north = 1
south = 2
west = 3
east = 4

ignoreStart = 12

northDir = {0, 1}
southDir = {0, -1}
eastDir = {1, 0}
westDir = {-1, 0}
startz = 68
startx = 0
starty = 0
x = 0
y = 0
z = startz

fuelStack = 1
yieldStart = 4

-- start at facing north
currentDir = north

local mov = {}
local rot = {}
local dig = {}

mov.forward = function(times)
        local boolean v = false
        for i=1,times do
                if turtle.detect() == false then
                        while not turtle.forward() do
                                sleep(1)
                        end
                        v = true
                else
                        v = false
                        return v
                end
        end
        return v
end

mov.back = function(times)
        local boolean v = false
        for i=1,times do
                while not turtle.back() do
                        sleep(1)
                end
                v = true
        end
        return v
end

mov.up = function(times)
        local boolean v = false
        for i=1,times do
                if turtle.detectUp() == false then
                        while not turtle.up() do
                                sleep(1)
                        end
                        v = true
                else
                        v = false
                        return v
                end
        end
        return v
end

mov.down = function(times)
        local boolean v = false
		print("mov.down");
        for i=1,times do
                if turtle.detectDown() == false then
						print("!detectDown");
                        while not turtle.down() do
                                sleep(1)
                        end
                        v = true
                else
						print("detectDown");
                        v = false
                        return v
                end
        end
        return v
end

mov.place = function()
    while not turtle.place() do
          sleep(1)
    end
    return true
end

rot.right = function()
    while not turtle.turnRight() do
            sleep(1)
    end

        if RotatePosition == "FORWARD" then
                RotatePosition = "RIGHT"
        elseif RotatePosition == "LEFT" then
                RotatePosition = "FORWARD"
        end
        filewriteline("BranchMineData", 5, RotatePosition)
    return true
end

rot.left = function()
    while not turtle.turnLeft() do
            sleep(1)
    end

        if RotatePosition == "FORWARD" then
                RotatePosition = "LEFT"
        elseif RotatePosition == "RIGHT" then
                RotatePosition = "FORWARD"
        end
        filewriteline("BranchMineData", 5, RotatePosition)
    return true
end

dig.forward = function()
        if turtle.detect() then
                while not turtle.dig() do
                                sleep(1)
                end
                return true
        else
                print("No Block to mine forward")
                return false
        end
end

dig.up = function()
        if turtle.detectUp() then
                while not turtle.digUp() do
                                sleep(1)
                end
                return true
        else
                print("No Block to mine up")
                return false
        end
end

dig.down = function()
        if turtle.detectDown() then
                while not turtle.digDown() do
                                sleep(1)
                end
                return true
        else
                print("No Block to mine down")
                return false
        end
end

function DigMoveForward()
        if mov.forward(1) == false then
                dig.forward()
                sleep(0.5)
                DigMoveForward()
        end
end

function DigMoveUp()
        if mov.up(1) == false then
                dig.up()
                sleep(0.5)
                DigMoveUp()

		else
			z = z + 1
        end

end

function DigMoveDown()
	print("moving down")
        if mov.down(1) == false then
				print("failed moving down - digging")
                dig.down()
                sleep(0.5)
				print("trying again")
                DigMoveDown()
		else
			print("aucceeeded")
			z = z - 1
        end
end


function faceEast()
    if(currentDir == north) then
	    turtle.turnRight()
    elseif(currentDir == west) then
	    turtle.turnRight()
		turtle.turnRight()
    elseif(currentDir == south) then
	    turtle.turnLeft()
	end
	currentDir = east;
end

function faceNorth()
    if(currentDir == east) then
	    turtle.turnLeft()
    elseif(currentDir == south) then
	    turtle.turnRight()
		turtle.turnRight()
    elseif(currentDir == west) then
	    turtle.turnRight()
	end
	currentDir = north;
end

function faceSouth()
    if(currentDir == east) then
	    turtle.turnRight()
    elseif(currentDir == north) then
	    turtle.turnRight()
		turtle.turnRight()
    elseif(currentDir == west) then
	    turtle.turnLeft()
	end
	currentDir = south;
end

function faceWest()
    if(currentDir == south) then
	    turtle.turnRight()
    elseif(currentDir == east) then
	    turtle.turnRight()
		turtle.turnRight()
    elseif(currentDir == north) then
	    turtle.turnLeft()
	end
	currentDir = west;
end

function forward()
	DigMoveForward()

    if(currentDir == east) then
	    x = x + 1
    elseif(currentDir == north) then
	    y = y - 1
   elseif(currentDir == south) then
	    y = y + 1
    elseif(currentDir == west) then
	    x = x - 1
	end
end

function goWest()
	faceWest()
	forward()
end

function goEast()
	faceEast()
	forward()
end

function goNorth()
	faceNorth()
	forward()
end

function goSouth()
	faceSouth()
	forward()
end

function goUp()
	DigMoveUp()

end

function goDown()
	DigMoveDown()

end



function doLeftRight()
	turtle.turnLeft()
	local doit = true
	for i = ignoreStart, 16 do
		turtle.select(i)
		if(not turtle.compare()) then
			doit = false
		end
	end
	if doit then
		dig.forward()
	end
	turtle.turnRight()
	turtle.turnRight()
	doit = true
	for i = ignoreStart, 16 do
		turtle.select(i)
		if(turtle.compare()) then
			doit = false
		end

	end
	if doit then
		dig.forward()
	end
	doit = true
	for i = ignoreStart, 16 do
		turtle.select(i)
		if(turtle.compareUp()) then
			doit = false
		end

	end
	if doit then
		dig.up()
	end

	doit = true
	for i = ignoreStart, 16 do
		turtle.select(i)
		if(turtle.compareDown()) then
			doit = false
		end
	end
	if doit then
		dig.down()
	end
	turtle.turnLeft()

end

function doDump()
	for i = ignoreStart, 16 do
		dump(i)
	end
end

function dump(index)

	local count = turtle.getItemCount(index)

	turtle.select(index)
	if count > 1 then
		turtle.dropUp(count - 1)
	end
end

local function readLines(sPath)
  local file = fs.open(sPath, "r") -- open the file
  if file then -- check if it's open
    local tLines = {} -- table to store the lines
    local sLine = file.readLine() -- read a line from the file
    while sLine do -- while there's a line in the file
          table.insert(tLines, sLine) -- add it to the table
          sLine = file.readLine() -- get the next line
    end
    file.close() -- close the file
    return tLines -- return the table with the lines
  end
  return nil -- there was an error opening the file, return nil to let the user know
end

local function writeLines(sPath, tLines)
  local file = fs.open(sPath, "w") -- open the file
  if file then -- check if the file is open
    for _, sLine in ipairs(tLines) do -- for each line in the table
          file.writeLine(sLine) -- write the line
    end
    file.close() -- close the file
  end
end

function filereadline(filename, line)
  local tLines = readLines(filename) -- read the lines from the file (using the previous functions)
  if not tLines then -- if there was an error
    return nil -- return nil/error
  end
  return tLines[line] -- return the line
end

function filewriteline(filename, line, text)
  local tLines = readLines(filename) -- read the lines from the file (using the previous functions)
  if tLines then -- if there was no error
    tLines[line] = text -- set the line
    writeLines(filename, tLines) -- write the lines back to the file (using the previous functions)
  end
end

function goto(tx, ty, tz)

	local dx = tx - x
	local dy = ty - y
	local dz = tz - z

--	if dz ~= 0 then
		while z ~= tz do
			print(z .. " - " .. tz)
			if z > tz then
				goDown()
			else
				goUp()
			end
			if(not testFuel()) then
				returnToRefuel()
			end
		end
--	end
--	if dx ~= 0 then
		while x ~= tx do
			print(x .. " - " .. tx)
			if x > tx then
				goWest()
			else
				goEast()
			end
			if(not testFuel()) then
				returnToRefuel()
			end
		end
--	end
--	if dy ~= 0 then
		while y ~= ty do
			print(y .. " - " .. ty)
			if y < ty then
				goSouth()
			else
				goNorth()
			end
			if(not testFuel()) then
				returnToRefuel()
			end
		end
--	end

end

function gotoreverse(tx, ty, tz)

	local dx = tx - x
	local dy = ty - y
	local dz = tz - z
--	if dx ~= 0 then
		while x ~= tx do
			print(x .. " - " .. tx)
			if x > tx then
				goWest()
			else
				goEast()
			end
			if(not testFuel()) then
				returnToRefuel()
			end
			doDump()
		end
--	end
--	if dy ~= 0 then
		while y ~= ty do
			print(y .. " - " .. ty)
			if y < ty then
				goSouth()
			else
				goNorth()
			end
			if(not testFuel()) then
				returnToRefuel()
			end
			doDump()
		end
--	end

--	if dz ~= 0 then
		while z ~= tz do
			print(z .. " - " .. tz)
			if z > tz then
				goDown()
			else
				goUp()
			end
			if(not testFuel()) then
				returnToRefuel()
			end
			doDump()
		end
--	end

end

function testFuel()
    local dist = math.abs(startx - x) + math.abs(starty - y) + math.abs(startz - z);

	local fuel = estimateFuel()
	print("Estimated distance: "..dist)
	if(fuel < dist + 10) then
		return false
	end

	return true
end

function estimateFuel()
	local a = turtle.getItemCount(1)
	local b = turtle.getItemCount(2)
	local c = turtle.getItemCount(3)

	local steps = (a + b + c) * 96
	print("Estimated fuel steps: "..(steps + turtle.getFuelLevel()))
	return steps + turtle.getFuelLevel();

end

function returnToRefuel()
	local ox = x
	local oy = y
	local oz = z
	goto(startx, starty, startz)
--	refuelStation();
	goto(ox, oy, oz)
end

function refuelStation()
	faceSouth()
	turtle.select(1)
	turtle.suck()
	turtle.refuel()
	turtle.suck()
	turtle.refuel()
	turtle.suck()
	turtle.refuel()
	turtle.suck()
	turtle.select(yieldStart)
	faceNorth()
end


for i = 0, 100 do
	gotoreverse (0, 0, startz)
	refuelStation()
	local c = 0;
	for y = 0, -64, -1 do
		goto (startx+(i*5), y, 5)
		dig.up()
		c = c + 1
		if c > 2 then
			fx = x
			fy = y
			fz = z
			for b = 1, 4 do
				goto (x+1, y, z)
				doLeftRight()
				goto (x, y, z+1)
				doLeftRight()
				goto (x, y, z-1)
			end
			goto(fx, fy, fz)
			c = 0
		end
	end
end