Autominer

lavaslot = 15
chestslot = 16

comingBack = false
length = 5

x,z,orient = 0,0,0

function start()
    if loadLoc() then
        checkChest()
        fixOrient()
        isComingBack()
    end
end

function checkChest()
    if turtle.getItemCount(chestslot) == 0 then
        turtle.select(chestslot)
        turtle.dig()
    end
    turtle.select(1)
end

function fixOrient()
    if orient == 1 then
        if x == length and isEven(z) == false then
            right()
        elseif x == length and isEven(z) then
            print("hep")
            forward()
            right()
        end
        if x == 0 and isEven(z) == false then
            forward()
            left()
        elseif x == 0 and isEven(z) then
            left()
        end
    end
end

function isComingBack()
    if isEven(z) then
        comingBack = false
    else
        comingBack = true
    end
end

function saveLoc()
    h = fs.open("location.dat","w")
    h.writeLine(tostring(x))
    h.writeLine(tostring(z))
    h.writeLine(tostring(orient))
    h.close()
end

function loadLoc()
    if fs.exists("location.dat") then
        h = fs.open("location.dat","r")
        x = tonumber(h.readLine())
        z = tonumber(h.readLine())
        orient = tonumber(h.readLine())
        h.close()
        return true
    else
        return false
    end
end

function isEven(number)
    if number%2 == 0 then
        return true
    else
        return false
    end
end

function grabLava()
    turtle.select(lavaslot)

    if turtle.place() then
        if turtle.refuel() == false then
            turtle.place()
        end
    end

    if turtle.placeUp() then
        if turtle.refuel() == false then
            turtle.placeUp()
        end
    end

    if turtle.placeDown() then
        if turtle.refuel() == false then
            turtle.placeDown()
        end
    end
    turtle.select(1)
end

function dig()
    grabLava()
    turtle.digUp()
    turtle.digDown()
end

--[[
function forward()
    while turtle.forward() == false do
        turtle.dig()
        sleep(0)
    end
    saveLoc()
    if orient == 0 then
        x = x+1
    elseif orient == 1 then
        z = z+1
    elseif orient == 2 then
        x = x-1
    elseif orient == 3 then
        z = z-1
    end
end
--]]

function forward()
    local cont = true
    turtle.dig()

    while cont do
        if orient == 0 then
            x = x+1
        elseif orient == 1 then
            z = z+1
        elseif orient == 2 then
            x = x-1
        elseif orient == 3 then
            z = z-1
        end
        saveLoc()
        if turtle.forward() then
            cont = false
        else
            turtle.dig()
            if orient == 0 then
                x = x-1
            elseif orient == 1 then
                z = z-1
            elseif orient == 2 then
                x = x+1
            elseif orient == 3 then
                z = z+1
            end
            saveLoc()
            sleep(1)
        end
    end
end

function right()
    if orient == 3 then
        orient = 0
    else
        orient = orient+1
    end
    saveLoc()
    turtle.turnRight()
end

function left()
    if orient == 0 then
        orient = 3
    else
        orient = orient-1
    end
    saveLoc()
    turtle.turnLeft()
end

function dump()
    if turtle.getItemCount(14) > 0 then
        turtle.select(chestslot)
        while turtle.place() == false do
            turtle.dig()
            sleep(0)
        end
        for i = 1, 14 do
            turtle.select(i)
            while turtle.drop() == false and turtle.getItemCount(i) > 0 do
                sleep(0)
            end
        end
        turtle.select(chestslot)
        while turtle.dig() == false do
            sleep(0)
        end
        turtle.select(1)
    end
end

function move()
    if comingBack then
        if x > 0 then
            forward()
        else
            left()
            forward()
            left()
            comingBack = false
        end
    else
        if x < length then
            forward()
        else
            right()
            forward()
            right()
            comingBack = true
        end
    end
end


start()
while true do
    dig()
    dump()
    move()
    sleep(0)
end