Excavate+

local tArgs = { ... }
local excludeItems = {}
if #tArgs < 1 then
    print("Usage: excavate <diameter> [<excluded items>]")
    return
elseif #tArgs > 1 then
    if tArgs[2] == "None" then
        excludeItems = nil
    else
        for i = 2, #tArgs do
            excludeItems[tArgs[i]] = true
        end
    end
else
    print('Using default exclude list (Cobblestone, Dirt, Granite, Gravel)...')
    excludeItems = {
        ["minecraft:cobblestone"] = true,
        ["minecraft:dirt"] = true,
        ["chisel:granite"] = true,
        ["minecraft:gravel"] = true,
        ["chisel:diorite"] = true,
	    ["chisel:limestone"] = true,
	    ["chisel:marble"] = true
    }
end

-- Mine in a quarry pattern until we hit something we can't dig
local size = tonumber(tArgs[1])
if size < 1 then
    print("Excavate diameter must be positive")
    return
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

-- Empty inventory and update count of total items
local function unload(_bKeepOneFuelStack)
    print("Unloading items...")
    for n = 1, 16 do
        local nCount = turtle.getItemCount(n)
        if nCount > 0 then
            turtle.select(n)
            if _bKeepOneFuelStack and turtle.refuel(0) then
                _bKeepOneFuelStack = false
            else
                turtle.drop()
                unloaded = unloaded + nCount
            end
        end
    end
    collected = 0
    turtle.select(1)
end

-- Return to surface, call unload and refuel if necessary before returning to previous position
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 = 2 * (x + y + z + 1)
    if not refuel(fuelNeeded) then
        unload(true)
        print("Waiting for fuel")
        while not refuel(fuelNeeded) do
            os.pullEvent("turtle_inventory")
        end
    else
        unload(true)
    end

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

-- Check if inventory full, update count of collected items
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
        elseif excludeItems[turtle.getItemDetail(n).name] then
            local nPreviousSlot = turtle.getSelectedSlot()
            turtle.select(n)
            turtle.drop()
            turtle.select(nPreviousSlot)
            bFull = false
            nCount = 0
        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

-- Check fuel level, refill if necessary and possible
function refuel(amount)
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" then
        return true
    end

    local needed = amount or (xPos + zPos + depth + 2) -- +2 = move 1 and back
    if fuelLevel < needed then
        for n = 1, 16 do
            if turtle.getItemCount(n) > 0 then
                turtle.select(n)
                if turtle.refuel(1) then
                    while turtle.getItemCount() > 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

-- Attempt to dig/attack in front of the turtle
local function dig()
    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(0.5)
    end

    return true
end

-- Attempt to dig/attack below the turtle
local function digDown()
    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(0.5)
    end
    return true
end

-- Attempt to dig/attack above the turtle
local function digUp()
    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(0.5)
    end

    return true
end

-- Try moving the turtle forwards, digging above and below the turtle prior to moving
local function tryForwards()
    if not refuel() then
        print("Not enough Fuel")
        returnSupplies()
    end

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

    if depth ~= 0 then
        digUp()
    end
    digDown()

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

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

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

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

    return true
end

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

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

-- Go to coordinates x,y,z facing the direction indicated by xd or xz
-- Coordinates are in a Cartesian coordinate system where the turtle's starting point is the origin
function goTo(x, y, z, xd, zd)
    while depth > y do
        if turtle.up() then
            depth = depth - 1
        else
            digUp()
        end
    end

    if xPos > x then
        while xDir ~= -1 do
            if zDir == -1 then
                turnRight()
            else
                turnLeft()
            end
        end
        while xPos > x do
            tryForwards()
        end
    elseif xPos < x then
        while xDir ~= 1 do
            if zDir == 1 then
                turnRight()
            else
                turnLeft()
            end
        end
        while xPos < x do
            tryForwards()
        end
    end

    if zPos > z then
        while zDir ~= -1 do
            turnLeft()
        end
        while zPos > z do
            tryForwards()
        end
    elseif zPos < z then
        while zDir ~= 1 do
            turnLeft()
        end
        while zPos < z do
            tryForwards()
        end
    end

    while depth < y do
        if turtle.down() then
            depth = depth + 1
        else
            digDown()
        end
    end

    -- TODO: Optimize to avoid useless turns
    while zDir ~= zd or xDir ~= xd do
        turnLeft()
    end
end

if not refuel() then
    print("Out of Fuel")
    while not refuel() do
        os.pullEvent("turtle_inventory")
    end
end

print("Excavating...")

local reseal = false
turtle.select(1)
if turtle.digDown() then
    reseal = true
end

local alternate = 0
local done = false

-- Blocks above the turtle will also be dug out so begin one block lower
if not tryDown() then
    done = true
end
-- Additional blocks are dug when calling tryForwards so for this instance, dig the bottom block manually
digDown()
while not done do
    for n = 1, size do
        for m = 1, size - 1 do
            if not tryForwards() then
                done = true
                break
            end
        end
        if done then
            break
        end
        if n < size then
            if math.fmod(n + alternate, 2) == 0 then
                turnLeft()
                if not tryForwards() then
                    done = true
                    break
                end
                turnLeft()
            else
                turnRight()
                if not tryForwards() then
                    done = true
                    break
                end
                turnRight()
            end
        end
    end
    if done then
        break
    end

    if size > 1 then
        if math.fmod(size, 2) == 0 then
            turnRight()
        else
            if alternate == 0 then
                turnLeft()
            else
                turnRight()
            end
            alternate = 1 - alternate
        end
    end

    for n = 1, 3 do
        if not tryDown() then
            done = true
            break
        end
    end
    -- Additional blocks are dug when calling tryForwards so for this instance, dig the bottom block manually
    digDown()
end

print("Returning to surface...")

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

-- Seal the hole
if reseal then
    turtle.placeDown()
end

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