gistfile1.lua

-- XAPI v0.1
-- A turtle API
-- By Xavura

--[[
	TODO:

		* Figure out if we can reliably overwrite turtle methods with our own.
]]--

local _turtle = {}
local backups = {}
local methods = {
	'craft',
	'turnLeft', 'turnRight',
	'refuel', 'getFuelLevel',
	'dig', 'digUp', 'digDown',
	'drop', 'dropUp', 'dropDown',
	'suck', 'suckUp', 'suckDown',
	'up', 'down', 'back', 'forward',
	'place', 'placeUp', 'placeDown',
	'attack', 'attackUp', 'attackDown',
	'detect', 'detectUp', 'detectDown',
	'select', 'getItemCount', 'getItemSpace',
	'compare', 'compareUp', 'compareDown', 'compareTo'
}

for k, v in ipairs(methods) do
	backups[v] = turtle[v]
end

local _turtleMeta = {
	__index = function(tbl, key)
		if backups[key] then
			return backups[key]
		end
	end
}

setmetatable(_turtle, _turtleMeta)


-- Constants

local DEBUG   = true
local VERSION = {0, 1, 0}

local NORTH = 1
local EAST  = 2
local SOUTH = 3
local WEST  = 4
local UP    = 5
local DOWN  = 6

local UPDATE_IDENT = '3924697'
local SOURCE_IDENT = '3904888'

local DIRECTIONS = {[1]="north", [2]="east",
                    [3]="south", [4]="west",
                    [5]="up",    [6]="down"}

local GPS_TIMEOUT = 3

--[[
local MOVE_MODES = {
	REMOVE_BLOCKS   = 1, -- Remove BLOCKS that block path(s)
	ATTACK_ENTITIES = 2, -- Attack ENTITIES that block path(s)
	FIND_ALTERNATE  = 4  -- Attempt to find an alternate route that avoids blocks and entities.
}

local MOVE_OPTIONS = {
	REMOVE_ATTEMPTS = 2, -- Attempts before giving up removal (because e.g. Bedrock)
	ATTACK_ATTEMPTS = 6, -- Attempts before giving up attacking
	REMOVE_ONLY     = {} -- Remove only blocks in these inventory slots.
}
--]]

-- Math Helpers

function vEqual(v1, v2)
	return v1[1] == v2[1] and v1[2] == v2[2] and v1[3] == v2[3]
end


-- State

local position  = {nil, nil, nil}
local direction = nil

--local movementMode = bit.band(MOVE_MODE['REMOVE_BLOCKS'], MOVE_MODE['ATTACK_ENTITIES'])


-- State Access

function getPos()
	return position
end

function getDir()
	return direction
end


-- Debugging

function debugVec(vec, str)
	str = str or "Vector"

	if type(vec) ~= "table" then
		return print(str..": Not a vector.")
	end

	print(str..": "..vec[1]..", "..vec[2]..", "..vec[3])
end

function debugPos(pos)
	return debugVec(position, "Position")
end

function debugDir(dir)
	if dir == nil then
		dir = direction
	end

	if DIRECTIONS[dir] then
		print("Direction: "..DIRECTIONS[dir])
	else
		print("Direction: INVALID ("..dir..")")
	end
end


-- Setup

local function locate()
	rednet.open("right")
	local cX, cY, cZ = gps.locate(GPS_TIMEOUT)
	rednet.close("right")

	if cX == nil then
		return false
	end

	return {cX, cY, cZ}
end

local function determineCardinalDirection()
	_turtle.forward()

	local facing      = 0
	local newPosition = locate()

	if newPosition == false then
		print("Fatal: Unable to connect to GPS @ determineCardinalDirection()")
		return shell.exit()
	end

	if newPosition[1] > position[1] then
		facing = EAST
	elseif newPosition[1] < position[1] then
		facing = WEST
	elseif newPosition[3] > position[3] then
		facing = SOUTH
	elseif newPosition[3] < position[3] then
		facing = NORTH
	end

	_turtle.back()
	--for i = 1, 2 do turtle.turnRight() end
	--turtle.forward()
	--for i = 1, 2 do turtle.turnLeft()  end

	return facing
end

local function locateManually()
	local pos  = {}
	local dir  = nil
	local tmp  = nil
	local line = 1

	term.clear()
	term.setCursorPos(1, 1)
	textutils.slowPrint('Unable to connect to GPS network!')
	textutils.slowPrint('Please enter turtle coordinates.')
	textutils.slowPrint('Note: F3 Y shows head position.')
	textutils.slowPrint('Subtract 1 to get foot position!')
	os.sleep(2)
	term.clear()

	for i = 1, 3 do
		repeat
			term.clearLine()
			term.setCursorPos(1, line)
			print(string.char(i+119)..': ')

			term.setCursorPos(4, line)
			tmp = tonumber(io.read())

			if tmp == nil then
				term.setCursorPos(4, line)
				term.write('Invalid input, please try again.')
				os.sleep(1)
			end
		until tmp ~= nil

		table.insert(pos, math.floor(tmp))
		line = line + 1
	end

	term.clear()
	term.setCursorPos(1, 1)
	textutils.slowPrint('Please enter direction.')
	textutils.slowPrint('Use debug (F3) screen, F value.')
	os.sleep(2)
	term.clear()
	term.setCursorPos(1, 1)

	repeat
		print('f: ')
		term.setCursorPos(4, 1)
		tmp = tonumber(io.read())

		if tmp == nil then
			term.setCursorPos(4, 1)
			term.write('Invalid input, please try again.')
			os.sleep(1)
		end
	until tmp >= 0 and tmp <= 4

	-- Convert F value 2, 3, 0, 1 -> 1, 2, 3, 4
	dir = math.ceil( (tmp + 3) % 4.1)

	return pos, dir
end

local function setup()
	position = locate()

	if position == false then
		position, direction = locateManually()
	else
		direction = determineCardinalDirection()
	end

	debugPos()
	debugDir()
end

local function updateCheck()
	local request  = http.get('https://raw.github.com/gist/'..UPDATE_IDENT)
	local response = nil
	local version  = nil

	term.clear()
	term.setCursorPos(1, 1)

	if request then
		response = request.readAll()
		request.close()

		version = (function()
			local result = {}
			string.gsub(response, '([^,]+)', function(m) table.insert(result, tonumber(m)) end)
			return result
		end)()

		print('Current Version: v'..table.concat(VERSION, '.'))

		if version[1] > VERSION[1] or version[2] > VERSION[2] or version[3] > VERSION[3] then
			print('A new version (v'..table.concat(version, '.')..') is available!')

			print('Update now (y/n): ')
			term.setCursorPos(19, 3)
			
			if io.read() == 'y' then
				shell.run('gist', 'get', 'xapi.tmp', SOURCE_IDENT)
				os.unloadAPI('xapi')
				shell.run('rm', 'xapi')
				shell.run('mv', 'xapi.tmp', 'xapi')
				os.loadAPI('xapi')
			end
		else
			print('You are running the latest version.')
		end
	else
		print('Error: Unable to check for updates.')
	end
end

-- Turning

local function updateDirection(change)
	direction = direction + change

	if direction == 0 then
		direction = 4
	elseif direction == 5 then
		direction = 1
	end
end

function turnLeft(count)
	count = count or 1

	if count > 1 then
		for i = 1, count do
			turnLeft(1)
		end
	end

	_turtle.turnLeft()
	updateDirection(-1)
end

function turnRight()
	count = count or 1

	if count > 1 then
		for i = 1, count do
			turnRight(1)
		end
	end

	_turtle.turnRight()
	updateDirection(1)
end

local function faceDirection(dir)
	if dir == direction then
		return
	end

	local reversed = false

	if dir - direction == 3 or direction - dir == 3 then
		reversed = true
	end

	while true do
		if dir > direction then
			if reversed == false then
				turnRight()
			else
				turnLeft()
			end
		else
			if reversed == false then
				turnLeft()
			else
				turnRight()
			end
		end

		if dir == direction then
			break
		end
	end

	--debugDir()
end

function faceNorth()
	return faceDirection(1)
end

function faceEast()
	return faceDirection(2)
end

function faceSouth()
	return faceDirection(3)
end

function faceWest()
	return faceDirection(4)
end


-- Basic Movement

local function updatePosition(backwards)
	--backwards = backwards or false

	local dir    = direction
	local index  = 0
	local change = 1

	--[[if backwards then
		dir = (dir + 2) % 4

		if dir == 0 then
			dir = 4
		end
	end]]--

	if dir == 1 or dir == 4 then
		change = -1
	end

	if dir == 2 or dir == 4 then
		index = 1
	else
		index = 3
	end

	position[index] = position[index] + change
	--debugPos()
end

function up(count, force)
	count = count or 1
	force = force or false

	if count > 1 then
		for i = 1, count do
			up(1, force)
		end
		return
	end

	if force and _turtle.detectUp() then
		_turtle.digUp()
	end

	local success = _turtle.up()

	if success then
		position[2] = position[2] + 1
	end

	return success
end

function down(count, force)
	count = count or 1
	force = force or false

	if count > 1 then
		for i = 1, count do
			down(1, force)
		end
		return
	end

	if force and _turtle.detectDown() then
		_turtle.digDown()
	end

	local success = _turtle.down()

	if success then
		position[2] = position[2] - 1
	end

	return success
end

function forward(count, force)
	count = count or 1
	force = force or false

	if count > 1 then
		for i = 1, count do
			forward(1, force)
		end
		return
	end

	local dug = nil

	if force and _turtle.detect() then
		dug = _turtle.dig()
	end

	local success = _turtle.forward()

	if not success then
		repeat
			_turtle.attack()
			success = _turtle.forward()
		until success
	end
	
	if success then
		updatePosition()
	end

	return success
end


function back(count, force)
	count = count or 1
	force = force or false

	if count > 1 then
		for i = 1, count do
			back(1, force)
		end
		return
	end

	--[[ Meh solution:
	if force then
		rotate(2)
		if turtle.detect() then
			turtle.dig()
		end
		rotate(2)
	end
	--]]

	local success = _turtle.back()

	if success then
		updatePosition(true)
	end

	return success
end


-- Advanced Movement

local function getMovementVector(movement)
	local vector = {0, 0, 0}

	if movement[1] > 0 then
		vector[1] = WEST
	else
		vector[1] = EAST
	end

	if movement[2] > 0 then
		vector[2] = DOWN
	else
		vector[2] = UP
	end

	if movement[3] > 0 then
		vector[3] = NORTH
	else
		vector[3] = SOUTH
	end

	return vector
end

function move(target, force) -- Relative movement.

end

function goto(target, force) -- Absolute movement.
	local move  = nil
	local force = force or false
	local moves = {position[1] - target[1],
	               position[2] - target[2],
	               position[3] - target[3]}

	local movement = getMovementVector(moves)

	--print("Face "..DIRECTIONS[movement[1]].." then move "..math.abs(moves[1]))
	--print("Move "..DIRECTIONS[movement[2]].." "..math.abs(moves[2]).. " times")
	--print("Face "..DIRECTIONS[movement[3]].." then move "..math.abs(moves[3]))

	if movement[1] == WEST then
		faceWest()
	else
		faceEast()
	end

	for i = 1, math.abs(moves[1]) do
		move = forward(1, force)

		if not move then
			return print("Aborted in east-west loop.")
		end
	end

	for i = 1, math.abs(moves[2]) do
		if movement[2] == UP then
			move = up(1, force)
		else
			move = down(1, force)
		end

		if not move then
			return print("Aborted in up-down loop.")
		end
	end

	if movement[3] == NORTH then
		faceNorth()
	else
		faceSouth()
	end

	for i = 1, math.abs(moves[3]) do
		move = forward(1, force)

		if not move then
			return print("Aborted in north-south loop.")
		end
	end
end

if shell ~= nil then
	local args = {...}

	if args[1] == 'update' then
		updateCheck()
	end
else
	setup()
end