What policies did the Tang Dynasty adopt towards Xinjiang and what role did it play?

In the Tang Dynasty, the central government administered the vassals of the western regions and the Han people separately, that is, Yizhou, Xizhou and Tingzhou, where the Han people were concentrated, implemented the same administrative system for the government, prefecture, county, township and village as the mainland; Economically, "land equalization system" (land system in Tang Dynasty) and "tenancy adjustment system" (tax system in Tang Dynasty) were implemented; Militarily, the "officer system" (the military system of the Tang Dynasty) was implemented. In areas where non-Han people live in concentrated communities, a "Jimi House" should be set up, that is, the administrative system of local ethnic leaders should be maintained, and the names of Duhu, DuDu and Zhou in the Tang Dynasty should be given, allowing them to govern their ministries with old customs. At the same time, military organizations were established in Qiuci, Yutian, Shule and Suiye (once Yanqi), which were called "Anxi Four Towns" in history.