turtle 3x1 tunnel

local tArgs = { ... }
if #tArgs ~= 2 then
    print( "Usage: t <length> <place torches y/n>" )

    return
end

-- Mine 3x1 tunnel until we hit end
local size = tonumber( tArgs[1] )
if size < 1 then
    print( "Excavate diameter must be positive" )
    return
end

local placeTorches = false
local slotStart = 1

if string.lower(tArgs[2]) == 'y' then
    placeTorches = true
    slotStart = 2
end

local depth = 0
local unloaded = 0
local collected = 0

local xPos,zPos = 0,0
local xDir,zDir = 0,1

local goTo -- Filled in further down
local refuel -- Filled in further down


local function unload()
    print( "Unloading items..." )
    for n=slotStart,16 do
        unloaded = unloaded + turtle.getItemCount(n)
        turtle.select(n)
        turtle.drop()
    end
    collected = 0
    turtle.select(1)
end

local function returnSupplies()
    local x,y,z,xd,zd = xPos,depth,zPos,xDir,zDir
    print( "Returning to surface..." )
    goTo( 0,0,0,0,-1 )

    local fuelNeeded = x+y+z + x+y+z + 1
    if not refuel( fuelNeeded ) then
        unload()
        print( "Waiting for fuel" )
        while not refuel( fuelNeeded ) do
            sleep(1)
        end
    else
        unload()
    end


    while not torchCheck() do
        print( "Waiting for torches" )
        while not torchCheck() do
            sleep(1)
        end
    end

    print( "Resuming mining..." )
    goTo( x,y,z,xd,zd )
end

local function collect()
    local bFull = true
    local nTotalItems = 0
    for n=1,16 do
        local nCount = turtle.getItemCount(n)
        if nCount == 0 then
            bFull = false
        end
        nTotalItems = nTotalItems + nCount
    end

    if nTotalItems > collected then
        collected = nTotalItems
        if math.fmod(collected + unloaded, 50) == 0 then
            print( "Mined "..(collected + unloaded).." items." )
        end
    end

    if bFull then
        print( "No empty slots left." )
        return false
    end
    return true
end

function torchCheck()
    if placeTorches  then
        if turtle.getItemCount(1) > 0 then
            return true
        else
            return false
        end
    else
        return true
    end

end

function refuel( ammount )
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" then
        return true
    end

    local needed = ammount or (xPos + zPos + depth + 1)
    if turtle.getFuelLevel() < needed then
        local fueled = false
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                turtle.select(n)
                if turtle.refuel(1) then
                    while turtle.getItemCount(n) > 0 and turtle.getFuelLevel() < needed do
                        turtle.refuel(1)
                    end
                    if turtle.getFuelLevel() >= needed then
                        turtle.select(1)
                        return true
                    end
                end
            end
        end
        turtle.select(1)
        return false
    end

    return true
end

local function tryDigUp()
    --Dig Up
    while turtle.detectUp() do
        if turtle.detectUp() then
            if turtle.digUp() then
                if not collect() then
                    returnSupplies()
                end
            else
                return false
            end
        elseif turtle.attackUp() then
            if not collect() then
                returnSupplies()
            end
        else
            sleep( 0.1 )
        end
    end
    return true
end

local function tryDigUp()
    --Dig Up
    while turtle.detectUp() do
        if turtle.detectUp() then
            if turtle.digUp() then
                if not collect() then
                    returnSupplies()
                end
            else
                return false
            end
        elseif turtle.attackUp() then
            if not collect() then
                returnSupplies()
            end
        else
            sleep( 0.1 )
        end
    end
    return true
end

local function tryDigDown()
    --Dig Down
    while turtle.detectDown() do
        if turtle.detectDown() then
            if turtle.digDown() then
                if not collect() then
                    returnSupplies()
                end
            else
                return false
            end
        elseif turtle.attackDown() then
            if not collect() then
                returnSupplies()
            end
        else
            sleep( 0.1 )
        end
    end
    return true
end

local function tryDigForward()
    while turtle.detect() do
        if turtle.detect() then
            if turtle.dig() then
                if not collect() then
                    returnSupplies()
                end

            else
                return false
            end
        elseif turtle.attack() then
            if not collect() then
                returnSupplies()
            end
        else
            sleep( 0.1 )
        end
    end
    return true
end


local function tryForwards()
    if not refuel() then
        print( "Not enough Fuel" )
        returnSupplies()
    end

    tryDigForward()

    while not turtle.forward() do
        if not tryDigForward() then
            return false
        end
    end

    xPos = xPos + xDir
    zPos = zPos + zDir
    return true
end

local function tryUp()
    if not refuel() then
        print( "Not enough Fuel" )
        returnSupplies()
    end

    tryDigUp()

    while not turtle.up() do
        if not tryDigUp() then
            return false
        end
    end

    depth = depth - 1
    if math.fmod( depth, 10 ) == 0 then
        print( "Descended "..depth.." metres." )
    end
    return true
end

local function tryDown()
    if not refuel() then
        print( "Not enough Fuel" )
        returnSupplies()
    end

    tryDigDown()
    while not turtle.down() do
        if not tryDigDown() then
            return false
        end
    end

    --print("Moved down one");

    depth = depth + 1
    if math.fmod( depth, 10 ) == 0 then
        print( "Descended "..depth.." metres." )
    end
    return true
end

local function turnLeft()
    turtle.turnLeft()
    xDir, zDir = -zDir, xDir
end

local function turnRight()
    turtle.turnRight()
    xDir, zDir = zDir, -xDir
end

local function placeTorch()
    turtle.select(1)
    turtle.placeDown()
end

function goTo( x, y, z, xd, zd )
    while depth > y do
        if turtle.up() then
            depth = depth - 1
        elseif turtle.digUp() or turtle.attackUp() then
            collect()
        else
            sleep( 0.5 )
        end
    end

    if xPos > x then
        while xDir ~= -1 do
            turnLeft()
        end
        while xPos > x do
            if turtle.forward() then
                xPos = xPos - 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    elseif xPos < x then
        while xDir ~= 1 do
            turnLeft()
        end
        while xPos < x do
            if turtle.forward() then
                xPos = xPos + 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    end

    if zPos > z then
        while zDir ~= -1 do
            turnLeft()
        end
        while zPos > z do
            if turtle.forward() then
                zPos = zPos - 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    elseif zPos < z then
        while zDir ~= 1 do
            turnLeft()
        end
        while zPos < z do
            if turtle.forward() then
                zPos = zPos + 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    end

    while depth < y do
        if turtle.down() then
            depth = depth + 1
        elseif turtle.digDown() or turtle.attackDown() then
            collect()
        else
            sleep( 0.5 )
        end
    end

    while zDir ~= zd or xDir ~= xd do
        turnLeft()
    end
end

if not refuel() then
    print( "Out of Fuel" )
    return
end

print( "Tunneling..." )

turtle.select(1)

local alternate = 0

if placeTorches then
    while not torchCheck() do
        print( "Waiting for torches" )
        while not torchCheck() do
            sleep(1)
        end
    end
end

tryUp()
tryDigUp()

for n=1,size do
    if n<size then
        tryForwards()
        tryDigUp()
        tryDigDown()
        if placeTorches then
            if math.fmod(n+9,10) == 0 then
                placeTorch()
            end
        end
    else
        print( "Tunnel complete." )
    end

end

if placeTorches then
    placeTorch()
end



print( "Returning to start..." )

-- Return to where we started
goTo( 0,0,0,0,-1 )
unload()
goTo( 0,0,0,0,1 )



print( "Mined "..(collected + unloaded).." items total." )