseif cellEnergy > highEnergy then
      -- High energy: switch reactor OFF and set control rod level to 100
      reactor.setActive(false)
      rodLvl=100
   elseif cellEnergy > lowEnergy then
      -- Enough energy: do not change state of reactor. Only recalculate
      -- control rod level.
      --
      -- * If the reactor ist switched off, we will wait until energy
      --   fall below low energy mark.
      --
      -- * If it is turned on, we generate more energy until the
      --   energy level exeeds the high energy mark.
      rodLvl=calcRodLevel(cellEnergy)
   end

   reactor.setAllControlRodLevels(rodLvl)

   displayStatus(reactor.getActive(), rodLvl, cellEnergy)

   os.sleep(5) -- Wait for 5s
end

--
-- EOF
--