Farmer (ComputerCraft)

-- Farmer
-- ----------------------------------------------------------

-- Not very portable, but it does the job.

-- ----------------------------------------------------------

-- Initialise important values:

-- ----------------------------------------------------------

-- Locations of interest:
local node = {{-1015,3444,63,"east"}, --   1, loot chest.
    {-1017,3441,63,"south"},       --   2, charcoal barrel.
    {-1013,3442,64,"east"},      --   3, fence top.
    {-1008,3442,64,"north"},       --   4, fence hopping spot.
    {-1008,3440,64,"east"}}      --   5, harvest start point.

local facing = {"north","east","south","west"}
local direction,x,y,z,report
local modem = peripheral.wrap("right")

-- Number of inventory servers (that should be) online:
local invServerCount, invServer = 0, {}

-- ----------------------------------------------------------

-- Functions and stuff:

-- ----------------------------------------------------------

-- Tell the turtle server I'm alive.
local function doTurtleServerReport()
    rednet.send(report,{"Hello TurtleServer",os.getComputerLabel()})
    report = nil
end

-- Poll the inventory servers re a given barrel.
local function getAmountOf(barreltype)
    local myMessage
    for i=1,3 do
        for i=1,invServerCount do rednet.send(invServer[i],barreltype) end
        myMessage = {rednet.receive(3)}
        if myMessage and tonumber(myMessage[2]) then break end
    end

    if not tonumber(myMessage[2]) then
        print("Warning: Could not get reading for amount of "..barreltype..".")
        return 0
    else return tonumber(myMessage[2]) end
end

-- Returns true if the turtle is carrying anything.
local function carrying()
    for i=1,15 do if turtle.getItemCount(i) ~= 0 then return true end end
    return false
end

-- Accepts strings representing compass-facings to turn the turtle.
local function faceDirection(targetdirection)
    local tardir = 1
    for i=1,4 do if targetdirection == facing[i] then tardir = i end end

    if tardir < direction then
        if tardir == 1 and direction == 4 then
            while not turtle.turnRight() do end
        else
            for i=1,direction-tardir do while not turtle.turnLeft() do end end
        end
    elseif tardir > direction then
        if tardir == 4 and direction == 1 then
            while not turtle.turnLeft() do end
        else
            for i=1,tardir-direction do while not turtle.turnRight() do end end
        end
    end

    direction = tardir
end

-- Travel to a co-ordinate.
local function goToPos(target,digger)
    while (x ~= node[target][1]) or (y ~= node[target][2]) or (z ~= node[target][3]) do
        if z > node[target][3] then
            if turtle.down() then z = z - 1 elseif digger then turtle.digDown() end
        elseif z < node[target][3] then
            if turtle.up() then z = z + 1 elseif digger then turtle.digUp() end
        end

        if x > node[target][1] then
            if direction ~= 4 then faceDirection("west") end
            if turtle.forward() then x = x - 1 elseif digger then turtle.dig() end
        elseif x < node[target][1] then
            if direction ~= 2 then faceDirection("east") end
            if turtle.forward() then x = x + 1 elseif digger then turtle.dig() end
        end

        if y > node[target][2] then
            if direction ~= 1 then faceDirection("north") end
            if turtle.forward() then y = y - 1 elseif digger then turtle.dig() end
        elseif y < node[target][2] then
            if direction ~= 3 then faceDirection("south") end
            if turtle.forward() then y = y + 1 elseif digger then turtle.dig() end
        end
    end

    faceDirection(node[target][4])
end

-- Enters the farm pen.
local function hopInFence()
    goToPos(3)
    goToPos(4)
end

-- Leaves the farm pen.
local function hopOutFence()
    goToPos(4,true)
    goToPos(3)
end

-- Refuel the turtle itself.
local function goGetFuel()
    print("I'm hungry. Off to eat some EU...")
    if x>-1009 then hopOutFence() end
    goToPos(2)
    print("OMNOMNOM")
    turtle.select(10)
    while turtle.getFuelLevel() < 10000 do
        turtle.suckUp()
        turtle.refuel()
        sleep(1)
    end
    print("Ah, that hit the spot!")
    print("")
end

-- Dumps the turtle's inventory into the dropoff chest.
local function dropOff()
    print("Dropping off loot...")
    if x>-1009 then hopOutFence() end
    goToPos(1)
    for i=1,15 do if turtle.getItemCount(i) ~= 0 then
        turtle.select(i)
        turtle.dropDown()
    end end
    print("")
end

-- Roam the plot collecting and planting.
local function harvest()
    print("I'm a farmer and I'm OK!")
    print("")

    turtle.select(16)

    for yy = 1,16 do for xx = 1,16 do
        -- Harvest & replant crop.
        turtle.digDown()
        turtle.placeDown()

        -- Move ahead.
        if xx < 16 then
            while not turtle.forward() do
                turtle.dig()
                turtle.attack()
            end
        else
            if bit.band(yy,1)==1 then
                while not turtle.turnRight() do end
                while not turtle.forward() do
                    turtle.dig()
                    turtle.attack()
                end
                while not turtle.turnRight() do end
            elseif yy<16 then
                while not turtle.turnLeft() do end
                while not turtle.forward() do
                    turtle.dig()
                    turtle.attack()
                end
                while not turtle.turnLeft() do end
            end
        end

        if report then doTurtleServerReport() end
    end end

    y,direction = 3455,4
end

-- ----------------------------------------------------------

-- Primary functions:

-- ----------------------------------------------------------

-- Deal with rednet.
local function turtleServer()
    local turtleServerTimeOut, myEvent = os.startTimer(0)
    while true do
        myEvent = {os.pullEvent()}
        if myEvent[1] == "timer" and myEvent[2] == turtleServerTimeOut then
            report = 65535
            turtleServerTimeOut = os.startTimer(600)
        elseif myEvent[1] == "rednet_message" and myEvent[3] == "Hey, you still there?" then
            report = myEvent[2]
            turtleServerTimeOut = os.startTimer(600)
        end
    end
end

-- Primary work loop.
local function main()
    while true do
        if carrying() then dropOff() end      -- Ensure I'm not carrying spare stuff.

        if turtle.getFuelLevel() < 2000 then goGetFuel() end

        if x<-1008 then hopInFence() end

        goToPos(5,true)

        for i=60,1,-1 do
            print("Waiting for crops to grow, "..i.." minutes remaining.")
            print("")
            sleep(60)
            if report then doTurtleServerReport() end
        end

        ---if getAmountOf("Seeds (295:0)") == 4096 and getAmountOf("Wheat (296:0)") == 4096 then
        --  print("I've filled my barrels, guess I'll take a breather...")
        --  print("")
        --  while getAmountOf("Seeds (295:0)") == 4096 and getAmountOf("Wheat (296:0)") == 4096 do
        --      sleep(60)
        --      if report then doTurtleServerReport() end
        --  end
        --end

        harvest()
    end
end

-- ----------------------------------------------------------

-- I've just booted up. Where am I? Who am I? etc...

-- ----------------------------------------------------------

-- Ping the GPS servers until I get a valid reading:
do
    local tempx, tempy, tempz
    while tempx == nil or tempy == nil or tempz == nil do
        tempx, tempz, tempy = gps.locate(5)
        sleep(5)
    end

    while not turtle.forward() do while not turtle.turnLeft() do end end
    x,z,y = gps.locate(5)

    if x < tempx then direction = 4
    elseif x > tempx then direction = 2
    elseif y < tempy then direction = 1
    else direction = 3 end
end

-- Broadcast until all inventory servers are identified.
rednet.open("right")
while #invServer < invServerCount do
    rednet.broadcast("Hello InvServer")
    local myTimer = os.startTimer(5)
    while true do
        local myEvent = {os.pullEvent()}
        if myEvent[1] == "timer" and myEvent[2] == myTimer then
            break
        elseif myEvent[1] == "rednet_message" and myEvent[3] == "Hello, InvServerClient!" then
            invServer[#invServer+1] = myEvent[2]
            for i=1,#invServer-1 do if invServer[i] == invServer[#invServer] then invServer[#invServer] = nil end end
            if #invServer == invServerCount then break end
        end
    end
end

print("I'm at "..x..","..y..","..z..", I have "..turtle.getFuelLevel().." fuel and I'm facing "..facing[direction]..".")
print("")

parallel.waitForAny(main, turtleServer)