In fact, its architectural style is a mixture of arts which the muslim learned in many muslim countries, and the previous art of the "visigoths" who ruled Spain previously. Its arches are an example, also seen in christian churches of that age.
The temple was shared by christians and muslims in the Middle Age, not always due to fanaticism.
Now there's a vindication of muslims who want to pray there, the same as the christians do, but there are also legal rules, it's an historical monument for visiting, like a museum. A mess.
RE: Prepare for the Caliph
In Europe religious freedom allows personal choices front to any kind of authority.Sectarian leads to communities are a warning sign.