chtreefarm

-- chtreefarm
-- refill fuel in slot FUEL_SLOT
-- requires at least farmLength saplings in slot SAPLING_SLOT
-- wood deposit at the beginning of the farm, saplings deposit at the end

local FUEL_SLOT = 1
local SAPLING_SLOT = 2
local SAPLING_TMP_SLOT = 3
local WOOD_SLOT = 4
local MIN_FUEL_FOR_STEP = 26
local args = {...}
local farmLength = tonumber(args[1])
local posX = 0
local orient = 0
local cycleCount = 0
local treesChopped = 0
local saplingsPlanted = 0
local distanceTraveled = 0
local farmingStarted = false

function forward(n)
    for i=1,n do
        turtle.forward()
        distanceTraveled = distanceTraveled + 1
        if orient==0 then
            posX = posX+1
        end
        if orient==2 then
            posX = posX-1
        end
    end
end
function left()
    turtle.turnLeft()
    orient = orient-1
    while orient<0 do
        orient = orient+4
    end
end
function right()
    turtle.turnRight()
    orient = orient+1
    while orient>3 do
        orient = orient-4
    end
end
function transferSaplings()
    result = true
    for i = 1,16 do
        if not i==SAPLING_SLOT then
            turtle.select(i)
            if turtle.compareTo(SAPLING_SLOT) and turtle.getItemCount(i)>0 then
                turtle.transferTo(SAPLING_SLOT)
            end
        end
    end

    if turtle.getItemCount(SAPLING_SLOT) < 2 then
        print("Not enough saplings in slot "..SAPLING_SLOT.."\n")
        -- result = false
        while turtle.getItemCount(SAPLING_SLOT) < 2 do
            os.sleep(10)
        end
    end
    return result
end
function stripLeaves()
    turtle.select(SAPLING_TMP_SLOT)
    if turtle.detectUp() then
        turtle.digUp()
    end
    for i=1,3 do
        right()
        if turtle.detect() then
            turtle.dig()
        end
    end
    transferSaplings()
    right()
end

function chop()
    local height = 0
    while turtle.detect() do
        turtle.select(WOOD_SLOT)
        turtle.dig()
        stripLeaves()
        if turtle.up() then
            height = height + 1
            distanceTraveled = distanceTraveled + 1
        end
    end
    turtle.select(SAPLING_TMP_SLOT)
    for i=1,height do
        turtle.digDown()
        turtle.down()
        distanceTraveled = distanceTraveled + 1
    end
    if height>2 then
        treesChopped = treesChopped + 1
    end
end
function plant()
    turtle.select(SAPLING_SLOT)
    if turtle.getItemCount(SAPLING_SLOT) < 2 then
        if not transferSaplings() then
            return false
        end
    end

    turtle.place()
    os.sleep(0.5)
    if turtle.detect() and turtle.compare() then
        saplingsPlanted = saplingsPlanted + 1
    end
    os.sleep(2)
    return true
end
function waitForTree()
    local treeDetectedCount = 0
    local waitingTime = 0
    local height = 0
    turtle.select(SAPLING_SLOT)
    while treeDetectedCount < 7 do -- because sometimes turtle does not compare reliably
        if turtle.compare() then
            treeDetectedCount = 0
        else
            treeDetectedCount = treeDetectedCount + 1
        end
        os.sleep(2)
        waitingTime = waitingTime + 2
        if waitingTime > 30 and turtle.detectUp() then
            height = 0
            while turtle.detectUp() do
                turtle.select(SAPLING_TMP_SLOT)
                turtle.digUp()
                if turtle.up() then
                    height = height + 1
                    distanceTraveled = distanceTraveled + 1
                    turtle.dig()
                end
            end
            for i=1,height do
                turtle.down()
                distanceTraveled = distanceTraveled + 1
            end
        end
    end
end
function handleTree()
    if not turtle.detect() then
        if not plant() then
            return false
        end
    else
        waitForTree()
        chop()
        if not plant() then
            return false
        end
    end
    return true
end
function dumpWood()
    for i = 1,16 do
        if (not i==SAPLING_SLOT) and (not i==FUEL_SLOT) then
            turtle.select(i)
            if not turtle.compareTo(SAPLING_SLOT) and turtle.getItemCount(i)>0 then
                turtle.dropDown()
            end
        end
    end
end

function step()
    local result = true
    forward(2)
    if posX <= 0 then
        right()
        right()
        dumpWood()
        cycleCount = cycleCount + 1
        print("cycles finished: "..cycleCount)
        print("saplings planted: "..saplingsPlanted)
        print("trees chopped: "..treesChopped)
        print("distance traveled: "..distanceTraveled)
        os.sleep(10)
    elseif posX >= farmLength then
        right()
        right()
        turtle.select(SAPLING_TMP_SLOT)
        turtle.suckDown()
        transferSaplings()
        os.sleep(10)
    elseif (posX % 4) == orient then
        right()
        result = handleTree()
        left()
    elseif (posX % 4) == (2-orient) then
        left()
        result = handleTree()
        right()
    end
    return result
end
function checkFuel()
    local result = true
    if turtle.getFuelLevel() < MIN_FUEL_FOR_STEP then
        turtle.select(FUEL_SLOT)
        turtle.refuel()
    end
    if turtle.getFuelLevel() < MIN_FUEL_FOR_STEP then
        result = false
    end
    return result
end

if farmLength==nil or farmLength<2 then
    print("Farm length too short.\n")
    return
end
if turtle.getItemCount(SAPLING_SLOT) < farmLength then
    print("Not enough saplings in slot "..SAPLING_SLOT.."\n")
    return
end

while true do
    if not checkFuel() then
        print("Not enough fuel\n")
        os.sleep(10)
        while not checkFuel() do
            os.sleep(10)
        end
        return false
    end
    if not step() then
        print("Step unsuccessfull, exiting.\n")
        return false
    end
    os.sleep(1)
end