-- argument
local tArgs = { ... }
if #tArgs ~= 2 then
	print( "Usage: island <height> <size>" )
	return
end

-- var
local height = tonumber( tArgs[1] )
local size = tonumber( tArgs[2] )

-- function
function countNeededBlock(size)
  needed = 0;
  for i=size,1,-2 do
    needed = needed + size*size;
  end
  return needed;
end

function countAvailableBlock()
    count = 0;
    for i=1,16 do
      count = count + turtle.getItemCount(i);
    end
    return count;
end

function calculateFuelNeed(size,height)
  return height*2 + countNeededBlock(size) + size;
end


-- main
-- report
print("need " .. countNeededBlock(size) .. " block to do so");
print(countAvailableBlock() .. " block available");
print("need " .. calculateFuelNeed(size,height) .. " moves");
print(turtle.getFuelLevel() .. " fuel available");

-- error control
if (countAvailableBlock() < countNeededBlock(size)) then
    print("need more block ");
    return;
end;

if turtle.getFuelLevel() < calculateFuelNeed(size,height) then
    print("need more fuel ");
    return;
end;

if height <= size/2 then
   print("should climb higher")
   return
end

-- main loop

--rise
for i=1,height do
  turtle.up()
end

for i=size,1,-2 do
  os.run({},"/rom/programs/turtle/platform",0,i);
  turtle.forward();
  turtle.turnRight();
  turtle.forward();
  if size%2 == 1 then
    turtle.forward();
  end
  turtle.turnLeft();
  turtle.down();
end

-- fall
for i=1,height do
  turtle.down()
end