--[[
 Expected slot assignment/content

 Slot 1: 64 Torches
 Slot 2: 1 Cobble (reserved for cobble compare)
 Slot 3: Fuel
 Slot 4: Enderchest
--]]

-- Parameters

local fuelSlot = 1  -- Inventory slot of torches

-- Variables

local firstProcessSlot = 2
local depth = 0
local collected = 0

-- Process commandline

local tArgs = { ... }
if #tArgs < 2 then
    print( "Usage: Floor <length> <width>" )
    print( "======================================" )
    print( "Process If true, content -> Enderchest")
    print( "")
    print( "Expected content in inventory of turtle:" )
    print( "Slot 1: Fuel" )
    print( "Slot 2 to 16: Material to use")
    return
end

local length = tonumber( tArgs[1] )
if length < 1 then
    print( "Area length must be 1+" )
    return
end

local width = 1

if #tArgs > 1 then
    width = tonumber( tArgs[2] )
    if width < 1 then
        print( "Area width must be 1+" )
        return
    end
end

local function checkSlot(slotNr,description)
   if turtle.getItemCount(slotNr)==0 then
      print("Expected item '"..description.."' in slot "..slotNr..".")
      return false
   end
   return true
end

-- Check slots

if not checkSlot(fuelSlot,"fuel") then return end

-- Main Code

local function collect()
    collected = collected + 1
    if math.fmod(collected, 100) == 0 then
        print( "Mined "..collected.." items." )
    end
end
local function refuel()
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" or fuelLevel > 0 then
        return
    end

    local function tryRefuel()
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                turtle.select(n)
                if turtle.refuel(1) then
                    turtle.select(1)
                    return true
                end
            end
        end
        turtle.select(1)
        return false
    end

    if not tryRefuel() then
        print( "Add more fuel to continue." )
        while not tryRefuel() do
            sleep(1)
        end
        print( "Resuming Tunnel." )
    end
end
local function tryDig()
    while turtle.detect() do
        if turtle.dig() then
            collect()
            sleep(0.5)
        else
            return false
        end
    end
    return true
end
local function tryDigUp()
    while turtle.detectUp() do
        if turtle.digUp() then
            collect()
            sleep(0.5)
        else
            return false
        end
    end
    return true
end
local function tryDigDown()
 while turtle.detectDown() do
  if turtle.digDown() then
    collect()
    sleep(0.5)
 else
   return false
  end
 end
 return true
end
local function tryUp()
    refuel()
    while not turtle.up() do
        if turtle.detectUp() then
            if not tryDigUp() then
                return false
            end
        elseif turtle.attackUp() then
            collect()
        else
            sleep( 0.5 )
        end
    end
    return true
end
local function tryDown()
    refuel()
    while not turtle.down() do
        if turtle.detectDown() then
            if not tryDigDown() then
                return false
            end
        elseif turtle.attackDown() then
            collect()
        else
            sleep( 0.5 )
        end
    end
    return true
end
local function tryForward()
    refuel()
    while not turtle.forward() do
        if turtle.detect() then
            if not tryDig() then
                return false
            end
        elseif turtle.attack() then
            collect()
        else
            sleep( 0.5 )
        end
    end
    return true
end

local resourceIndex=2

local function seekFirstResourceSlot()
   while resourceIndex<17 do
      turtle.select(resourceIndex)
      if turtle.getItemCount(resourceIndex)>0 then
        return true
      end
      resourceIndex=resourceIndex+1
   end
   return false
end

local function mine()
    print( "Flooring..." )
    local rotation=0
    if not seekFirstResourceSlot(resourceIndex) then
       return false
    end
    for m=1,width do
        for n=1,length-1 do
            tryDigDown()
            turtle.placeDown()
            if turtle.getItemCount(resourceIndex)==0 then
                if not seekFirstResourceSlot(resourceIndex) then
                   return false
                end
            end
            tryDig()
            if not tryForward() then
                return false
            end
        end
        if m < width then
            if rotation==0 then
                turtle.turnRight()
            else
                turtle.turnLeft()
            end
            tryDig()
            if not tryForward() then
                return false
            end
            if rotation==0 then
                turtle.turnRight()
            else
                turtle.turnLeft()
            end
            rotation = 1 - rotation
        end
    end
    return true
end

if mine() then
    print( "Flooring complete." )
else
    print( "Flooring aborted prematurely.")
end