local tunnelLength = 100
local cycles = 0

local ENUM_ORES = {"ore", "uranium","coal", "iron", "copper", "silver", "ruby", "tin", "redstone", "emerald", "diamond", "lapis", "gold", "yellorite", "sapphire", "ruby", "galena"}

function work()
    while true do
        subIterator = 1
        while subIterator <= tunnelLength do
            if turtle.getFuelLevel() < 150 then
                detail = turtle.getItemDetail(1)
                detail = detail or {}

                if detail.name ~= "minecraft:coal" then
                    print("We're out of fuel :(")
                    os.sleep(10)
                end

                turtle.select(1)
                turtle.refuel(1)
            end

            if subIterator % 15 == 0 then
                turtle.back()
                turtle.select(2)
                turtle.placeDown()
                for k=2,16 do
                    itemDetail = turtle.getItemDetail(k)
                    if itemDetail ~= nil then
                        if not isAnOre(itemDetail) then
                            turtle.select(k)
                            turtle.drop()
                        elseif itemDetail.name == "minecraft:coal" then
						                     	turtle.select(k)
                            turtle.transferTo(1)
                        end
                    end
                end
            end


            forward(1)
            while followVein() do end
			up(1)
            while followVein() do end
			down(1)
			down(1)
			while followVein() do end
			up(1)
            subIterator = subIterator + 1
        end

        turtle.turnLeft()
        turtle.turnLeft()
        forward(tunnelLength)

        if cycles > 0 then
            turtle.turnLeft()
            forward((cycles * 2)+1)
            turtle.turnRight()
        end

        success,blockData = turtle.inspect()

        if not success then return false end
        --if blockData.name ~= "minecraft:chest" then return false end

        for k=2,16 do
            itemDetail = turtle.getItemDetail(k)
            if itemDetail ~= nil then
                if isAnOre(itemDetail) then
                    turtle.select(k)
                    turtle.drop()
                elseif itemDetail.name == "minecraft:coal" then
					turtle.select(k)
                    turtle.transferTo(1)
                end
            end
        end

        cycles = cycles + 1

  turtle.turnRight()
  for i=0,cycles*2 do
    forward(1)
    digUp(1)
    digDown(1)
  end
     turtle.turnRight()
    end
end

instructions = {}

function followVein()
    instructions = {}
    lastFound = 0
	oresFound = 0

    while true do
        if isBlockAnOre(turtle.inspect()) then
            forward(1)
            insertIntoTable("fwd")
            lastFound = 0
			oresFound = oresFound + 1
        elseif isBlockAnOre(turtle.inspectUp()) then
            up(1)
            insertIntoTable("up")
            lastFound = 0
			oresFound = oresFound + 1
        elseif isBlockAnOre(turtle.inspectDown()) then
            down(1)
            insertIntoTable("down")
            lastFound = 0
			oresFound = oresFound + 1
        else
   lastFound = lastFound + 1
			if lastFound == 1 then
				turtle.turnLeft()
				insertIntoTable("tl")
			elseif lastFound == 2 then
				turtle.turnRight()
				turtle.turnRight()
				insertIntoTable("tr")
				insertIntoTable("tr")
			else
				turtle.turnLeft()
				insertIntoTable("tl")
				break
			end
		end
    end

    for k,v in pairs(instructions) do
        print("Print: ["..k.."] Backtracking: "..v)
        if v == "fwd" then
            turtle.back()
        elseif v == "up" then
            down(1)
        elseif v == "down" then
            up(1)
        elseif v == "tr" then
            turtle.turnLeft()
        elseif v == "tl" then
			turtle.turnRight()
		end
    end

	return oresFound > 0
end


function insertIntoTable(dataString)

	if table.getn(instructions) == 0 then
		table.insert(instructions, 1, dataString)
		return
	end

	lastInstruction = instructions[1]

	if lastInstruction ~= nil
	and (lastInstruction == "up" and dataString == "down"
	or lastInstruction == "down"and dataString == "up"
	or lastInstruction == "tl" and dataString == "tr"
	or lastInstruction == "tr" and dataString == "tl") then
		table.remove(instructions, 1)
	else
		table.insert(instructions, 1, dataString)
	end

end

function isBlockAnOre(success, data)
    if not success then return false end

    print("Testing"..data.name)
    name = string.lower(data.name)
    for k,v in pairs(ENUM_ORES) do
        if string.find(name, v) then
            return true
        end
    end
end

function isAnOre(data)
    name = string.lower(data.name)
    for k,v in pairs(ENUM_ORES) do
        if string.find(name, v) then
            return true
        end
    end
end

function down(amount)
    for i=1,amount do
        while not turtle.down() do
            digDown()
        end
    end
end

function up(amount)
    for i=1,amount do
        while not turtle.up() do
            digUp()
        end
    end
end

function forward(amount)
    for i=1,amount do
        while not turtle.forward() do
            dig()
        end
    end
end

function digUp()
    while turtle.detectUp() do
        turtle.digUp()
        os.sleep(0.3)
    end
end

function digDown()
    while turtle.detectDown() do
        turtle.digDown()
        os.sleep(0.3)
    end
end

function dig()
    while turtle.detect() do
        turtle.dig()
        os.sleep(0.3)
    end
end

work()