gps tower builder

--#############################################################################
--#
--# This program will take 4 computers, 4 wireless modems a disk drive and a
--# disk to build a gps tower at max height
--#
--#############################################################################


local fNames = { "south", "west", "north", "east" }
local fIndex = 0
local pos = {}
local yStart = 0
local slotComputer = 1
local slotModem = 2
local slotFuel = 3
local slotDisk = 4
local slotDrive = 5
local diskSide = ""
local hitSky = false
pos[1], pos[2], pos[3] = "", "", ""
local move = { east = {1, 0, 0}, west = {-1, 0, 0}, south = {0, 0, 1}, north = {0, 0, -1} }

function isnumber(test)
    --print(type(test))
    if type(test) == "number" then
        return true
    else
        return false
    end
end

function isdirection(test)
    if test == "east" or test == "west" or test == "north" or test == "south" then
        for i = 1,4 do
            if test == fNames[i] then
                fIndex = i
            end
        end
        return true
    else
        return false
    end
end

function moveUp()
    while not hitSky do
        moved, dug, attack = false, false, false
        moved = turtle.up()
        if not moved then
            if turtle.detectUp() then
                dug = turtle.digUp()
            else
                attacked = turtle.attackUp()
            end
        else
            pos[2] = pos[2] + 1
        end
        hitSky = not (moved or dug or attacked)
        print(pos[1].." "..pos[2].." "..pos[3].." "..f)
    end
end

function moveDown()
    while not turtle.down() do
        if turtle.detectDown() then
            turtle.digDown()
        else
            turtle.attackDown()
        end
    end
    pos[2] = pos[2] - 1
    print(pos[1].." "..pos[2].." "..pos[3].." "..f)
end

function moveForward()
    while not turtle.forward() do
        if turtle.detect() then
            turtle.dig()
        else
            turtle.attack()
        end
    end
    for i = 1,3 do
        pos[i] = pos[i] + move[f][i]
    end
    print(pos[1].." "..pos[2].." "..pos[3].." "..f)
end

function left()
    turtle.turnLeft()
    fIndex = fIndex - 1
    if fIndex == 0 then
        fIndex = 4
    end
    f = fNames[fIndex]
    print(pos[1].." "..pos[2].." "..pos[3].." "..f)
end

function right()
    turtle.turnRight()
    fIndex = fIndex + 1
    if fIndex == 5 then
        fIndex = 1
    end
    f = fNames[fIndex]
    print(pos[1].." "..pos[2].." "..pos[3].." "..f)
end


if turtle then      -- build a gps tower
    print("i'm a turtle")
    print("provide me with the following items:")
    print("slot 1: 4 computers")
    print("slot 2: 4 wireless modems")
    print("slot 3: enough fuel to get me to max y and back. < insert calculated amount here >")
    print("what are my current coordinates? use the integers on the f3 screen or REI's minimap")
    while not isnumber(pos[1]) do
        print("x = ")
        pos[1] = tonumber(read())
        if not isnumber(pos[1]) then
            print("that's not a number")
        end
    end
    while not isnumber(pos[2]) do
        print("y = ")
        pos[2] = tonumber(read())
        if not isnumber(pos[2]) then
            print("that's not a number")
        end
    end
    yStart = pos[2]
    while not isnumber(pos[3]) do
        print("z = ")
        pos[3] = tonumber(read())
        if not isnumber(pos[3]) then
            print("that's not a number")
        end
    end
    while not isdirection(f) do
        print("which direction am i facing?")
        f = read()
        if not isdirection(f) then
            print("that's not a valid direction")
        end
    end
    -- check inventory (can only check for matching numbers atm)
    if turtle.getItemCount(1) == 4 and turtle.getItemCount(2) == 4 then
        --get disk from drive
        for k,v in pairs(redstone.getSides()) do
            if disk.isPresent(v) then
                diskSide = v
                print(diskSide)
            end
        end
        if diskSide == "left" then
            turtle.turnLeft()
            turtle.suck()
            turtle.dig()
            turtle.turnRight()
        elseif diskSide == "right" then
            turtle.turnRight()
            turtle.suck()
            turtle.dig()
            turtle.turnLeft()
        elseif diskSide == "top" then
            turtle.suckUp()
            turtle.digUp()
        elseif diskSide == "bottom" then
            turtle.suckDown()
            turtle.digDown()
        elseif diskSide == "front" then
            turtle.suck()
            turtle.dig()
        elseif diskSide == "back" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.suck()
            turtle.dig()
            turtle.turnLeft()
            turtle.turnLeft()
        end
        turtle.select(slotFuel)
        while turtle.getFuelLevel() < 64 + 2*(254-pos[2]) do
            turtle.refuel(1)
        end
        moveUp()
        -- build gps array
        for c = 1,2 do
            for d = 1,2 do
                for m = 1,3 do
                    moveForward()
                end
                turtle.select(slotComputer)
                turtle.place()
                local gpspos = {}
                for i = 1,3 do
                    gpspos[i] = pos[i] + move[f][i]
                end
                left()
                moveForward()
                moveForward()
                right()
                moveForward()
                right()
                turtle.select(slotModem)
                turtle.place()
                right()
                moveForward()
                left()
                moveForward()
                moveForward()
                moveForward()
                left()
                turtle.select(slotDrive)
                turtle.place()
                turtle.select(slotDisk)
                turtle.drop()
                --write gps program to disk
                local labelString = "os.setComputerLabel('gps_"..gpspos[1].."_"..gpspos[2].."_"..gpspos[3].."')"
                local gpsString = "shell.run('gps','host',"..gpspos[1]..","..gpspos[2]..","..gpspos[3]..")"
                f = fs.open("disk/gpsstartup", "w")
                f.writeLine(labelString)
                f.writeLine(gpsString)
                f.close()
                -- turn on computer
                left()
                moveForward()
                right()
                m = peripheral.wrap("front")
                m.turnOn()
                -- retreive disk and drive
                right()
                moveForward()
                left()
                turtle.select(slotDisk)
                turtle.suck()
                turtle.select(slotDrive)
                turtle.dig()
                -- reboot gps computer
                left()
                moveForward()
                --m = peripheral.wrap("right")
                --m.reboot()
                -- go back to center
                left()
                for i = 1,3 do
                    moveForward()
                end
            end
            moveDown()
            moveDown()
            left()
        end
    end
    while pos[2] > yStart do
        moveDown()
    end
else
    print("i'm a computer")
    fs.move("disk/gpsstartup","startup")
    sleep(5)
    os.reboot()
end