Turtle miner 2

function checkRot(inDir)
    for i = 1, 4 do
        if rotation[i] == inDir then
            return i
        end
    end
    return false
end

function turnAroundDir(numDir)
    if numDir <= 2 then
        return numDir + 2
    else
        return numDir - 2
    end
    return false
end

local rotation = {"north", "east", "south", "west"}

if not fs.exists("/.persistance") then
    print("Persistant variable folder not found. \n Creating...")
    fs.makeDir("/.persistance")
    print("Created")
end

function store(sName, stuff)
    local filePath = fs.combine("/.persistance", sName)
    if stuff == nil then
        return fs.delete(filePath)
    end
    local handle = fs.open(filePath, "w")
    handle.write(textutils.serialize(stuff))
    handle.close()
end

function pull(sName)
    local filePath = fs.combine("/.persistance", sName)
    local handle = fs.open(filePath, "r")
    local stuff = handle.readAll()
    handle.close()
    return textutils.unserialize(stuff)
end

if not fs.open(".persistance/turtleCoords", "r") then
    coords = { }
    coords["x"] = 0
    coords["y"] = 0
    coords["z"] = 0
    store("turtleCoords", coords)
else
    coords = pull("turtleCoords")
end
if not fs.open(".persistance/turtleDir", "r") then
    direction = "north"
    store("turtleDir", direction)
else
    direction = pull("turtleDir")
end

if coords["x"] == 0 and coords["z"] == 0 and coords["y"] == 0 then
    local originalDir = direction
    local behindDir = turnAroundDir(checkRot(direction))
    faceTo(behindDir)
    local success, idtable = turtle.inspectDown()
    if success and idtable.name == "minecraft:chest" then
        print("Home chest found")
        faceTo(originalDir)
    else
        error("Need chest behind turtle to start work!")
        faceTo(originalDir)
    end
end

function mineAround()
    if turtle.inspectDown() then
        turtle.digDown()
    end
    if turtle.inspectUp() then
        turtle.digUp()
    end
    local returnLoc = direction
    local numReverseLoc = turnAroundDir(checkRot(direction))
    for f = 1, 4 do
        local f2 = turnAroundDir(f)
        if f2 ~= numReverseLoc then
            faceTo(rotation[f])
            local success, idtable = turtle.inspect()
            if success and idtable.name ~= "minecraft:chest" then
                turtle.dig()
            end
            faceTo(returnLoc)
        end
    end
end

function testForInv()
    local invSpace = 16
    for i = 1, 16 do
        turtle.select(i)
        if turtle.getItemDetail() then
            invSpace = invSpace - 1
        end
    end
    if invSpace <= 4 then
        return false
    else
        return true
    end
end

function forward(dirToGo)
    if dirToGo == "north" then
        coords["z"] = coords["z"] + 1
        store("turtleCoords", coords)
        if direction == "north" then
            turtle.forward()
        elseif direction == "south" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "west" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "east" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "north"
        store("turtleDir", direction)
    elseif dirToGo == "east" then
        coords["x"] = coords["x"] + 1
        store("turtleCoords", coords)
        if direction == "north" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "west" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "east" then
            turtle.forward()
        elseif direction == "south" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "east"
        store("turtleDir", direction)
    elseif dirToGo == "south" then
        coords["z"] = coords["z"] - 1
        store("turtleCoords", coords)
        if direction == "south" then
            turtle.forward()
        elseif direction == "north" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "east" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "west" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "south"
        store("turtleDir", direction)
    elseif dirToGo == "west" then
        coords["x"] = coords["x"] - 1
        store("turtleCoords", coords)
        if direction == "west" then
            turtle.forward()
        elseif direction == "east" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "south" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "north" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "west"
        store("turtleDir", direction)
    end
    if dirToGo == "up" then
        coords["y"] = coords["y"] + 1
        store("turtleCoords", coords)
        turtle.up()
    elseif dirToGo == "down" then
        coords["y"] = coords["y"] - 1
        store("turtleCoords", coords)
        turtle.down()
    end
    --fuelTestCount()
end

function moveTo(x2, y2, z2)
    if x2 > coords["x"] then
        local x3 = x2 - coords["x"]
        for f = 1, x3 do
            forward("east")
        end
    elseif x2 < coords["x"] then
        local x3 = math.abs((math.abs(x2)) - coords["x"])
        for f = 1, x3 do
            forward("west")
        end
    end
    if y2 > coords["y"] then
        local y3 = y2 - coords["y"]
        for g = 1, y3 do
            forward("up")
        end
    elseif y2 < coords["y"] then
        local y3 = math.abs((math.abs(y2)) - coords["y"])
        for g = 1, y3 do
            forward("down")
        end
    end
    if z2 > coords["z"] then
        local z3 = z2 - coords["z"]
        for h = 1, z3 do
            forward("up")
        end
    elseif z2 < coords["z"] then
        local z3 = math.abs(math.abs(z2) - coords["z"])
        for h = 1, z3 do
            forward("down")
        end
    end
end

function faceTo(dirToTurn)
    if dirToTurn == "north" then
        if direction == "south" then
            for i = 1, 2 do turtle.turnRight() end
        elseif direction == "east" then
            turtle.turnLeft()
        elseif direction == "west" then
            turtle.turnRight()
        end
        direction = "north"
        store("turtleDir", direction)
    elseif dirToTurn == "south" then
        if direction == "north" then
            for i = 1, 2 do turtle.turnRight() end
        elseif direction == "east" then
            turtle.turnRight()
        elseif direction == "west" then
            turtle.turnLeft()
        end
        direction = "south"
        store("turtleDir", direction)
    elseif dirToTurn == "east" then
        if direction == "west" then
            for i = 1, 2 do turtle.turnRight() end
        elseif direction == "north" then
            turtle.turnRight()
        elseif direction == "south" then
            turtle.turnLeft()
        end
        direction = "east"
        store("turtleDir", direction)
    elseif dirToTurn == "west" then
        if direction == "east" then
            for i = 1, 2 do turtle.turnRight() end
        elseif direction == "north" then
            turtle.turnLeft()
        elseif direction == "south" then
            turtle.turnRight()
        end
        direction = "west"
        store("turtleDir", direction)
    end
end

function dropOff()
    moveTo(0,0,0)
    for i = 1, 16 do
        turtle.select(i)
        turtle.dropDown()
    end
    turtle.select(1)
end

function mine()
    for x = 0, 15 do
        for z = 1, 15 do
            for y = 0, -4, -1 do
                if not testForInv() then dropOff() end
                mineAround()
                moveto(x,y,z)
            end
        end
    end
end