How to run a command (using /execute) based on a player having 7 or more xp points in Minecraft?

Question

I'm trying to build a datapack that lets you craft xp bottles from glass bottles at the expense of 7 xp per bottle (because they drop 3 to 11 xp so the average is 7). I have almost everything working except for a check for if they have too little xp. If they have 7 or less xp, I would like to remove one bottle of enchanting from their inventory and give them one glass bottle, because the function for removing xp is called after they've crafted one and a scoreboard has counted it. My remove function currently looks like this:

#create dummy scoreboard to multiply bottles crafted by seven to get xp to be removed
scoreboard objectives add 7xp dummy
scoreboard players set @s 7xp -7
scoreboard players operation @s xpCrafted *= @s 7xp

#how do I get the value in xpCrafted into the command to remove xp?
xp add @s -7 points

#cleanup
scoreboard players reset xpCrafted
scoreboard players reset 7xp
scoreboard players set @e xpCrafted 0
scoreboard objectives remove 7xp

And my tick function like this:

execute as @e[scores={xpCrafted=1..}] at @s run function craft_xp:removexp

As the inline comment says, how do I get that value in xpCrafted into my xp removing command, and also how should I check to make sure the player has enough xp for the operation in the tick command (or elsewhere)? Presumably I would run a different command to remove the extra bottle if they didn't have enough xp, but I don't know how because there doesn't seem to be any type of if/else structure in commands. Finally, should a question like this be in two different questions or is one ok on this forum?

Answer 1

There is an xp scoreboard type:

/scoreboard objectives add scoreboardName xp {"text":"scoreboardDisplayName"}

For XP points that already existed before you set up the scoreboard, you can use the subcommand of the /xp command called "query", with it you can get the current level and the points since the last level:

/execute store result score @s <scoreboard> run xp query @s points

Additionally, you'll probably also track people with 1 or more complete XP levels, like this: @a[xp=1..]

Answer 2

So I've created this function to be run when someone crafts a bottle (or multiple bottles):

#controller - sets up and then decides whether to cancel the crafting operation or remove the xp

#setup
scoreboard objectives add xpOwed dummy
scoreboard objectives add xpCurrent dummy
scoreboard objectives add xpDifference dummy

scoreboard players set @s xpOwed -7
execute store result score @s xpCurrent run xp query @s points

scoreboard players operation @s xpOwed *= @s xpCrafted
execute store result score @s xpDifference run scoreboard players operation @s xpCurrent -= @s xpOwed

#xpOwed has the amount of xp they owe, xpCurrent has how much they have,
#xpCrafted has the amount of bottles they crafted, and xpDifference is
#the difference of xp points between what they have and what they owe.

#somehow I need to loop the execute ... run function commands below a certain amount of times based on a scoreboard value

#if they are lacking xp, refund their bottles and xp
execute if score @s xpOwed > @s xpCurrent as @s run function craft_xp:cancel
execute if score @s xpOwed > @s xpCurrent as @s run say Sorry @s, but you don't have enough experience. Try crafting less bottles.
#if they have enough xp, remove the xp owed
execute if score @s xpOwed <= @s xpCurrent as @s run function craft_xp:removexp

#cleanup
scoreboard players reset xpOwed
scoreboard players reset xpCurrent
scoreboard players reset xpDifference
scoreboard players reset xpCrafted
scoreboard players set @e xpCrafted 0
scoreboard objectives remove xpOwed
scoreboard objectives remove xpCurrent
scoreboard objectives remove xpDifference

I also have these two functions, which are referenced in the above function.

#removexp - takes xp away based on how many bottles they've crafted
#needs to be looped @s xpOwed times
xp add @s -1 points

and

#cancel - gives player the amount of glass bottles that 
#they used and removes the amount of xp bottles they crafted
#needs to be looped @s xpCrafted times
clear @s minecraft:experience_bottle 1
give @s minecraft:experience_bottle 1

How do I loop the bottom two functions a certain amount of times based on a scoreboard score? I get that I decrement the score and test each time, but I don't really get how to actually implement it in my situation. Also, I know that xpDifference doesn't do anything yet. I might use it later so I left it in.

Edit: I'm trying recursion to see if it will work, so I'll probably open a new thread about how to fix my recursion bugs.

Edit 2: Here's the link to the finished datapack. Instead of crafting it, I just have the player throw glass bottles into a cauldron in order to convert them to bottles of enchanting.