harvestDown

blockCount = 0
SLOT_COUNT = 16

function getItemIndex(itemName)
    for slot = 1, SLOT_COUNT, 1 do
        local item = turtle.getItemDetail(slot)
        if (item ~= nil) then
            if(item["name"] ==itemName) then
                return slot
            end
        end
    end
end

function grab()
    for i = 1, 6, 1 do
        turtle.suckDown()
    end
end


function fuelCheck()
    local coalIndex = getItemIndex("minecraft:coal")
    if turtle.getFuelLevel() < 100 then
        if coalIndex ~= nil then
            turtle.select(coalIndex)
            turtle.refuel()
        else
            return false
        end
    end
end
function growCheck()
    local isBlock, data = turtle.inspectDown()
    while true do
        if isBlock then
            if (data["state"]["age"] == 7) then
                return true
            else
                return false
            end
        end
    end
end

function plantDetect()
    local isBlock, data = turtle.inspectDown()
    wheatSeedIndex = getItemIndex("minecraft:wheat_seeds")
    turtle.select(wheatSeedIndex)
    if turtle.placeDown() == false then
        if turtle.inspectDown() == false then
            return true
        else
            return false
        end
    else
        return true
    end
end

function selectNext()
    local wheatSeedIndex = getItemIndex("minecraft:wheat_seeds")
    local coalIndex = getItemIndex("minecraft:coal")
    fuelCheck()
    turtle.forward()
    if plantDetect() then
        if fuelCheck() == false then
            turtle.suckUp()
            fuelCheck()
        end
        turnAround()
    end
end


function harvest()
    while true do
        local wheatSeedIndex = getItemIndex("minecraft:wheat_seeds")
        local boneMealIndex = getItemIndex("minecraft:bone_meal")
        if turtle.inspectDown() == false then
            turtle.select(wheatSeedIndex)
            turtle.placeDown()
            if boneMealIndex ~= nil then
                turtle.select(boneMealIndex)
                repeat
                    turtle.placeDown()
                until growCheck() or boneMealIndex == nil
            end
        elseif (growCheck()) then
            turtle.digDown()
            grab()
            turtle.select(wheatSeedIndex)
            turtle.placeDown()
        end
        if plantDetect() == false and growCheck() == false then
            if boneMealIndex ~= nil then
                turtle.select(boneMealIndex)
                repeat
                    turtle.placeDown()
                until growCheck() or boneMealIndex == nil
            end
        end
    selectNext()
    end
end


function turnAround()
   turtle.turnLeft()
   turtle.turnLeft()
end

while true do
    harvest()
end