Tortois

-------------------------------------------------
-- Copyright 2019 Fatboychummy
-- You can edit and redistribute, but keep this
-- copyright info in the code, untampered with.
-------------------------------------------------


if not turtle then
  error("Why are you trying to run this on a non-turtle computer?", 0)
  -- seriuzly tho y
end

local funcs = {}
local nt = {}

-------------------------------------------------
-- function: doIf [private]
-- info    : runs a function, if it's first returned thing is true, run a second
--           function with the extra inputs
-- inputs  : self, ifThis [function], thenThis[function], [extra]
-- returns : whatever ifThis returns
-------------------------------------------------
local function doIf(self, ifThis, thenThis, ...)
  local ptal = {ifThis()} -- run the func and put output to table
  if ptal[1] then -- if the first item is true
    thenThis(self, ...) -- run the second func
  end
  return table.unpack(ptal) -- return what the first function returned
end

-------------------------------------------------
-- function: moveBy
-- info    : Changes the turtle object's position by df and du
-- inputs  : self, df (distance moved forward), du (distance moved up)
-- returns : nil
-------------------------------------------------
local function moveBy(self, df, du)
  if not df then df = 0 end -- default df to 0
  if not du then du = 0 end -- defualt du to 0

  if self.facing == 0 then -- facing towards positive Z
    self.z = self.z + df
  elseif self.facing == 1 then -- facing towards negative X
    self.x = self.x - df
  elseif self.facing == 2 then -- facing towards negative Z
    self.z = self.z - df
  elseif self.facing == 3 then -- facing towards positive X
    self.x = self.x + df
  end
  self.y = self.y + du -- add du, which is default 0
end

-------------------------------------------------
-- function: turtle movement functions
-- info    : move the turtle AND set turtle data
-- inputs  : nil
-- returns : whatever the equivalent turtle function returns
-------------------------------------------------
function nt:forward()
  return doIf(self, turtle.forward, moveBy, 1, 0)
end

function nt:back()
  return doIf(self, turtle.back, moveBy, -1, 0)
end

function nt:up()
  return doIf(self, turtle.up, moveBy, 0, 1)
end

function nt:down()
  return doIf(self, turtle.down, moveBy, 0, -1)
end

function nt:turnLeft()
  return doIf(self, turtle.turnLeft,
  function()
    self.facing = self.facing - 1
    self.facing = self.facing % 4
  end
  )
end

function nt:turnRight()
  return doIf(self, turtle.turnRight,
  function()
    self.facing = self.facing + 1
    self.facing = self.facing % 4
  end
  )
end

-------------------------------------------------
-- function: setHome
-- info    : sets the turtle's "home" position
-- inputs  : nil
-- returns : nil
-------------------------------------------------
function nt:setHome()
  self.home = {
    x = self.x,
    y = self.y,
    z = self.z
  }
end

-------------------------------------------------
-- function: getHome
-- info    : gets the turtle's "home" position
-- inputs  : nil
-- returns : home[x], home[y], home[z]
-------------------------------------------------
function nt:getHome()
  return self.home.x, self.home.y, self.home.z
end

-------------------------------------------------
-- function: getPos
-- info    : gets the turtle's current relative position
--           (from it's starting point)
-- inputs  : nil
-- returns : pos[x], pos[y], pos[z]
-------------------------------------------------
function nt:getPos()
  return self.x, self.y, self.z
end

-------------------------------------------------
-- function: getFacing
-- info    : gets the relative direction the turtle is facing
--           (from it's starting point)
-- inputs  : nil
-- returns : the turtle's direction (0-3)
-------------------------------------------------
function nt:getFacing()
  return self.facing
end

-------------------------------------------------
-- function: load
-- info    : load turtle positional data from file
-- inputs  : fileFrom[string]
-- returns : nil
-------------------------------------------------
function nt:load(fileFrom)
  fileFrom = type(fileFrom) == "string" and fileFrom
            or error("NO DAT IS NOT FILE NAME", 2)
  local dat = loadfile(fileFrom)()
  self.facing = dat.facing
  self.x = self.x
  self.y = self.y
  self.z = self.z
  self.home = {}
  self.home.x = dat.home.x
  self.home.y = dat.home.y
  self.home.z = dat.home.z
end

-------------------------------------------------
-- function: save
-- info    : save turtle positional data to file
-- inputs  : fileTo[string]
-- returns : nil
-------------------------------------------------
function nt:save(fileTo)
  fileTo = type(fileTo) == "string" and fileTo
            or error("NO DAT IS NOT FILE NAME", 2)
  local h = io.open(fileTo, 'w')
  h:write("return {\n")
  h:write("  facing = " .. tostring(self.facing) .. ",\n")
  h:write("  x = " .. tostring(self.x) .. ",\n")
  h:write("  y = " .. tostring(self.y) .. ",\n")
  h:write("  z = " .. tostring(self.z) .. ",\n")
  h:write("  home = {\n")
  h:write("    x = " .. tostring(self.home.x) .. ",\n")
  h:write("    y = " .. tostring(self.home.y) .. ",\n")
  h:write("    z = " .. tostring(self.home.z) .. '\n')
  h:write("  }\n")
  h:write("}")
  h:close()
end

-------------------------------------------------
-- function: equip
-- info    : creates a turtle positional object
-- inputs  : nil
-- returns : Tortois
-------------------------------------------------
function funcs.equip()
  local tmp = setmetatable(
    {
      facing = 0,
      x = 0,
      y = 0,
      z = 0,
      home = {
        x = 0,
        y = 0,
        z = 0
      }
    },
    {__index = nt}
  )

  return tmp
end

-------------------------------------------------
-- function: uhhhhhhhhhhhhhhhhh
-- info    : uhhhhhhhhhhhhhhhhhh
-- inputs  : uhhhhhhhhhhhhhhhhhhhhhhh
-- returns : uhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
-------------------------------------------------
function funcs.unequip()
  -- is this actually needed?
end

return funcs