Crop Farmer

local sideLength = 9
local inspectAttempts = 5
local desiredFuelPercent = 0.5

local move = {
    forward = function()
        while not turtle.forward() do
            turtle.dig()
        end
    end,
    up = function()
        while not turtle.up() do
            turtle.digUp()
        end
    end,
    down = function()
        while not turtle.down() do
            turtle.digDown()
        end
    end
}

local checkBlock = {
    forward = function(name)
        local i
        for i = 1, inspectAttempts do
            local success, blockData = turtle.inspect()
            if success then
                return blockData.name:find(name) ~= nil
            end
        end
    end,
    up = function(name)
        local i
        for i = 1, inspectAttempts do
            local success, blockData = turtle.inspectUp()
            if success then
                return blockData.name:find(name) ~= nil
            end
        end
    end,
    down = function(name)
        local i
        for i = 1, inspectAttempts do
            local success, blockData = turtle.inspectDown()
            if success then
                return blockData.name:find(name) ~= nil
            end
        end
    end
}

local function doAction()
    turtle.placeDown()
end

while true do
    turtle.select(1)
    move.forward()
    doAction()

    local i, j
    for i = 1, sideLength do
        for j = 1, sideLength - 1 do
            move.forward()
            doAction()
        end
        if i < sideLength then
            if i % 2 == 1 then
                turtle.turnRight()
                move.forward()
                doAction()
                turtle.turnRight()
            else
                turtle.turnLeft()
                move.forward()
                doAction()
                turtle.turnLeft()
            end
        end
    end

    move.forward()
    turtle.turnRight()
    turtle.turnRight()
    if
        turtle.getFuelLevel() ~= 'unlimited' and checkBlock.down('condenser') and
            turtle.getFuelLevel() < turtle.getFuelLimit() * desiredFuelPercent
     then
        turtle.select(16)
        turtle.suckDown()
        turtle.refuel()
    end
    sleep(60)
end