build.lua

local tArgs = { ... }
local src_url
if #tArgs < 1 then
    print( "Usage: build [pastebin_url]" )
    return
else
    src_url = tArgs[1]
end

local orientation = "north"
local bot_x = 1
local bot_y = 1
local bot_z = 1

local function get_plan_str()
    write( "Connecting to pastebin.com... " )
    local response = http.get(
        "https://pastebin.com/raw/"..textutils.urlEncode(src_url)
    )

    if response then
        print("Success.")

        local sResponse = response.readAll()
        response.close()
        return sResponse
    else
        print("Failed.")
        return false
    end
end

local function split(inputstr, sep)
    if sep == nil then
        sep = "%s"
    end
    local t={} ; i=1
    for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
            t[i] = str
            i = i + 1
    end
    return t
end

local function parse_meta_block(plan)
    local meta = split(plan, "#")[1]
    local dimensions = split(meta, ":")
    return dimensions[1], dimensions[2], dimensions[3]
end

local function parse_plan(plan_str)
    -- Starts with x:y:z#
    -- 0 = empty
    local x, y, z = parse_meta_block(plan)

    local plan = {}
    plan_str = split(split(plan_str, "#")[2], ",")

    local str_index = 1
    for l_y = 1, y do
        plan[l_y] = {}
        for l_z = 1, z do
            plan[l_y][l_z] = {}
            for l_x = 1, x do
                plan[l_y][l_z][l_x] = plan_str[str_index]
                str_index = str_index + 1
            end
        end
    end
    return plan
end

local function refuel(amount)
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" then
        return true
    end

    if turtle.getFuelLevel() < amount then
        local fueled = false
        turtle.select(16)
        if turtle.getItemCount(16) > 0 then
            turtle.select(16)
            if turtle.refuel(1) then
                while turtle.getItemCount(16) > 0 and turtle.getFuelLevel() < amount do
                    turtle.refuel(1)
                end
                if turtle.getFuelLevel() >= amount then
                    turtle.select(1)
                    return true
                end
            end
        end
        turtle.select(1)
        return false
    end

    return true
end

local function turn(direction, amount)
    for a = 1, amount do
        change_orientation(direction)
        if direction == "left" then
            turtle.turnLeft()
        else
            turtle.turnRight()
        end
    end
end

local function orient_to(direction)
    while orientation ~= direction do
        turn("left", 1)
    end
end

local function change_orientation(direction)
    if direction == "left" then
        if orientation == "north" then
            orientation = "east"
        elseif orientation == "east" then
            orientation = "south"
        elseif orientation == "south" then
            orientation = "west"
        else
            orientation = "north"
        end
    else
        if orientation == "north" then
            orientation = "west"
        elseif orientation == "east" then
            orientation = "north"
        elseif orientation == "south" then
            orientation = "east"
        else
            orientation = "south"
        end
    end
end

local function move_forward()
    if not refuel(1) then
        print("Waiting for fuel")
        while not refuel(1) do
            os.pullEvent("turtle_inventory")
        end
    end

    turtle.forward()
    if orientation == "north" then
        bot_z = bot_z - 1
    elseif orientation == "south" then
        bot_z = bot_z + 1
    elseif orientation == "east" then
        bot_x = bot_x + 1
    elseif orientation == "west" then
        bot_x = bot_x - 1
    end
end

local function has_block(number)
    for s = 1, 15 do
        if string.find(number, tostring(s)) ~= nil then
            turtle.select(s)
            if turtle.getItemCount() > 0 then
                return true
            end
        end
    end
    return false
end

local function select_block_x(number)
    if has_block(number) then
        return
    end

    print("Failed to find block for", number)
    while not has_block(number) do
        os.pullEvent("turtle_inventory")
    end
end

local function do_plan_block(number)
    if number == 0 then
        -- Empty
        return
    end

    select_block_x(number)
    turtle.placeDown()
end

local function buildZ(z_plan)
    local start_x = nil
    local end_x = nil
    if orientation == "east" then
        start_x = 1
        end_x = #z_plan
    else
        start_x = #z_plan
        end_x = 1
    end

    for l_x = start_x, end_x do
        do_plan_block(z_plan[l_x])
    end
end

local function buildY(y_plan)
    for l_z = 1, #y_plan do
        buildZ(y_plan[l_z])

        if l_z ~= #y_plan then
            if orientation == "east" then
                turn("right", 1)
                move_forward()
                turn("right", 1)
            elseif orientation == "west" then
                turn("left", 1)
                move_forward()
                turn("left", 1)
            end
        end
    end
end

local function move_up_y()
    -- Should be left at coords X,Z or 1,Z
    -- move to 1,1

    if bot_x > 1 then
        -- X = X, not X = 1
        orient_to("west")
        while bot_x > 1 do
            move_forward()
        end
    end
    orient_to("north")
    while bot_z > 1 do
        move_forward()
    end
end

local function move_to_start(plan)
    -- Move forward Z units
    local z = #plan[1]

    for l_z = 1, z do
        turtle.forward()
    end
    turn("right", 1)
end

local function build(plan)
    move_to_start(plan)
    for y = 1, #plan do
        buildY()
        if y ~= #plan then
            move_up_y()
        end
    end
end

local function init()
    local plan_str = get_plan_str()
    if not plan_str then
        return
    end

    build(parse_plan(plan_str))
end

init()