OC Wheat Bot

local component = require("component")
local term = require("term")
local robot = require("robot")
local sides = require("sides")
local geolyzer = component.geolyzer
local inventory_controller = component.inventory_controller

term.write("Enter length (number): ")
local length = term.read()

term.write("Enter width (number): ")
local width = term.read()

local right = true

function turn()
    if (right) then robot.turnRight() else robot.turnLeft() end
end

function tryForward()
    if (not robot.forward()) then tryForward() end
end

function isSelectingSeed()
    local selectedItem = inventory_controller.getStackInInternalSlot()
    return (selectedItem and selectedItem.name == "minecraft:wheat_seeds")
end

function plant()
    local lastSlot = robot.inventorySize()
    robot.select(lastSlot)
    robot.dropDown(robot.count())
    inventory_controller.equip()
    if (not isSelectingSeed()) then
        local i = 1
        while true do
            robot.select(i)
            if (isSelectingSeed()) then
                break
            end
            if (i == lastSlot) then
                i = 1
            else
                i = i + 1
            end
        end
    end
    inventory_controller.equip()
    robot.useDown()
end

function farm()
    robot.select(1)
    local block = geolyzer.analyze(sides.bottom)
    if (block.growth == 1 and block.name == "minecraft:wheat") then
        robot.swingDown()
        plant()
    end
end

function moveX(j)
    for i = length, 1, -1 do
        farm()
        if (i > 1) then
            tryForward()
        elseif (j > 1) then
            turn()
            farm()
            tryForward()
            turn()
        end
    end
end

function moveY()
    for i = width, 0, -1 do
        if (i > 0) then
            moveX(i)
            right = not right
        end
    end
    robot.turnAround()
    right = not right
end

while true do
    moveY()
end