Mine

--TODO continue after chunk reload

function printUsage()
    print( "Usage:" )
    print( "Mine <forward> <right> <down>" )
end

tArgs = { ... }
if #tArgs ~= 3 then
    printUsage()
    return
elseif tonumber(tArgs[1]) == nil or tonumber(tArgs[2]) == nil or tonumber(tArgs[3]) == nil then
    printUsage()
    return
end

dropped = 0
attacked = 0
turn = 0
mined = 0
deep = 3
slot = 2
turtle.select(slot)
A = tonumber(tArgs[1])
B = tonumber(tArgs[2])
C = tonumber(tArgs[3])

if A < 1 or A > 256 then
    print("forward must be between 1 and 256")
    error()
elseif B < 1 or B > 256 then
    print("right must be between 1 and 256")
    error()
elseif C < 1 or C > 256 then
    print("down must be between 1 and 256")
    error()
end

forward = A - 1
right = B - 1
down = math.floor(C / 3) - 1
downRemaining = math.fmod(C,3)

if down < 0 then
    down = 0
    downRemaining = 0
end

if C < 3 then
    oneLayer = 0
else
    oneLayer = C - 3
end

function fuel()
    fuelNeeded = (A * B - 1) * math.ceil(C / 3) + oneLayer
    fuelLevel = turtle.getFuelLevel()
    fuelDifference = fuelNeeded - fuelLevel
    fuelCoal = math.ceil(fuelDifference / 80)
    if fuelLevel >= fuelNeeded then
        print("*Fuel usage: ".. fuelNeeded .." out of ".. fuelLevel .."")
        print("*Enough fuel to proceed")
    else
        print("*Need ".. fuelDifference .." more fuel (".. fuelCoal .." Coal)")
        while fuelNeeded > fuelLevel do
            C = C - 1
            if C < 3 then
                oneLayer = 0
            else
                oneLayer = C - 3
            end
        fuelNeeded = (A * B - 1) * math.ceil(C / 3) + oneLayer
        end
        print("*Max area with current fuel: ".. A .." ".. B .." ".. C .."")
        print("*Shutting Down...")
        error()
    end
end

fuel()
print("'Put an enderchest in slot 1'")
print("'Turtle will mine forward, right, down'")
print("'Type in anything to start'")

io.read()

function full()
    if turtle.getItemCount(16) > 0 then
        dropOff()
    end
end

function dropOff()
    turtle.select(1)
    while turtle.placeUp() == false do
        if turtle.digUp() == false then
            turtle.attackUp()
        end
    end
    turtle.select(2)
    slot = 2
    for e=1, 15 do
        turtle.select(slot)
        turtle.dropUp()
        slot = slot + 1
    end
    turtle.select(1)
    turtle.digUp()
    dropped = dropped + 1
end

function mine()
    full()
    while turtle.forward() == false do
        if turtle.dig() == false then
            turtle.attack()
            mined = mined - 1
            attacked = attacked + 1
        end
        mined = mined + 1
    end

    full()
    if turtle.digDown() == true then
        mined = mined + 1
    end
    full()
    if turtle.digUp() == true then
        mined = mined + 1
    end
end

function line()
    for x=1, forward do
        mine()
    end
end

function square()
    for y=1, right do
        line()
        if turn == 0 then
            turtle.turnRight()
            mine()
            turtle.turnRight()
            turn = turn + 1
        else
            turtle.turnLeft()
            mine()
            turtle.turnLeft()
            turn = turn - 1
        end
    end
    line()
end

function cube()
    full()
    if turtle.digDown() == true then
        mined = mined + 1
    end
    full()
    if turtle.digUp() == true then
        mined = mined + 1
    end

    square()
    for z=1, down do
        digCube()
    end
    if downRemaining ~= 0 then
        deep = downRemaining
        digCube()
    end
end

function digCube()
    for d=1, deep do
        while turtle.down() == false do
            if turtle.digDown() == false then
                turtle.attackDown()
                mined = mined - 1
                attacked = attacked + 1
            end
            mined = mined + 1
        end
    end
    full()
    if turtle.digDown() == true then
        mined = mined + 1
    end
    turtle.turnRight()
    turtle.turnRight()
    square()
end

cube()
dropOff()
print ("mined ".. mined .." blocks")
print ("attacked ".. attacked .." times")
print ("dropped off ".. dropped .." times")