local position = {
	x = 0, y = 0, z = 0
}

local start_point = {
	x = 0, y = 0, z = 0
}



function Deploy_minions()
	clear();
	for i=1,4,1 do
		turtle.select(i);
		turtle.place();
		turtle.turnRight();
	end
end

function Excavate()
	local a = peripheral.wrap('front');
	local b = peripheral.wrap('left');
	local c = peripheral.wrap('back');
	local d = peripheral.wrap('right');
	a.turnOn(); b.turnOn(); c.turnOn(); d.turnOn();
end

function clear()
	for i=1,4,1 do
		turtle.dig();
		turtle.turnRight();
	end
end

function Wait_for_minions()
	while true do
		if turtle.inspect() then
			turtle.turnRight();
			if turtle.inspect() then
				turtle.turnRight();
				if turtle.inspect() then
					turtle.turnRight();
					if turtle.inspect() then
						turtle.turnRight();
						break;
					end
				end
			end
		end
	end

	if position.y < 22 then
		Redstone_pulse();
		Up();
	else
		Break_minions();
		Ascend();
	end

end

function Break_minions()
	for i=1, 4, 1 do
		turtle.dig();
		turtle.turnRight();
	end
	Ascend();
end

function Descend()
	while position.y > 8 do
		Down();
	end
end

function Ascend()
	while position.y < start_point.y do
		Up();
	end

end

function Populate_position()
	--[[ Terrible code. ]]
	for i,v in ipairs(arg) do
		if (i == 1) then
			start_point.x = v;
			position.x = v;
		end
		if (i == 2) then
			start_point.y = v;
			position.y = v;
		end
		if (i == 3) then
			start_point.z = v;
			position.z = v;
		end
	end
end


function Down()
	if turtle.detectDown() then
		turtle.digDown();
	end
	turtle.down();
	position.y = position.y - 1;
end

function Up()
	if turtle.detectUp() then
		turtle.digUp()
	end
	turtle.up()
	position.y = position.y + 1;
end

function Forward()
	if turtle.detect() then
		turtle.dig();
	end
	turtle.forward()
end

function Redstone_pulse()
	redstone.setOutput('front', true);
	redstone.setOutput('back', true);
	redstone.setOutput('left', true);
	redstone.setOutput('right', true);
	sleep(0.5);
	redstone.setOutput('front', false);
	redstone.setOutput('back', false);
	redstone.setOutput('left', false);
	redstone.setOutput('right', false);
end

print(start_point);
print(position.hi);
local lowest_level = 8;
local highest_level = 22;

--[[ turtle.refuel();
turtle.select() ]]
function Init()
	Populate_position();
	Descend()
	Deploy_minions();
	Excavate();
	Redstone_pulse();
	sleep(8);
	Wait_for_minions();
end

Init();