buildCol.lua

-- Build a column of the material in inv 1 , starting where the bot is sitting,
--    until out of material, a ceiling is reached, or a specified height
-- by Alexander "SquidLord" Williams (SaladinVrai)

-- Gist: https://gist.github.com/SquidLord/4741925

-- The MIT License (MIT)

-- Copyright (c) 2012 Alexander Williams

-- Permission is hereby granted, free of charge, to any person obtaining a copy
-- of this software and associated documentation files (the "Software"), to deal
-- in the Software without restriction, including without limitation the rights
-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-- copies of the Software, and to permit persons to whom the Software is
-- furnished to do so, subject to the following conditions:

-- The above copyright notice and this permission notice shall be included in all
-- copies or substantial portions of the Software.

-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-- SOFTWARE.

-- Set up environ
local ARGS = {...}
local SLOT = 1
local COLHEIGHT = tonumber(ARGS[1])
local MAXBLOX = turtle.getItemCount(SLOT)

-- Get the system label for identification
local SYSNAME = os.getComputerLabel()
if not SYSNAME then SYSNAME = "UNNAMED NODE" end

-- Open rednet for status spurts
--   Iterate over all sides for rednet.open
for N,M in ipairs(rs.getSides()) do
  rednet.open(M)
end

--
-- Function Definition
--

-- PlaceCol(Int)
--   Recursively try placing a block, then moving up. Failures return a (discarded) 1.

local function PlaceCol(ColHeight)
  if ColHeight == 0 then
    print("  Reached max height.")
    rednet.broadcast(":"..SYSNAME..": reached given column height; returning to start")
    return false
  elseif not turtle.place() then
    print("  Could not place block; ending column.")
    rednet.broadcast(":"..SYSNAME..": could not place block; returning to start")
    return false
  elseif not turtle.up() then
    print("  Hit ceiling or block; returning down.")
    rednet.broadcast(":"..SYSNAME..": hit ceiling or block; returning to start")
    return false
  else PlaceCol(ColHeight - 1)
    turtle.down()
    return true
  end
end

--
-- Main Loop Identify
--

print("SquidOS Column Builder ...")
print("  Running on: "..SYSNAME)

-- If there are no blocks in SLOT, complain loudly
if MAXBLOX == 0 then
  print("  No blocks to build column with.")
  rednet.broadcast(":"..SYSNAME..": No blocks to build with.")
  return false
end

-- If there aren't enough blocks in the inventory to build that column, 
--   only plan to build as much as you have.
if not COLHEIGHT then COLHEIGHT = 64 end

if MAXBLOX < COLHEIGHT then COLHEIGHT = MAXBLOX end
  
print("  Building to "..COLHEIGHT)
rednet.broadcast(":"..SYSNAME..": building column to "..COLHEIGHT)

if not turtle.back() then
  print("  Cannot back up. Clear the position and try again.")
  rednet.broadcast(":"..SYSNAME..": failed to back up.")
  return false
end

-- Target the colmn material block for placement
turtle.select(SLOT)

-- Recursively place blocks
if not PlaceCol(COLHEIGHT) then
  turtle.forward()
end

print("  Build complete.")
rednet.broadcast(":"..SYSNAME..": Finished building "..COLHEIGHT.." pillar.")
return true