-- chunkminer.lua
-- Mines a 16x16 chunk, auto-refuels from a chest behind it

-- === CONFIG ===
local LENGTH = 16
local WIDTH = 16

-- === STATE ===
local x, y, z = 0, 0, 0 -- Position tracking
local dir = 0 -- 0=north,1=east,2=south,3=west
local layer = 0

-- === HELPERS ===
local function turnLeft() turtle.turnLeft(); dir = (dir + 3) % 4 end
local function turnRight() turtle.turnRight(); dir = (dir + 1) % 4 end

local function forward()
while not turtle.forward() do
turtle.dig()
turtle.attack()
sleep(0.4)
end
if dir == 0 then z = z - 1
elseif dir == 1 then x = x + 1
elseif dir == 2 then z = z + 1
elseif dir == 3 then x = x - 1 end
end

local function up()
while not turtle.up() do
turtle.digUp()
turtle.attackUp()
sleep(0.4)
end
y = y + 1
end

local function down()
while not turtle.down() do
turtle.digDown()
turtle.attackDown()
sleep(0.4)
end
y = y - 1
end

-- === REFUELING ===
local function refuel()
if turtle.getFuelLevel() == "unlimited" then return end
if turtle.getFuelLevel() > 100 then return end

print("Refueling...")
local turned = false

-- Turn around to face the chest
turnLeft()
turnLeft()
turned = true

-- Try to suck fuel from chest
for slot = 1, 16 do
local detail = turtle.getItemDetail(slot)
if detail == nil then
turtle.suck()
detail = turtle.getItemDetail(slot)
end
if detail and turtle.refuel(1) then
while turtle.refuel(1) do end
end
end

if turned then
turnLeft()
turnLeft()
end

print("Fuel Level: " .. turtle.getFuelLevel())
end

-- === MINING ===
local function mineLayer()
for row = 1, WIDTH do
for col = 1, LENGTH - 1 do
refuel()
turtle.digDown()
turtle.dig()
forward()
end
if row < WIDTH then
if row % 2 == 1 then
turnRight()
turtle.dig()
forward()
turnRight()
else
turnLeft()
turtle.dig()
forward()
turnLeft()
end
end
end

-- Return to start of this layer
if WIDTH % 2 == 1 then
turnRight()
else
turnLeft()
end
for i = 1, WIDTH - 1 do
forward()
end
if WIDTH % 2 == 1 then
turnRight()
else
turnLeft()
end
for i = 1, LENGTH - 1 do
forward()
end
end

-- === MAIN ===
local function main()
print("Starting 16x16 chunk mining...")
refuel()

-- Go down until solid
while not turtle.detectDown() do
down()
end

-- Mine layers upward until ceiling hit or full inventory
while true do
mineLayer()
print("Layer complete. Going up...")
up()

if turtle.detectUp() then
print("Ceiling reached, stopping.")
break
end
end

print("Chunk mining complete!")
end

main()