smart quarry

-- things not to veinmine
local blacklist = {
    "minecraft:stone",
    "minecraft:dirt",
    "minecraft:diorite",
    "minecraft:andesite",
    "minecraft:granite",
    "minecraft:gravel",
    "quark:slate"
}

-- vars to identify the current pos relative to start point
local x = 0
local y = 0
local z = 0
local rotation = 0

-- params
local x_size, y_size, depth, increment = ...
x_size, y_size, depth, increment = tonumber(x_size), tonumber(y_size) - 1, tonumber(depth), tonumber(increment)


--this is mostly for gravel
local function better_forward()
    while not turtle.forward() do
        turtle.dig()
        turtle.attack()
    end
end

-- function that returns to start point
local function return_to_origin(up)
    --switch for when something is blocking its way
    local offset = false
    -- rotating it to face the starting wall
    if rotation ~= 2 then
        if rotation > 2 then
            repeat turtle.turnLeft() rotation = rotation - 1 until rotation == 2
        elseif rotation < 2 then
            repeat turtle.turnRight() rotation = rotation + 1 until rotation == 2
        end
    end
    -- moving it out of the way if theres a block in front of it
    if turtle.detect() and x ~= 0 then
        offset = true
        turtle.turnRight()
        better_forward()
        turtle.turnLeft()
    end
    -- returning to start
    for i = 1,y do
        better_forward()
    end
    turtle.turnRight()
    if offset then
        for i = 1,x-1 do
            better_forward()
        end
    else
        for i = 1,x do
            better_forward()
        end
    end
    --rotating back to 0
    turtle.turnRight()
    -- going back to the top if desired
    if up then
        for i = 1, z do
            turtle.up()
        end
    end
end



local function mine_sector()
    -- switch to alternate digging left/right
    local left = false
    for i = 1, x_size do
        --digging forward
        for i = 1, y_size do
            better_forward()
            if not left then y = y + 1
            else y = y - 1 end
        end
        --turning using switch
        if x ~= x_size - 1 then
            if not left then
                turtle.turnRight()
                better_forward()
                turtle.turnRight()
                left = true
                rotation = 2
                x = x + 1
            else
                turtle.turnLeft()
                better_forward()
                turtle.turnLeft()
                left = false
                rotation = 0
                x = x + 1
            end
        end
    end
end



local function dig_deeper()
    return_to_origin(false)
    for i = 1, increment do
        z = z + 1
        turtle.digDown()
        turtle.down()
        if z == depth then return end
    end
end

local function quarry()
    for i = 1,4 do
        dig_deeper()
        x,y,rotation = 0,0,0
        if z >= depth then break end
        mine_sector()
    end
    return_to_origin(true)
end

quarry()