args = { ... }

garbage = {
    "minecraft:cobblestone",
    "minecraft:dirt",
    "minecraft:gravel",
    "minecraft:diorite",
    "minecraft:andesite",
    "minecraft:granite",
    "chisel:marble",
}

function digForward()
    while turtle.detect() do
        turtle.dig()
    end
end

function digUp()
    while turtle.detectUp() do
        turtle.digUp()
    end
end

function digDown()
    while turtle.detectDown() do
        turtle.digDown()
    end
end

function forward(count)
    for i = 1, count do
        digForward(1)
        while not turtle.forward() do
            digForward(1)
            turtle.attack()
        end
    end
end

function up(count)
    for i = 1, count do
        digUp(1)
        while not turtle.up() do
            digUp(1)
            turtle.attackUp()
        end
    end
end

function down(count)
    for i = 1, count do
        digDown(1)
        while not turtle.down() do
            digDown(1)
            turtle.attackDown()
        end
    end
end

function turnLeft(count)
    for i = 1, count do
        turtle.turnLeft()
    end
end

function turnRight(count)
    for i = 1, count do
        turtle.turnRight()
    end
end

function dig3x3InFront()
    forward(1)
    turnLeft(1)
    for i = 1, 2 do
        digForward(1)
        up(1)
    end
    digForward(1)
    turnRight(2)
    for i = 1, 2 do
        digForward(1)
        down(1)
    end
    digForward(1)
    turnLeft(1)
end

function isGarbage(val)
    for index, value in ipairs(garbage) do
        if value == val then
            return true
        end
    end
    return false
end

function checkForAndDropGarbage()
    for i = 1, 16 do
        local data = turtle.getItemDetail(i)
        if data then
            if isGarbage(data.name) then
                turtle.select(i)
                turtle.drop()
            end
        end
    end
    turtle.select(1)
end

function digLoop(length)
    for i = 1, length do
        dig3x3InFront()
    end
    checkForAndDropGarbage()
    turtle.back()
    turnRight(1)
    forward(1)
    dig3x3InFront()
    dig3x3InFront()
    dig3x3InFront()
    turtle.back()
    turnRight(1)
    forward(1)
    for i = 1, length do
        dig3x3InFront()
    end
    checkForAndDropGarbage()
    turtle.back()
    turnLeft(1)
    forward(1)
    dig3x3InFront()
    dig3x3InFront()
    dig3x3InFront()
    turtle.back()
    turtle.turnLeft(1)
    forward(1)
end

function refuel()
    for i=1,16 do
        turtle.select(i);
        turtle.refuel()
    end
end

function dropAll()
    for i = 1, 16 do
        turtle.select(i)
        turtle.drop()
    end
    turtle.select(1)
end

if table.getn(args) ~= 2 then
    print("arguments 'width' and 'depth' expected (width is multiplied by 3)")
else
    local x = tonumber(args[1])
    local y = tonumber(args[2]) - 2
    for j = 1, x do
        digLoop(y)
        refuel()
        if turtle.getItemCount(10) > 0 then
            checkForAndDropGarbage()
            turnLeft(1)
            forward(6 * j)
            dropAll()
            turnLeft(2)
            forward(6 * j)
            turnLeft(1)
        end
    end
    checkForAndDropGarbage()
    turnLeft(1)
    forward(6 * x)
    dropAll()
    turnRight(1)
end