Automatic Turtle Treefarm

local shouldOutput = false
local width = 0
local length = 0

local function loadSettings()

    file = io.open( "settings.txt", "r" )
    while true do
        line = file:read()
        if line == nil then break end

        if line == "true" then
            shouldOutput = true
        else
            shouldOutput = false
        end

        line = file:read()
        if line == nil then break end

        width = tonumber(line)

        line = file:read()
        if line == nil then break end

        length = tonumber(line)

        file:close()

        return true
    end

    file:close()

    return false

end

local function createSettings()

    term.clear()
    term.setCursorPos( 1,1 )
    print( "Set the settings." )

    write( "Output Redstone on cycle: " )
    local str = string.lower( read() )
    if str == "1" or str == "yes" or str == "true" then
        shouldOutput = true
    else
        shouldOutput = false
    end

    write( "Rows: " )
    width = tonumber(read())

    write( "Trees: " )
    length = tonumber(read())

    file = io.open("settings.txt", "w")
    if file == nil then
        --error? could be locked
        return
    end

    if shouldOutput then
        file:write( "true" )
        file:write( "\n" )
    else
        file:write( "false" )
        file:write( "\n" )
    end

    file:write( width )
    file:write( "\n" )
    file:write( length )
    file:write( "\n" )

    file:close()

    term.clear()
    term.setCursorPos( 1,1 )
    print( "Ready to cycle" )


end

term.clear()
term.setCursorPos( 1,1 )
print( "Logger program starting..." )

if fs.exists( "settings.txt" ) then
    if not loadSettings() then
        createSettings()
    end

    term.clear()
    term.setCursorPos( 1,1 )
    print( "Ready to cycle" )

else
    createSettings()
end

rednet.open( "right" )

local function tryMove( direction )

    if direction == "down" then
        if turtle.detectDown() then
            turtle.digDown()
        end
        while not turtle.down() do
            turtle.digDown()
            sleep(1)
        end
    end

    if direction == "forward" then
        if turtle.detect() then
            turtle.dig()
        end
        while not turtle.forward() do
            turtle.dig()
            sleep(1)
        end
    end

    if direction == "up" then
        if turtle.detectUp() then
            turtle.digUp()
        end
        while not turtle.up() do
            turtle.digUp()
            sleep(1)
        end
    end

end

local function plantTree()

    turtle.select(1)
    l = turtle.getItemCount(1)
    turtle.placeDown()
    t = turtle.getItemCount(1)

    if t == l then --must have not been able to place a sapling
        turtle.select(2)
        tryMove("down")
        if turtle.detectDown() then turtle.digDown() end
        turtle.placeDown()
        turtle.select(1)
        tryMove("up")
        turtle.placeDown()
    end

    turtle.select(9)
end

local function harvestTree()

    steps = 1
    tryMove("forward")

    while turtle.detectUp() do
        tryMove( "up" )
        steps = steps + 1
    end

    while steps > 2 do
        tryMove( "down" )
        steps = steps - 1
    end
    plantTree()

end

local function checkTree()

    if turtle.detect() then
        tryMove( "down" )
        harvestTree()
    else
        tryMove( "forward" )
        if not turtle.detectDown() then
            plantTree()
        end
    end

end

local function harvest()

    turtle.select(1)
    tryMove( "forward" )
    tryMove( "up" )
    checkTree()

    bump = false

    for w=1, width do

        for l=1, length do

            if l~=length then
                tryMove( "forward" )
                tryMove( "forward" )
                checkTree()
            end

        end

        if w~=width then
            if not bump then
                turtle.turnLeft()
                tryMove( "forward" )
                tryMove( "forward" )
            else
                turtle.turnRight()
                tryMove( "forward" )
                tryMove( "forward" )
            end
            checkTree()

            if bump then
                turtle.turnRight()
            else
                turtle.turnLeft()
            end

            bump = not bump
        end

    end


    --Return
    if not bump then
        turtle.turnLeft()
        tryMove( "forward" )
        turtle.turnLeft()
        for i = 1, length do
            tryMove( "forward" )
            tryMove( "forward" )
            if i~=length then
                tryMove( "forward" )
            end
        end
    else
        tryMove( "forward" )
        tryMove( "forward" )
    end
    turtle.turnLeft()

    if width == 1 then
        tryMove( "forward" )
    else
        for i=1, width - 1 do
            tryMove( "forward" )
            tryMove( "forward" )
            tryMove( "forward" )
        end
        if not bump then
            tryMove( "forward" )
        end
    end

    turtle.turnLeft()
    tryMove( "down" )
    turtle.select(9)


    --Drop off and resupply
    if shouldOutput then
        redstone.setOutput("left", true)
        output = true

        while output do

            for i=3, 9 do
                if turtle.getItemSpace( i ) ~= 64 then
                    break
                elseif i==9 and turtle.getItemSpace( 9 ) == 64 then
                    output = false
                end
            end
            sleep(0.5)
        end

        redstone.setOutput("left", false)
    end

    print( "Ready to cycle" )

end

while true do
    event, p1, p2 = os.pullEvent()

    if event == "rednet_message" and p2 == "startLoging" then
        harvest()
    end

    if event == "char" and p1 == "s" then
        createSettings()
    end

    if event == "char" and p1 == "r" then
        print("User overide, havest starting.")
        harvest()
    end
end