--(( Settings ))--

-- side relative to the computer
-- or path if you are using cables
local grindstone = peripheral.wrap("left")
or error("Unable to wrap the grind stone!",0)

local monitor = peripheral.wrap("top")
or error("Unable to wrap the monitor!",0)

-- colors
local BG = colors.black
local LOW = colors.red
local MED = colors.orange
local HIGH = colors.yellow
local TOP = colors.lime

-- how many times to draw per second
local updateRate = 5

--(( Variables ))--

local ores = 0
local dusts = 0
local total = 0
local oresPercentage = 0
local dustsPercentage = 0

local mW,mH = monitor.getSize()
local tW,tH = term.getSize()

--(( Functions ))--

local function getAllStacks( inv )
	local t = {}
	local size = inv.getInventorySize()
	for slot = 1,size do
		local item = inv.getStackInSlot(slot) or {}

		item.rawName = item.rawName or ""
		item.qty = item.qty or 0
		item.dmg = item.dmg or 0
		item.name = item.name or ""
		item.id = item.id or 0

		t[slot] = item
	end
	return t
end

local function updateItems()
	local items = getAllStacks(grindstone)

	ores = 0
	dusts = 0
	total = 0
	percentage = 0

	for slot,item in pairs(items) do
		-- ores
		if slot >= 1 and slot <= 3 then
			ores = ores + item.qty
		end

		-- dusts
		if slot >= 4 and slot <= 6 then
			dusts = dusts + item.qty
		end
	end

	total = ores + dusts
	oresPercentage = ores / total
	dustsPercentage = dusts / total

	if ores == 0 then oresPercentage = 0 end
	if dusts == 0 then dustsPercentage = 0 end
end

local function draw()
	-- drawing a big bar over the monitor
	-- drawing from left to right

	-- black area
	monitor.setBackgroundColor(BG)
	for column = math.ceil(dustsPercentage * mW),mW,1 do
		for row = 1,mH,1 do
			monitor.setCursorPos(column,row)
			monitor.write(" ")
		end
	end

	-- colored area
	if dustsPercentage > 0 then
		-- 0% to 33%
		if dustsPercentage < 1/3 then
			monitor.setBackgroundColor(LOW)
		end
		-- 33% to 66%
		if dustsPercentage >= 1/3
		and dustsPercentage < 2/3 then
			monitor.setBackgroundColor(MED)
		end
		-- 66% to 100%
		if dustsPercentage >= 2/3
		and dustsPercentage < 1 then
			monitor.setBackgroundColor(HIGH)
		end
		-- 100%
		if dustsPercentage == 1 then
			monitor.setBackgroundColor(TOP)
		end
	end
	for column = 1,math.floor(dustsPercentage * mW),1 do
		for row = 1,mH,1 do
			monitor.setCursorPos(column,row)
			monitor.write(" ")
		end
	end

	-- on screen info
	term.clear()

	local ore = "ore" if ores > 1 then ore = "ores" end
	local dust = "dust" if dusts > 1 then dust = "dusts" end

	local text1 = "Currently "..ores.." "..ore.." and ".. dusts.." "..dust
	local text2 = math.floor(dustsPercentage*100).."% done"

	term.setCursorPos(tW/2-#text1/2,tH/2-1)
	term.write(text1)
	term.setCursorPos(tW/2-#text2/2,tH/2+1)
	term.write(text2)
end

--(( Main program ))--

-- main loop
while true do
	updateItems()
	draw()
	sleep(1/updateRate)
end