-- Define the peripherals connected to the computer

-- Monitor
monitor  = peripheral.wrap("right")

-- Item Selector to display and edit the items to be stocked
selector = peripheral.wrap("top")

-- ME interface for crafting requests
interface = peripheral.wrap("back")


--Some Parameters
local w,h = monitor.getSize()
local stockBuffer = 0.05
local craftingInterval = 10
local stockItems = {}
local stockItemsCount = 0

-- Meta class
StockItem = {
   item     = 0,
   stockQty = 0,
   status   = "",
}

function StockItem:new(o,item,stockQty)
   o = o or {}
   setmetatable(o, self)
   self.__index = self
   self.item = item or nil
   self.stockQty = stockQty or 0
   self.status = "Not Sure"
   return o
end

function StockItem:setQty(stockQty)
   self.stockQty = stockQty
end



function checkQuantities()
   local details
   while true do
      if stockItemsCount > 0 then
         for iStock = 1, stockItemsCount, 1 do
            local item =  stockItems[iStock].item
            local stockQty =  stockItems[iStock].stockQty
            -- get current quantity in the ME system
            if interface.getItemDetail(item) ~= nil then
               details = interface.getItemDetail(item).basic()

               if details.qty < stockQty then

                  if requestCrafting(item,details.qty,stockQty,status) then
                     stockItems[iStock].status = "Crafting"
                  else
                     stockItems[iStock].status = "Error"
                  end
               else
                  stockItems[iStock].status = "Fullfilled"
               end
               print(string.format("%s: %d  %s",details.display_name,stockQty,stockItems[iStock].status))
            end
         end
      end
      os.sleep(craftingInterval)
   end
   return true
end


function requestCrafting(item,currentQty,stockQty,status)
   local craftingQty = stockQty * (1 + stockBuffer) - currentQty
   local success
   interface.requestCrafting(item,craftingQty)
   return true
end

function optionsMenu()
   local key_pressed = false
   while not key_pressed do
      local event, key = os.pullEvent( "key" )
      if key == keys.r then -- if the key pressed was 'strg'
         addItem()
      end
   end
end


function addItem()
   print( "You pressed [E]. Please place the Item to craft in the upper left slot of the Item Selector" )
   while true do
      local item = selector.getSlot(1)
      if item ~= nil then
         io.write("Enter the desired Quantity: ")
         stockQty = io.read()
         stockItemsCount = stockItemsCount + 1
         stockItems[stockItemsCount] = StockItem:new(nil,item,tonumber(stockQty))
         break
      end
      os.sleep(1)
   end
end



--display text text on monitor, "monitor" peripheral
function drawText(x, y, text, text_color, bg_color)
  monitor.setBackgroundColor(bg_color)
  monitor.setTextColor(text_color)
  monitor.setCursorPos(x,y)
  monitor.write(text)
end

--draw line on monitor
function drawLine(x, y, length, color)
    monitor.setBackgroundColor(color)
    monitor.setCursorPos(x,y)
    monitor.write(string.rep(" ", length))
end

--clear lines on monitor
function clearLine(...)
    for _,y in ipairs(arg) do
       monitor.setCursorPos(1,y)
      monitor.clearLine()
   end
end

function itemKey(item)
  local key = item.id .. "/" .. item.dmg

  if item.nbt_hash ~= nil then
    key = key .. "/" .. item.nbt_hash
  end

  return key
end


while true do
   parallel.waitForAny(checkQuantities,optionsMenu)
end