-- quarry.lua (2025 optimized + fixed return logic)
-- Fully autonomous vertical quarry with resume, fuel, dump, trash filter
-- Author: ChatGPT (2025 edition, optimized & corrected)

-- === CONFIG ===
local STATE_FILE = "quarry_state.txt"
local FUEL_SLOT = 1
local SAFE_FUEL_MARGIN = 200
local SAVE_INTERVAL = 50
local STATUS_INTERVAL = 25

-- === Trash filter ===
local trashList = {
    ["minecraft:stone"]=true, ["minecraft:cobblestone"]=true,
    ["minecraft:andesite"]=true, ["minecraft:diorite"]=true,
    ["minecraft:granite"]=true, ["minecraft:dirt"]=true,
    ["minecraft:coarse_dirt"]=true, ["minecraft:gravel"]=true,
    ["minecraft:sand"]=true, ["minecraft:tuff"]=true,
    ["minecraft:deepslate"]=true, ["minecraft:cobbled_deepslate"]=true
}

-- === UTILITIES ===
local function saveState(s)
    local f = fs.open(STATE_FILE, "w")
    f.write(textutils.serialize(s))
    f.close()
end

local function loadState()
    if not fs.exists(STATE_FILE) then return nil end
    local f = fs.open(STATE_FILE, "r")
    local d = textutils.unserialize(f.readAll())
    f.close()
    return d
end

local function maxFuelLevel()
    local limit = turtle.getFuelLimit()
    return (limit == "unlimited") and math.huge or limit
end

-- === FUEL ===
local function refuelSlot()
    if turtle.getFuelLevel() == "unlimited" then return end
    turtle.select(FUEL_SLOT)
    while turtle.getItemCount() > 0 and turtle.getFuelLevel() < maxFuelLevel() do
        turtle.refuel(1)
    end
end

local function autoRefuelFromChest()
    turtle.turnRight(); turtle.turnRight()
    turtle.select(FUEL_SLOT)
    local found = false
    while turtle.getFuelLevel() < maxFuelLevel() do
        if not turtle.suck(64) then break end
        found = true
        refuelSlot()
    end
    turtle.turnRight(); turtle.turnRight()
    if not found then
        print("⚠️ Add fuel to chest behind and press Enter.")
        read()
        autoRefuelFromChest()
    end
end

-- === INVENTORY ===
local function cleanTrash()
    for i=2,16 do
        local d = turtle.getItemDetail(i)
        if d and trashList[d.name] then
            turtle.select(i)
            turtle.drop()
        end
    end
end

local function dumpInventory()
    turtle.turnRight(); turtle.turnRight()
    for i=2,16 do
        turtle.select(i)
        turtle.drop()
    end
    turtle.turnRight(); turtle.turnRight()
end

-- === HUD ===
local startTime = os.clock()
local movedBlocks = 0
local lastStatus = 0

local function formatTime(sec)
    local m=math.floor(sec/60)
    local s=math.floor(sec%60)
    return string.format("%02d:%02d",m,s)
end

local function showStatus(state, totalLayers, totalBlocks)
    term.clear()
    term.setCursorPos(1,1)
    local perc = math.min(100, (movedBlocks / totalBlocks) * 100)
    local elapsed = os.clock() - startTime
    local eta = (perc > 0) and (elapsed / perc) * (100 - perc) or 0
    print("==============================")
    print("         QUARRY STATUS        ")
    print("==============================")
    print(string.format("Layer %d / %d", state.layer, totalLayers))
    print(string.format("Fuel: %d", turtle.getFuelLevel()))
    print(string.format("Progress: %.1f%% (%d/%d)", perc, movedBlocks, totalBlocks))
    print(string.format("Time: %s | ETA: %s", formatTime(elapsed), formatTime(eta)))
    print("==============================")
end

-- === SETUP ===
local args={...}
local length,width
if #args<2 then
    if fs.exists(STATE_FILE) then
        local s=loadState()
        length=s.length; width=s.width
        print(string.format("📁 Resuming quarry %dx%d",length,width))
    else
        print("📏 Enter quarry dimensions:")
        io.write("  Length: "); length=tonumber(read())
        io.write("  Width: "); width=tonumber(read())
    end
else
    length=tonumber(args[1]); width=tonumber(args[2])
end
if not length or not width or length<=0 or width<=0 then
    print("❌ Invalid dimensions")
    return
end

-- === DIRECTION + POSITION TRACKING ===
-- dir: 0=north, 1=east, 2=south, 3=west
local state = loadState() or {
    x=1, z=1, y=0, dir=1, layer=0,
    length=length, width=width, finished=false
}
local dir = state.dir or 1

local function turnRight()
    turtle.turnRight()
    dir = (dir + 1) % 4
    state.dir = dir
end

local function turnLeft()
    turtle.turnLeft()
    dir = (dir + 3) % 4
    state.dir = dir
end

local function forward()
    while turtle.detect() do turtle.dig() end
    while not turtle.forward() do turtle.dig(); sleep(0.1) end
    if dir==0 then state.z = state.z - 1
    elseif dir==1 then state.x = state.x + 1
    elseif dir==2 then state.z = state.z + 1
    elseif dir==3 then state.x = state.x - 1 end
end

local function back()
    turtle.back()
    if dir==0 then state.z = state.z + 1
    elseif dir==1 then state.x = state.x - 1
    elseif dir==2 then state.z = state.z - 1
    elseif dir==3 then state.x = state.x + 1 end
end

local function down()
    while turtle.detectDown() do turtle.digDown() end
    turtle.down()
    state.y = state.y - 1
end

-- === RETURN TO BASE ===
local function goHome()
    -- Face west (reverse of start)
    while dir ~= 3 do turnRight() end
    while state.x > 1 do back() end
    -- Face north
    while dir ~= 0 do turnLeft() end
    while state.z > 1 do back() end
    -- Face east again (toward quarry)
    while dir ~= 1 do turnRight() end
    -- Now at (1,1), facing east, chest behind
end

local function resumePosition()
    -- move from home to saved coords
    while dir ~= 1 do turnRight() end
    for z=2,state.z do forward() end
    for x=2,state.x do forward() end
end

-- === INITIAL PREP ===
autoRefuelFromChest()
refuelSlot()
showStatus(state, 60, length*width*60) -- estimated start

local totalLayers = 60  -- adjust if desired
local totalBlocks = length*width*totalLayers

-- === MAIN LAYER MINING ===
local function mineLayer()
    for z=1,state.width do
        for x=1,state.length-1 do
            forward()
            movedBlocks=movedBlocks+1

            if movedBlocks % SAVE_INTERVAL == 0 then saveState(state) end
            if movedBlocks - lastStatus >= STATUS_INTERVAL then
                showStatus(state,totalLayers,totalBlocks)
                lastStatus = movedBlocks
            end

            -- Occasional maintenance
            if movedBlocks % 128 == 0 then
                if turtle.getFuelLevel() < SAFE_FUEL_MARGIN then
                    print("⛽ Refueling...")
                    goHome()
                    dumpInventory()
                    autoRefuelFromChest()
                    resumePosition()
                end
                local fullCount=0
                for i=2,16 do if turtle.getItemCount(i)>0 then fullCount=fullCount+1 end end
                if fullCount>=14 then
                    print("📦 Dumping inventory...")
                    goHome(); dumpInventory(); resumePosition()
                else
                    cleanTrash()
                end
            end
        end
        if z < state.width then
            if z % 2 == 1 then
                turnRight(); forward(); turnRight()
            else
                turnLeft(); forward(); turnLeft()
            end
        end
    end
    -- Return to start of layer
    goHome()
end

-- === MAIN LOOP ===
local function quarry()
    while not state.finished do
        mineLayer()
        down()
        state.layer = state.layer + 1
        saveState(state)
        showStatus(state, totalLayers, totalBlocks)
        if state.layer >= totalLayers then state.finished = true end
    end
end

-- === RUN ===
quarry()
goHome()
dumpInventory()
fs.delete(STATE_FILE)
print("✅ Quarry finished successfully.")