Turtle Branch Miner

-- This program branch mines...
-- It will also place torches. Make sure
-- there's torches in the 1st slot.
-- It will also deposit its items into
-- a chest below where it started when
-- it's inventory is full.
--
--================ ARGUMENT FLAGS ================================
--> -t  <true/false>|<0/1>
--      If true, turtle will place torches from slot 1.
--      Default is true.
--> -l  <int:[1, inf)>
--      Specifies the length in blocks of each branch.
--      Default is 12. Past that, mobs can spawn.
--> -b  <int:[1, inf)>
--      Specififes the number of segments, or branches*2, to mine.
--      Default is 21. Past that, it runs out of torches.
--> -s  <int:[0, inf)>
--      Specifies the number of blocks inbetween each branch.
--      Default is 3. The optimal space for diamond mining.
--> -d  <true/false>|<0/1>
--      If true, turtle will deposit it's items into the chest when it's full.
--      Default is true.
--================================================================
--  Author : Matthew (FaceInCake) Eppel
--    Date : Sept 14, 2019
-- Version : 2.0

local args = {...}
-- These are all the changable values
local branches = 21
local length = 12
local space = 3
local placeTorches = true
local dropItems = true

function checkInteger(s)
  local n = tonumber(s)
  if n == nil then
    print("[ERROR]: '"..s.."' is not a number")
    return nil
  end
  n = math.floor(n)
  if n < 0 then
    print("[ERROR]: '"..s.."' is not an integer")
    return nil
  end
  return n
end

-- Parse all the arguments
function parseArguments()
  for i=1, #args do
    local s = tostring(args[i])
    if s:sub(1,1) == '-' then
      i = i + 1
      if i > #args then
        break
      end
      local c = s:sub(2,2)
      if c == 'b' then
        local n = checkInteger(args[i])
        if n == nil then
          return 1
        end
        branches = n
      elseif c == 'l' then
        local n = checkInteger(args[i])
        if n == nil then
          return 1
        end
        length = n
      elseif c == 's' then
        local n = checkInteger(args[i])
        if n == nil then
          return 1
        end
        space = n
      elseif c == 't' then
        local s = tostring(args[i])
        if s == "false"
        or s == "0"
        or s == "off" then
          placeTorches = false
        elseif s ~= "true"
        and s ~= "1"
        and s ~= "on" then
          print("[ERROR]: '"..s.."' is not a valid boolean")
          return 1
        end
      elseif c == 'd' then
        local s = tostring(args[i])
        if s == "false"
        or s == "0"
        or s == "off" then
          dropItems = false
        elseif s ~= "true"
        and s ~= "1"
        and s ~= "on" then
          print("[ERROR]: '"..s.."' is not a valid boolean")
          return 1
        end
      end
    end
  end
  return 0
end

-- Digs forward, but checks if a new block fell into place, and digs it
function delete()
  while turtle.detect() do
    turtle.dig()
    os.sleep(0.1)
  end
end

-- Goes forward one space until it is successful
function forward()
  while not turtle.forward() do
    os.sleep(0.2)
  end
end

-- Goes backwards until it reaches `dist` blocks away
function back(dist)
  local count = 0
  while count < dist do
    if turtle.back() then
      count = count + 1
    else
      os.sleep(0.2)
    end
  end
end

-- Returns false if there is at least 1 space of inventory, true otherwise
function inventoryFull()
  for i=16, 1, -1 do
    if turtle.getItemCount(i)==0 then
      return false
    end
  end
  return true
end

-- Sideways offset from chest.
-- Positive is to the right.
local xOffset = 0

-- Forwards offset from chest
local yOffset = 0

-- Direction. 0=forward, 1=right, etc.
local face = 0

-- Turns left and increments 'face'
function turnLeft()
  turtle.turnLeft()
  face = face - 1
  if face < 0 then
    face = 3
  end
end

-- Turns right and increments 'face'
function turnRight()
  turtle.turnRight()
  face = face + 1
  if face > 3 then
    face = 0
  end
end

-- Does a 180deg turn and increments 'face'
function oneEighty()
  if face >= 2 then
    face = face - 2
    turtle.turnLeft()
    turtle.turnLeft()
  else
    face = face + 2
    turtle.turnRight()
    turtle.turnRight()
  end
end

-- Increments xOffset/yOffset by n, depending on the current 'face'
function increment(n)
  if face == 0 then
    yOffset = yOffset + n
  elseif face == 1 then
    xOffset = xOffset + n
  elseif face == 2 then
    yOffset = yOffset - n
  elseif face == 3 then
    xOffset = xOffset - n
  else
    return false
  end
  return true
end

-- This function returns to where it was originally placed
function recall()
  if xOffset > 0 then
    -- face needs to be 3
    if face==0 then
      turnLeft()
    elseif face==1 then
      oneEighty()
    elseif face==2 then
      turnRight()
    end
  elseif xOffset < 0 then
    -- Face needs to be 1
    if face==0 then
      turnRight()
    elseif face==2 then
      turnLeft()
    elseif face==3 then
      oneEighty()
    end
  end
  -- Move to middle
  for i=1, math.abs(xOffset) do
    forward()
  end
  -- Face needs to be 2
  if face==0 then
    oneEighty()
  elseif face==1 then
    turnRight()
  elseif face==3 then
    turnLeft()
  end
  -- Move to chest
  for i=1, yOffset do
    forward()
  end
  -- Move down
  while not turtle.down() do
    os.sleep(0.1)
  end
  -- Face back again
  oneEighty()
end

-- This long function takes control of the turtle, it
-- will return to where it was placed when this program
-- was run and drop all of it's items below itself, then
-- return back to where it was and continue mining.
function deposit()
  -- Store value so they can be reset
  local _xOffset = xOffset
  local _yOffset = yOffset
  local _face = face
  -- Returns to the chest
  recall()
  -- Drop all items
  for i=16, 2, -1 do
    turtle.select(i)
    turtle.dropDown(64)
  end
  -- Reselect the torches
  turtle.select(1)
  -- If we're not carrying torches, drop'em
  if not placeTorches then
    turtle.dropDown(64)
  end
  -- Move up
  while not turtle.up() do
    os.sleep(0.1)
  end
  -- Move back to the branch it was at
  for i=1, _yOffset do
    forward()
  end
  -- Turn to face '_face'
  for i=1, _face do
    turnRight()
  end
  -- Go back to original spot in branch
  for i=1, math.abs(_xOffset) do
    forward()
  end
  -- Reset our values just in case
  xOffset = _xOffset
  yOffset = _yOffset
  face = _face
end

function branch()
  for i=1, length do
    delete()
    if dropItems then
      if inventoryFull() then
        deposit()
      end
    end
    forward()
    increment(1)
    turtle.digDown()
    if dropItems then
      if inventoryFull() then
        deposit()
      end
    end
  end
  back(1)
  if placeTorches then
    turtle.place()
  end
  back(length-1)
  increment(-length)
end

function main()
  if parseArguments()~=0 then
    return -1
  end
  while turtle.detectUp() do
    turtle.digUp()
    os.sleep(0.2)
  end
  while not turtle.up() do
    os.sleep(0.1)
  end
  for i=1, branches do
    for j=0, space do
      delete()
      if dropItems then
        if inventoryFull() then
          deposit()
        end
      end
      forward()
      increment(1)
      turtle.digDown()
      if dropItems then
        if inventoryFull() then
          deposit()
        end
      end
    end
    if placeTorches then
      turtle.placeDown()
    end
    turnLeft()
    branch()
    oneEighty()
    branch()
    turnLeft()
  end
  recall()
  return 0
end

main()