ManicMiner2

print("How deep?:")
local depth = tonumber(read())
print("How wide?:")
local width = tonumber(read())
print("How long?:")
local length = tonumber(read())

local complete = 0
local curX = 1
local curY = 1
local curZ = 1
local dir = 1

local lastX = 1
local lastY = 1
local lastZ = 1

local check1 = true
local check2 = true
local check3 = true
local check4 = true

local debug = true

function turnLeft()
    turtle.turnLeft()
    dir = dir - 1
    if dir < 1 then dir = 4 end

    if debug then
        if dir == 1 then print("Turned left, facing forward") end
        if dir == 2 then print("Turned left, facing right") end
        if dir == 3 then print("Turned left, facing backward") end
        if dir == 4 then print("Turned left, facing left") end
    end
end

function turnRight()
    turtle.turnRight()
    dir = dir + 1
    if dir > 4 then dir = 1 end

    if debug == 1 then
        if dir == 1 then print("Turned right, facing forward") end
        if dir == 2 then print("Turned right, facing right") end
        if dir == 3 then print("Turned right, facing backward") end
        if dir == 4 then print("Turned right, facing left") end
    end
end

function moveDown()
    if debug then print("Moving down") end

    if curZ > depth then
        if debug then print("Reached required depth.") end
        return false
    end
    if not turtle.down() then
        if debug then print("Failed to move down, blocked.") end
        return false
    end

    curZ = curZ + 1
    if debug then print("Moved down, now at level "..curZ..".") end
    return true
end

function moveUp()
    if debug then print("Moving up") end

    if curZ <= 1 then
        if debug then print("Surfaced.") end
        return false
    end
    if not turtle.up() then
        if debug then print("Failed to move up, blocked.") end
        return false
    end

    curZ = curZ - 1
    if debug then print("Moved up, now at level "..curZ..".") end
    return true
end

function moveForward()
    if curX == 1 and dir == 3 then
        if debug then print("Failed to move forward, mining limit reached.") end
        return false
    end
    if curX == length and dir == 1 then
        if debug then print("Failed to move forward, mining limit reached.") end
        return false
    end
    if curY == 1 and dir == 4 then
        if debug then print("Failed to move forward, mining limit reached.") end
        return false
    end
    if curY == width and dir == 2 then
        if debug then print("Failed to move forward, mining limit reached.") end
        return false
    end

    if not turtle.forward() then
        if debug then print("Failed to move forward, blocked.") end
        return false
    end

    if dir == 1 then curX = curX + 1 end
    if dir == 2 then curY = curY + 1 end
    if dir == 3 then curX = curX - 1 end
    if dir == 4 then curY = curY - 1 end

    if debug then print(curX..","..curY.."(X,Y)") end
    return true
end

function nextLevel()
    if debug then print("Moving to next level") end
    if curX ~= 1 or curY ~= 1 or dir ~= 1 then
        -- Moving to 1,1 position
        while dir ~= 3 do turnRight() end
        while curX > 1 do moveForward() end
        turnRight()
        while curY > 1 do moveForward() end
        turnRight()
    end
    for d = 1, 3 do
        if turtle.detectDown() then
            if debug then print("Digging down") end
            if not turtle.digDown() then
                print("Failed to dig down, bedrock.")
                return false
            end
        end
        if debug then print("Moving down") end
        if not moveDown() then
            print("Failed to move down, blocked.")
            return false
        end
    end
    return true
end

function itemCheck()
    if debug then print("Checking available exclusions") end
    if turtle.getItemCount(1) == 0 then check1 = false end
    if turtle.getitemCount(2) == 0 then check2 = false end
    if turtle.getItemCount(3) == 0 then check3 = false end
    if turtle.getItemCount(4) == 0 then check4 = false end
end

function checkUp()
    if check1 then
        turtle.select(1)
        if turtle.compareUp() then return false end
    end
    if check2 then
        turtle.select(2)
        if turtle.compareUp() then return false end
    end
    if check3 then
        turtle.select(3)
        if turtle.compareUp() then return false end
    end
    if check4 then
        turtle.select(4)
        if turtle.compareUp() then return false end
    end
    return true
end

function checkDown()
    if check1 then
        turtle.select(1)
        if turtle.compareDown() then return false end
    end
    if check2 then
        turtle.select(2)
        if turtle.compareDown() then return false end
    end
    if check3 then
        turtle.select(3)
        if turtle.compareDown() then return false end
    end
    if check4 then
        turtle.select(4)
        if turtle.compareDown() then return false end
    end
    return true
end

function mine()
    if checkUp() then turtle.digUp() end
    if checkDown() then turtle.digDown() end
end

while complete == 0 do
    if not nextLevel() then
        complete = 1
    else
        for y = 1, width do
            for x = 1, length - 1 do
                mine()
                if turtle.detect() then turtle.dig() end
                moveForward()
            end
            mine()
            if y~= width then
                if dir == 1 then
                    turnRight()
                    turtle.dig()
                    moveForward()
                    turnRight()
                else
                    if dir == 3 then
                        turnLeft()
                        turtle.dig()
                        moveForward()
                        turnLeft()
                    end
                end
            end
        end
    end
end