PeatFarm

local waterRow = {false,true,false,false,true,false,false,true,false}

local keepFuel = 5

-- FUNCTIONS

local function refuel()
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" or fuelLevel > 0 then
        return
    end

    local function tryRefuel()
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                turtle.select(n)
                if turtle.refuel(1) then
                    turtle.select(1)
                    return true
                end
            end
        end
        turtle.select(1)
        return false
    end

    if not tryRefuel() then
        term.setCursorPos(12,7)
        term.clear()
        print( "Gimme som Fuel!" )
        while not tryRefuel() do
            sleep(1)
        end
        term.setCursorPos(15,7)
        term.clear()
        print("I'm on it...")
    end
end

function turnR(n)
    if n == nil then n=1 end
    for i = 1,n do
        turtle.turnRight()
    end
end

function turnL(n)
    if n == nil then n=1 end
    for i = 1,n do
        turtle.turnLeft()
    end
end

function go(nDistance)
    refuel()
    if not nDistance then nDistance=1 end
    while nDistance > 0 do
        refuel()
        if turtle.forward() then
            nDistance = nDistance - 1
        else
            sleep(0.5)
        end
    end
end

local function SelectSlot()

    local function trySelect()
        for i = 1,4 do
            if turtle.getItemCount(i) > 0 then
                turtle.select(i)
                return true
            end
        end
        turtle.select(1)
        return false
    end

    if not trySelect() then
        term.setCursorPos(12,7)
        term.clear()
        print( "Gimme som Bogearth!" )
        while not trySelect() do
            sleep(1)
        end
        term.setCursorPos(15,7)
        term.clear()
        print("I'm on it...")
    end
    return true
end

local function digPeat()
    turtle.select(16)
    if turtle.compareDown() then
        turtle.select(5)
        turtle.digDown()
        SelectSlot()
        turtle.placeDown()
    end
end

function digRow()
    for i = 1,9 do
        digPeat()
        if i ~= 9 then
            refuel()
            go()
        end
    end
end

function digWaterRow()
    for i = 1,9 do
        if not waterRow[i] then
            digPeat()
        end
        if i ~= 9 then
            refuel()
            go()
        end
    end
end

function dropStuff()
    turtle.select(5)
    local nTransfer = keepFuel - turtle.getItemCount(15)
    if turtle.getItemCount(5) > 0 and nTransfer > 0 then
        turtle.transferTo(15, nTransfer)
    end
    if turtle.getItemCount(15) > keepFuel then
        turtle.select(15)
        turtle.drop(turtle.getItemCount(15) - keepFuel)
    end
    for i = 5,14 do
        turtle.select(i)
        turtle.drop()
    end
end

function getStuff()
    turtle.select(1)
        if (turtle.getItemCount(1) + turtle.getItemCount(2)) < 128 then
            while turtle.suck() do
                if (turtle.getItemCount(1) + turtle.getItemCount(2)) >= 128 then break end
            end
        end
    if turtle.getItemCount(3) > 0 then
        turtle.select(3)
        turtle.drop()
    end
    turtle.select(1)
end

-- MAIN PROGRAMM

while true do
    term.setCursorPos(12,7)
    term.clear()
    print("Ready to roll...")

    event = os.pullEvent("redstone")

    term.setCursorPos(12,7)
    term.clear()
    print("I'm on it...")
    turtle.select(1)
    if (turtle.getItemCount(1) + turtle.getItemCount(2)) < 128 then
        turnL(2)
        go()
        turnL()
        getStuff()
        turnL()
        go()
    end
    go()
    for i = 1,9 do
        if waterRow[i] then
            digWaterRow()
        else
            digRow()
        end
        if i ~= 9 then
            if i % 2 == 0 then
                turnR()
                go()
                turnR()
            else
                turnL()
                go()
                turnL()
            end
        end
    end

    turnR()
    go(8)
    turnR()
    go(11)
    turnL()
    dropStuff()
    turnL()
    go()
    turnR()
    getStuff()
    turnL()
    go()
    sleep(1)
end