[1.15.2] How to add villager and structure to village

[lisilew]

I want to add a structure to vanilla villages where custom villager will be spawned in.

I know I should ask questions after I have tried something but I absolutely have no ideas where and how to begin with.

I would really appreciate some helps regarding things below.

1. I want a custom villager who does not trade but open a GUI when right clicked. I believe I should use EntityInteract or override openMerchantContainer to open the GUI instead of trade. Then, how can I prevent the villager from getting profession and make it use one texture regardless of biomes?
2. I want to add a custom structure to all biomes villages. I might create different structures for different biomes but for now, I just want one structure regardless of biomes. Do I just add nbt files under data/minecraft/structures/village or are there more steps I should take?
3. Is it possible to set in which structure the villager is going to spawn? For example, if I do not want the structure to spawn all the time (which I also want to know how to set probability), I also do not want the villager to spawn without the structure. If setting probability is not possible, i just want the villager to spawn in the structure. It is okay to move around in the village, but I want the initial spawn to be the structure.

Instead answering all questions, providing me with mod that achieves the same would also help.

[lisilew]

Bump

[lisilew]

So far, I have found out that I need to register my NBT files using JigsawPatternRegistry to generate structures.

And I can use jigsaw block to spawn entity.

I have registered my structures using coremod to call my PlainsVillagePools#init instead of vanilla one but I feel like there is a way to do it without using coremod.

Also, how do I make my structures are generated only one per village with probability?