--[[
Known Issues:
	Also, allow this to work with fuel, though this was originally
	built with fuel disabled, if it runs in a world that requires fuel
	it may get stuck if its not fueled properly.

]]

redstone.setOutput("left",false)
local dn = 15 -- Distance notification, basically tells you how far the turtle has dug in increments
local length, walk = ...
local delay = 0.25 -- This is to accomodate Sand falling, or obsidian forming
if length == nil then
	print("No length argument was given")
	return false -- Closes Program
end

if walk == 'true' then
	walk = true
else
	walk = false
end


--These variables keep track of the Turtles position and
--orientation relative to the turtles Starting Position
X = 0
Y = 0
Z = 0
O = 0

--[[
Orientation List
Forward = 0
Right = 1
Back = 2
Left = 3
]]--


-- These functions are used to keep track of
-- The Turtles Position Relative to its
-- Starting Point

function left(q)
	if q == nil then q = 1 end
	for i=1,q do
		turtle.turnLeft()
		if O == 0 then
			O = 3
		else
			O = O - 1
		end
	end
    return true
end

function right(q)
	if q == nil then q = 1 end
	for i=1,q do
		turtle.turnRight()
		if O == 3 then
			O = 0
		else
			O = O + 1
		end
	end
    return true
end

function up(q)
	if q == nil then q = 1 end
	for i=1,q do
		while not turtle.up() do
			digUp()
			turtle.up()
			sleep(delay)
		end
		Y = Y + 1
	end
    return true
end

function down(q)
	if q == nil then q = 1 end
	for i=1,q do
		while not turtle.down() do
			digDown()
			turtle.attackDown()
			sleep(delay)
		end
		Y = Y - 1
	end
    return true
end

function forward(q)
	if q == nil then q = 1 end
	for i=1,q do
		while not turtle.forward() do
			turtle.dig()
			turtle.attack()
			sleep(delay)
		end
		if O == 0 then
			X = X + 1
		elseif O == 1 then
			Z = Z + 1
		elseif O == 2 then
			X = X - 1
		elseif O == 3 then
			Z = Z - 1
		end
	end
    return true
end

function back()
	right()
	right()
	forward()
	left()
	left()
	return true
end

function orient(arg1)
    while arg1 ~= O do
            right()
    end
	return true
end

function dig()
	while turtle.detect() do
		turtle.dig()
		sleep(delay)
	end
	return true
end

function digUp()
	while turtle.detectUp() do
		turtle.digUp()
		sleep(delay)
	end
	return true
end

function digDown()
	while turtle.detectDown() do
		turtle.digDown()
		sleep(delay)
	end
	return true
end

--[[ Tells turtle where to go for longer movements,
 such as going to and from the chest.
 This may error if theres blocks in the way, but
 Given the way we will have the turtle move in this
 program, it will be fine. How ever if I were to
 copy this function over to another program, I'd
 probably fix this issue.]]
function go(lx,ly,lz)
    if X < lx then
		orient(0)
		for i=1,(lx-X) do
			forward()
		end
	end

	if X > lx then
		orient(2)
		for i=1,X-lx do
			forward()
		end
	end

	if Y < ly then
		for i=1,ly-Y do
			up()
		end
	end

	if Y > ly then
		for i=1,Y-ly do
			down()
		end
	end

	if Z < lz then
		orient(1)
		for i=1,lz-Z do
			forward()
		end
	end

	if Z > lz then
		orient(3)
		for i=1,Z-lz do
			forward()
		end
	end
end



-- Deposits Items into a chest
-- Warning! This may error if
-- the chest is full, so make sure
-- its emptied
function deposit()
	for i=1,16 do
		turtle.select(i)
		while turtle.drop() == false and turtle.getItemCount() ~= 0 do -- Waits until turtle can deposit item
			sleep(1)
		end
		turtle.drop()
	end
	turtle.select(1)
	return true
end



--[[
This function is what tells the
turtle to mine and when to go back
to empty its inventory
]]--
function mine()
	dig()
	forward()
	digUp()
	digDown()
	up()
	left()
	dig()
	right(2)
	dig()
	down()
	dig()
	left(2)
	dig()
	down()
	dig()
	right(2)
	dig()
	left()
	up()
end


-- Checks if turtle is full
function check()
	if turtle.getItemCount(15) == 0 then -- Checks second last slot. I'd like to leave 2 slots empty just to be safe
		return false
	else
		return true
	end
end

function notify(include)
	if X % dn == 0 and X ~= 0 then
		print("The turtle has traveled "..X.."/"..length+include.." blocks so far")
	end
	return true
end

local dni = 0 -- Blocks for distance notification to include in length, from the walk program
if walk then
	while turtle.detect() == false do
		forward()
		dni = dni + 1
		notify(dni) -- Notifies Distance
	end
end

for i=1,length do
	mine()
	notify(dni) -- Notifies Distance
	if check() then -- Checks if turtle should deposit items
		local lx,ly,lz = X,Y,Z
		go(0,0,0)
		orient(2) -- Faces Chest
		deposit()
		orient(0)
		go(lx,ly,lz)
	end
end

-- Returns to chest and deposits items before ending program
go(0,0,0)
orient(2) -- Faces Chest
deposit()
orient(0)
print("Program Ended, thank's for using BowWhalley's Digging Program")
sleep(1)
redstone.setOutput("left",true)