In the story I'm writing, there is a city located entirely underground in a complex network of artificial and nature tunnels and chambers under and inside of a mineral-rich mountain range. An important part about their society is that they are very xenophobic and try to interact with the surface as little as possible. I need to know if they would actually be self-sufficient and if they're not, what can be done to make them self-sufficient.
Currently, the city lives off a subterranean river, which starts near the top of the mountain and pours into a sinkhole and exits another hole in a sheer cliff. The river provides drinking water and small amounts of hydroelectric power. The sinkhole also provides the main ventilation shaft. Using hydroelectric power they are able to run dim lights, simple electric stoves, and large fans to ensure proper airflow.
Grain and similar foods are grown in large chambers equipped with a system of mirrors that reflect sunlight onto crops. The people supplement their diet with mushrooms that grow on the banks of the river, large moles that they farm, rats, and sometimes insects that live in the caves. Any organic waste is used for compost.
The houses are simply carved out of the walls. The metal needed to maintain the machines and farms is gathered from the rich veins of various ores surrounding the city. The mineshafts can later be turned into additional living space once the ore runs out. Using furnaces fueled with animal fat and bellows, metals (mostly iron, aluminium and copper) are smelted or recycled to be used for the various fixtures in the city.