Command Computer's Turtle API (ComputerCraft)

-- http://www.computercraft.info/forums2/index.php?/topic/22479-command-computers-turtle-api/

if turtle and not commands then
    if not fs.isDir("disk") then error("A disk drive with an inserted floppy must be available.") end

    local inventory = {}
    for i = 1, 16 do inventory[i] = turtle.getItemDetail(i) end

    local output = fs.open("disk\\inventory.txt","w")
    output.writeLine(textutils.serialise(inventory))
    output.close()

    print("Inventory content documented to disk.")
elseif commands then
    local inventory, selected, events, fuel = {}, 1, 1, 1000000000
    local x, y, z, dir, visible
    local translate = {[0] = 2, 5, 3, 4}

    print("\nEnter X position:")
    repeat x = tonumber(read()) until x

    print("\nEnter Y position:")
    repeat y = tonumber(read()) until y and y > -1 and y < 256

    print("\nEnter Z position:")
    repeat z = tonumber(read()) until z

    print("\nEnter facing (N/S/E/W):")
    repeat dir = ({n = 0, e = 1, s = 2, w = 3})[read():sub(1, 1):lower()] until dir

    print("\nVisible \"turtle\"? (y/n)")
    visible = read():sub(1, 1):lower() == "y"

    if visible then commands.setblock(x.." "..y.." "..z.." ComputerCraft:command_computer "..translate[dir]) end

    if fs.exists("disk\\inventory.txt") then
        local input = fs.open("disk\\inventory.txt","r")
        inventory = textutils.unserialise(input.readAll())
        input.close()
    end

    local function pullEvent()
        os.queueEvent("turtle_response", events)
        repeat local myEvent, par1 = os.pullEvent("turtle_response") until par1 == events
        events = events + 1
    end

    _G.turtle = {}

    turtle.select = function(slot)
        pullEvent()
        if slot < 1 or slot > 16 then error() end
        selected = slot
        return true
    end

    turtle.getSelectedSlot = function()
        return selected
    end

    turtle.getFuelLevel = function()
        return fuel
    end

    turtle.getFuelLimit = function()
        return 1000000000
    end

    turtle.refuel = function()
        pullEvent()
        fuel = 1000000000
        return true
    end

    turtle.drop = function(amount)
        amount = amount or 64
        if amount < 0 or amount > 64 then error() end
        pullEvent()
        if inventory[selected] then
            inventory[selected].count = inventory[selected].count - amount
            if inventory[selected].count < 1 then inventory[selected] = nil end
            return true
        else return false end
    end

    turtle.dropUp, turtle.dropDown = turtle.drop, turtle.drop

    turtle.attack = function()
        pullEvent()
        return false
    end

    for index, value in ipairs({"attackUp", "attackDown", "suck", "suckUp", "suckDown", "equipLeft", "equipRight"}) do turtle[value] = turtle.attack end

    turtle.getItemCount = function(slot)
        slot = slot or selected
        if slot < 1 or slot > 16 then error() end
        return (not inventory[slot]) and 0 or inventory[slot].count
    end

    turtle.getItemSpace = function(slot)
        slot = slot or selected
        if slot < 1 or slot > 16 then error() end
        return inventory[slot] and (64 - inventory[slot].count) or 64
    end

    turtle.getItemDetail = function(slot)
        slot = slot or selected
        if slot < 1 or slot > 16 then error() end
        return textutils.unserialise(textutils.serialise(inventory[slot]))
    end

    turtle.compareTo = function(slot)
        pullEvent()
        slot = slot or selected
        if slot < 1 or slot > 16 then error() end
        if inventory[select] and inventory[slot] then
            return inventory[select].name == inventory[slot].name and inventory[select].damage == inventory[slot].damage
        else return (type(inventory[select]) == "nil" and type(inventory[slot]) == "nil") end
    end

    turtle.transferTo = function(slot, amount)
        pullEvent()
        slot = slot or selected
        amount = amount or 64
        if slot < 1 or slot > 16 or amount < 0 or amount > 64 then error() end
        if amount == 0 or not inventory[selected] then return true end

        if not inventory[slot] then
            inventory[slot] = textutils.unserialise(textutils.serialise(inventory[selected]))
            inventory[slot].count = 0
        end

        if turtle.compareTo(slot) then
            local toMove = math.min(inventory[selected].count, amount, turtle.getItemSpace(slot))
            inventory[selected].count = inventory[selected].count - toMove
            inventory[slot].count = inventory[slot].count + toMove
            if inventory[selected].count < 1 then inventory[selected] = nil end
            return true
        else return false end
    end

    turtle.turnLeft = function()
        pullEvent()
        dir = dir > 0 and (dir - 1) or 3

        if visible then
            commands.setblock(x.." "..y.." "..z.." ComputerCraft:command_computer "..translate[dir])
        end

        return true
    end

    turtle.turnRight = function()
        pullEvent()
        dir = dir < 3 and (dir + 1) or 0

        if visible then
            commands.setblock(x.." "..y.." "..z.." ComputerCraft:command_computer "..translate[dir])
        end

        return true
    end

    local function frontBlockPos()
        if dir == 0 then
            return x, y, z - 1
        elseif dir == 1 then
            return x + 1, y, z
        elseif dir == 2 then
            return x, y, z + 1
        else
            return x - 1, y, z
        end
    end

    local indetectable = {["minecraft:air"] = true, ["minecraft:water"] = true, ["minecraft:lava"] = true, ["minecraft:flowing_water"] = true, ["minecraft:flowing_lava"] = true}

    local function detect(x, y, z)
        if indetectable[commands.getBlockInfo(x, y, z).name] then return false else return true end
    end

    turtle.detect = function()
        return detect(frontBlockPos())
    end

    turtle.detectUp = function()
        return detect(x, y + 1, z)
    end

    turtle.detectDown = function()
        return detect(x, y - 1, z)
    end

    turtle.inspect = function()
        return turtle.detect() and commands.getBlockInfo(frontBlockPos()) or false
    end

    turtle.inspectUp = function()
        return turtle.detectUp and commands.getBlockInfo(x, y + 1, z) or false
    end

    turtle.inspectDown = function()
        return turtle.detectDown and commands.getBlockInfo(x, y - 1, z) or false
    end

    local function compare(x, y, z)
        local block = commands.getBlockInfo(x, y, z)
        if not inventory[selected] then return block.name == "minecraft:air" end
        return block.name == inventory[selected].name
    end

    turtle.compare = function()
        return compare(frontBlockPos())
    end

    turtle.compareUp = function()
        return compare(x, y + 1, z)
    end

    turtle.compareDown = function()
        return compare(x, y - 1, z)
    end

    turtle.forward = function()
        local oldX, oldZ = x, z

        if turtle.detect() or fuel == 0 then
            return false
        elseif dir == 0 then
            z = z - 1
        elseif dir == 1 then
            x = x + 1
        elseif dir == 2 then
            z = z + 1
        else
            x = x - 1
        end

        if visible then
            commands.setblock(oldX.." "..y.." "..oldZ.." minecraft:air")
            commands.setblock(x.." "..y.." "..z.." ComputerCraft:command_computer "..translate[dir])
        end

        fuel = fuel - 1
        return true
    end

    turtle.back = function()
        dir = dir + 2
        if dir > 3 then dir = dir - 4 end

        local result = turtle.forward()

        dir = dir + 2
        if dir > 3 then dir = dir - 4 end

        if visible and result then
            commands.setblock(x.." "..y.." "..z.." ComputerCraft:command_computer "..translate[dir])
        end

        return result
    end

    turtle.up = function()
        if turtle.detectUp() or y == 255 or fuel == 0 then
            return false
        else
            if visible then
                commands.setblock(x.." "..y.." "..z.." minecraft:air")
                commands.setblock(x.." "..(y+1).." "..z.." ComputerCraft:command_computer "..translate[dir])
            end

            y = y + 1
            fuel = fuel - 1
            return true
        end
    end

    turtle.down = function()
        if turtle.detectDown() or y == 0 or fuel == 0 then
            return false
        else
            if visible then
                commands.setblock(x.." "..y.." "..z.." minecraft:air")
                commands.setblock(x.." "..(y-1).." "..z.." ComputerCraft:command_computer "..translate[dir])
            end

            y = y - 1
            fuel = fuel - 1
            return true
        end
    end

    local function place(x, y, z)
        if detect(x, y, z) or not inventory[selected] then return false end

        local result = commands.setblock(x, y, z, inventory[selected].name, inventory[selected].damage)

        if result then
            inventory[selected].count = inventory[selected].count - 1
            if inventory[selected].count == 0 then inventory[selected] = nil end
        end

        return result
    end

    turtle.place = function()
        return place(frontBlockPos())
    end

    turtle.placeUp = function()
        return place(x, y + 1, z)
    end

    turtle.placeDown = function()
        return place(x, y - 1, z)
    end

    local function dig(x, y, z)
        if detect(x, y, z) then
            local block = commands.getBlockInfo(x, y, z)
            if block.name == "minecraft:bedrock" then return false end
            commands.setblock(x, y, z, "minecraft:air", 0)

            if not inventory[selected] then
                inventory[selected] = {["name"] = block.name, ["damage"] = 0, ["count"] = 1}
            else for i = 1, 16 do
                if not inventory[i] then
                    inventory[i] = {["name"] = block.name, ["damage"] = 0, ["count"] = 1}
                    break
                elseif inventory[i].name == block.name and inventory[i].count < 64 then
                    inventory[i].count = inventory[i].count + 1
                    break
                end
            end end

            return true
        else return false end
    end

    turtle.dig = function()
        return dig(frontBlockPos())
    end

    turtle.digUp = function()
        return dig(x, y + 1, z)
    end

    turtle.digDown = function()
        return dig(x, y - 1, z)
    end

    local native = {}
    for key, value in pairs(turtle) do native[key] = value end
    turtle.native = native

    local oldgetBlockPosition = commands.getBlockPosition

    commands.getBlockPosition = function()
        pullEvent()
        return x, y, z
    end

    if visible then
        local oldReboot, oldShutdown = os.reboot, os.shutdown

        os.reboot = function()
            commands.setblock(x.." "..y.." "..z.." minecraft:air")
            oldReboot()
        end

        os.shutdown = function()
            commands.setblock(x.." "..y.." "..z.." minecraft:air")
            oldShutdown()
        end
    end

    term.setBackgroundColour(colours.brown)
    term.clear()

    local oldTerm = term.current()

    local myWindow = window.create(oldTerm, 1, 1, 39, 13)
    term.redirect(myWindow)

    print("\nI am now the PRETTIEST TURTLE!!!!\n")
    shell.run("shell")

    _G.turtle = nil
    commands.getBlockPosition = oldgetBlockPosition

    if visible then commands.setblock(x.." "..y.." "..z.." minecraft:air") end

    term.redirect(oldTerm)
    term.setTextColour(colours.white)
    term.setBackgroundColour(colours.black)
    term.setCursorPos(1, 1)
    term.clear()
else error("Run me on either a turtle or a command computer.") end