# Paginated GUI Example

# Made by AsuDev

# Requirements
# Skript 2.3.6+

# Tested on Paper Spigot 1.13.2

# Function that returns true or false based on if the player can open a specific page
function checkForSpecifiedPage(slot: number, guiSize: number, list: objects) :: boolean:
	set {_counter} and {_format} to 0
	loop {_list::*}:
		if {_counter}+1 is between {_slot} and {_slot}+({_guiSize}-1):
			add 1 to {_format}
		add 1 to {_counter}
	if {_format} is 0:
		return false
	else:
		return true

# Example Paginated GUI
command /pagtest [<integer=1>]:
	trigger:

		# Make sure to block anhything below 0 as a page
		if arg 1 is less than or equal to 0:
			message "&c0 &7is not a valid page."
			stop

		# Example size of the inventory / Must be divisible by 9 and up to 53
		# In the example I am using, I cannot use 53 size because I am going to
		# dedicate 1 row for the page switchers, therefore the max size in this
		# example can only be 45
		set {_guiSize} to 9

		# List to use as an example for the GUI
		set {_c} to 0
		loop 14 times:
			add 1 of apple named "&cApple %{_c}%" to {_list::*}
			add 1 to {_c}

		# Gets the slot to start at on specified page
		set {_slot} to ((arg 1 * {_guiSize}) + 1) - {_guiSize}

		# Checks if the specified page has anything in it / Gets how many available pages there are
		if checkForSpecifiedPage({_slot}, {_guiSize}, {_list::*}) is false:
			set {_availablePages} to ceil(size of {_list::*}/{_guiSize})
			message "&7Invalid page. &7You have &c%{_availablePages}% &7available pages."
			stop

		# Open the Gui to the player / I used +1 because I want a row dedicated for the page turners
		open chest with ({_guiSize}/9) + 1 rows named "&cApples &8(&9Page %arg 1%&8)" to the player

		# Example buttons to switch to different pages / The last row in this case is dedicated to these
		set slot {_guiSize}+2 of player's current inventory to 1 of feather named "&c&l<- PREVIOUS PAGE&r"
		set slot {_guiSize}+6 of player's current inventory to 1 of feather named "&a&lNEXT PAGE ->&r"

		# Formats the gui
		set {_counter} and {_format} to 0
		loop {_list::*}:
			if {_counter}+1 is between {_slot} and {_slot}+({_guiSize}-1):
				set slot {_format} of player's current inventory to loop-value
				add 1 to {_format}
			add 1 to {_counter}

# You need some kind of identifier to know what inventory your clicking in.
# In this examples case, I will use the GUI name.
# You also need an identifier to get what page you are currently on. I also used the name for this.
on inventory click:
	name of player's current inventory contains "&cApples &8(&9Page "
	if name of clicked item is "&a&lNEXT PAGE ->&r" or "&c&l<- PREVIOUS PAGE&r":
		cancel event

		# Gets the page you are on
		set {_getCurrentPage} to name of player's current inventory
		# Removes all text other than page number from name of the GUI / This is one method
		# of getting the page they are on
		replace all "&cApples &8(&9Page " and "&8)" with "" in {_getCurrentPage}
		set {_getCurrentPage} to {_getCurrentPage} parsed as integer

		# Adds 1 or removes 1 based on if your clicking next page or previous page
		if name of clicked item is "&a&lNEXT PAGE ->&r":
			add 1 to {_getCurrentPage}
		else:
			remove 1 from {_getCurrentPage}

		# Makes sure the player doesn't open page 0
		if {_getCurrentPage} is 0:
			message "&c0 &7is not a valid page."
			stop

		# Open the new page to the player by command
		# You can also create a function if you do not want
		# to use a command for this
		make player execute command "pagtest %{_getCurrentPage}%"