plant.lua

local robot = require('robot')
local component = require('component')
local craft = require('craft')

local dye = 'Bone Meal'
local bone = 'Bone'
local boneBlock = 'Bone Block'
local fruitBone = 'Boneus Fruit'
local currentDyeSlot = 2
local currentSeedSlot = 1

local seed = craft.getItemName(1)

function placeItem(slot)
    print('placeItem', slot)
    local count = robot.count(slot)

    robot.select(slot)
    robot.placeDown()

    if robot.count(slot) < count then
        return true
    else
        return false
    end
end

function placeSeed()
    if craft.isItem(currentSeedSlot, seed) then
        if not placeItem(currentSeedSlot) then
            robot.useDown()
        end
    end
    local slot = craft.findItem(seed, 1)
    if slot == 0 then
        slot = craft.findItemOnSides(seed)
        if slot == 0 then
            return false
        end
    end
    currentSeedSlot = slot
    return placeSeed()
end

function placeDye()
    if craft.isItem(currentDyeSlot, dye) then
        if placeItem(currentDyeSlot) then
            return 1
        else
            return 0
        end
    end
    local slot = craft.findItem(dye, 1)
    if slot == 0 then
        slot = craft.findItemOnSides(dye)
        if slot == 0 then
            return 2
        end
    end
    currentDyeSlot = slot
    return placeDye()
end

function runPlaceDye()
    local ret = placeDye()
    if ret == 2 then
        craft.mergeItems()
        if not craft.crafting1(boneBlock) then
            if not craft.crafting1(bone) then
                if not craft.crafting1(fruitBone) then
                    return false
                end
            end
        end
    elseif ret == 0 then
        return true
    end
    return runPlaceDye()
end

function main()
    -- craft.scanItemsOnSides()
    robot.swingDown()
    if seed == '' then
        print('Error: seed not found.')
        return
    end
    while true do
        if not placeSeed() then
            break
        end
        if not runPlaceDye() then
            break
        end
        robot.swingDown()
    end
end

main()